Frequently Asked Questions

Taco technical services specialists answer thousands of questions a year. Here we’ve collected some of the most frequently asked questions and their responses. Browse by product category to narrow your search. Then click on a question to reveal the answer. You can print the FAQ for future reference, if needed. If you can’t find an answer to your question here, please contact Taco Technical Support.

Water Circulation Pumps & Circulators


Closed loop. pressurized HVAC (or hydronic) hot and chilled water systems (max 175 PSI, from 14 to 230 Deg F).

Are Taco pumps self priming, or does Taco make a self-priming pump?

No, but all Taco pumps will lift water if you follow these steps: Install a foot valve (check valve) at the end of a pipe submerged in a tank, Fill the line and pump with the fluid to be pumped, and Make sure the NPSH required of the pump is satisfied.

Are the Cast iron and bronze and Stainless 00 circulators furnished with Norel impellers?

Bronze and stainless circulators are equipped with Norel (black) impellers. The cast iron models are equipped with polypropylene (white) impellers.

Can a 60 cycle 00″ Series circulator run at the lower 50 cycle?

Yes, however there will be approximately 10% degradation in output. As the cycles are reduced, so is the pump speed causing the reduction in output. Additionally, I should mention that a 50 cycle pump cannot operate at a higher cycle

Can I control the Viridian using a DC signal?

Yes, to do this you must set I1 to “No Function” and set I2 to “Run”. When above 8 volts DC (max 32 volts) is applied to IO2/24V, the pump will run. When below 2 volts DC is applied to IO2/24V, the pump will go into stand-by mode (Flashing blue light).


Can I install a 00 circulator outside?

Yes, as long as it is protected by the elements. We recommend some type of shroud.

Can I modulate the speed of the Viridian externally?

No, the speed is determined internally within the pump’s brain. You can however control the pump externally via the digital inputs (turn on/off, and force the pump to run on maximum or minimum speed)

Can I monitor the pump’s status externally?

Yes, using the relay outputs (NO or NC) you can see if the pump is running, off, in alarm mode or the status of I2.

Can I run the VR25 and VR30 down to 208 Volts?

In the VR25 and VR30, there was a change made to the internal fuse so they could operate down to 208V. The -1 versions of the VR25 and VR30 had a voltage range of 230V-240V. The -2 versions of the VR25 and VR30 (with the new fuse) now have a range of 208V-240V.

Can I use a potentiometer , or rheostat to control the flow rate of a 00 pump?

You can use a potentiometer similar to a one used to control a ceiling fan. However, the motor can get hot and cause premature failure. For that reason it’s not recommended

Can I use an external demand to “call” the pump on and off?

Yes, to do this, you must have a thermostat or an end switch trigger the pump to run. Next, power must always be applied to the pump comtrol. Now go into the programming of the Viridian and set I1 to “No Function” and set I2 to “Run”. Now you will have the ability to wire a switch across the IO2 and 24V terminals. When the circuit is closed, the pump runs (solid blue light) and when the circuit is opened, the pump goes into standby mode (flashing blue light).
Attachment: Viridian switch to run image

Can I use the alarm contacts from the Viridian to send a speed feedback signal to a DDC controller?

Yes, there are relay outputs (either NO or NC) that can monitor various pump operating functions. The factory default is “Error”. If the pump goes into an overload condition the relay will change position (NO will close and NC will open). The relay “trigger” can be changed to Run (or monitor if the pump is running), Off or position of digital input I2. The relay rating is 250 VAC, 8 Amps.

Can I, just a homeowner, install a 00 cartridge myself?

If you have shut off valves before and after the circulator, it would be a piece of cake. If not, you will have to drain off the excess pressure of the system after you have shut off the supply water, which is normally just before the pressure reducing valve. Close off all the valves in the water piping around the boiler, including air vents. Turn off the power to the boiler and make sure no zone valves are open.

  • Open the drain in the boiler again to relieve any residual water. You now should be able to remove the four 5/16 hex head screws. Have a bucket beneath the pump as there will still be some water in the line. Once the water has stopped draining, you can remove the motor completely.
  • Pull the cartridge from the plate and motor. Insert the new cartridge through the plate and into the motor. The plate should come up under the flange of the cartridge.
  • Remove the old o-ring from the casing and install the new o-ring.
  • Pick up the motor and cartridge assembly and position it against the casing. Note that the flange of the cartridge should seal against the o-ring. Line up the bolt holes and install the screws. Here comes the hard part if you don\’t have shut off valves at the pump:
    1. Open the feed valve to the system. The pressure gage on the boiler should rise to 12PSI. If you have zone valves, open one valve manually.
    2. Hook up a hose to the hose bib on the return line for that zone or on the main return header.
    3. Using the fast fill lever on the pressure reducing valve, get the boiler pressure up to 28psi. When it reaches that point, open the hose bib on the return while keeping the fast fill open. If the pressure drops down to 15psi, close the hose bib until the pressure rises to 28, then open the hose bib again. Do this several times until the water comes out steady, with no air, from the hose. Release the fast fill and close the hose bib.
    4. Close the first zone valve and go to the next and open it. Move the hose to the hose bib on this zone return (if there is one), or leave the hose on the hose bib on the return header. Repeat the purging process. Do this whole process to each zone.
    5. When you are finished, close the zone valves, Pressure Reducing Valve on auto. Open all valves that were originally open, and all air vents. Turn on the power and you should be ready to fire up the system.


Can standard pump seals (ethylene propylene, and carbon on ceramic) be used when pumping ethylene or propylene glycol?

Yes. The glycol does not cause the seal to leak. The leak is caused by the excess treatments, and the presence of sodium silicate, which is abrasive to the seal faces. The suction pressure should be maintained so the glycol does not vaporize at the seal faces and leave deposits on the faces.

Can Taco 00 series circulators be used to pump fluid other than water?

Taco 00 series pumps can be used to pump fluids other than water. However, the media has to be compatible with {EPDM elastomer} o-rings used on the pump. Additionally, there is a temperature / viscosity curve that needs to be considered when pumping a media that is temperature sensitive meaning that the pump curves will behave differently with media of different viscosities.

Link: Compatibility Guide

Can the 1900 series pump be installed with the motor in a vertical orientation?

Yes, the 1900 series pumps can be installed with the motor vertically oriented because it is a close coupled design. However, the similar 1600 pumps cannot be oriented vertically.

Link: Close CoupledLink to the Mc Nally home page

Can the vent on the top of the RMB be replaced? What is the model number?

Yes, it is model number 419-1.

Can you help select a comparable taco pump to replace my B & G 100 series?

The Taco 110, 3 pc pump is the same as the B & G. As an alternative to the 110 pump, the taco circulator 0010, or the 007 will also work. curve.
Link: Taco Cross Reference Guide

Can you vary the speed of the Viridian using a 0-10 Volt DC signal?

The Viridian is capable of being turned on and off using 0-10 Volt DC signal. You are not able to actually change the speed of the pump based on a change in the DC voltage. See “Can I control the Viridian using a DC signal?” in the Viridian FAQ section.

Do I need the internet to communicate with the Viridian?

Communication with the Viridian is done through an ethernet connection. The Viridian control is its own “intranet”. You do not use the actual internet to make this connection.

Have multiple zones, each with its own circulator. Why is Hot water passing into zones that are not calling for heat?

If you are not using zone valves, you need either Flo-Checks or a circulator with an Internal Flow Check (IFC). This is required to prevent thermosyphoning, a condition in which lighter, hot water rises, and heavier, cool water sinks, causing a flow in the system.

How do I communicate with the Viridian? (PC Windows 7 version and Mac.)

In order to communicate with a Viridian, you will need the following: Window 7 operating system, a CAT 4 or better ethernet cable and power to the pump. First you will need to set a ‘Static’ IP address on your computer. To do this, got to the Start Menu, then Control Panel. Go to Network and Internet, then open Network and Sharing Center. Select Change Adapter Settings and right click on a wired Local Area Connection and select Properties. In Properties, select Internet Protocol Version 4(TCP/IPv4)and then select the Properties tab to the bottom right. Click on the radial ‘Use the following IP address’. In the IP Address space, type: (The last 3 numbers can be any number 2-244). The Subnet mask will automatically be inserted. Select OK. You can now open a web browser ( Internet Explorer, Mozilla, Firefox, Safari, Chrome etc) and type in the address bar ‘’ (245 is the factory default address for each Viridian) or ‘http://viridian’.

How do I find the IP address of my Viridian pump?

You can use any IP search program available online. Use a program called wireshark (you can use any other program that can look on at your network traffic). The program looks traffic on the network adapter, which you choose. It is preferred that you have the pump connected only an Ethernet cable and wireless turn off, so that you don’t have too much traffic. The pump is always looking for its twin pump, so it sends a transmission over the network in which it is asking: ?Who has Tell yyy.yyy.yyy.yyy? (where x is the IP of the twin, and y is your address).

Attachment: WireShark
Attachment: WireShark
Attachment: WireShark

How do I force the pump to run at maximum power?

To do this, leave the factory defaults, I1 to “Run” and I2 to Max”. Then, place a jumper across terminals IO2 and 24V (Solid blue light). To stop the pump, either remove the jumper between IO2 and 24 V or place the jumper between IO1 and OV to put into standby mode (flashing blue light).
Attachment: Viridian switch to run

How do I replace the cartridge in my 00 circulator?

Isolate the pump. Remove the 4 bolts between the motor housing and casing. Pull the cartridge out by grabbing the impeller. Slide the new cartridge in and reassemble the pump. For additional information see attached instructions.
Link: 00 Instructions

How do I save and report information collected from the data logger?

This can be accomplished by copy/paste or saving screen shots of the various web pages.

How do I size a circulator, or pump for my system?

We offer a document TD10 that can step you through the process of sizing a circulator. Please refer to the attached documents for additional information.
Link: Selecting and sizing a pump

How do I wire a 00 series pump?

From the electrical box, there will be a yellow and a white wire. Your 120v power supply can be attached to either color and the pump will always run correctly. (ex. you can attach black to yellow and white to white or vise versa).

How do you set the 24-hour timer?

Turn the dial clockwise until the hour and minute hand are approximately set and the exact time, in 15-minute intervals, is lined up with the pointer at the 2 o’clock position. To set the on/off times in 15-minute intervals, push the tripper levers away from the face for ON operation. Leave the tripper pointing toward the center for OFF operation. For automatic operation, the small, white button at the 4 o’clock position on the inner area of the dial should be in the middle of the slot. All the way UP is ON constant and all the way DOWN is OFF constant.

How does the pump measure flow with no external sensors?

The pump’s brain calculates flow by seeing changes in the relationship between the magnetic field of the PM rotor and stator as the system curve changes the loading on the impeller.

How should a single pipe hydronic system be installed in a 1200 sq. ft. home with baseboards?

Assuming you have a 30x40 home and all walls are covered with baseboard, you would have about 140 ft. of baseboard. At 600 BTU/Hr./Ft. x 140 ft. = 84000 BTU/Hr. The GPM required at 20 differential temperature would be calculated by the formula: BTU load = 500 x delta T x GPM. Solve for GPM. 500 x 20 = 10000. The load is 84000 divided by 10000 = 8.4 GPM. Split the loop in half and put 4.2 GPM down each side.

How to control two Viridians with one control?

1).If you want both pumps to be enabled when the boiler enable circuit is open, simply connect this to I01 and 0V terminals – factory default is OK as is. OR 2).If you want both pumps to be enabled when the boiler enable circuit is closed, connect to I02 and 24V terminals. Factory defaults would have to be set Input I1 (I01) “no-function” and Input I2 (I02) set to “Run”. NOTE: Using the crossover Ethernet cable will have only one pump run and alternate (with both pumps enabled). If both are disabled, neither will run.

I have a 00 circulating pump that stopped working. It does nothing when plugged in, but gets very hot. Do I have to replace the whole pump or only a part?

Since this is a water recirculating pump, minerals in the water exchange inside the pump can eventually bind the pump rotor. The pump is constructed so the rotating part of the pump, and not the whole pump, can be replaced if the rotor has bound up. The motor can stall and not burn up. The part number for the cartridge is 005-020R. Hopefully, you have shut off valves on either side of the circulator. If not, you\’ll have to shut off the water to the hot water heater and drain the pressure from the line by opening a hot water faucet. Remove the four 5/16\” hex screws that hold the motor to the pump casing. Once the motor is free from the pump housing, grab the impeller and see if it will turn. If it is bound, pull the cartridge from the motor and note that the cartridge passes through the plate into the motor. Grab the cartridge with one hand and the impeller with the other and try to free the impeller. If it\’s truly locked, it will slip on the shaft and you definitely need a new cartridge.

The reason I wanted to try and free up the impeller was to see if the motor was still good and if it would start the rotor/impeller. If you do free the cartridge, you will still need a new one in the near future, but you can test the motor by installing the cartridge in the motor and energizing it. If it starts, you are good to go. If it doesn\’t, grab the impeller and give it a spin. If it runs, turn off the power and then turn it back on again. If it starts by itself, the motor is good, but you still need a new cartridge.

I have a 006-B2 pump that is not working properly. My electric water heater is 2 years old and the water coming out of the outlets is not hot.

The 006-B2 does not make the hot water. It is used to recirculate the hot water around the house, but the water must be hot in the hot water heater. Open a hot water faucet and feel the pipe coming out of the hot water tank to see if it is hot. If it isn\’t, the heating element in your tank might have failed or the circuit breaker has tripped.

If the hot water heater is OK, you need to check the pump. Is there a timer on the pump or is it connected directly to run all the time? If there is a switch nearby, put the blade of a screwdriver to the casing and the handle to your ear. Turn off the pump and listen for a change in sound. Turn the switch on again and listen to a change in sound. If you hear the motor coast down and speed up, the pump motor is OK but the impeller might have dissolved. The hot domestic water in some areas has dissolved some impellers. We have changed over to a different plastic to solve this problem.

If the motor is cold, you either don\’t have any power to the circulator, or the motor windings are fried. If the motor is fried, you will have to buy a new circulator, but you will not have to solder the new pump into the line. Unbolt the four 5/16\” hex screws holding the motor housing to the casing and transfer the new motor and cartridge to the new casing. Put the new o-ring into the old casing.

If the motor is hot, it\’s possible that the rotor is locked and you\’ll need a new cartridge. Either way, you\’ll have to take the pump apart to check the cartridge. The replacement cartridge part number is 007-045. I hope there are shut off valves before and after the circulator, otherwise you\’ll get wet. If the pump connects to the top of the cold water line, you can shut off the cold water supply and not have to drain anything. Don\’t open any hot water faucets and you can hold the water in the pipes. The latest 006 is a 006-B4.

I have a 007 Pump that came with two circular gaskets. I was told to install it with the gasket in the groove of the pump, and to use a second, larger gasket which is in the shape of the flange, on top of it. Is this correct?

If you are mating with a flat pipe pump flange, we recommend using just the square, cross-section o-rings in the groove of the pump flange. If you are using our shut-off flanges, use the o-ring and the flat gasket that comes with the flanges.

I have a 008-S7 or a 008-V2. Are there replacements for these models?

These are obsolete models. The 008-S7 was a variation of our 008-V1(V2) Solar pump but had a special Viton o-ring seal for use with hydrocarbon fluids. That pump has long since been discontinued when the Solar industry declined. But to replace the pump we suggest the following: To just replace just the catridge; use a 008-044RP cartridge. Or you can replace the motor with cartridge just use a new 008-F4, remove the cast iron casing and o-ring, replace with the Viton o-ring (for an oil solar system) (part # 008-047RP) and attach the new motor/cartridge assembly to the old casing. You may need four 10-32 nuts to attach to the old screws since our motor housing is now stamped steel instead of cast aluminum. Most suppliers will not stock the Viton or-ring so it will be a special order.

I have an old VL2508, what is the current replacement?

The current replacement vertical inline pump is the KV series. In order to select the correct model, the GPM and Head must be known along with the model pump you have.
Attachment: KV Series

I made an adjustment to my MPV valve and now it has a steady drip.

If the packing nut has nearly bottomed out you may have to add an additional packing ring. Follow the stem packing instructions and simply add an additional packing ring.
Attachment: Stem Packing Procedure

I need a pump for a drain-down solar hot water system. What is the right selection for a 12 foot head?

When selecting a pump for a drain down system, you need to know the elevation of the top of the solar collectors to the pump in the basement at the tank. We had originally designed a 009 pump for drain down system with a head of 34FT. Once the return line is full and coming back to the tank, the siphon effect takes over and you only need a pump that can overcome system resistance.

I wanted to compare different pumps to see which one would meet my needs. Couldn’t find anything that would show me a side by side comparison. So I moved on. Way to difficult to find anything here.

Thank you very much for visiting the Taco Web Site. I am sorry that you found our Pump Wizard too difficult to use. Because of the amount of space available on screen, we do not show side by side pump performance curves for comparison. However, when you make a pump selection, we show a table of data with information on impeller diameter, RPM, NPSHr, Efficiency, HP, Non-oveloading HP and connection sizes. In the table, we also show a “thumbnail” of the actual pump performance curve (too small for much analysis, but you can see where your design point falls relative to the max and min impeller diameters and the ends of the impeller curves). Selecting a pump from the list of pumps opens a tab on the page with a larger performance curve and more specific information on the pump selected. This tab also allows you to open a full size performance curve as well as access any of the literature associated with the particular pump. When you are done analyzing the pump, you can either close the tab, or click on the “Results” tab to analyze another pump. Selecting another pump will open another tab so you can quickly go back and forth between pumps. Changing the input parameters while on the results page will select a range of new pumps while leaving all other pump tabs unchanged. I would be very interested in hearing any suggestions you have to make the Pump Selection Wizard easier to use, especially for comparison purposes. Our goal is to make our site the easiest to use I the industry. Thanks again for your interest in Taco, Inc. T. R. Smith Director Of Marketing Programs

If my RMB is set up in the Delta T mode can I control the temperature to a fixed temperature?

NO, there are three modes of operation delta T, set point, and reset. If your design mode is delta T, it will maintain a fixed delta. If it’s a set point mode, it will deliver a certain temperature only, and outdoor reset looks at outside air temperature. Having said that, it’s important to first determine which mode of operation meets your design criteria.

Is additional support required when installing the 1600 Series circulators?

The 1600 series is a resilient mount design, to help reduce vibration transmitted into the piping. Resilient mount motor is supported by the bracket. If you apply an upward force on the bracket, either by a hanger or a foot support on the floor, it is possible to cause misalignment with the couplings, causing premature, uneven wear on the seal faces, and stress on the bearings. The piping should be rigid enough to support the overhung load of the motor, but be careful of torsional stress on the piping. To prevent that, you may have some type of foot support or hanger on the cast iron bracket, just adding some support.

Is it ok for my 00 series pump to run all the time?

Yes, Taco 00 series pumps are designed to run 24/7 with no detriment to the pump, and or motor.

Is the location of the pump important in relation to the expansion tank and boiler?

Yes, the expansion tank is the point of no pressure change. If the pump is placed so that it pumps toward the expansion tank, the head produced by the pump will show up as a drop in pressure on the suction side of the pump. This drop in pressure is equal to the head produced by the pump. A pump that develops more than 12 feet of head should be piped so it pumps away from the expansion tank. This way, the head produced by the pump will show up as a rise in system pressure on the discharge of the pump. The positive pressure will improve the elimination of air problems in a system.

The expansion tank and pump should be located after the boiler so the boiler is also at the point of no pressure change. The Pressure Reducing Valve (fill valve) should be connected next to the expansion tank.

Is the Viridian in the Taco selection software?


Minimum flow applications (low mass boilers for example).

For applications where minimum flow is a concern, the low flow differential head can be increased by increasing the H max or changing the slope of the pump curve (% proportional). In addition, the Viridian can be set to constant and any of the 12 speeds may be selected (more for constant flow applications).

My “00” series circulator is running but I am not getting hot water

This is a typical symptom of an air blockage in the volute of the pump. The system will need to be purged of air or you can try burping the pump to get the air blockage cleared.

My 00 Series Circulator Motor housing is hot to the touch. Is it OK?

Yes, these circulator do run hot and would probably burn your hand if you left it on the motor housing. The motor is cooled by the system fluid and the windings have high temperature insulation. The motor windings are impedance protected.

My circulator turns on, but why wont the pump pump any water?

Sounds like there could be an air blockage in the volute of the pump. The system needs to be purged of air.
Link: Air Elimination

My inline 1600 series pump has an Emerson motor on it. Is the motor warranteed by Emerson or Taco?

All 121-138 and 1600 series pumps utilizing an Emerson motor is covered by Taco Commercial Warranty. See attached.
Attachment: Commercial Pumps Warranty

My Taco strap on Aquastat does not turn the pump on and off accurately. Do I have a bad unit?

You do not have a bad unit. The Aquastat depends on good heat transfer for the unit to operate properly. To improve the heat transfer, wrap some bare copper wire around the clip and between the clip and body of the Aquastat. The pipe and Aquastat should now be insulated. This should solve your accuracy problems.

One of our process pumps will be taken out of service and put away for long-term storage. Any suggestions on proper storage?

Here are some general suggestions for long term storage. The applicability of all, or some, of these suggestions depends on several factors such as type of equipment, length of storage, and condition of the environment: 1. Drain the casing completely and dry it thoroughly, including its bearing housing and stuffing box, or seal chamber. Apply a coat of soluble rust preventive solution both internally and externally. 2. Cover all openings. Flanged openings (such as suction and discharge nozzles) should be covered with blind flanges with elastomer gasket. Threaded openings should be covered with steel plugs or caps. 3. Remove the shaft coupling; it may cause the shaft to develop a permanent sag during prolonged storage. 4. Wrap the exposed shaft and key with corrosion inhibitor waterproof paper or waxed cloth. 5. Protect the bearing housing from moisture by placing bags of vapor phase inhibitor crystals around the housing. 6. Cover the equipment with industrial strength plastic, preferably transparent to allow visual inspection, including its nameplate, without uncovering the unit. 7. Store the unit in its normal position in a dry, clean place. 8. Inspect the unit periodically and turn the shaft a few times plus 1/4 turn. Turning the shaft prevents pitting of finished surfaces. The extra 1/4 turn is to displace the sag and prevent the shaft from developing a permanent bow.
Attachment: Procedures for long-term storage

Overload protection – what, how and the effects (auto reset or manual).

Note each number below corresponds to the number of pulses of the red overload light on the face of the VFD: 1. Low load (dry run) – pump shuts off after approximately 60 seconds. Reset by turning main power supply off/on. 2. Overload (Locked rotor) – pump shuts off. Free up rotor (or impeller) and reset by turning main power off/on. 3. Motor Overheat – pump runs at reduced power until motor cools off. 4.VFD failure – pump shuts off. Attempt reset by turning main power off/on. If unable to reset replace pump (power head at least). 5. Motor/Stator failure – pump shuts off. Attempt reset by turning main power off/on. If unable to reset replace pump (powerhead at least).

Sizing and “dialing in” to match the required H/Q.

Simply stated, a line between H max at maximum RPM and head at zero flow should come close to intersecting the desired operating point.

We are replacing 3hp basemount B&G pumps with Viridian V25s. We will connect as follows: (1) a 3″ butterfly valve will neck down to 2.5″ then connect to the suction side of the pump. (2) pump will hang (north to south) (3) Discharge will be connected to a 90 deg elbow (4) 2 1/2 inch flowcheck will be horizontal to ground (5) 2 1/2 to 3″ transition (6) 90 deg elbow up to flex connector (7) flex connector to 3′ butterfly. Is this OK? Anything we should know?

Hello Robert… The Viridian is installed with the same considerations as any other pump – however the motor shaft needs to be horizontal and it has to be installed in a pressurized system (typical of any closed loop HVAC system). I always recommend at least 3 pipe diameters of straight pipe on the inlet side of any pump install – or at the very least do not bolt a y strainer, globe valve or 90 deg elbow directly on the inlet of the pump – all pumps are happier pumping laminar (non-turbulent) fluid. The check on the discharge is OK (although as you know swing check valves can not be installed in a vertical pipe). Feel free to call me on my cel (401) 441-2934 or E Mail directly at anytime. Thank you for using Taco!

What are the cartridge part Numbers for the XPB?

They both take the 008 ss cartridge, part # 008-045RP.

What are the model numbers of the cartridges on the RMB?

The top (injection) pump cartridge part # is 005-020RP. The bottom (system) pump cartridge part # is 008-045RP.

What are the model numbers of the circulators on the RMB?

The top pump (injection pump) is a 006-stainless and the bottom pump (system pump) is a 008-stainless.

What are the motor replacement numbers on the RMB?

The top (injection) motor is part # 193-015RP. The bottom (system) motor is part # 193-016RP.

What are the replacement motor numbers for the XPB?

The top (variable speed, boiler) pump is part # 193-024RP. The bottom (radiant) pump is part # 193-025RP.

What circulator will replace the old 150, 152, & 195?

For small and medium size systems (3 & 4 zone), the 007 will do just fine. The 0010 should be used for systems up to 7 zones. These selections are good if proper pipe sizing is followed.

What do the factory defaults (head setting and proportional) and what do they do?

Head max is set to 23′ and proportional is 50%. This means the differential head is set to 23′ at maximum speed and the head at zero flow (dead head) is 50% of 23′ or 11.5′. Both head maz and % proportional can be adjusted to meet specific system.

What does the 007-BF5-J nomenclature mean?

This is a 007 pump with an iron casing and a stainless steel cartridge originally designed for boiler manufacturers that wet test the boilers. It is also commonly used in open systems such as wood boilers.

What effect does ethylene glycol or propylene glycol have on pumps?

Typically, with a 30 to 40% concentration and at 40°F, the specific gravity of the fluid increases the brake horsepower. On pumps operating fewer than 10gpm, there is no correction for head, flow and horsepower.

What flexible coupling should be used on my frame mounted pump when a variable speed drive is controlling the motor?

We recommend a coupling that has its flexible element either bonded to the hubs or clamped securely to the hubs. The standard engaged flexible elements do not last as long, as they need to be loaded to their rating for best service.

What happens to the performance of pumps when they are piped in parallel or in series?

If pumps are piped in parallel, the flow produced by each pump will be additive, at the same head of each pump. For example, if one pump puts out 20GPM at 35 ft. and another puts out 30GPM at 35ft., the total flow at 35ft. head will be 50GPM. If pumps are piped in series, their heads will be additive, at the same flow rate. For example, if one pump puts out 20ft at 15GPM and another puts out 25ft at 15GPM, the total head will be 45ft at 15GPM.

What is a good circulator for an injection pump application?

A Taco Variable Speed Circulator with integral flow check is a good candidate for injection pump applications. The integral flow check facilitates piping and saves money. Flow checks on the supply and return will minimize migration into the secondary loop. Even though the tees for the secondary loop are closely spaced together at the piping interface, the pressure drop is still not eliminated. Without some type of flow control valve, some hot water will migrate from the primary circuit into the secondary circuit while it’s inactive. From a performance perspective, the advantage of using an injection pump with an IFC is the minimal pressure drop through the valve. Additionally, it only takes approximately 1/4 psi to open the valve, sufficient to prevent any hot water from flowing freely into the secondary circuit when the pump is idle.

What is the current replacement for a CE model pump?

The current replacement would be determined by the original CE model. The GPM and head conditions are also required in order to properly select the best replacement. The new CI series will not be a drop in replacement and some piping modifications will be required.

What is the current replacement for a CM pump?

The current replacement would be determined by the original CM model. The GPM and head conditions are also required in order to properly select the best replacement. The new CI series will not be a drop in replacement and some piping modifications will be required.

What is the current replacement for an FE model pump?

The current replacement would be determined by the original FE model. The GPM and head conditions are also required in order to properly select the best replacement. The new FI series will not be a drop in replacement and some piping modifications will be required.

What is the difference between a 007 Green and a 007 Black?

Nothing, except for the color. Taco Green is synonymous with cast iron circulators that are merchandized through normal retail outlets. The Black colored pumps are synonymus with OEM (Original Equipment Manufacturers).

What is the difference between a JP and a JM frame motor?

A JP motor is a close coupled pump motor where the motor shaft is the pump shaft. It has a longer shaft so that the pump can be constructed with either a soft packed seal or a mechanical seal. A JM motor is also a close coupled pump motor, however the shaft is shorter and only allows the use of a mechanical seal in the pump assembly.

What is the difference between NPSHA and NPSHR?

NPSHA stands for Net Positive Suction Head Available. NPSHR stands for Net Positive Suction Head Required. It’s basically checks and balances; you need to have enough available to satisfy the required.

What is the minimum speed of the motor of a pump controlled by a variable speed drive?

A centrifugal pump is a variable torque device where the torque is reduced with the cube of the ratio of the reduction in speed. At a low RPM there would be virtually no load on the motor. The fan in the motor should be sufficient to cool the motor.

What is the procedure for plotting the performance curve of a pump if you have an impeller diameter that falls between 2 known diameter impeller cuts?

Follow these steps to draw in a curve between 2 published pump curves with a known diameter: Look at the pump curves of the pump in question. Note the diameter of each curve on each side of the diameter curve to be plotted. I.e., FI1511 needs a curve for 10.85\” and we need to know the head that diameter will generate at 104 GPM. 11.25\” & 10.50\” Subtract the difference between the diameters. 11.25\” – 10.50\” = .750\” Subtract the smaller diameter from the to be drawn dia. Impeller 10.85\” – 10.50\” = .350\” With a scale of 50 graduations/inch, measure the distance between the known curves. You will need to do this in equal increments along the curve to plot point to draw the curve. I.e., at 50 GPM the distance is .310\” Calculate the new curve point by solving the following equation: .350\”/.750\” = X /.310\”, X = .350\”/.750\” X .310\”, X = .4666 X .310\” = .145\” Measure up from the lower known curve (10.50\” dia) and plot the point. Continue with the same procedure along the curve in equal increments. Using a French curve, connect the plotted points to generate a smooth curve.

What is the proper way to mount my 00 circulator?

We like to see the motor end of pump in a horizontal position (parralel with the floor), with the electrical box at the 3, 9 or 12 o’clock position, never under or at the 6 o’clock position. The circ can be mounted with the motor in a verticle position (motor end facing ceiling), as long as there is more than 20 psi in the system.

What procedure should be followed when purging air from a loop that has an IFC circulator?

If a 007-IFC is piped on the supply and pumping away from the expansion tank, the normal purging of a zone or of the system should purge the system. Remember to close the main return valve and purge before it.If the 007-IFC is on the return, close the main return and place a purge valve between it and the pump so the zone water is purged through the pump. An IFC pump on the return can create a problem because air sometimes stays in the pump. Remember to open the main return valve after purging. The higher you raise the system pressure without lifting the relief valve, the better the purge. You can do this by manually opening the fill valve and opening the purge valve just as the pressure reaches 30 psi.

What size flange does the Viridian pump use?

The Viridian uses standard ANSI flanges: VR15 = 1.5 inch, VR20 = 2 inch, VR25 = 2.5 inch and VR30 = 3 inch.

What type of motor should be used with a variable speed drive?

Some manufacturers have an invert duty motor; others have made their premium efficient motor to be used with variable speed drives. These motors are called Inverter Ready.

What type of seal is the CI series pump equipped with.

Taco CI, and FI series pumps are equipped with a John Crane Type 21 mechanical seal as a standard. The stationary seat is ceramic and the rotating element mating ring is carbon. Optional seal configurations are available, including sealide C, Ni-Resist and Tungsten carbide.

When selecting a pump, do I include the head required to get the water to the top of the system?

Not if it is a closed loop system and the fill pressure is set to equal the elevation + some extra. If the system is charged properly, the pump will need to overcome only the system resistance. In an open system, if the return line comes all the way back to the tank, the pump needs only enough head to fill all the piping. Once the piping is filled and the fluid is flowing back, the pump only has to take care of the system resistance and the gap between the top of the fluid in the tank and the end of the pipe.

Where can I get instructions for diagnostics on a 00 series pump?

To evaluate a pump without dismantling the pump, a clamp amp is recommended to measure the amp load. If it’s close to nameplate amps, the pump could be running but not pumping water. This would suggest a system related problem, where simply purging the system should correct the problem. If the Amp reading is approx. 1 1/2 times nameplate amp, you’re in a locked rotor condition. Replacing the cartridge assembly will rebuild the pump
Link: Purging

Why does the seal leak when the pump runs, and stop leaking when the pump stops?

Here are some possibilities: (A) Something is restricting the free movement of the seal. The product is viscous and some products become more viscous with agitation (e.g., cream becomes butter with agitation). These products are called dilatants. A recirculation line from the discharge of the pump is aimed at the seal and interfering with its movement. A foreign object is in the stuffing box. A protruding gasket is touching the movable part of the seal.The shaft is being displaced, causing the seal to hit something as it rotates, or causing the rotating face to run off the stationary face. The pump is operating off of its best efficiency point (B.E.P.), causing the shaft to bend. The rotating assembly is out of dynamic balance. The shaft is bent. There is misalignment between the motor and the pump. Pipe Strain is twisting the pump stuffing box. Heat causes expansion, leading to the possibility for rubbing or wear. Cavitation, slip stick, harmonic vibration, bad bearings or some other form of vibration is causing excessive movement of the shaft. The shaft sleeve is not concentric with the shaft, causing it to run “off center.” The pump designed with sleeve or babbitted bearings and shaft movement is excessive. The seal face is being distorted by either temperature or pressure. The product is vaporizing between the seal faces, causing the faces to blow apart. If boiler feed water vaporizes, it leaves behind all of the chemicals that were added to the water to prevent hardness, adjust PH, soften boiler scale, etc. In cryogenic (cold) applications, the vaporizing fluid can freeze any lubricant that might have been placed on the seal faces. This frozen lubricant can damage the carbon/graphite seal face.

Why doesn’t my digital timer show a display?

The reset “R” button needs to first be pressed to bring on the display

Why is my hot water coming out of the cold water line?

The pressure drop is high enough to suck hot water from the cold line when the cold water is used. remedy; install another check valve in series with the with the 18 inch pound one already installed in the pump.

Why is my RMB making a chattering or growling noise?

It could be that the flow is too low causing the check valve to chatter. The check valve can be removed. It is located in the top left hand port where the boiler supply comes in.

Will a 006-B4 replace a 006-B4-3?

The 006-B4-3 has a relay attached (OEM Product) and the 006-B4 does not. You can use the -B4 with a single zone relay (SR501), in it’s place

Will a 007-F5 replace a 007-F2, F3, F4 circulator?

Generally, with all of the \”00\” Series pumps, the first 3 digits tell the performance of the pump, something which does not normally change over the years. So, yes it will. The F always means iron flanged. The number after the F is if we make a design change which does not affect interchangeability, we change the 2 to a 3 etc, on up. So, yes, the F5 can replace the others.

Will the Bumble Bee ( HEC-2) run without sensors?

There is one mode of operation in which this circulator operates without sensors. It is called ‘CP – Constant Power Mode (Fixed Speed) (allows for 4 fixed circulator speeds, [SP1, SP2, SP3, SP4])’. Please Refer to instruction sheet 102-435 for programming information.
Attachment: 102-435

Hydronic Accessories

3350 pressure reducing valve,PRV cartridge a replaceable part? What is the part number?

Yes, the cartridge can be replaced with part number 3350-004RP. the same cartridge fits all sizes.

Are taco heat motor zonevalves suitable for use outdoors?

Taco, does not offer weather resistant valves, or valves suitable for Exposure to the elements directly.

Can I use a current robbing thermostat with a Taco zone valve and what does current robbing mean?

Yes, but because the internal switch opens and closes the circuit when the valve is operating, a resistor will have to be installed across terminals #1 & #2 of the zone valve power head to maintain a continuous circuit. The thermostat uses the power from the 24volt transformer through a continuous zone valve circuit to power the thermostat. If this does not happen the program will be lost the first time the zone valve operates. The thermostat manufacturers are now supplying the required resistors in the package for use when a heat motor type Taco zone valve operator is used. This resistor is around 1000 ohms, .5 watts. Contact the thermostat manufacturer for the proper size.

Can I Wire a WAGS valve to a water heater with an Oil Burner?

Yes, the WAGS valve can be used with a water heater with an oil fired burner.

Can the 570-2 series zonevalve be used in an open system, such as domestic water?

No, the materials of construction are meant for a closed loop system where the same water goes around and around in the system. Our 560-G2 and 5101-G2 are recommended for open systems.

Can the Accu-flo circuit setter be used in a system with cutting oil?

Unfortunately not, Accu-flo valves use EPDM elastomer o-ring that are not compatible with any petroleum based products.

Can the WAGS valve be used on water heaters that are not gas-fired?

YES. The WAGS valve works with all styles of water heaters (natural gas, propane, oil, electric). If using a gas-fired water heater attach the included wiring harness. If using another style water heater the wiring harness can be discarded.

Does the Taco Buffer tank comply with any codes?

ASME Code Section VIII Division 1, Max Design Pressure and Temperature: 125# @ 375F. Registered with the National Board of Pressure Vessel Manufacturers
Attachment: Submittal Data Information

Does the WAGS valve need electricity to work?

No. The valve is fully mechanical and requires no external power source.

Does the WAGS valve require any regular scheduled service?

NO. Just make sure that the holes in the bottom of the valve that let the water in do not get blocked.

How do I know when the WAGS valve has been activated?

Three ways. 1) You don’t have hot water. 2) The drip pan under the water heater is full of water. 3) There will be a red pop-up tab on the WAGS valve.

How do I pipe the Taco three way (bypass) zone valve?

The 560 series valves are designed to be installed down-stream of a fan coil unit. The discharge of the fan-coil would be connected to the unit connection of the valve. A tee would be installed in the upstream side of the fan-coil supply line. The branch connection of the tee would be connected to the bypass connection of the valve. The main side of the valve would be connected to the return main of the system. The system fluid flows through the bypass connection to the return main when the valve is not energized and from the unit connection to the return main when the valve is energized. The bypass connection is not a positive shut off when the valve is energized.

How many protocols can the loadmatch thermostat be used with?

3 bacnet, echelon, lontalk, and non communicating

How to tell if your 500 series zone valve is good

1st you can take a voltage reading across terminal 1 & 2 of the zone valve head, to see if you have 24 volts from the transformer, to rule out a bad transformer. If you have the 24 volts, then you would disconnect either terminal 1 wire or terminal 2 wire from the zone valve. You then can take an Ohm reading across terminals 1 & 2. You should read between 20-23 ohms. If this checks out reconnect the wires, energize operator with operator on valve body. Wait 1 1/2 to 2 minutes for the valve to open and then pull down the manual lever. If the lever move freely all the way the valve is open. If it starts easy and then goes hard, the valve is not open. This indicate the operator is bad and needs replacing. Caution: Do Not Remove Operator From Valve When Energized!!

I am having a problem maintaining temperature at my zones when my taco zonevalve model 570 is in auto mode. Any suggestions?

There are many reasons why your rooms are not reaching temperature. What is the outdoor temperature at the time the rooms would not heat? Were the zone valves open? You can check by pulling down on the manual lever. If there is no resistance, the valve is open. You should read 24V across terminals #1 and #2 if the zone valve is activated.

  • If you have baseboard heat, the top louvers should be open.
  • Was the circulator running? If it\’s a Taco 007, get a screwdriver and place the tip to the casing and the handle to your ear. Have someone turn the boiler switch on and off. Listen to hear the pump slow down and then speed up. The pump is so quiet, you would normally only hear a hum if it is running or not.
  • Have you changed thermostats lately? The heat anticipator should be set for 1.0 Amps.
  • Have you had anything changed in the system lately which would require draining the system, which might have caused an air block?

I have a 3-zone residential system with a 219 Flo-Chek on each zone. The manual override thumb screws are all open ~2 turns. Should these be fully closed?

The bypass knob should be turned clockwise all the way for normal operation. For bypass mode, turn the knob counterclockwise until you have reached the position desired.

I have a taco IFS flow switch that is not tripping when the flow travels trough the piping; what’s wrong?

Remove the switch cover and turn the sensitivity adjustment screw clockwise to increase the flowrate required to to actuate the switch, or turn the screw counter-clockwise to decrease the flow rate required to actuate the switch.

I have an exsisting water heater, and I want to protect it with a wags valve. Can i install the wags valve on my water heater that is already installed?

Yes, In conjunction with installing a new Wags valve, you can also install a dam ( WD1000-1) around the water heater to allow water to reach the 3/4″ level to let the wags valve trip and shut off the water.
Attachment:Installing Water Dam

I’m having trouble setting up the differential bypass valve model number 3196. Can you help?

There is an 8 step process on the instruction sheet reference # 102-163. You have to turn the adjustment dial all the way to the left. Make sure all the valves are open, and calling for heat. Turn the valve’s indicator counterclockwise until you notice an increase in temperature out of the valve. Once you reach this point turn the indicator approximately one full turn clockwise to stop flow through the valve with all the zones open.

Attachment: 3196 Instruction Sheet
Attachment: 3196 Catalog

I’m using the 788 differential pressure gauge with the Accu-flo and I’m not able to get a reading.

The Accu-flo requires a differential gauge that measures in inches of water. The 788 gauge measures in feet and is not sensitive enough to measure below 1 foot, the 779 gauge is recommended as it measure in inches.

I’m using this valve is a well pump application, but the valve is allowing flow through when not calling for heat?

This is a high head capacity valve typically used in high rise applications. The heavy duty construction allows this valve to operate at head pressures up to 150 ft. However, if the pump head is greater then the 150 ft, it will lift the seat and allow flow through. Check the pump head output, and throttle the flow down to reduce the differential head.

If the WAGS valve works and shuts off my water supply to the tank will all the water in the tank still leak out?

It depends if a vacuum breaker is installed in the system. It is possible that the remaining water in the tank could leak out, but that’s a lot better then having a constant supply of water causing extensive flooding.

Is the Taco zone valve a three wire zone valve and how do I wire it?

No, it is a 3 TERMINAL zone valve. One terminal of a 24 volt, 40VA transformer is wired to one side of the thermostat. The other side of the thermostat is wired to terminal # 1 of the zone valve operator. The #2 terminal of the zone valve operator goes back to the other terminal of the transformer. There is an end switch connected between terminal #2 & #3 of the zone valve operator. To activate the boiler control we run another wire from #2 terminal to one of the T terminal of the boiler control. We run another wire from the #3 terminal of the zone valve to the other T or TV terminal of the boiler control.

Is the WAGS valve harness required with electronic control?

No the valve will interupt the water supply regardless of the harness. The harness is commonly used with a gas valve and thermocouple. Currently, we offer the harness as a separate component. Part number GOKIT7200-1 MUST be purchased and installed when the WAGS valve is installed on a gas or oil fired water heater. Not all Gas valves are compatible with the WAGS valve. Your gas valve must be capable of accepting the gas valve adaptor packaged with the WAGS wiring kit. See page 4 of instructions for installing the wiring kit GOKIT7200-1. If you have a Honeywell® WV8840 gas valve, you will need to use GOKIT7201 Wiring Kit instead.

Attachment: Wags Valve Instruction sheet

Is there any power between terminals #2 and #3 of the zone valve operator?

No. Terminals #2 and #3 are only connected to a micro switch and there is no power across them. They are called dry contacts.

May I have some information on balancing valve flow corrections for glycol solutions?

These correction factors are applied to the differential reading which is taken with a differential pressure gauge. The corrected reading is applied to the flow chart. If you have a formula that the differential is applied to, the correction is the square root of the difference in specific gravities of the flowing fluid, divided by the specific gravity of the standard fluid, water at 60°F. The viscosity does not affect the flow meter but can slow the flow due to the added resistance in the system.

My home oil burner serves two zones that are zoned using 573-2 and 572-2 zone valves. The 572-2 only works by opening manually. It worked fine for years. How do I check and possibly repair the valve without replacement?

The valves you have are 572-2 and 573-2 zone valves. There should be 3 terminals marked #1, #2 and #3. #1 and #2 should have 24 volts going to them when the thermostat is calling for heat. If you have 24 volts, the valve should open after 1½ minutes. If you don\’t have 24 volts, the problem is with the wiring, the thermostat, or the transformer. If other zones are operating off the same transformer and working fine, the problem isn\’t with the transformer. If you have 24V at #1 and #2, then it is internal to the operator.

Remove the wire from the #1 terminal and apply an ohm meter across terminals #1 and #2. The meter should read 22 ohms +/- 1 ohm. If the meter needle doesn\’t move or the digital reads 0.L, the circuit is open or the internal contact of the internal leaf switch is dirty. If you get an ohm reading of 16 to 22 ohms, the circuit is good but there might be a failure of the heat motor. With the #1 wire removed from the operator for 5 minutes, you can twist the operator and remove it from the valve body. The replacement power head part number is 555-050RP. You don\’t have to change the whole valve and the operator can be removed without taking the pressure off the system. When you remove the power head, if you see a dark brown wax around the piston, then the diaphragm in the heat motor has failed.

My system pressure keeps rising and causing the relief valve to spew water out, do I need to replace the pressure reducing valve, PRV?

You can try adjusting the valve using the adjustment knob at the top of the valve. If the pressure continues to fluctuate, you could have a faulty expansion tank.

My Taco i series valve is not working properly.

As in any troubleshoot procedure it is important to isolate the problem. The error messages greatly simplify troubleshooting the valve. If the diagnostic lights are flashing identify the coded flash using the matrix found at the end of the instruction manual 102-145

My water heater is 7 years old. Do I need to buy a new water heater or can I install the WAGS valve on my existing water heater?

The WAGS valve can be installed onto an existing water heater or a new water heater. Taco offers a Dam kit for retrofit applications to allow water to accumulate to a level of 3/4″.

My zone sentry valve has a blinking green light. What’s wrong?

The rapid blinking light indicates the valve is charging. if the blinking light comes on while the capacitor control failure. You may have to replace the control.

My zone valve power head was removed while it was still hot. Causing the piston in the power head to cool & harded in the open postion. how do I replace the powerhead?

Push the piston back into place using a blunt object, and then place the power head back on the valve body & apply power to reheat the head. Power head will return back to its normal operating mode once it is reheated.

Taco no longer makes the 568. Are the newer thermostats with no heat anticipators compatible with Taco zone valves? The instructions with the 571 valve say that the thermostat heat anticipator must be set to 0.9A to match the valve. Will the valve function correctly without a heat anticipator in the zone?

Taco still offers a thermostat #568-20. It may not look like your original, but it functions the same. Many people mistakenly think the 571 zone valve is a 3-wire zone valve because it has 3 terminals. All the Taco 500 series zone valves are 2-wire, 3-terminal zone valves. The heat anticipator has no bearing on the operation of the zone valve. Its purpose is to trick the thermostat into shutting off ahead of time, allowing the heat left in the piping system to dissipate into the room and not overshoot the temperature setting. The current draw of the circuit had to be matched to the heat anticipator so it would work properly. A lot of the new thermostats do not require a heat anticipator. All of the battery operated thermostats will work with the resistor and the units that require a third wire (C) to get power from the transformer. It is the digital units that either steal power, need the resistor, direct power, or battery. All the other conventional units work, but make sure they handle a current rating of 1 Amp.

The Zone Sentry actuator has a sticker warning against using this valve on an indirect water heater, and suggests using a tempering valve.

The Taco zone sentry valve could fail in the open position, which can raise the DHW temperature to the same temperature as the boiler water. The tempering valve will help protect against scalding if the valve fails in the open position.

What causes my thermostat to short cycle?

Electro-mechanical thermostats have a small variable heater built into them. It tricks the thermostat into thinking that the room temperature is satisfied so the temperature doesn’t overshoot.

The setting of the heat anticipator is based on the current draw of the connected zone valve wiring. A low current drawing valve requires a longer heater wire to create the same amount of heat. A high current draw circuit requires only a short heater wire.

Taco zone valves of the 550, 560, and 570 series draw about 1 amp, so the heat anticipator should be set accordingly. If the thermostat is short cycling, increase the setting to a higher amp setting.

What else do I need to complete the installation other than the valve?

Water heater drip pan or other suitable device that will allow the water to rise to a level of 7/8″. See sizing chart below. – Two ¾” male threaded x sweat adapters – Two lengths of copper(or other approved tubing). Length will vary by installation. Connection from cold water supply line to valve and from valve to the “cold in” port of the water heater. – Two to four (depending on the installation) 90° copper (or other approved) elbows. Drip Pan Sizing: Water Heater Diameter Up to 17.75 = min. 20″ pan 18″ – 23″ = minimum 24″ pan 24.5″ = minimum 26″ pan

What happens if the WAGS valve gets splashed by the PRV valve or when I’m mopping the floor?

The water soluble fiber element in the WAGS valve is encapsulated and protected from the accidental splashing of water on the valve. Water needs to enter the bottom of the valve through the slots and accumulate to a level of ¾” before the valve is activated.

What is the difference between the 555-151rp, and the 555-154rp replacement actuators?

The stroke depth changed. if you use the old style 555-151rp you can have a condition where the endswitch might not close, or the motor stays energized and not cycle every 30 seconds per design.

Attachment: Replacement Parts List
Attachment: Replacing Power Head Instructions


What is the formula for calculating the pressure differential for a given flow when using the Accu-Flo valve?

The chart on the submittal data sheet is the flow chart for measuring the flow. The actual pressure drop, with the balancing valve wide open, can be calculated by using the Cv or the slide rule.

The formula would be (flow required/Cv) squared X 27.72 = resistance in inches of water at the required flow rate with the valve wide open. For resistance reading with the balancing valve throttled, you need the slide rule. Example: (106.8/212) squared X 27.72 = 7.03 inches of water resistance.

What is the general purpose of Venturi Tees?

To help divert flow from a given zone to a bypass loop when the flow is not adequate to satisfy the load at that branch of the main loop.
Attachment: Venturi Tee Catalog

What is the minimum pipe length required on the inlet side of the Accu-Flo valve?

Although a minimum length is required on most circuit setters, the Accu-Flo does not require a minimum because of the differential across the fixed venturi orifice with minimal turbulance and optimal accuracy.

Attachment: Accu-flo Instruction

What is the purpose of a tank drainer fitting?

Maintain adequate air cushion to provide sufficient pressurization and for draining the tank if it becomes waterlogged

Attachment: Tank Fitting

What is the purpose of the Flo-Chek?

The Flo-Chek serves two purposes: It prevents flow from going in reverse direction from the arrow on the valve, and it prevents thermosiphoning when the pump is not running. Thermosiphoning is a condition in which water in a heating system rises when it is hot and sinks when it is cool. The home can be heated if the pump is not working by manually lifting the disk of the Flo-Chek. This can be done by screwing the stem counter clockwise, which will lift the stem and disk.

What is the typical application for the loadmatch thermostat?

Loadmatch systems, because of the capacity of interfacing with different protocols including BACnet, Echelon-Lontalk, and non communicating networks.

Attachment: Loadmatch Thermostat Catalog

When using the WAGS valve, do I need to install a pan?

Yes. You need some sort of water retention device that will allow water to rise to a level of ¾” to activate the valve?

Where is the hydraulic separator installed in the system?

Primary piping around boilers with higher pressure drops which allows for the possible use of a smaller zone circulator. The hydraulic separator allows a hydraulic connection to the secondary loops off the primary loop. The Hydro-sep also has the added benfits of venting air by means of the Taco Hy-Vent and sediment removal via the bottom valve.


Why do you supply a dam and condensate drain tube with the valve?

In some installations, code requires that no standing water (usually condensate) be present under the water heater. In those cases the condensate drain tube is placed under the dam so standing water can be diverted through the drain tube to a drain line. The dam is installed over the tube, so in the event of a failure the water would accumulate quicker then the flow through the tube and would be able to reach a level of 3/4″ in the pan, triggering the valve.

Why does my Flo-Chek leak by?

Typically this is caused by debris accumulating on the disk or seat. This would be the case if the valve worked fine when it was first installed. You will have to take the valve apart and clean the seat, disk, and stem to bring the valve back to original. The stem should be vertical.

Why does my hot water circulate when my Taco pump is off?

Something has adhered to the Flo-Chek seat or disk. The Flo-Chek is a weighted disk check valve that normally prevents thermosiphoning. That is, it prevents the lighter, hot water from rising to the radiation and the heavier, cool water from sinking, causing a flow in the system without a pump. If the system worked fine before and then started to act up, the disk is stuck or something is on the seats.

Why does my zone valve let flow through it when it is not powered?

There are several reasons: 1.The 570 series can only hold back 50ft of head and if you have a pump upstream of the valve producing more than 50 ft, the valve will be pushed open. 2.If the manual lever has been pulled down, the valve will be manually opened. 3.Depending on the environment the zone valve is in could cause the piston of the operator to stick and not allow the valve to close.

Why does the voltage read across terminals #1 & #2 vary between 24 & 28 volts?

For the first 1½ minutes, you will read 24 volts across terminals #1 and #2. The valve will have reached its operating stroke in that time. An internal switch will open the circuit to allow the heater to cool and control the length of stroke of the valve. When the circuit is opened, the load is taken off the transformer and the voltage jumps up to 28 volts. Once the valve gets into its cycle, there will be a current draw for 10 seconds and no current draw for 20 seconds.

Why is my check valve taco flow chek making a rattling noise?

Normally a check valve is noisy if the valve is oversize for the flow going through the valve. The flow velocity is not high enough and can not lift the disk all the way open so the weight bangs within the body of the valve.

Why is my Flo-Chek or MPV noisy?

Normally a check valve is noisy if the valve is oversized for the flow going through the valve. The flow cannot lift or swing the disk all the way open so the disk bangs back and forth within the body of the valve.

Why is the valve not allowing flow through to the system?

The most likely cause of flow not going to the system is the boiler protection is engaged. Disconnect the power supply, and then disconnect the boiler return sensor from the valve. Reenergize the valve with 24 volts, and the valve will work normally. You must find an alternative way of protecting the boiler, if the return temperature will be less than the boiler manufacture recommends.

Why would I need a buffer tank in my hydronic system?

If the heat source can not keep up with the high demand at peak times, and the system dynamics can not achieve this, the buffer tank is stored energy that will help satisfy the load when the demand is the highest.
Attachment: Buffer Tank Catalog

Will high humidity environments cause the WAGS valve to trip prematurely?

NO. We have actively tested the valve in the most humid of conditions over a long period of time. The element will only absorb a certain amount of water due to humidity, but nowhere near the amount of water required to trigger the valve. An example of this would be if you had a cardboard box full of books. If you left the box in an extremely high humidity environment the cardboard would absorb a certain amount of moisture. It you tried to lift the box the books might drop through the bottom, but at no point will the box absorb so much humidity that it would disappear and leave only a pile of books.

5000 Series Mixing Valve

I have an old Taco PANELTROL valve in my radiant heating system. Does Taco still make this product and are there any replacement parts for it?

Taco no longer makes this product and we don’t have any replacement elements. The PANELTROL was designed to reduce the water temperature being supplied to a radiant panel loop. The reduction in water temperature allowed the radiant loop to operate at a lower temperature than the boiler, which might be needed for other higher temperature requirements. The return water from the radiant loop is used to temper the hot water. Taco does make a new tempering valve, the 5000 Series Valve, that could take its place. The PANELTROL had 1¼” connections but our 5004-C1 should work.

I have a Taco 5000 series mixing valve that I’m experiencing erratic flow at the point of use. What’s wrong?

If it’s a tankless heater application the coil may be fouled from high lime content in the water. Try using a lime X to clean the heat exchanger so the water passes through the coil easier. Fouling is typical when using a heat exchanger.

What is the best way to pipe a 5000 Mixing Valve when used for radiant heating?

Pipe the system as primary /secondary with a pump circulating the primary loop and using 2 tees close together with the branch of the one Tee supplying the hot connection of the tempering valve and the return from the radiant loop supplying the cold connection of the valve and the branch of the other Tee. A pump, sized for the radiant loop or loops should be pumping the mixed port of the valve and supplying the radiant loop/s.

When I try to adjust my 5000-2 tempering valve to a low temperature the stem starts leaking.

You have turned the stem down too low so back off (counter-clockwise) 2 turns to assure a good seal. This will be the lowest temperature you will be able to achieve and is also based on the cold water entering the tempering.

Air Elimination & Control

Can a Taco bladder or diaphragm-style expansion tank be installed in the horizontal position?

The Taco bladder type CA tanks and CX tanks can be installed in the vertical or horizontal position. The NSF/ANSI 61-G certified PAX tank can only be installed vertically while the non NSF/ANSI 61-G certified PAX tank can be installed horizontally or vertically. The CBX is limited to vertical installation. If the tank is installed in the horizontal position, Taco’s U-bolt saddle set or cradle type saddle set will likely be required. Remember to check local code requirements to insure proper tank installation and mounting. When installing Taco CA model expansion tanks in the horizontal position it is important to ensure that the tank is installed with the system connection pointing towards the floor to allow for easier tank and/or bladder maintenance.

Link: Taco Expansion Tanks

How do I check the air charge pressure in a Captive Air Expansion Tank?

Isolate the tank from the system and break the connection to it so that any fluid inside can be allowed to escape. The true air charge can\’t be determined until all the fluid is removed. The air charge will equal the system pressure until the fluid is removed from the bag. If the air charge is higher than the system pressure, there should be no water in the bag and the pressure reading should be the true air pressure reading.

Remember, the water is inside the bag and the air is between the inside of the steel shell and the outside of the bag. If the tank does not have an air charge, air should be introduced which will squeeze any remaining water out of the bag. When the fluid stops coming out

Should I connect a drain to the bottom of my Captive Air Expansion Tank?

No, doing so could cause an air leak at each pipe joint, packing gland and valve seal. Remember that the water is inside the bag. Unlike the old, plain-steel type tanks, the CA tank doesn’t need to be drained.

What is the correct air charge pressure for my Captive Air Expansion Tank?

The air charge pressure should be equal to either the system fill pressure or the PRV setting if the tank is at the same elevation as the PRV. If the tank is located at any other elevation in the system, the charge pressure in the tank should be the cold pressure of the system at that elevation.

What is the purpose of the screen in the system connection on top of the expansion tank?

The screen is there to protect the bag from being forced out of the connection port when installed in a high pressure system.

Why do I need an expansion tank in my chilled water system?

A chilled water system is filled with water at a temperature between 50 and 60°F. When the chiller is turned on, the temperature of the water drops to 45°F. When the water contracts, the system pressure drops, and the fill valve allows more water to enter the system to maintain the system pressure.

If the chiller shuts down and the water in the system warms up to room temperature, the rise in temperature from 45° to ambient will cause the water in the system to expand. Without an expansion tank, the relief-valve would blow. The tank can be smaller than the one used in a hot water system, because the temperature is rising from 45°F to ambient, instead of from ambient to 200°F.

Heat Transfer Products

What information is required to order a replacement tube bundle for my shell and tube heat exchanger?

In order to purchase the correct replacement parts for a heat exchanger, including tube bundles, it is necessary to provide the heat exchanger’s serial number. The serial number is stamped onto the heat exchanger three times in three different locations, as illustrated in the attached diagram. Because piping arrangements and the addition of insulation to the heat exchanger may make locating the serial number difficult, any one of these three will do (they’re all the same). However, if possible, the serial number off of the tube plate is preferable.

Attachment: Heat Exchanger Serial Number Locations

Electric Controls

Can I use the screws of an end switch on a ZVC or SR board to check continuity?

Yes, however you might not get a good reading if the screw is not clamping a wire. Instead, use the test points on the front of the board, or look on the back of the block for the exposed test points.

Can the outdoor reset control PC700 be used with a SR board when used in a primary/secondary piping system?

You certainly can, however, the PC700-2 cannot operate the system pump when any of your heat zones call for heat. You will have to run the system pump continuously. An Alternative is the PC702 2 boiler staging control which works as a reset control, and boiler staging control. You will need to turn the boiler rotation off, put the mode switch on the control board to normal, and Wire the primary pump to ZR with the jumper left in the place.

Can use the priority feature on a SR502/503 when used with an SR503/4/6 EXP?

Yes, remove jumper on ZC &ZR of EXP board. Run a wire from P on SR502 or 3 to ZC and Prioity Switch OFF

How do I run a system pump on my SR504/506?

Leave the jumper in between ZC ZR and tie the hot leg of pump to the ZR terminal. Tie the neutral leg of the pump to the neutral coming from your power supply. ZR (with jumper in) will put out 120V when any zone calls for heat.

How do I wire a Honeywell V8043F Zone Valve to a Taco ZVC control board?

Wiring from a Taco ZVC valve terminal block at the bottom of the board to the Honeywell V8043F valve is as follows: Screw term. #1 goes to TR term. on the V8043F Screw term. #2 goes to TH term. on the V8043F Screw term. #3 goes to the lefthand end switch term. on the V8043F Screw term. #4 goes to the righthand end switch term on the V8043F Nothing gets connected to the TH/TR terminal on hte V8043F. See diagram attached

How do I wire a White Rodgers 1361 Zone Valve to a Taco ZVC control board?

From the Taco ZVC valve terminal block going to the White Rodgers valve as follows: screw term. #1 to screw term. #1 on the WR valve screw term. #2 to screw term. #4 on the WR valve screw term. #3 to screw term. #3 on the WR valve screw term. #4 has no wire connected to it on the ZVC control. From screw term. #2 from the WR zone valve goes to the right-hand thermostat screw term. at the TOP of the ZVC thermostat connections.


How do I wire a ZVC404 or ZVC406 so the system pump does NOT run on a DHW priority call?

The wiring diagram on the instruction sheet for optional system or DHW circulator causes both the system & DHW pump to run when there is a DHW call. If you only want the DWH circulator to run then the wiring is as follows; Instead of bringing 120v into the right side of the extra end switch, you only have to put it into the common screw terminal of the dry contacts. Then connect a wire from the N/C terminal on the dry contact to the right side of the extra end switch. Now when there is a DHW call the power will be removed from the extra end switch.

How do you wire a 3 wire thermostat to a SR control board?

On the old -2 revision boards (SR503-2) you can connect the R & W wires from the thermostat to the {TT terminals} at the top of the SR board. The common wire (C) from the thermostat can be wired to the common screw terminal of the 24v terminal block on the left side of the board. On the new revision 4 models (SR503-4)there is R,W,C at the TT connections.

Attachment: 3 Wire thermostat Connected to a SR board

I have a gas boiler with Taco controls that is short cycling. The problem seems to relate only to the 2nd floor zone. What can be causing this?

Check the heat anticipator on the thermostat for the zone or zones you think are short cycling. The thermostat should be on an inside wall, with no radiation under it, and away from outside drafts. Also check that there are no bad connections and that 20-gage wire is used, not telephone wire. The current draw should be about 1 AMP. When the boiler cycles, watch the water temperature to see if the boiler aquastat is cycling the boiler. The upstairs zone might be small and not much of a load on the boiler. You might want to lower the boiler water temperature until the outdoor temp drops. Our PC700 is an outdoor reset control used in conjunction with our -EXP controls.

I have a Honeywell L8148E limit control which came with my gas boiler. It has one 24vac zone for a thermostat. I want to implement the SR503 into the circuit, as I have two zone 120vac thermostats. I need to know what the output of the thermostat zones are, along with a n/o contact set I can use for the 24vac zone on the Honeywell. It will be used for a cold start boiler operation with continuous ignition.

Put all of your circulators on the SR503. Remove the circulator that is attached to the L8148E and transfer it to the SR503. Run thermostat wire from the X-X terminals of the SR503 to the T-T terminals of the L8148E. If you don\’t do it this way, you will have to power one of the X terminals with 110V and run a black 110v (hot when X-X close) back to the \”B\” terminal of the aquastat to fire the boiler. Use the same power supply coming from the boiler safety switch to power the SR503.

I have installed a sr503-1 with priority in a primary secondary loop and an in direct water heater (priority). In total I have four pumps, one for my primary loop and one for each of three zones. I want my primary pump to come on for 2 zones but not to come on when my indirect water heater calls for heat. Can this be done?

Unfortunately, not with the control you have. Alternatively, you can use the SR503 as it is currently wired, but install a SR501 to energize a system pump whenever any of the three zones call for heat, and bring the aquastat from the indirect to a separate SR501 for the DHW pump, and bring the isolated end switch directly to the boiler TT terminals circumventing the system pump.

I need technical details on how the ZR and ZC terminals interface with the aquastat on a boiler. I wire many boilers and all directions specify cold start or hot start, black box type instructions. I do not fully understand the inner workings, or what happens electrically with either application.

In our Control Instructions, we give two examples: a cold start boiler or a tankless coil boiler. For the cold start, the X, X goes to the TT terminals in the boiler control. For the tankless, the ZC and ZR go to the ZC, ZR terminals of the boiler. Boiler controls that don\’t have ZC and ZR terminals can be hooked like the cold start. These hook ups are conditional, in that you move the circulator that was originally wired to C1 and C2 over to the Taco Control.

If you plan to leave the circulator on the boiler aquastat, and a thermostat connected to the TT terminals of the aquastat, you will need to get into the firing circuit of the aquastat. This would be the ZR connection. Run a wire from the ZR of the aquastat to the ZR of the Taco control. If there is no ZR, run a black wire from the ZR of the Taco control to the B terminal of the aquastat.

When an aquastat has the ZC and ZR terminals, the ZC is connected to the low temperature switch of the aquastat and to the ZC terminal of the Taco control. The ZR is connected to the ZR. These will be 120 Volt wiring. When the boiler water temp is too low, the low limit switch connected to ZC opens and drops the voltage to the ZC of the Taco board, killing all the pumps until the boiler catches up. The ZR is a 120 Volt supply to the burner circuit to fire the boiler, but this goes through the high limit switch to control the boiler water temperature.

I need to power my thermostat as there is C,R,W terminals on the Thermostat. How do I get a C connection? I have a SR board.

On all of the SR multi zone boards, except the SR502 &503, the TT terminals at the top of the board are: Right Hand T is R, Left Hand T is W. You can pick up the C terminal from the Common -24 Volts terminal block next to the transformer. Note: The SR502 and 503 boards the Right Hand T is W and the Left Hand T is R

If a ZC wire from the aquastat is wired to the SR board and the temperature of the boiler is low, will the indicator lights be on, and the circulator be on if there is a call for heat?

The indicator light will be lit but the circulator will not come on until the boiler aquastate is above the low temperature setting and the ZC terminal puts out 120Volts

Is the SR EXP switching relay control and the ZVC EXP control for zonevalves compatible; or used together?

No, on like controls can be used together.

My thermostat needs power, and are C, R, and W terminals on the thermostat. Where do I connect the C wire on my ZVC board?

On a ZVC board your T terminals at the top of the board are where your thermostat is connected. The Right Hand T is R, Left Hand T is W. Go to the bottom terminal strip, where you connect your zone valves, with terminals 1,2,3,4 and connect your C wire to terminal #1. This is your C terminal on all of the zone valve blocks.

What are the ZC and ZR terminals on the Switching Relay boards and how are they used?

ZC/ZR terminals on the SR board go to ZC/ZR terminals on the triple aquastat with ZC/ZR terminals, using minimum 14 gauge wires. These terminals will prioritize domestic water coil. When there is a demand for heat from the thermostat, ZR becomes hot, sending 120 volts to the triple aquastat. When the boiler temperature rises above the minimum temperature setting (typically 140°), ZC becomes hot, sending 120 volts to the SR board and powering the relay for the circulators. To recap, the circulators cannot run until the boiler is keeping up with demand.

Why do the relays chatter when a zone calls for heat on a SR502-2 or SR503-2?

A common mistake that is made when wiring the incoming power to the board is to put the 120v hot lead (black) to the P terminal instead of the H terminal. The P terminal stands for priority.

Why is it that in the Taco controller module the terminal 3 & 4 have to be jumped for 2 wire zone valves?

The 3 and 4 terminals are looking for a zone valve end-switch closure to close the main end-switch which is typically interfaced with the boiler thermostat terminals. If you use a two wire zone valve without an end-switch we need to simulate an end switch closure by placing the shunt across the 3, and 4 end-switch terminals.


What are the advantages and disadvantages between the conventional Taco Zone vales and the Taco 00 line of circulators with Integral Flow Check values?

From an operational standpoint, there really is no difference between using one circulator and several zone valves compared to using several circulators. As long as everything is sized and installed properly, both will provide you with equal comfort and longevity. Installation wise, you may find that a zone valve installation may take up less space and will require less line voltage wiring than an all-circulator installation, and will use less electricity overall. Using all circulators has the advantage of redundancy – if a circulator should fail you have other circulators to provide heat – and it makes circulator sizing and selection very simple. Bottom line – both work well and both have advantages and either choice will provide you with years of reliable service with proper installation and maintenance.

Pump was installed in my drain back solar system. Rust has now accumulated into the water in the sealed loop visible in the site glass indicates. I was told the pump is responsible and it should only be stainless, copper or brass which would have prevented this problem? Is this a fact?

Is the system pressurized? When you refer to gravity feed, is it a drain back system? When we refer to open, or closed system, the determining factor is if it’s vented to atmosphere. If the system is non-pressurized open to atmosphere, then it’s considered open. If the system is closed, non-vented it’s considered closed. However, if you’re using pex tubing semi-permeable (non-oxygen barrier tubing) you are susceptible to osmosis a phenomenon that allows oxygen to penetrate the tubing and attacking all the ferrous components in the system? Osmosis is exasperated when there are only a few ferrous components.

On an SKV or SKS wired in alternation, where can I apply a start/stop signal to control the pumps?

Using a dry contact relay make and break the Common terminal on Relay 1 that is wired between terminals 18 on each of the drives. See wiring diagram
Attachment: Alternation Wiring Enable/Disable

My Taco radiant control does not provide heat. What is Warm Weather Shut Down ( WWSD )and how do I turn on my radiant heat?

Most Taco radiant controls come with Warm Weather Shut-Down within its programming. This is the outdoor temperature at which the system is shut down. On some models, this is represented by WWSD on the display. This could also be a toggle switch. Please check the control for the WWSD setting. By default they are set to 70 F. This WWSD functions, in part, with an outdoor sensor. If the sensor is not operating correctly, it may provide a false temperature to the control. The sensor can be checked by using an ohm meter and referring to the ohm/temperature chart within the manual

I recently installed a Radiant Mixing Block to heat 2 zones of radiant floor. When the block injection pump injects at the 20-40% range, it makes a growling noise that sounds similar to dry bearing. Any suggestions?

The check valve in the inlet connect from the boiler supply line is making the noise. To prove a point, put an ice cube on the radiant supply sensor which should make the injection pump speed up. If the noise goes away when the pump speeds up, then it is the check.

To eliminate the noise, break the hot water supply connection and unscrew the adaptor fitting from the block manifold. Look inside that connection and you should see the check and a snap ring holding it in place. Remove the snap ring and then the check. Reinstall the adaptor fitting and re-splice the copper tubing.

This noise problem has occurred once in a while and we are developing a new check that should overcome it. At this time, this is our only solution and I have not heard of any problem operating without the check.

I have a domestic water recirculation pump that is programmed but I do not get instant hot water

If the pump is on a timer check that the clock is programmed properly. If the timer is set for on check to see if the pump is running by placing a screw driver blade against the pump casing and the hand to your ear. Turn the pump off and then on and listen for a cost down and speed up. If this is ok you have an air block in the return line. Shut off the valve between the pump discharge and the hot water tank. Hopefully the plumber installed a hose bib between the shut off and the pump. If not shut off the cold water to the hot water heater , loosen the motor bolts, place bucket under the pump, turn on the cold water and wait for the air to be purged from the return line through the pump. When the water is steady, shut off the cold water, check o-ring seating and reseal the pump. Reopen the cold water line and check for leak. Open the valve between the pump and hot water tank and you should have hot water.

I have a 008-V2 pump on my solar system. Do you still make this pump?

No, but you can convert a current day model 008. Remove the casing from the new pump and install the new motor, cartridge, and o-ring to the -V2 casing and you will have a modern pump. The V2 pump had a special casing that combined an air scoop and pump, together with tappings for a pressure gage and a vent.

I am using a 008-S7 pump in a solar heating system without flanges. What do I cross it to?

Your pump is a 008-V2 with viton o-rings. If you are now using water, you can buy a current day 008-F6. Unbolt the motor and cartridge assembly from the pump casing, throw the pump casing away and bolt the motor and cartridge to the old casing. If you are still using bray oil, you will need a viton o-ring for the casing, but you would still purchase a 008-F6. It is 1/25 HP.

How to fix a Boiler Sensor Error on an RMB or XPB

1st you will need to go into the ADJUST menu and turn the Boiler Min setting to “off”. Make sure you hit the item button after setting the boiler min to off to save it. Next, on the back of the control, you will need to put the toggle switch in the upper right hand corner to the “off” position. You will then need to unplug the unit, wait approx 15 seconds and turn the unit back on. Error should be gone.

How do you clean and de-grease a LoadMatch installation?

We recommend the following sequence for cleaning and start-up of a LoadMatch® system:

  • 1. Initially, start the primary pumps only. Leave the LoadMatch® secondary circulators off. This will ensure that you don\’t pump construction debris through the terminal units.
  • 2. Continue to clean the start-up screens in the suction diffusers until the start-up screens are clean.
  • 3. Start the LoadMatch® secondary circulators and continue to clean the start-up screens.
  • 4. When the start-up screens stay clean, remove the start-up screens and turn the system to automatic operation.

How do I get my house warmer when using an outdoor reset control?

You may want to get your house warmer without increasing the water temperature. This is especially important with radiant panel heating as high fluid temperatures may cause damage to the floor, wall or ceiling coverings. A safe way to get a more reactive system is to increase the ‘Outdoor Design temperature’. The ‘Target’ temperature is met when the ‘Outdoor Design Temperature’ is reached. An example of this is if you set your ‘Target’ to 130 degrees F, and the ‘Outdoor Design Temperature was set to 10F, you would have to wait until it is actually 10F outside before you will get the 130F to the radiant panel. Moving the ‘Outdoor Design Temperature’ up to 30F will get you the 130F water to your radiant panel sooner.

Do I need an Inverter Duty Motor when my pump and motor assembly are controlled by a Variable Speed Drive?

Not necessarily, both inverter duty and inverter ready motors can be used. A centrifugal pump is a variable torque device where the torque reduces with the cube of the ratio of the speed. Baldor has designed their Super E motor with special insulated wire that allows the windings to pass the Corona Inception Voltage test. These windings pass the requirements of NEMA MG 1 Part 31 for peak voltage (1600 volt peaks) when used on inverters. These motors are labeled Inverter Ready. NEMA Part 31, Definit -Purpose Inverter Motors, lists many requirements other than just peak voltage.

A true Inverter Duty Motor meets all the requirements of Part 31 and is expected to perform satisfactorily for torque, temperature, noise and vibration over the entire speed range. This applies to constant torque applications. A pump is a variable torque application and only concerns us with the 1600 volt peaks produced by the VSD. The temperature, noise and vibration reduce as the motor slows and unloads. These will not be factors for pump applications.

Design Tools

I’m a FloPro Team member. When I click on a link to join the Neighborhood, all I get is the log-on screen. I have tried different links, but with the same result. What gives? Thanks Ian – FTS

Hi Ian … You’ll need to register separately for The Neighborhood…it’s a quick and simple process, but it is necessary. We hire a private firm to operate The Neighborhood, and as a result the FloPro Team and The Neighborhood are not linked – so membership in the FloPro Team doesn’t automatically register you for The Neighborhood. So all you’ll need to do is complete the registration process for the Neighborhood and you’ll be in. If you bookmark the page you won’t have to login every time you want to check it out. You’ll definitely enjoy it – we have several interesting Discussion Forums going on right now, including a fascinating troubleshooting exercise. Hope to see you there soon! If you have any trouble registering for The ‘Hood, you can trying using this link:

Please let me know if you have any difficulties… John Barba Taco, Inc

I am looking for an on-line selction program for your plate and frame heat exchangers. Do you have one, and if so can you direct me to it? Thanks!

We currently do not have a plate and frame program for distribution. If you require assistance with a plate and frame selection, I would recommend that you contact your local Taco representative as most of our offices have the capability to run selections for you.

Dear Pls send to me the user manual for FloPro program. Regards

Good Morning — Thanks for your inquiry on the Taco FloPro Designer software. Unfortunately, there is not printed manual – the entire manual is included in the “Help” section of the software. It is printable if you’d prefer to have hard copy. Also, we have a person on staff to provide you with technical support, advice and one-on-one instruction online. His name is Ra Puriri and he may be reached via email (trade or toll free at 877-270-4685. Please feel free to contact me directly if you have any questions. Thanks… John Barba Taco, Inc

I encounter problems when I try to update my copy of the TacoNet software. What can I do?

If you have not updated your version of TacoNet for some time or are trying to install TacoNet onto a new computer from an older CD version of the software, you will have difficulties, because of the cumulative effect of many small updates made to TacoNet over time.

A patch to the TacoNet software that will fix this problem and enable updates is available for download here.

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