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MANUALS (3)
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Product Highlights
Description
Features
- One Add-on Power Control Plug
- Premium Sealed Relays
- Interface with all -EXP Multi-Zone Controls
- External Indicator Lights
- Universal Replaceability
- Snap-in PC Board
- Simplified Wiring
- Fully Enclosed Snap-Out Relays
- Fuse Protected (with spare)
- 100% Factory Tested
- Contractor Friendly PC Board Layout
- Universal Thermostat Compatibility
- UL and CSA Approved
- Extended 3 Year Warranty
- Made in the USA
Specs
| Application: | Zoning |
|---|---|
| Number of Zones: | 1 |
| Width: | 4-1/4" |
| Height: | 5-1/4" |
| Depth (Inches): | 2-3/4" |
| Amperage: | 5 |
| PowerPort Slots: | 0 |
| Power Control Plugs: | 1 |
| Power Method: | 120 VAC Input |
| Voltage: | 120v |
Questions?
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Product Reviews
Most Liked Positive Review
Taco 503exp-4
Most Liked Negative Review
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Old Product
Old Product
yes I will
Definitely recommend
Solid product
good control
Good services and product
terrific
These Taco Exp controls are night and day improved!
Perfect for my needs
I will continue to buy this product. Great company.
Product Q&A
15 QuestionsQ: Hi, I currently have a zvc406-exp-4 board and a pc-702 reset control. The zone valve control board is currently full and I would like to add a zone for DHW. Being this control is exp, is it possible to connect to the expansion ports on my current board to add the DHW?
Asked by rick 10 years ago
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Verified Reply- SupplyHouse StaffIf you added another board than this would be dependent on the model number of this board. That being said this should be available as long as the priority is turned off if that is an existing option.
Q: I have 6 zones Sr 516 exp. When a red light comes on for a zone, what is the light telling me?
Asked by Rick 12 years ago
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The red light is telling you that zone is calling for heat.
Hi Rick, It means that the T terminals, at the top of the controller, for that zone has been shorted together. Usually by a thermostat. This in turn, turns on the relay for that zone and applies power to the Z terminals at the bottom of the controller, for that zone, and also turns on the red light for that zone. Gary
The red indicator light is simply telling that there is a thermostat calling for that zone. As the relay is triggered the red light shines. The green light simply indicated power to the control box.
Q: I have taco sr504-exp relay currently running 4 zone pumps from thermostats. I also need to run my primary loop pump to cut off and on with my existing 4 zone pumps. Right now i have to run the primary pump constantly even when my 4 zone pumps are not running to supply heat to my heat exchanger for domestic hot water. One solution might be to add a flow switch in my domestic hot water line to activate the primary loop circut but i am not sure how to keep the 4 zones off when heat is not needed to suplly heat to the 4 zones. Right now i am wasting heat because i have to leave the main loop pump on all the time unless i manually shut the switch off. Any idea,s would help Thanks Terry Fouts
Asked by Terry 14 years ago
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Verified Reply- PexSupply StaffWe would recommend that you install a dedicated circulator for just the domestic hot water loop.
I do not understand how your setup is. Why don't you make a total of 5 zone pumps? This way you can put the water heater on the 5th zone pump. The pumps usually have a backflow preventer valve and when they are off you should not get hot water through that zone. I am not an expert in the area but it seems odd to me to have a main pump and 4 additional zone pumps. Perhaps you actually have 4 zone valves not 4 pumps, that would make more sense. If that is the case then you will need another zone valve for the heater. All the zone valves should have a switch that would trigger the pump when the switch is wide open. Elad
Wire the primary loop pump directly to the terminals on the aquastat. I had a similar setup using the Honeywell 8148 aquastat on my boiler and the sr504. The aquastat triggered the boiler circulator when the thermostat called for heat as well as the sr504 triggering the appropriate zone pump.
Doesn't your DHW heat exchanger have an aquastat? That's how I handle it. My DHW heat exchanger has priority (by means of an extra relay that I added) over the heating zones. If your DHW can be treated as just another zone then that's easy. Mine can't, but even with that I'm able to let the aquastat handle switching of the main loop pump.
One of several options is to pick up an additional SR501 relay and run 18/2 wire from end switch on SR405 to TT terminal on SR501 that is now powering your primary circulator. The cheapest option is to run a hot line to the Com circuit on the SR504 and then run a lead from the N/O to the primary circulator. Many options, but these are two that come to mind immedialtely. <email@powerrevie wsemail.com> To Sent by: <****@***.***> "PowerReviews" cc <email@powerrevie wsemail.com> Subject Can you help a fellow shopper? 09/08/2012 04:08 Please respond to <reply-fe93167771 62007875-100997_H TML-381803375-106 4144-2208@powerre viewsemail.com> "I have taco sr504-exp relay currently running 4 zone pumps from thermostats. I also need to run my primary loop pump to cut off and on with my existing 4 zone pumps. Right now i have to run the primary pump constantly even when my 4 zone pumps are not running to supply heat to my heat exchanger for domestic hot water. One solution might be to add a flow switch in my domestic hot water line to activate the primary loop circut but i am not sure how to keep the 4 zones off when heat is not needed to suplly heat to the 4 zones. Right now i am wasting heat because i have to leave the main loop pump on all the time unless i manually shut the switch off. Any idea,s would help Thanks Terry Fouts" Can you answer Terry's question about this product?
Q: I have this existing relay on my furnace (New) The furnce is 62 years old ( American Standard) and by Fall I will replace with a Buderus G115WS4. I know you recommend the Honeywell but will my existing Taco work? Thanks
Asked by Mike 14 years ago
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Verified Reply- PexSupply StaffThis switching relay will work as long as you are zoning by circulator.
Yes it should Sent from my iPhone
The Taco pump control relay will work. Just be sure to wire the priority zone for the hot water if you are doing an indirect. Stan
Yes, it will work.
Most likely it would work fine. This switch have a contact that turns on the furnace when needed. Since this switch is a modern technology most likely will be compatible with your new furnace.
Q: what is the best thermostat to use with the Taco 4 zone with four zones to operate
Asked by Madhatter 14 years ago
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Verified Reply- PexSupply StaffTaco switching relays work with any low-voltage thermostats, so you have plenty of options. You need to decide whether you want programmability, a digital display, cooling capability, etc.
If its a straight forward hydronic radiant heat application, I'm using Uponor A3030101 heat-only, two wire thermostats. They're inexpensive and work with the the Uponor actuators in using. I actually bought this and didn't realize it was the 120v version and bought the ZVC406EXPs that use 24v for the actuator side. -Jonathan
Any thermostat will work with the Taco control. Which one to choose depends on your application, whether you want programmability, both heat and cool control, your budget, etc. If replacing old battery powered tstats make sure you have enough conductors in the cable to operate a new line powered Tstat properly. You should consult with an electrician or heating contractor if unsure.
Any thermostat will work great with this unit. If you are looking for a setpoint controller for a floor sensor or something like that I use the Tekmar series on setpoint controllers. If you are just looking for a basic thermostat you don't need to spend a lot of money on that, a cheapy from Home Depot will work great.
I have a Taco 4 zone and I am using the Honeywell ForcusPro programable thermostat. These suit my purpose. However, if you are willing to spend the money there are some pretty fancy thermostats available. Some have motion detection and will change the setting when someone walks into the room. Others can be set with an app on your smart phone. Arthur Alexander Elkins Park, PA
I have used the Wirsbo thermostats with good success.
Any
Any thermostat will work (digital or dial). Sent from my iPhone
Q: I need a switch for my wood boiler system. I have two zones controlled by zone valves and a Grundfos Alpha pump, and I have a domestic water heater with a circulator. Will this switch take care of both or do I need two seperate switches? If yes, which ones? Thank you.
Asked by Henrik 15 years ago
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Verified Reply- PexSupply StaffYou would need two separate controls. We would recommend a ZVC403-2 for the zone valves (no two-zone ZVC is available) and a SR502-2 for the circulators (with the DHW circulator given priority). You can tie the end switch on the zone valve control into the thermostat terminal on the switching relay.
Q: What type of wire should I be using to wire up the expansion ports between a SR503-Exp and an SR501-EXP?
Asked by CoreyZ 15 years ago
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To wire the expansion ports on the 1 Taco Zone Switching Relay w/Priority & 3 Powerports you can use any 18 AWG wire, with up to four connectors.
Q: can i use this to control a wood fired boiler? it would have 2 heating zones and 1 heat dump zone controled by aquastat for when 2 heat zones are not calling for heat I will use a seperate pump to each of the 3 zones. thank you
Asked by klem 15 years ago
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Verified Reply- PexSupply StaffYes, this control will work if you are using zone pumps.
Q: I am planning to install a system with 6 zones and a circulator on each zone. Will this unit be able to supply 120 V to each circulator?
Asked by Dane 15 years ago
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Verified Reply- PexSupply StaffYes, it will.
Q: hi, I would like to purchase the taco SR506 to replace my 503 to increase my ability to add more zones. I printed out the wiring diagrams for the SR506 and I'm not sure how to duplicate how the jumpers would be like they are on my 503. The 503 has a jumper that goes from P-ZC-H-X1. X2 goes to the aqustat which goes to the power vent For the boiler. My boiler is a Biasi cold start. Your help would be appreciated. Thanks
Asked by 15 years ago
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Verified Reply- PexSupply StaffThe SR506 has a switch inside of it instead of a jump. The switch acts like the jumper in the 503.