Deep Dive Switching Relays and Zone Valve Controllers 

Thank you, Levi!

Hi Dave, thanks for watching one of the Taco Tuesday webinars, we greatly appreciate it. Below is the link to our complete wiring guide, look for your application starting around page 83. www.tacocomfort.com/documents/FileLibrary/100-92.pdf

That is correct, you would need the SR506-EXP, it has the two dry contacts you are looking for.

@abacojack13 Thanks for watching Taco Tuesday, greatly appreciated. There are several ways this wiring can be completed. The first is if the manifolds are remotely located. I would install a zone valve controller (ZVC) at each manifold location, thermostats and actuators wired at that location. Then take the end switch wire from each ZVC and bring it to the mechanical room where the circulators are. At that point, you would need a switching relay (SR) to handle the 4 circs. That end switch wire will then go to the TT terminal for the corresponding circ.

The second way is if the manifolds are near the circulators, then you would need a ZVC for each manifold and the corresponding circ would then be wired to the ZVC

If both circulators are designed to turn at the same time, then a SR501 can be used if you are using circs with a total load of under 6 amp power draw. For a thermostat, you can use whatever brand and features you want. It will depend upon the number of wires in the wall that are from the room you are heating and the mechanical room.

Hello Tony, The wifi style thermostats on a SR 503 panel can be challenging. The quick answer to your question is yes, you can use the top left terminals for 24v power. The second part of this answer there may not be enough power at those terminals to power the controller and those new thermostats. That terminal is designed for smaller power loads. Our suggestion is to use an external transformer to power the thermostats. If you are not sure how to connect or your instructions from the thermostat manufacturer are not sufficient, please contact your plumbing and heating professional and/or Technical Services here at Taco. Thank you

Ted, DHW circulators do not need to be setup on the ZVC controllers. Most of the time it is based upon the boilers being used and recovery time of the the DHW tank. If you do not want to use the Priority feature of the controller, you don't have to do anything, the default setting of the ZVC is that that zone operates just like any other.

Hello The Plumber, When it comes to a multiple temperature system like this where you need a lower temperature for the radiant floor zone, then yes, you need an additional circulator after the mixing valve, that's why it hasn't worked well. However the Zone Valve Controller can only control one circulator and you already have it used with the 5 zones of copper fintube. So you will need an additional SR501. I hope this helps.

I wouldn't go more that 75' with 18/4 wire to the zone valves. However, the beauty of the ZCV-EXP models allow you to install the Zone Valve Controller remotely (close to the zone valves) and then using the Expansion terminals ABC, you can daisy-chain from one controller to the other.