Taco Zone Valve Control Relay (ZVC) triggering Zone Switching Relay (SR)

brady

My system is primarily controlled by a SR504-EXP-4 which is currently triggered by two heat zone thermostats and one indirect domestic hot water tank. I'm adding a third and forth heat zone but both come off the same supply and return pump (SR Zone 3). Where Zone 3 and 4 split, I have two Taco zone valves which will be controlled by separate thermostats.

Can I hook the new zone valves + thermostats to a ZVC and then wire the "X X" coming off of the ZVC to SR Zone 3 "R W"? Essentially the ZVC would consolidate the thermostat calls and if either of them request heat, trigger SR Zone 3 on the master.

I haven't been able to find a wiring diagram showing this. My (crud) attempt at something along the same lines:

HomerJSmith

Can I hook the new zone valves + thermostats to a ZVC and then wire the "X X" coming off of the ZVC to SR Zone 3 "R W"? Essentially the ZVC would consolidate the thermostat calls and if either of them request heat, trigger SR Zone 3 on the master.

I"m not so sure that I fully understand your desires. Any thermostat calling for heat on the ZVC 404 will close the XX relay, which is just a switch which is normally use to turn on a boiler. Since you have two zones valves + thermostats (one for each zone that you want to control separately) controlled by one pump, I would think that the thermostats and the zone valves must be on the ZVC. And...the ZVC can control the SR zone 3, activating the zone 3 relay, turning on the zone 3 pump sending flow to either or both zone valves depending on the call for heat. I think that would work.

But...You can only have two thermostats that you want to add to SR zone 3 pump on the ZVC. The pump would turn on when any other thermostat ON THE ZVC would call for heat and the SR zone 3 pump would turn on and if the zone 3 zone valves would be closed then the pump would dead head.

You may have to change your strategy if you have more than those two thermostats on the ZVC. It can probably be done with two isolation relays .

HomerJSmith

If you already have a ZVC that's one thing. If you are thinking of buying a ZVC that's another. You could achieve your goals I think with isolation relays and an aux transformer. A lot cheaper.

pedmec

Does zone 1 and 2 have zone valve? How do you stop them from getting heat when zone 3 or 4 calls for heat and the circulator comes on?