Taco SR501 switching relay

Sweto

I need help! I am trying to add the taco sr501 one zone switching relay to my system to control my in floor radiant heat. The problem I am having is my in floor has a zone valve and the wiring diagram from SR501 does not show how to wire in the zone valve. The In floor system has its own T-stat, zone valve, and circ pump, using a common boiler. I am using the ZVC404-4 for the other 4 zones in the house with hot water being my primary.

hot_rod

You want a ZVR, zone valve relay, not a ZSR zone switching relay ,pump relay. The zone valve relay has a easily accessible 24V supply, and a larger transformer, for the zone valve.

Generally a zone valve relay box will be at least 2 or 3 valve connection. So you have a spare or two.

A 6 valve ZVR as example.

Sweto

I read an old discussion stating what I’m trying to do can be done, however the discussion has been closed so I can not see any images that where posted showing how to wire in the zone valve.

Big Ed_4

Once you wired the relay to the radiant circulator . Wire the end switch of the zone valve to the thermostat TT terminals of the 501 . From a fused 24V transformer wire through the thermostat the zone valve . With a call of heat from the thermostat , it will power up the zone valve . When the zone valve fully opens it will close the end switch and the 501 will pull in to turn on the circulator …

That is the basic

109A_5

" I am using the ZVC404-4 for the other 4 zones " So now you actually have 5 zones ???

Big Ed_4

What size is the radiant zone ?

109A_5

One method to do it.

Sweto

I have solved the problem and system is working. Thanks to those who actually tried to help.

109A_5

OK, good you have it working. I missed that you stated you have a circulator too. Updated drawing if anyone needs it.

Joe Mattiello

couple of techs already mentioned it.

Protocol, thermostat to ZV, end switch from ZV to RW on SR50, and end switch on SR501 to TT on boiler.

BDR529

Interesting.. No one says anything about outside re-set and/or room sensor, Not a T-stat and relay

Clearly says in floor radient heat. Hope you have a 3-way mixing valve.

109A_5

https://forum.heatinghelp.com/discussion/comment/1864284#Comment_1864284

A few questions were asked, with no response. The OP did not seen to want to discuss the rest of the system. Have no idea what they have, a 4 wire zone valve would have been easier, so I used a three wire zone valve. No power needing thermostat was mentioned. Hopefully they don't have the zone valve after the SR-501.

hot_rod

Or what type of thermostat. How large is the transformer in those switching relays? Some of the heat motor ZV take a bit of Va.

GroundUp

If it's piped correctly, there is no reason to have a zone valve at all.

EdTheHeaterMan

https://forum.heatinghelp.com/discussion/comment/1864293#Comment_1864293

I found that out when the zone valve for my air handler coil failed. I robbed the motor from my radiant heat zone to get heat and just left the zone valve open manually. I was using a ZVC-404 and placed a jumper across the end switch terminals. I just figures that radiant zone would overheat for a few days until I got a replacement zone valve motor. As it turns out, leaving the zone valve open manually did not cause any overheating of the radiant zone. That is because the thermostat for the radiant needs to call for heat to operate the low temperature. circulator from the mixing valve. I never replaced the zone valve motor and it is still operating perfectly with no zone valve.

I have redesigned subsequent radiant floor systems since that discovery. Sometimes you need to see it (experience it) to believe it.