Radiator thermostat wiring

maitoboika

If I have panel radiators installed with thermostatic valves attached, do I need to run any thermostat wire from the radiators to the boiler?

delcrossv

You still need some way to tell the boiler to end the call for heat. But that isn't from the radiator, that's from an average location in the house (not near an emitter)

Jamie Hall

Or to put it another way — the TRV on the radiator (or radiators) can neither tell the boiler to start nor to stop. They have no wires or switches in them to do that. In fact, as a bottom line, they can only tell their individual radiator to stop heating when the system is running. They can't tell the radiator to start.

bburd

https://forum.heatinghelp.com/discussion/200845/radiator-thermostat-wiring

No.

maitoboika

…that’s what I figured, thanks. Would that not make the thermostatic valves redundant, as there would be a thermostat in the room? Don’t know much about radiators…

Jamie Hall

If there is a thermostat in the room — not only would a TRV redundant, but — if it were turned down for some reason — would prevent the thermostat from sensing the heat, and the rest of the building would overheat.

A TRV is only of value if there are rooms which you may want to have cooler than the thermostat will hold them — the thermostat being located in some agreeable central position. Further, it is important the remember that a TRV can only reduce the heating of a space, not increase it. They are very useful — but only in a limited way.

delcrossv

Well, if isolated, they could run a room warmer than the thermostat. But you'd need specific conditions for that to happen.

hot_rod

if you use an ECM circulator in the delta P mode, a relay like this is as an option

So a TRV opens, the pump wakes up, the relay detects current and fires the boiler