2 zones of heat on same thermostat with zone controller

curley

I have a room with radient heat that I would like to use first with baseboard as secondary. The radient is tied to a Taco sr501, with 2 zone valves for this and another radient zone. The baseboard is connected to a Taco sr506. I am presently using a Honeywell thermostat and can get the first zone (radient) to come on but not the 2nd (baseboard). I am also planning to change the thermostat to a Nest. I have a 7wire running to the thermostat. R&W go to the 501, I do not know what to run to the 506.

Jamie Hall

If you have radiant heat, you do not want a Nest, unless for decoration. If you do get one, disable all its smart functions.

Now. Having said that. The control strategy for a radiant floor is completely different from that for baseboard. The objective of the exercise is to use relatively low temperature water, flowing continuously, to keep the floor at an even temperature just high enough to offset the heat loss from the space. There are several ways to do this -- outdoor reset is usually part of the game. A floor temperature thermostat often is, as well.

Baseboard can also be effectively controlled by outdoor reset with constant or near constant circulation, although it can also be controlled by a conventional room thermostat. Either way, the water temperature required is quite different from that required for a radiant floor.

You need to run a thermostat -- preferably a fairly simple one (again, a Nest -- or any other smart thermostat -- does not play well with baseboards) to the control for the baseboards.