I need a thermostat (or a better plan)

[Jon_E]

I am having a hard time finding the appropriate thermostat for my application. I have in-floor radiant heat tubing in my garage, and I need to control the circulator pump with a thermostat. This is being fed from an outdoor wood boiler 150 feet away, so the loop from the boiler will run continuously but I only want the loop for the slab to run when there is a call for heat. The two loops are separated by a plate-style heat exchanger. I want to hard wire the circulator pump into the thermostat so that I can use a line voltage thermostat to control the hot water flow in the system. Every line voltage thermostat I can find is for electric heating.

Is there another simple solution I should be looking into? I really don't have the experience to figure this out. My basement mechanical room has a 6-zone Taco controller, but I only need a single zone. I am wondering if I need a zone controller anyway, and a low-voltage (24v) thermostat? Pump connected to zone controller, which in turn is connected to t-stat?

 

[mrpizza]

Likely the easiest solution is to install a single zone control on that loop with a 24v stat.

 

[Stuff]

Could use a fan control center or a Aube transformer/relay (https://www.amazon.com/dp/B000PY2856/?tag=atomicindus08-20 or https://www.amazon.com/dp/B00D5YLY2G/?tag=atomicindus08-20).

 

[Cword]

I use an Aube transformer relay (https://www.aartech.ca/rc840t-120-aube-120v-relay-with-24v-transformer.html) and a nest thermostat to run my pump, the nest also has a radiant heat mode so overshooting and temperature anticipation are taken care of.

 

[Radix2]

While the fancier thermostat/relay solution has more features, I don't see any reason a simple electric heat thermostat won't work...why do you think it won't work?

The simplest of these are just a set of contacts controlled by a bimetal...they don't care if the load is a circ or a heating element.

 

[kj_mustang]

Single zone relay hooked up to the pump and the thermostat, simple.

http://www.supplyhouse.com/Honeywell-RA89A1074-1-Zone-120V-Switching-Relay-w-internal-transformer-1-Spst-line-relay-4121000-p

 

[Stuff]

I don't see any reason a simple electric heat thermostat won't work...why do you think it won't work?

Good point. Some line voltage thermostat is rated for resistive loads only, not motor loads. Others are rated for both. Usually the ones are also marked "heavy duty."

 

[Jon_E]

Single zone relay hooked up to the pump and the thermostat, simple.

http://www.supplyhouse.com/Honeywell-RA89A1074-1-Zone-120V-Switching-Relay-w-internal-transformer-1-Spst-line-relay-4121000-p

That's the thing, what I need. Thank you.

 

[kj_mustang]

If you buy that model, the instructions really ****.

 

[Jon_E]

I guess I should have said - that's the type of thing I need. I was leaning toward the Taco or Grundfos single zone control.