ways to control floor heat temps.

[mud puppy]

I have a floor heat system in my wash that seems to let the concrete get too cold before coming on and then it gets too hot before shutting off. I saw some information about monitoring glycol temps to turn on the boiler instead of a thermostat buried in the concrete. Can anyone refresh my memory or lead me to someplace to get more info.

 

[washnvac]

The following works well at my locations: I have 2 outdoor air temp sensors located on each side of the building. When the set air temp is reached on either sensor, the floor heat circulator turns on, and stays on until temp goes above setpoint. Then there is a thermostat mounted directly to the return fluid line in the equipment room. This thermostat fires the heater when the fluid temp falls below the setpoint.

In my case, I set air temp at 34. The return temp is generally set around 70, but during very windy conditions I may need to raise it to 80 or 85. I have no slab stats. This was my original set up, and it has always worked fairly well.