I put a temp sensor on the return to the floor heat boiler. The thought is that when the air tempature is below 36, that the circ pump kicks on. When the return from the floor is below 60, then the boiler will fire. I'm hoping that when it's cold, that the liquid being circulated will keep the pad warmer with the help of the sun shining on one side of the building. Before, I just had a slab stat and when the heat kicked on, it ran forever. Now I can kill it all night long and the boiler only fires when the return temp gets too low. Hope that makes sense. I believe that others have configured it this way as well.
Thanks,
Lighthouse.