Crazy scenario.....I live in a single level townhome. End unit, cement pad in southern Minnesota. We have radiant, infloor, water, boiler supplied heat as well as forced air heating from the ceiling. We turn the forced air on in the fall when temperature reaches the 50 degree or so range. We then turn on the in floor heating system when the temperature gets down to the low 40's for daytime highs. (The foreced air is then turned off) We have lived in our new home for 7 years. The two thermostats for the heating systems are mounted in the hallway, side by side and about 5 feet off the floor. The in floor themostat has never been very accurate. I would have to set the temperature 4 to 8 degrees higher than what I would want for the air temp. Last week I got a digital thermostat for the in floor heat system. Followed the directions to the letter. The new 'stat' read the air temperature 8 degrees higher than the other thermostat right next to it! I took the stat off the wall and put it in the living room next to a indoor thermometer and they both ready exactly the same. What is going on here? :confused: Any ideas and or suggestion are appreciated!