help with floor furnaces

My house has 2 floor furnaces, each with it's own thermostat independent of the other. Lately it seems no matter what I set the thermostats for, the furnaces seem to just come on when they feel like it. This happens with both furnaces. The pilot lights are on and they do come on occasionally. But if I put the thermostat on say 90 degrees where I know they should come on, they may or may not. One weird thing is there is a light switch by one of the thermostats and I've never been able to quite figure out what it does. There was one time in the past where one of the furnaces wasn't coming on and I flipped the switch and it came on but now that's not working either. Do I need to replace both thermostats? We've only lived here for about 4 years and have never had any problems before. Thanks in advance. Ryan
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time to call a pro.
A buddy of mine had one of those in his old house. His heat man finally REFUSED to work on it any more. Cracked heat exchanger. His new system works great
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Sounds like you have a loose connection in the wiring.
Call a licensed *competent* heating technician to look at it...

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Thanks for the responses. Turns out the "mystery switch" connects to the breaker that also connects the electrical outlets on the hallway in our house. I had a lamp that wouldn't come on and checked the breaker and it had thrown. Flipped it back on and the furnaces came up with the lamp!! Weird, huh? Oh well, toasty warm now.
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