Thermostat seems to work fine. Except at night. When it gets cold.
Quick background info: We bought this house a year ago. Yay! Ran into this same problem almost immediately. The heat works fine. Sometimes.
Last night my wife came home after I'd already gotten in bed. She said "it's freezing in here!" and I suddenly realized it was pretty cold. Temp had been falling steadily since I'd gone to bed at ten or so. So, rough night and two grumpy toddlers later, we were trying to figure out what happened. Then the heat (the glorious HEAT!) came on. And all was good. Last night it got cold again.
The thermostat seems to be the problem. Says the temp is 66 degrees. Says it SHOULD be 74. Fan is on AUTO and blows continuously, cool to (cold!) room temp air. It seems like it's TRYING to heat, but it has no heat to give. The next day, all is good again. What is it about cold winter nights (we had this problem last year right after we bought the house and muddled through the rest of the winter after the thing seemed to auto-correct itself.)
If I didn't know better, I'd think we had accidently programmed the thing to cool down to 66 at night. But we checked the programs. Daily and weekly. The temporary override feature also says it's working to bring the temp up, but it stubbornly stays at 66. I mean, a SOLID 66. Which is why I think the thermostat is to blame.
When it does heat, it blazes like the noonday sun, and does a great job. But at night, it's a different story. Anyone have an explanation for this? Similar problem that you fixed? We thought about calling a technician, but we're afraid he'll just come and charge us $150 to show us how to program our thermostat. But we're tired of shivering under the covers at night.
Here is the manual for the thermostat.
It's the 5000 model.