I have a 10 year old furnace and thermostat (sears programmable
digital thermostat). Recently, on some nights, the furnace doesn't
seem to be kicking on enough, and we wake up to the house being 10
degrees colder than it should be. We'll have the thermostat set at 73,
and the house will be 63... and the furnace won't be on...
Usually, at some point in the morning, it kicks on. Or, sometimes i go
downstairs and power off the entire furnace (there's a switch by the
furnace) for one minute, then turn it back on, and it's starts warming
At first I was concerned that the programmable features of the
thermostat was screwing up, so I set it on a constant temperature. But
that didn't seem to make a difference. It doesn't do this every
night... but more nights than not now.
It's cold here at night (single digits farenheit), but it's not an
unprecedented cold. The furnace has never had this problem before.
* Should I start with assuming the thermostat is bad? I can replace
that myself (I'm comfortable with following wiring schematics, etc...)
and that would be cheaper than a service call.
* Has anyone experienced this kind of problem before?