The furnace sometimes will not turn on when the temp drops below the programmable Honeywell thermostate setting. The batteries have been replaced in the thermostate and when you hit the temp up button the furnace still will not turn on. The only thing that works is when you turn the circuit breaker switch off and then on, then the furnace will run. I should note the breaker did not trip either. This works only temporarly and there is no telling how long before you have to switch the breaker off and on again to start the furnace. Any ideas on what would cause this? Faulty breaker maybe?

Brand of furnace
Exact model of furnace?

I am having the same problem but I haven't tried tripping the breaker. I have no clue what kind of furnace I have, it only says Plus 80 High Efficiency Furnace on it, it was installed in 1995. My programmable thermostat is a Hunter. When it isn't working you don't hear any noise coming from it. It can take from 1 to 4+ hours for it to kick back on.

Look for a status light on the front/blower panel, and a label with codes & instructions. Try to find brand/model# while you're at it.