I turn our thermostat down to 60F every night. It's the old Honeywell mercury bulb type. We have a 10 year old 90% efficient gas furnace.
For the the past 2 days when I turn the thermostat up to 66F in the morning the furnace won't start. The room temp is at 56F on the thermostat. It usually starts within a few seconds in this situation. I wait awhile thinking "doesn't it normally fire up by now?". Then it's 10 steps out to the garage to check the breaker. The circuit breaker isn't tripped but I flip it anyhow and in 5 seconds the furnace starts. It runs and heats fine, but it's 2 days in a row now and I'm concerned.
Is it just a coincidence, that flipping the breaker off and on the last 2 days did the trick?
It's been 20F colder than usual for 2 days. Could that have anything to do with this?
Thanks in advance for any help.