Plumbers, is this a stuck damper motor?
Here's what happened: Yesterday I turned the diningroom thermostat on to test my heat. The circulator pump came on and the burner fired, and that was it for yesterday. Heat was off again after the test.
This morning I put the living room thermostat up to call for heat, circulator on, big burner didn't fire. Then I put on diningroom heat (circulator on, but didn't fire).
So I went to observe the burner and it had a pilot light, and the damper was open. So that's odd, damper open but it wouldn't fire. So all I did was tap on the damper motor and the gas burner fired instantly. Now the damper is working properly. Could it have been stuck in the open position from yesterday's system test, and this caused it not to fire? Everything is working as it should now. What do you think happened?