I woke up this morning to a cool house and the thermometer showed it was only 66 degrees though the furnace thermostat was set on 72. The furnace thermostat would click, I would hear the furnace kick on. The blower would blow cool air up the vents. I feel the air is not as hot as usual. What's the problem of the furnace? How to fix it? Thanks
Probably your igniter is bad and the heater kicks on but the igniter will not lite the pilot light so just cool air blows. Try having it go out on a saturday morning and on Monday by the time the reapir guy gets there it is about 48 degrees in the house. happened to me last winter.