Our furnace has not been used as the weather has been fairly warm lately. It may have turned on for a minute the previous night, but I do not know. Anyways I was walking past furnace and noticed I could feel heat coming through the covers. I removed the cover and it was pretty warm. The blower motor felt kind of hot. I flipped the breaker to cut off power supply to the furnace. I did not smell burnt wiring but there was a hot smell. How could the furnace have been so warm when it hasn't been ran regularly the last few weeks?

  • Where are you located on this planet?
    – JACK
    Jul 8, 2020 at 1:11
  • Does the furnace blow air or does it move water or steam? You call it a “blower motor”. Does the blower motor turn on and off?
    – Lee Sam
    Jul 8, 2020 at 3:39
  • Yes it blows air. The thing I'm concerned about is the fact that it has been in the 80s-90s for about a week so we haven't been using the heater at all. The thermostat was set on 58, and it was about 80 degrees outside all day so the heater never started running. I think the heating element may have turned on for no apparent reason?
    – Hunter92
    Jul 8, 2020 at 4:18
  • What sort of thermostat?
    – isherwood
    Jul 13, 2020 at 15:05
  • Depending on where on the furnace you felt the heat and what kind of air-conditioning you have (making assumptions...), it could be coming from A) the blower motor running to push the cold air through the house (the motor will generate heat), or B) the heat exchanger where the AC is exchanging warm air in the house with the cold refrigerant from the condenser coils - the now hot refrigerant is now hot and you may have felt that heat radiating into the room.
    – FreeMan
    Jul 13, 2020 at 15:18

1 Answer 1


Could be a faulty thermostat. If you have a multimeter, check if there is any potential on the output, change the setting for a temperature, higher than the ambient and check again. If the electrical potential is the same you may need to change the thermostat. IDK, but I think the heater can't just turn on by itself- there must be a stuck relay/contactor or the thermostat is faulty.

  • "Potential" means voltage, btw. Set the multimeter to DC and digital meters to the lowest number above 24.
    – isherwood
    Jul 13, 2020 at 15:04

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