I have an electric furnace that blow cold air sometimes. I replaced the thermostat and that did not fix it. The fan blows fine.

If I shut if off for a few minutes and then try again, about half the time it will blow hot air.

It has a clean air filter in it also.

  • The heating elements are turned on with a heavy duty relay called a contactor. Sometimes the contacts get pitted and do not connect, this may be the problem. Turning on and off can help reseat the contacts. On home units once they start failing they need to be replaced.
    – Ed Beal
    Apr 9 '16 at 11:57
  • 1
    What's the make and model of the furnace?
    – Tester101
    Apr 9 '16 at 13:38

When the thermostat stops calling for heat, the furnace will turn the electric heating coils off, but allow the fan to continue blowing air until the coils cool down. Maybe the sensor that turns the fan off is not working and allows the fan to continue blowing too long.


It sounds like the heating coil(s) are going bad.

You should have it serviced by a qualified HVAC technician.

Good luck!

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