there is only elec. no gas and no venting to outside and the thermostat has auto on system cool off heat em heat what does em heat mean
Sounds like you have a heat pump system since you say the outdoor fan is running. The electric heat is used for back up heat. It will come on to assist the heat pump when the indoor temperature drops more than 2 degrees below the thermostat setting. In the Emergency heat, (em heat) mode the heat pump is shut down and the electric becomes the primary heat supply. Emergency heat should only be used in cases of a failure or problem with the outdoor unit or in a instance when the outdoor temperature drops so far below normal season average temperature that the heat pump is no longer able to supply enough heat to heat the home. Also, if the thermostat is set to the Auto setting it wil run either the Air conditioning or the heat depending on room temperature. You should set it on Heat or Cool depending on winter or summer operation.
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