01-03-2007, 11:15 AM
If your house is warm and it is being heated to the temperature set on your thermostat, then you can be sure that you have electric backup heating. Most properly sized heat pumps are sized to be able to supply all the heat needed down to about 30 degrees, after that the heat pump isn't able to extract enough heat from the air, so it uses the electric coils built into the indoor evaporator unit to supply additional heat to maintain the set temperature. You probably have two ways to tell that your electric coils are in use, the first is to look at the thermostat and see if you have a light labeled aux heat or emergency heat, if so then if the thermostat is wired properly when the electric coils kick in the light will come on, or the second way is to check the air temp out of the registers. With heat pumps, the air out of the registers normally feels cool, it is usually 80 plus degrees but being less than body temp it feels cool, when the electric coils kick in the air from the registers will feel warm because the air temp will be higher than your body temp.