This may have been asked before, if so sorry, but I need answers anyway.

We recently bought a house with an electric heat pump. On cold nights, it runs and runs without getting up to temp, set at 65, which doesn't seem very energy efficient, plus is very annoying. I have to get up and manually adjust the thermostat to get the auxiliary heat to come on. I read somewhere on here (I can't find it again) that I can switch the thermostat to emergency, would that keep the auxiliary heat on so the pump doesn't drive us crazy all night? Is that the right thing to do and is it safe to do on a regular basis in very cold weather?

It also seems the auxiliary heat kicks on arbitrarily, at 66, 67 or 68. Why would that be?

Thanks for any info.

A friend of mine had the same problem in a home he bought that had been vacant for 2 years. Did the same thing. When summer arrived he had no air conditioning. He was too cheap to call a repairperson in the winter but ended up biting the bullet in the summer. It was a blown fuse in the pump. Call your repairperson as this situation will not magically correct itself. You are right, this is not a very efficient way of heating if it keeps running and running like that.

On a cold night a heatpump cannot produce enough BTU's of heat to maintain temperature inside the home. It is very cheap heat above 30 degrees even if it seems to run constantly. Thermostats for heat pumps use a temperature differential inside the thermostat to bring on the aux' heat (same as emergency heat minus the heat pump). So if you set the thermostat at 70 it may get down to 67 or 68 before the aux' heat kicks in. If you switch it over to emergency heat the resistive heat will kick in on first stage of thermostat say 70 again. But even though the heat pump doesn't seem to be keeping up, the heat produced by it, is still cheaper than the electric heat. The little heat produced can be added to the total BTU output of the equipment. (resistive heat running plus the heat pump BTU's)

If it is super annoying a low ambient control can be placed in the heatpump. It works like this. If you set it for 29 degrees the heat pump will work above 29, below 29 it sends voltage into the furnace for the electric heat to run and not the heat pump, this is called restrictive mode.

Hope this helps

Yes, thanks. Not having experience with heat pumps, we just weren't sure if something was wrong, but it sounds like it's doing what it's supposed to.