Help with heat pump and nest

Old 01-30-19, 04:38 AM
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Help with heat pump and nest

I have a heat pump and a nest. I have had someone come out, and they can't figure out what's wrong, but here's what's going on.

When the weather gets below around 25, the compressor outside stops turning on, but it doesn't turn on the auxiliary heat right away. Instead, if I have the heat set to 65, and the indoor temp drops, the system will turn on the indoor fan system and be "heating" but all it will be doing is blowing the cold indoor air around. The heat will slowly drop in my house. It will get down to like 60, and then it will finally kick in the auxiliary heat. Which then has to work even harder because of how cold it got

I can't detect a difference in this pattern whether I have the nest set to max savings or max comfort. And the compressor lockout doesn't seem to make a difference either.

Once it starts doing this, even when it gets above freezing and should be using the compressor again, the compressor will not turn on until I flip the switch for a minute on the breaker and reset the whole system. Help! It's so cold!
Old 01-30-19, 05:50 AM
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Nest time it happens I would try bypassing the thermostat. Take it off the wall and then twist the R, G, and Y wires together. This should activate the outside compressor and the inside fan. If it works then it is the Nest. If it doesn't then the dual fuel board or defrost control or possibly low on refrigerant.
Other option is to try another thermostat.
Old 01-30-19, 05:48 PM
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I didn't see a gas furnace mentioned. Shouldn't be any dual fuel control. I've come across some AUX heat issues with the nest. The thermostat should bring the AUX on with the heat pump. I'm leaning towards a nest issue.

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