I live in Florida now and my outside AC unit is also my Heat Pump. The outside AC unit and the inside heat exchanger are new. My question is about the inside thermostat. It has a heat setting, a green auxiliary light, and also an emergency setting with a red light. When set on emergency heat the red light comes on and the outside AC unit shuts off, as it should. My question is about the green auxillary light. The green light only comes on when the outside AC unit is running. Sometimes the green light is on when the outside unit is running, sometimes the green light is off when the unit is running. When the green light is on sometimes the air coming out of the vents is only room temperature. Other times the green light may be off and heated air comes out of the vents. It appears to me the green light has no effect on the temperature of the air coming out of the vents. Many times the green light never comes when the outside unit is running. I would think auxiliary heat means the emergency is running along with the outside unit. That's just my thinking. The unit does work good as for as keeping the temperature as set. The unit does seem to run a long time, often blowing room temperature while the outside unit is running.
I am from Wisconsin and know very little about heat pumps. It is too cold up there for a heat pump to do much good.

Thank you,
billj

Last time I checked there are 1,129 different thermostats available. Since my crystal ball is still in the repair shop I wonder if you would be kind enough to post the EXACT brand and model number since your question was about the thermostats to start with.

The thermostat is a;
SECO
Stone Electronics
TA 2060
24 VAC Heat Pump Thermostat

The thermostat is a;
SECO
Stone Electronics
TA 2060
24 VAC Heat Pump Thermostat

I have no information for that model. Sorry.

Something in the old memory banks tells me that if X and X2 are closed the green light comes on but I forget what exactly it is a indication of. It could posibly be a outside sensor that is operating.