Heat pump in cold weather

[gooned]

Hello,

I just installed a Honeywell 7500 thermostat for my 2 stage heat pump. Being new to heat pumps, I'm not quite sure of some things. While on heat and cold weather outside (25F), I notice the compressor and indoor fan is on almost constantly. The thermostat is set on Heat.

The thermostat manual says the following:

Heat - Thermostat controls only the heating system

Em Heat (only for heat pumps with auxillary heat) - Thermostat control Emergency and Auxillary Heat. Compressor is locked out.

Two questions:

1) What is the difference between Emergency and Auxillary heat?

2) Which setting should I use?

Any help or rules of thumb are appreciated.

Thank you,

T

[HayZee518]

emergency and auxillary heat are almost synonymous with each other. there is a heating coil in the air flow path within your A coil ducting. if the extracted earth heat is insufficient then the aux heat element will turn on. the heating coil may all come on at once or may be a sequential stepper for heat.

[hvacwiz]

If you switch to emergency heat you eliminate the outdoor heat pump. On a call for heat your indoor unit comes on first. eleltric heat strips or gas furnace