45 degrees: Heat pump aux. heat?

[univmd]

Dear experts, it seems that my heat pump is using it's aux. heat only. It is 45 degrees outside. Is this normal? What is the operating temerature of a heat pump before it starts to use aux. heat only (heat coming out of registers but outdoor unit not working). --James

[dash]

They get setup differently by many contractors,so it's difficult to know how yours is setup.

Fact is the heat pump can produce heat for less then the electric aux. heaters done to around zero.So it should or could be running,with the aux. heaters being ,truly auxillary to the heat pump.

Best to have a tech check it out,after being sure the breaker is not tripped to the outdoor unit.

[dale_k]

Do you have any previous history? Did it used to work better than this? Seems a little weak to me. I've had 3 different systems on 2 houses and the weakest one only went to aux heat at 31. The strongest system would go to about 25 before it needed the resistance heat.

[smokin68]

It should never be auxilary heat only,unless the heatpumps broken.....call for service.The heatpump isn't locked out, the auxilary is. Now a dual fuel could be different at low temperatures......