I have a recently purchased Payne heat pump - model #'s PF4MN & PH3AN. The unit was installed in the summer and the cooling cycles worked fine. When we had the first chilly days in the fall I turned the heat on - it works fine but the heat seems to defer to the Aux Heat quite frequently.
I called the contractor and he indicated that the unit accesses the heat strips if the request for heat is 5 degrees above the thermostat setting or when the cycle runs past a certain point. He indicated the unit was working fine.
The last month or so has been chilly to cold nights with mild days. I've been monitoring electric usage and the unit is using more power than my old electric baseboard system. Even in a relatively mild month usage is over 2000KWH which is a great deal.
Is this an installation issue - are there settings at the time of installation that would determine appropriate power and/or cycle settings? Or is this a thermostat issue - current is a Total Line nonprogrammable P274 -0300?

The house is very old and will present a heating challenge but based on the usage I'm seeing I'll be looking at electric bills of $500 or more during prime heating season.
I'm looking for any insights that may help me get more efficiency out of the unit. The original contractor has not been helpful and Payne has basically refused to talk to me.

I'm going to suggest that you change the thermostat to one of the Vision Pro models with at least 2 stage heat with an outdoor sensor. The señor has to be purchased separately.

At least with this model, you can lock out the strips. You can have strips, strips+HP, HP all based on outdoor temperature.

Configuration would be fun.

You would need to determine the number of stages of heat and cool before selecting the stat.

The following site is laid out well:

Buy Honeywell VisionPro 8000 Programmable MultiStage Thermostat with Dehumidification | Honeywell TH8321U1006

Seldom will a manufacturer talk to a customer since they only manufacturer equipment and it is the installers job to install it correctly.

I am at a severe disadvantage trying to calculate what the problem could be since you did not mention if a manual J was performed on your home before the equipment was selected. A manual J is done to make sure your equipment is sized correctly for your home. The only info you gave that helps is a statement that your A/C unit seemed to work OK.

Since you are now blowing the heat around instead of just leting it drift up naturally out of the baseboard heaters the heat you have might feel colder when the heat pump does run because of the draft created by the blower. This in turn could cause you to compensate by having the thermostat higher than you did with the base board heaters. This is just a guess on my part but I have seen this happen before when switching from baseboard heat to a blower powered air system.

You could try a experiment and have the HVAC company disconnect the electric resistance heaters for a day or two just to see how well the heat pump will do on its own. If you are knowledgeable enough to disconnect some low voltage wires you could do this yourself but since the installer has there reputation at stake I would offer this little job to them first. I have done this experiment many times over the years to help clear the air so to speak of heat problem concerns with customers.

If your heat bill is going to be expensive so be it but if you can find a problem and a solution you will be much happier. It could be as simple as the thermostat bringing on the heat strips to soon or in some cases with a oversize set of heat strips bringing on to many of the heat strips at one time. Many times I have found that the electric furnace worked better with one or more of the heat strips disconnected so the temperature does not overshoot the settings.

General worksmanship like sealing the duct work from leaks and thermostat location can also play a part in this problem. Contact your installer and see what he thinks about the simple test procedure to try and help find you high usage problem.

Looks like keeitsimplestupid beat me to the draw. His idea is also a good one also.