This statement is wrong. Electric resistance is never cheaper than a heat pump (except in arctic climates). The btus that the heat pump puts out drops as the temperature decreases, but so does the power consumption of the compressor.
At 15F, my heat pump has a COP (Coefficient of Performance) of 2.46. This means that 2.46 kw of heat are produced for every 1 kw of electricity consumed. It is basically 246% efficient at 15F.
Many people do not want their compressors running constantly because of wear and tear, but that's a different issue.
Great point, Gary G!!! Heat pumps with aux heat strips, especially if they are staged heat strips should always run no matter what the outside temperature. I'm also concerned with heat pump compressor running constantly when I first had the heat pump installed. But I finally got it squared away in my mind that heat pumps are not like furnaces (because most are oversized) and need to run lots. This is why I keep the set point temperature on the low side during the day and set back only 2 degrees at night.
If common sense is so common how come so few of us have it!
I new to HP's also. Some of my first info stated that run times may be very long as outside temps drop.
This is my third season. This month, the second stage has not been used on purpose. Maybe I'm a glutten for punishment but I'm looking forward to my PG&E bill.
The first year was terrible. Everytime one of us felt a chill, up went the
T-Stat to bring on the second stage. The highest bill was $400. No more of that. Trying a set it and forget it approach and ( Let 'em run )
Agreed, heat pump will almost always be more efficient than electric strip. Try letting the Tstat control when aux comes on. Lock out the outdoor probe and see how well that works. Aux should only come on when pump can no longer keep up to heat loss.
I'd be curious to know the model equipment you have. If lock outs are set then lower them. The charge of the system could be off. I would hope you would have a staged electric heater if the setting is that high. Mine wouldn't turn on unless 1) time on stage 2 heat pump expires or 2) defrost or 3) I manually set the t stat for elec heat. I have limited expierence with Nordyne equipment, Do they use TXV's at the outdoor unit? Good Luck