We just had an American Standard Platinum ZM20 heat pump with a new Platinum ZV air handler installed to replace our aging Trane 24+ year old 13 seer heat pump. The new unit seems to be operating very often on the aux heat strips. I understand that heat pumps will run on the heat strips if there is a 3+ degree difference between the inside temp and the set point, but it runs on aux heat when the set point and indoor temp are the same at the thermostat (set point 68 and inside temp of 68). It doesn't always operate on the heat strips when the set point and temp are the same and it doesn't always operate on the heat strips when there is a temp differential- say set point 70 and indoor temp of 68. It does very often though on both accounts. Several times when I have checked and the aux heat strips were being used I walked away and checked a few minutes later and it was then not operating on aux heat, but still heating with no change to the set point or inside temp. We have the temp differential set for no more than 2 degrees, ie. sleep set at 68, wake set at 70.
Outside temp has been up to the mid 40's during the day and down to around 24 at night. It has been operating on the heat strips throughout the day- even when the outside temp is 40+.
The unit was installed Friday 1-18 with several error codes showing on the thermostat. Another tech came out Saturday and evidently fixed what needed to be fixed and there are now no error codes. It is a communicating system with an outside temp sensor. When I asked my salesman yesterday (Monday) I was told that I should wait a couple weeks to give the unit time to learn. I would like to know if I am being fed a line of BS. It seems to me that if the set point and temp are the same then it should not operate on the aux heat strips- ever!
If anyone could enlighten me on the learning process of the communicating system I would appreciate that too.
My salesman also implied that I could turn down the temp at night more than 2 degrees and it wouldn't be an issue with the heat strips, but it seems to me that the system will run much more on aux heat if I do that- especially since it is running on aux heat with little to no temp differential.
Outdoor Unit: Platinum ZM 20, 4A6Z0036B1000A
Indoor Unit: Platinum ZV AMSTAM8A0C36V31CA
Comfort Control: Yes (AMS) (ACONT900AC43UA)
Heat Strips Yes ABAYEVBC20BK1AA
Air Cleaner: Accuclean AFD235CLAH000C