I recently had a new Rheem Heat pump system installed and I am trying to configure my thermostat,air handler, and heat pump for the most efficient and economical operation. The equipment is as follows. Rheem RPRL 036JEZ condenser unit, RHPL HM3621JC air handler with strip heating for aux, and a Rheem Comfort Control 2 TST501 CMMS communicating thermostat. The system is wired using the 4 wire config for the communicating system. I live in zone 5. Ephrata Pa (between Reading and Lancaster). I realize my installer should know the answer to these questions but apparently he does not. The system was installed a few months ago. He did recently come out to check the system to make sure it was charged properly. The readings he wrote down at the end of Sept were SC 8.1 and Delta T was 19. My goal is to set up my stat to minimize the activation of the strip heat. There is a setting on my stat AH which indicates it disables the strips above a certain temperature. The temp range seems to only allow me to disable strip hearing between 50-95 degrees F. 50 is the default. There is another setting HP, which disables the heat pump and uses only electric heat below a specified temperature. The setting available for that are OFF, or 5-50 degrees F. Before I can even set these I have to input the Balance Point. So my questions are as follows; What balance point should I use? Why am I limited to 50 degrees and higher on my strip heat lockout? That doesn't make sense to me since this is a 17.5 SEER 9.4 Seasonal efficiency system and should be able to satisfy the thermostat into the 20's in my opinion. What settings do you recommend?