I had the setting on HP1 so I am not sure this will fix my problem. I will do as you state above regarding heating / cooling - right now I have had it in "Cooling" mode. I am in Orlando, Fl. The inside temp has remained at 83 since about 5:00 PM and I have the thermostat set at 78. I have checked several times and both the inside and outside units are working. I will accept your answer now since I am not sure what else we can do.
I just went through the settings on the thermostat again. Yes, I can take the cover off but what do I look for then? Also I believe the unit is still under warranty. The people who installed the unit didn't answer the phone when I call - after 6:00 PM so I can call in the morning???