My heat pump is on in Maryland. I set it to 84, but the pool temp is only 80 as of 1:30 PM, with temperatures in the 60s in the shade, but over 80 in the full sun. The pool is in the sun. I ran it overnight with temps down probably to the high 40s or low 50s, and the pool was 81 at 10 PM last night. I've never been happy with the heat pump, except when it barely needs to work to maintain temperature. How long does it take for your heat pump to raise the temperature?