We recently purchased a used Titan TI III heat pump for our pool. It appears to be working fine but it seems to be taking a long time to heat the pool. We have an 18X36 pool with a solar cover. The pool water is 70 degrees, the air temperature is 70 degrees, we ran the heater for 6 hours and it only raised the water temperature 1 degree reaching 71 degrees. The water being returned to the pool was lukewarm compared to the pool. I was expecting it to be a lot warmer. Of most concern is that the electricity meter went up by 30, so I'm assuming that's KWh's.
Can anyone let me know, if this sounds normal for a heat pump?