Your pool heater is already set and operating. Pools heaters are set to reach 88 degrees and will run on a pre-programmed timer for12 hours each day during the winter season. Note: Pool water evaporates! If the heater does not seem to be heating efficiently, make sure the water line is high enough to reach the return, (where water flows back to the heater.) Add water with the provided garden hose, and the heater will restart working properly. For $50/day, 24-Hour pool heating or a customized pool temperature can be arranged.