The AQUAHEAT is a pump controller that controls the water flow through an electric heat pump or gas heater when the water temperature is below the desired temperature limit. A pump sampling period setting allows the pump to stop for this time period once the desired temperature limit is achieved. After the elapsed time, the pump will then automatically run for 3 minutes to obtain an accurate temperature and continue to run if heating is required.  If no heating is required, the pump will stop and the last accurate temperature will be displayed until the next sample period. A 1st HEAT feature allows the controller to heat the pool until the desired temperature is reached, the controller then reverts to time-clock automatic operation.