If I'm heating up my pool and my pump timer ends, should the pool heater automatically shutoff? If so, should it be an automatic hard shutoff? When my pump stops running, my heater keeps going. Eventually the thermostat gets to the set point which turns it off, i'm guessing since there's no moving water once the pump is off, the water in the heater gets up to the desired temperature and shuts off the heater. Is that how it's supposed to normally function? My pump runs off the digital on board timer.