5 Reasons Not to Leave a Pool Heater On All Night

Gas and propane heaters waste money overnight You are burning fuel to heat water that loses most of its heat before morning. Evaporation is brutal at night, so the heat escapes quickly.

A cover helps but does not solve the problem Even with a cover, pool water cools down fast. Running a gas heater for 8 hours costs a surprising amount for little gain.

Heat pumps are efficient but still wasteful overnight They are cheaper to run but heat slowly. Leaving one on all night might gain a few degrees, but only makes sense if you need the pool hot at sunrise.

Continuous low-speed operation can damage the pump Running a heat pump all night may fry the contactor if your pump cannot handle it. Check your equipment before trying this.

Save the money for chemicals instead You are better off setting a timer to heat the pool a few hours before swimming. Let the heater coast, not run all night.