The licensed technicians at McCallum’s Pool Service answer hundreds of questions from property managers and homeowners about whether they should keep their pool heater overnight. Many callers manage three or four pools at commercial swimming centers and are concerned about heating costs. We also know many residents want to reduce the workload of their propane pool heaters and pool heat pumps by keeping their water temperature consistent.
McCallum’s Pool Service is Phoenix’s go-to source of information for pool heating, ambient air temperature, and maintenance. We have decades of experience repairing, automating, and maintaining nearly every model of electric heat pump and solar heating system.
Read on to learn whether it is ideal to leave your pool water heater running overnight, no matter which model you use.
Should You Leave Your Pool Heater Running Overnight?
Pools come in all shapes and sizes, and our technicians maintain hundreds of swimming pools with different heating requirements every month. We generally do not recommend keeping your heater running overnight if you own a small to mid-sized residential swimming pool between 80 to 200 square feet. Most residential swimming pools have power-efficient heating units and do not require that much energy to reach a comfortable temperature.
We only recommend keeping your pool heater on overnight if you expect family or guests to take a dip. The nighttime outdoor temperatures in Phoenix and other cities we serve in Arizona can dip below 40 degrees Fahrenheit. So, your heater will work need to work harder to maintain a consistent temperature.
Leaving your heater on overnight will always draw an immense amount of power. Prepare for a drastic increase in your electric bills whenever you do it, even just for one night.
We only recommend leaving a pool heater overnight to commercial pool owners who expect customers 24/7. That’s because it takes three to four hours to heat a sizeable swimming pool. It takes even longer at night when the water has been sitting still for several hours.
The Benefits of Leaving Your Pool Heater Running
Keeping your pool heater running overnight will prevent rapid heat loss and stop your heating units from working double-time to compensate for it. If you expect overnight swimmers and partygoers on your pool deck, keeping your pool warm while the sun is down is the way to go.
An electric heating system can require up to 45 minutes to heat a small water spa. Naturally, you do not want to keep your guests waiting until your pool is ready for swimming.
Unless you’re preparing for a social event or are in charge of a 24/7 commercial establishment, we do not recommend keeping your pool heaters running overnight. Doing so will cost you a small fortune.
The Drawbacks of Leaving Your Pool Heater On
Most pools we work on feature electric or natural gas heating systems. Natural gas heaters have cheaper parts and are easier to install, while electric systems pay for themselves with unmatched energy efficiency. However, these systems will experience undue wear and tear when you leave them running overnight or through cold seasons.
We do not recommend leaving a pool heater on overnight for most property owners, even ones with advanced solar heating systems. The massive power draw will negate any savings they gain from using solar cells and receiving renewable credits from the government.
Warm water is also more hospitable toward microbes, germs, and other contaminants. So, you’ll need to replace your filters more frequently and check your chemical balance each day.
How to Keep Your Pool Water from Getting Cold without a Heater
Instead of using a gas-powered or electric heater to keep your pool warm overnight, our technicians recommend you use a solar blanket. This energy-efficient option keeps the warmth in your swimming pool long after sunset.
Solar blankets disperse the heat of sun rays equally onto the topmost layer of your pool water. It stops wind and air from interacting with your swimming pool, eliminating the two most prevalent factors that cool ocean and pool water.
The best setup is an automated pool cover that turns on your filtration system. This configuration circulates warm water from the top to the bottom of your pool without human intervention.