How much does a pool heater cost to run in Ohio?

Left alone, a Northeast Ohio pool is comfortable from roughly Memorial Day to Labor Day, and even inside that window a run of cool nights can drop the water fast. The National Weather Service in Cleveland lists the average last spring freeze at Akron-Canton as April 29 and the average first fall freeze as October 19. Those dates frame the season you can realistically swim with heat: May through September, and into October for people who cover the pool every night.

That is why every package we sell includes a pool heater. Most people then ask what it costs to run, and public data from the Department of Energy and the Energy Information Administration gives a reasonable estimate.

The U.S. Department of Energy publishes a table of annual heat pump pool heating costs by city, for an outdoor pool with and without a cover. Ohio is not on it, but Chicago is, with a May 1 to September 30 season, which matches Northeast Ohio closely. For Chicago, the DOE lists:

• At 78 degrees: $1,104 a year uncovered, $143 with a cover.
• At 80 degrees: $1,410 uncovered, $204 with a cover.
• At 82 degrees: $1,730 uncovered, $266 with a cover.

The DOE's table assumes electricity at 13.01 cents per kWh and a seasonal average COP of 5.0, meaning the heat pump delivers five units of heat for every unit of electricity it uses. Ohio power costs more than that now. The U.S. Energy Information Administration reports an Ohio residential average of 19.45 cents per kWh for July 2026. Scale the DOE figures by that ratio, about 1.5, and the 80 degree season comes to roughly $2,100 uncovered and roughly $300 covered.

That is a rough estimate, not a bill. The DOE's figures are for a 1,000 square foot pool, which is larger than most backyard pools; our biggest fiberglass package, a 16x40, has about 640 square feet of water. A smaller pool costs proportionally less to heat. The estimate also assumes the DOE's conditions, and your electric rate depends on your utility and supplier. What it shows clearly is the gap. A cover changes the cost of heating by a factor of about seven.

Most of the heat a pool loses leaves through evaporation from the surface. The DOE says covering a pool when it is not in use is the single most effective way to reduce pool heating costs, with savings of 50% to 70% possible, and its city table shows even larger savings where nights are cool. Each pound of warm water that evaporates carries away far more heat than it took to raise that pound one degree, so stopping evaporation overnight stops most of the loss.

Northeast Ohio nights are the problem. A sunny June afternoon can warm the surface nicely, then a clear night in the 50s pulls it back down. A cover holds that heat in until morning. An automatic cover helps most, because it actually gets closed every evening.

Opening day is when the heater works hardest, because it has to lift the whole body of water. The physics is simple. It takes one BTU to raise one pound of water by one degree, and a gallon of water weighs about 8.34 pounds.

Say you have a 20,000 gallon pool and want to raise it 10 degrees. That is 20,000 times 8.34 times 10, or about 1.67 million BTU of heat, before any losses. A kilowatt-hour equals 3,412 BTU, so that is about 489 kWh of heat. A heat pump running at a COP of 5 would use about 98 kWh of electricity to deliver it, which is roughly $19 at 19.45 cents. With a cool May night stealing some of the heat back and the COP dropping in cooler air, expect the actual figure to be meaningfully higher, but the order of magnitude holds.

With gas, 1.67 million BTU is about 16.7 therms of delivered heat. Federal rules require new gas pool heaters to be at least 82% efficient, and ENERGY STAR notes the best models reach 95%. So you would buy roughly 18 to 20 therms of gas, times whatever your gas bill says you pay per therm.

A heat pump moves heat from the air into the water instead of making it by burning fuel, which is why its efficiency is measured in multiples. The DOE notes that heat pump pool heaters work efficiently as long as the outside air stays above the 45 to 50 degree range, and get less efficient as the air cools. In Ohio that covers most of June through early September comfortably, and a lot of May and late September on mild days.

A gas heater burns natural gas or propane and heats the water quickly regardless of air temperature. It costs more per degree, but it is the better tool for fast heat on demand, such as a spa or a cold weekend in May.

For daily summer swimming with a cover, a heat pump usually wins on running cost. For occasional use, very early or very late swims, or a spa that needs heat in a hurry, gas makes sense. Some families put in both. Our guide on heat pump versus gas heaters covers the choice in more depth.

HomeGuide's 2026 figures put a natural gas or propane pool heater at $1,500 to $4,500 installed and a heat pump at $2,000 to $6,000 installed. HomeGuide's national running estimates, $200 to $500 a month for gas and $50 to $150 a month for a heat pump, are useful for comparing the two, though your Ohio bill depends on your rates, your cover habits and how warm you like the water.

Installation details can move the price. A heat pump needs a dedicated electrical circuit. A gas heater needs a gas line of the right size run to the pad. Both need space and clearance at the equipment pad, which we plan in the 3D design so the heater does not end up squeezed against a fence.

Solar pool heating runs pool water through collectors, usually on a roof, and uses the sun to warm it. HomeGuide notes the running cost is mostly the pump electricity, around $10 to $25 a month. The catch in Northeast Ohio is timing. Solar works best on the long, sunny days when you need the least help, and it does little on the cloudy, cool spring and fall days when you want heat most. It also needs a large, sunny, south-facing roof area near the pool.

For most of our customers, a heat pump or gas heater paired with a good cover is the more dependable way to add weeks to the season. Solar can make sense as a supplement for a family with the right roof who mostly swims in July and August.

• Cover it every night. By the DOE's numbers, this is worth more than any equipment choice.
• Pick a set-and-hold temperature. Each degree you add costs more to hold. Many families settle at 80 once they see the difference between 80 and 84.
• Block the wind. Wind across the water speeds evaporation. A fence, hedge or pool house on the windward side helps.
• Let the sun help. Place the pool where it gets afternoon sun if the lot allows. We look at this in the 3D design.
• Run a variable-speed pump sensibly. Our packages include a Pentair variable-speed pump, which can run slowly most of the day and ramp up only when the heater needs flow.

Timing matters too. A heat pump works best in the warm part of the day, so scheduling most of its run time from late morning through late afternoon, while the cover goes on at dusk, lets it work at its most efficient. On a cold May weekend when you want the pool warm fast, that is when a gas heater earns its place, which is why some families choose one for the spa and a heat pump for the pool.

Yes. All pools lose most of their heat through the surface, which is why the cover matters for everyone. The walls and floor lose the rest to the ground, and here construction matters. ICF concrete pools have insulated walls that reduce that loss, which is a big part of why we build them for families who plan to heat from May into October. Fiberglass and vinyl pools sit directly against the soil, and a cover and a sensible target temperature do most of the work.

The DOE sizes heaters by surface area and the temperature rise you want over the average air temperature of your coldest swimming month, with adjustments for wind and cool nights. We run that math for your pool, your yard's exposure and how early and late you want to swim, then recommend a heater and a cover together, because one without the other leaves money on the table.