How much does it cost to heat a pool in Ontario?

Swimpool 360 and Apex Electric Mechanical both put a natural gas heater at roughly $250 to $600 a month during active heating on an average inground pool, and a heat pump at $100 to $250. This page builds the same figure from the tariffs instead of quoting the range: the heat your pool loses, converted into cubic metres or kilowatt hours, priced at Enbridge Gas's Rate 1 charges and the Ontario Energy Board's Regulated Price Plan.

What does natural gas actually cost in the GTA right now?

Three variable charges add up on Enbridge's Rate 1 for residential customers, effective 1 July 2026: delivery at 12.3904 cents per cubic metre once you are over 170 cubic metres in a month, transportation at 5.4267, and an effective gas supply rate of 9.0498. That is 26.87 cents a cubic metre before HST. The $27.69 monthly customer charge sits outside that, because you pay it whether the heater runs or not.

Why is a heat pump so much cheaper to run?

Because it moves heat rather than making it. Both Ontario sources on this page put a pool heat pump at roughly four to five units of heat delivered for every unit of electricity it draws, and Swimpool 360 puts it as using about a quarter of the energy of a gas heater for the same warmth. The catch is the weather: a heat pump pulls its heat out of the air, so output falls as the air cools below about 10 to 15 degrees, which is exactly the shoulder season you bought a heater for.

How much does a solar cover save?

Between 40 and 70 percent of the heating cost, per Swimpool 360, because most of what a pool loses overnight is evaporation off the surface rather than heat through the shell. Their example is blunt: on a pool running a gas heater at $400 a month, a $400 cover pays for itself in a single season. Nothing else on the equipment pad does that.

Why does the calculator ask for surface area rather than litres?

Because holding a temperature is a surface problem, not a volume one. Once the pool is up to temperature the only question is how fast the heat leaves, and it leaves through the top. The published Canadian rule is 10 BTU an hour per square foot per degree the water sits above the air. Volume decides how long the first heat-up takes, which is what the heater sizing page works out.

Will my bill match this exactly?

No, and it is not meant to. Enbridge rate zones differ, a retailer contract changes the supply line, an electricity bill carries delivery and regulatory charges that the OEB does not set as one province-wide number, and a heat pump on a cold morning does not deliver its rated output. What this gives you is the shape of the number and the levers that move it, checked against what GTA heating companies publish for the same job.

What does it cost to heat a pool here?

Last updated:August 26, 2026By The Pool Trade Desk

Built from the tariffs rather than a quoted range: the heat your pool loses, converted into cubic metres or kilowatt hours, priced at what Enbridge Gas and the Ontario Energy Board actually charge in 2026.

What the heater adds to the bill each month

Water surface area (sq ft)

Heat leaves through the top, so this is the number that counts.

Temperature you hold (degrees C)

Average air temperature (degrees C)

Over the whole 24 hours, nights included.

Hours a day the heater holds it (hours)

Days in the month you heat (days)

Which heater?

Natural gas heaterWorks whatever the air is doingElectric heat pumpFour to five units of heat per unit of power

A solar or thermal cover goes on when nobody is swimming

Per month, no cover

$229.82 to $232.59of energy, before tax

Heat the pool loses, 18.0 degrees F above the air10 BTU/hr per sq ft per degree F (Pool Supplies Canada), times the hours and the days: 25,402,000 BTU
Natural gas that takes, at 83 to 84 percent efficiencyCanada Energy Regulator: 0.0373 GJ in a cubic metre of gas: 855 to 866 m3
At the Enbridge Rate 1 variable charges12.3904 delivery over 170 m3, plus 5.4267 transportation, plus 9.0498 supply, all cents per m3, effective 1 July 2026: $229.82 to $232.59

Published check: Swimpool 360 (Ontario, 2026) and Apex Electric Mechanical (Toronto and GTA) put this heater at $250 to $600 a month during active heating on an average inground pool. Enbridge's fixed $27.69 monthly customer charge is not in the figure above, because you pay it whether the heater runs or not.

Size the heater first What a heater costs to buy and fit

This is the energy the water loses and what that energy costs at published Ontario tariffs. It is not a heating bill: your rate zone, your retailer contract and a heat pump losing output on a cold morning all move it. Treat it as the shape of the number and the reason it moves, and read the published monthly ranges beside it as the reality check.

How a heating bill is actually built

Method

Three steps, and each one uses a published figure. First, how much heat the pool loses: 10 BTU an hour for every square foot of water surface, for every degree Fahrenheit the water is held above the air, times the hours a day you hold it and the days you do. Second, what that heat costs to make: a gas heater turns 83 to 84 percent of the energy in the gas into water heat, and a cubic metre of natural gas holds 0.0373 gigajoules per the Canada Energy Regulator. A heat pump does not make heat at all, it moves it, and delivers four to five units for every one it draws.

Third, the tariff. Enbridge Gas publishes Rate 1 for residential customers, and three of its lines vary with how much you burn: delivery at 12.3904 cents per cubic metre once you are over 170 in a month, transportation at 5.4267, and an effective supply rate of 9.0498. Added, that is 26.87 cents a cubic metre. On the electricity side the Ontario Energy Board sets four prices under the Regulated Price Plan and the tool lets you pick the one you are actually on, because the gap between overnight off-peak and on-peak is more than double.

Two charges are deliberately outside the figure and both are named beside it. Enbridge bills a fixed $27.69 customer charge every month whether the heater runs or not, so it is not a cost of heating. And an electricity bill carries delivery and regulatory lines that the OEB does not publish as one province-wide number, so the electric answer here is the commodity only and says so.

The lever that moves this more than anything is the cover. Most of what a pool loses overnight evaporates off the surface rather than conducting through the shell, and Swimpool 360 puts a solar or thermal cover at a 40 to 70 percent reduction in heating cost, with the observation that a $400 cover pays for itself in one season on a pool running a $400-a-month gas heater. Nothing else you can buy does that.

Frequently asked questions

How much does it cost to heat a pool in Ontario?: Swimpool 360 and Apex Electric Mechanical both put a natural gas heater at roughly $250 to $600 a month during active heating on an average inground pool, and a heat pump at $100 to $250. This page builds the same figure from the tariffs instead of quoting the range: the heat your pool loses, converted into cubic metres or kilowatt hours, priced at Enbridge Gas's Rate 1 charges and the Ontario Energy Board's Regulated Price Plan.
What does natural gas actually cost in the GTA right now?: Three variable charges add up on Enbridge's Rate 1 for residential customers, effective 1 July 2026: delivery at 12.3904 cents per cubic metre once you are over 170 cubic metres in a month, transportation at 5.4267, and an effective gas supply rate of 9.0498. That is 26.87 cents a cubic metre before HST. The $27.69 monthly customer charge sits outside that, because you pay it whether the heater runs or not.
Why is a heat pump so much cheaper to run?: Because it moves heat rather than making it. Both Ontario sources on this page put a pool heat pump at roughly four to five units of heat delivered for every unit of electricity it draws, and Swimpool 360 puts it as using about a quarter of the energy of a gas heater for the same warmth. The catch is the weather: a heat pump pulls its heat out of the air, so output falls as the air cools below about 10 to 15 degrees, which is exactly the shoulder season you bought a heater for.
How much does a solar cover save?: Between 40 and 70 percent of the heating cost, per Swimpool 360, because most of what a pool loses overnight is evaporation off the surface rather than heat through the shell. Their example is blunt: on a pool running a gas heater at $400 a month, a $400 cover pays for itself in a single season. Nothing else on the equipment pad does that.
Why does the calculator ask for surface area rather than litres?: Because holding a temperature is a surface problem, not a volume one. Once the pool is up to temperature the only question is how fast the heat leaves, and it leaves through the top. The published Canadian rule is 10 BTU an hour per square foot per degree the water sits above the air. Volume decides how long the first heat-up takes, which is what the heater sizing page works out.
Will my bill match this exactly?: No, and it is not meant to. Enbridge rate zones differ, a retailer contract changes the supply line, an electricity bill carries delivery and regulatory charges that the OEB does not set as one province-wide number, and a heat pump on a cold morning does not deliver its rated output. What this gives you is the shape of the number and the levers that move it, checked against what GTA heating companies publish for the same job.

Where these figures come from

Provenance

The two rates come from the bodies that set them, Enbridge Gas and the Ontario Energy Board, rather than from anyone's summary of them. The energy conversions are the Canada Energy Regulator's, and the equipment figures come from a Canadian retailer's own product page and two Ontario heating companies.