What is the average cost to heat a pool in Ottawa with a gas heater for one season?

Heating an average residential inground pool in Ottawa with a natural gas heater for one full season costs approximately $1,200 to $3,000, with most homeowners spending around $1,500 to $2,200 over the roughly 14 to 18 weeks between late May and mid-September — though the actual figure depends heavily on your target water temperature, pool size, whether you use a solar cover, and how aggressively you heat during Ottawa's cooler shoulder weeks in May, June, and September.

Natural gas pool heaters work by burning gas to heat water as it passes through a heat exchanger on its way back to the pool. They are the fastest way to raise water temperature — capable of increasing a pool's temperature by 1 to 2 degrees Celsius per hour for a standard 40,000 to 60,000-litre pool — and they work regardless of air temperature or sunshine, which makes them the go-to choice in Ottawa where spring nights regularly dip to 5 to 10 degrees Celsius well into June.

The primary cost driver is your thermostat setting relative to the ambient temperature. Most Ottawa pool owners set their heater to maintain water between 26 and 28 degrees Celsius (79 to 82 degrees Fahrenheit). In July and August, when daytime highs average 26 to 27 degrees and overnight lows sit around 15 to 17 degrees, the heater runs moderately — perhaps 3 to 5 hours per day — to offset overnight heat loss and maintain the set temperature. During these peak months, monthly gas costs typically run $200 to $400. In June and September, when overnight lows drop to 8 to 12 degrees and daytime highs only reach 20 to 23 degrees, the heater works significantly harder, and monthly costs can spike to $400 to $600 if you insist on maintaining the same 27-degree target.

Pool size has a direct, proportional impact on heating cost. A small plunge pool or cocktail pool of 20,000 litres costs roughly half as much to heat as a full-size 50,000-litre pool. For a standard 14-by-28-foot pool holding approximately 45,000 litres, a 400,000-BTU natural gas heater (the most common residential size in Ottawa) consumes roughly 4 to 5 cubic metres of natural gas per hour at full output. At Enbridge's current Ottawa residential rate of approximately $0.28 to $0.35 per cubic metre for the gas commodity (plus delivery charges that bring the effective all-in rate to roughly $0.45 to $0.55 per cubic metre), running the heater for 5 hours costs roughly $10 to $14 per day. Over a 120-day season with variable daily run times, total gas consumption typically falls between 2,500 and 5,500 cubic metres.

A solar blanket or liquid solar cover is the single most effective way to reduce gas heating costs in Ottawa. An uncovered pool loses the vast majority of its heat through evaporation from the water surface, especially on Ottawa's breezy evenings. A properly fitted solar blanket — costing $150 to $400 for a standard residential pool — reduces heat loss by 50 to 70 percent and can cut gas heating costs by 30 to 50 percent over the season. Ottawa pool professionals almost universally recommend running a solar blanket whenever the pool is not in active use. Many Ottawa homeowners who complain about $3,000 gas bills are operating without a cover; those who use one religiously tend to land in the $1,200 to $1,800 range for the same pool and thermostat setting.

The heater's efficiency rating also matters, though less dramatically than cover usage. Modern gas pool heaters have thermal efficiency ratings of 82 to 95 percent. An 84-percent-efficient heater wastes 16 cents of every dollar on gas that goes up the flue instead of into the pool water. A 95-percent-efficient condensing heater captures more of that energy, reducing gas consumption by roughly 10 to 13 percent compared to a standard unit. The price premium for a high-efficiency unit is $800 to $1,500 over a standard model, which typically pays for itself in 3 to 5 Ottawa seasons.

Enbridge bills natural gas in Ottawa using a combination of commodity charges, delivery charges, and various regulatory riders. The commodity price fluctuates quarterly based on wholesale natural gas markets, while delivery charges are relatively stable. When calculating your expected pool heating cost, use the all-in rate shown on your bill (total charges divided by total cubic metres consumed) rather than just the commodity rate. Most Ottawa homeowners see an all-in rate between $0.45 and $0.60 per cubic metre after all charges are included.

Gas Heater Versus Heat Pump: The Ottawa Cost Comparison

An electric heat pump costs roughly 40 to 60 percent less to operate per season than a gas heater in Ottawa, but it cannot heat effectively when air temperatures drop below 10 to 12 degrees Celsius — a limitation that bites hard during Ottawa's cool May evenings and September mornings. Many Ottawa pool owners who want the lowest operating cost opt for a heat pump as their primary heater and add a small gas heater as a backup for shoulder-season use or rapid heat-up before a weekend gathering. This hybrid approach typically costs $800 to $1,500 per season in combined electricity and gas.

For pure gas heating, budget $1,500 to $2,200 per season as a realistic middle-ground estimate for a standard Ottawa inground pool with a solar cover and a thermostat set to 27 degrees. Without a cover, expect $2,200 to $3,000. With disciplined cover use, a high-efficiency heater, and a willingness to lower the target to 25 or 26 degrees during shoulder weeks, some Ottawa homeowners get through the season for under $1,200.

Thinking about the most cost-effective way to heat your Ottawa pool? Ottawa Pool Installation connects homeowners with local heating specialists who can size the right system for your pool and budget.