Water heater prices in Ontario (2026)
A gas tank water heater typically costs $1,800 to $3,200 installed in Ontario and a gas tankless unit $3,500 to $6,000, before 13% HST. Venting and gas line work decide where you land, and if you rent today, a quick break-even check shows whether buying pays.
Water heater replacement prices
Hot water$1,800to$6,000
Typical installed price, Ontario 2026, all options shown
- Tank water heater40 to 50 gal, gas $1,800 to $3,200
- Tankless water heatergas $3,500 to $6,000
Installed price in Ontario, before 13% HST ($2,034 to $6,780 with HST). Replacement of an existing gas water heater with the old tank removed; venting or gas line changes can add to it.
On this page
- Tank or tankless: the short version
- What tankless saves on gas
- Conventional, power-vent and direct-vent tanks
- Why a furnace upgrade can strand your water heater
- Gas line upsizing for tankless
- What moves a water heater quote
- Renting vs buying a water heater in Ontario
- Heat with a boiler? Consider a combi
- Heat pump water heaters
- Questions people ask
Tank or tankless: the short version
| What differs | Tank, 40 to 50 gal | Tankless |
|---|---|---|
| Typical installed price | $1,800 to $3,200 | $3,500 to $6,000 |
| Typical lifespan | About 8 to 12 years | About 15 to 20 years with descaling |
| Venting | Chimney (conventional) or plastic pipe through the wall (power vent) | Plastic pipe through the wall or roof |
| Gas input | Roughly 35,000 to 50,000 BTU/h, fits a standard line | Up to 199,000 BTU/h, often needs a larger line |
| Hot water | A stored tankful, then a wait while it recovers | Continuous, at a limited flow rate |
| In a power outage | Conventional models with a standing pilot keep working | No hot water without power |
| Best for | Lowest upfront cost, simple swaps | Long showers, tight spaces, staying put for years |
Typical installed ranges before 13% HST. Lifespans vary with water hardness and maintenance.
For a like-for-like replacement, a new tank is usually the cheapest correct answer, and the least expensive of the fifteen systems in the Ontario Furnace Prices price index. Tankless earns its price when you want showers that never run cold, need the floor space or plan to stay for years. It rarely pays back on gas alone.
What tankless saves on gas
Assume a household using about 200 litres of hot water a day, heated about 45°C above the cold supply, with natural gas at about $0.50 per m³ all-in.
- Gas a year, standard tank
- $310About 615 m³ at an energy factor near 0.60
- Gas a year, condensing tankless
- $200About 395 m³ at an energy factor near 0.93
- Saving a year
- $110At today's gas price
At the midpoints of our ranges, tankless costs about $2,250 more installed, so the saving takes roughly 20 years to repay it: about the unit's whole life. Its longer life helps, since over 20 years you might buy one tankless unit or two tanks. Treat tankless as a comfort and space upgrade, not an investment.
Conventional, power-vent and direct-vent tanks
A conventional tank vents up the chimney on natural draft. It is the cheapest tank and works in a power outage, but needs a chimney that draws properly. A power-vent tank uses a fan to push exhaust through plastic pipe out a side wall. It sits toward the top of the tank range and needs an outlet, but it frees you from the chimney. Direct-vent models also draw combustion air from outdoors, for tight utility rooms.
A 40-gallon tank suits one or two bathrooms with ordinary use; a 50-gallon tank suits a busier home or a large tub. Electric tanks cost roughly twice as much to run as gas at about $0.15 per kWh, and sit outside our gas price table.
Why a furnace upgrade can strand your water heater
Older Ontario homes often vent the furnace and a conventional water heater into one masonry chimney. A high-efficiency furnace vents out the wall instead, leaving the water heater alone in a flue sized for two. Its small, cool exhaust drafts weakly, condenses inside the chimney and can spill combustion gases into the basement.
Before
Two streams of warm exhaust keep the chimney drawing.
After a high-efficiency furnace
The furnace vents out the wall. The water heater is orphaned in a flue sized for two.
| Fix | Typical cost before HST | Good to know |
|---|---|---|
| Line the chimney for the water heater | $300 to $1,500 | Keeps your tank; restores draft and protects the masonry. |
| Switch to a power-vent tank | Within $1,800 to $3,200 | Vents through the wall; needs an outlet. |
| Go tankless | $3,500 to $6,000, plus gas line work if needed | Wall vent, longer life, continuous hot water. |
| Boiler home: switch to a combi | $7,000 to $13,000 | One appliance for heat and hot water. |
Raise this with any furnace quote (see furnace installation cost). Ontario's Fire Code requires carbon monoxide alarms next to sleeping areas in homes with a fuel-burning appliance, and since January 1, 2026, on every storey of the home, so test yours after any venting change.
Get a real price for your water heater
Tell us what you have now and what you are considering. A participating local heating and cooling company turns these ranges into a written quote.
Free, no obligation. About a minute to request.
Gas line upsizing for tankless
A gas tank burns roughly 35,000 to 50,000 BTU/h. A whole-house tankless unit can fire at up to 199,000 BTU/h the moment a shower starts, while the furnace, stove and dryer may be running too. The old branch to the water heater is often too small, so the line from the meter or main trunk is upsized, typically $300 to $1,200, sized from total gas load and pipe length.
What moves a water heater quote
-
Venting changes
Raises the price: +$300 to $1,500
A chimney liner for a tank left alone on the chimney, or a new wall vent when you change type.
-
Gas line upsizing for tankless
Raises the price: +$300 to $1,200
Needed when the existing line cannot carry the tankless unit with everything else running.
-
Hard water
Raises the price: Ongoing cost
Groundwater supplies, as in Guelph and much of Waterloo Region, are hard. Tankless units need regular descaling; a softener helps either type.
-
Returning a rental tank
Can go either way: Check your contract
The old rental tank goes back to the rental company, and some contracts charge a removal or return fee.
-
Like-for-like swap
Lowers the price: Lowest quotes
Same type, same spot, same vent: old tank out and new one in, usually within a few hours.
Renting vs buying a water heater in Ontario
Ontario is unusual in how many homes rent their water heater, a holdover from the days when gas utilities rented them out. The charge appears on your gas bill or a separate invoice, and the rental company repairs or replaces the tank if it fails.
Renting turns a $1,800 to $3,200 purchase into a monthly charge for as long as you keep the tank, and some contracts allow yearly increases. The calculator below adds up your charge and shows the break-even: the monthly charge above which buying costs less.
Rent or buy: your water heater break-even
Estimates update as you change the inputs. Nothing is sent anywhere.
Break-even rental charge
Buying at $2,500 beats any rental charge above this over 12 years, before tax.
- Cost to buy, with repair budget$2,500
- Rent paid over the periodAdd your charge
- DifferenceNot yet
Buy
Rent
Get the real number for your home: a free, no-obligation quote.
Planning arithmetic only, before tax on both sides. It ignores the repair and replacement cover a rental typically includes, and interest on money spent upfront.
The arithmetic leaves out risk: a rental typically covers repairs and replacement, while an owner relies on the manufacturer's warranty. If your rental tank is already old, compare any buyout figure with the price of a new tank.
Check before you sign or cancel a rental
- What is the monthly charge today, and can it rise each year?
- Is there a minimum term, and what does it cost to end the contract early?
- What is the buyout price now, and how does it change over time?
- Is there a removal or return fee when you replace the tank with your own?
Since March 2018, Ontario's Consumer Protection Act has barred businesses from signing water heater, furnace and air conditioner contracts in your home unless you contacted them first, and contracts signed at home carry a 10-day cooling-off period. For furnace rentals and buyouts, see rent or buy a furnace.
Heat with a boiler? Consider a combi
If a boiler heats your home, a combi can replace both boiler and water heater: $7,000 to $13,000 installed, one wall-hung appliance and no tank to rent. Some newer Ontario townhouses already use one gas appliance for both jobs, feeding an air handler in the ducts; there, replacing the water heater means replacing the heat source. See boiler prices.
Heat pump water heaters
A heat pump water heater moves heat from the surrounding air into the tank and uses far less electricity than an electric tank. It needs floor space, a condensate drain and a basement that can spare some heat, and suits homes replacing an electric tank. It is outside our reviewed price table; ask for it as an option in your quote.
Gas work needs a registered contractor
In Ontario, installing a gas water heater or changing its vent or gas line must be done by a TSSA-registered contractor; ask for the registration number. If you smell gas, leave the house and contact your gas utility from outside.
Questions people ask
How long does a gas water heater last in Ontario?
A gas tank commonly lasts about 8 to 12 years. Hard water, a high temperature setting and skipped maintenance shorten that; draining sediment and checking the anode rod help it last. Tankless units often reach 15 to 20 years if descaled on schedule. Rusty water, rumbling or moisture at the base of a tank are signs to start pricing a replacement.
Is it cheaper to rent or buy a water heater?
It depends on your monthly charge. At the midpoint of our range, a $2,500 tank kept 12 years costs less than any rental charge above about $17 a month, before tax. Renting buys convenience, since repairs and replacement are typically covered. Run the calculator on this page with the charge from your own bill and any yearly increase in your contract.
Will a tankless water heater keep up in an Ontario winter?
It will if it is sized for January. Incoming water can be only a few degrees above freezing then, so the same unit delivers less hot water than in summer. A 199,000 BTU/h condensing unit gives roughly 17 litres a minute at shower temperature in winter, enough for two low-flow showers at once. Ask the installer to size for your coldest inlet temperature.
Can I put a tankless unit where my tank is now?
Usually, but it is rarely a straight swap. Tankless units mount on a wall, vent through plastic pipe out a side wall or the roof, need a 120-volt outlet and a condensate drain, and often need a larger gas line. Those changes are why tankless jobs typically land at $3,500 to $6,000. In Ontario the gas work must be done by a TSSA-registered contractor.