Furnace buying guide for Ontario homes

New gas furnace prices in Ontario by type

Heating

$4,000to$11,000

Typical installed price, Ontario 2026, all options shown

• Gas furnace, single-stage95 to 96% AFUE $4,000 to $6,500
• Gas furnace, two-stage96% AFUE, ECM blower $5,500 to $8,000
• Gas furnace, modulating97 to 98% AFUE, variable speed $7,000 to $11,000
• $0$3k$6k$9k$12k

Installed price in Ontario, before 13% HST ($4,520 to $12,430 with HST). Standard replacement in a detached home with usable ductwork and venting.

On this page

1. Step 1: Decide whether to repair or replace
2. Step 2: Size it with a load calculation
3. Step 3: Choose staging and efficiency
4. Step 4: Price a heat pump or dual fuel before you commit
5. Step 5: Get two or three written quotes and compare them line by line
6. Step 6: Decide whether to buy, finance or rent
7. Step 7: Register the warranty and keep the paperwork
8. Step 8: Install day and the first few weeks
9. Questions people ask

Step 1: Decide whether to repair or replace

Start with the furnace you have. A well-kept gas furnace usually lasts about 15 to 20 years (see how long furnaces last). Under 10 years old, most failures are one part: an igniter at $250 to $450 or a control board at $500 to $1,100 is almost always worth fixing, and may still be under warranty.

Past 15 years, an inducer motor at $600 to $1,200 or a variable-speed blower motor at $900 to $1,800 buys time, not a new furnace. A cracked heat exchanger is usually replacement-level, but ask to see the evidence and get a second opinion before you sign. Try the repair or replace check, see furnace repair costs, or weigh a repair against current Ontario furnace prices for a new system.

Step 2: Size it with a load calculation

The size on your old furnace’s rating plate is not a sizing method. Many older Ontario furnaces were oversized from the start, and new windows and insulation cut heat loss further. An oversized furnace heats in short bursts: rooms swing between warm and cool, and the extra starts wear out parts.

The proper method in Canada is a room-by-room heat loss calculation to CSA F280, the standard the Ontario Building Code references for house heating design. It also limits how far the furnace’s output may exceed the calculated load, so a replacement often comes out smaller than the old unit. Rules of thumb show why it matters: at 25 to 45 BTU/h per square foot, a 2,000 sq ft home needs anywhere from 50,000 to 90,000 BTU/h. The furnace size calculator narrows that for planning.

Two details trip people up on quotes. Furnaces are sold by input, but your house needs output: a 60,000 BTU/h input furnace at 96% AFUE delivers roughly 57,600 BTU/h. And with central air, the new blower must suit your AC coil, so the quote should say whether the coil stays.

Step 3: Choose staging and efficiency

Efficiency is the smaller decision. Under federal rules, a standard indoor gas furnace made for Canadian homes since July 3, 2019 must reach at least 95% AFUE, and its blower’s electricity use is capped too. So the gap between entry and premium models is a few points. What you are really choosing is how the burner and blower run.

Type	Typical installed price	How it runs	Best for
Single-stage	$4,000 to $6,500	Full fire every time, then off	Tight budgets, smaller or well-sealed homes
Two-stage	$5,500 to $8,000	Low fire most of the winter, full fire on the coldest days	Most detached homes
Modulating	$7,000 to $11,000	Adjusts the flame in small steps to match heat loss	Larger homes with hot and cold rooms, long ownership

Typical installed prices in Ontario, before 13% HST.

What are efficiency points worth? Say your home burns about 2,000 cubic metres of gas a year for heat, roughly $1,000 at $0.50 per cubic metre. Replacing an old 80% mid-efficiency furnace with a 96% one cuts that by about a sixth, around $165 a year. Going from 96% to 98% saves about $17 a year. Pay for staging if you want comfort, not for AFUE points.

Step 4: Price a heat pump or dual fuel before you commit

If your central air is also old, compare before you sign. A cold-climate heat pump replaces the AC and does much of the heating; paired with a gas furnace for the coldest days, it becomes a dual fuel system.

Option	Typical installed price
New gas furnace only (keeps your AC)	$4,000 to $11,000
Furnace and central AC together	$8,000 to $15,000
Ducted cold-climate heat pump	$9,000 to $18,000
Dual fuel: heat pump with gas furnace backup	$11,000 to $20,000

Before 13% HST. Electrical work for a heat pump can add to the heat pump options.

Heat pumps can qualify for incentives that a furnace cannot. On October 4, 2026, Home Renovation Savings listed rebates for purchased air-source heat pumps of $500 per ton, up to $2,000, in homes heated with Enbridge natural gas, with higher caps for electric, oil, propane or wood heat. Pre-approval before installation is mandatory, and a standalone gas furnace or cooling-only AC is not a heat pump rebate measure. The Canada Greener Homes Loan closed to new applications on October 1, 2025. Programs change: confirm before you buy. See heat pump rebates in Ontario, the heat pump buying guide and the heating cost calculator.

Step 5: Get two or three written quotes and compare them line by line

Quotes for the same house can differ by thousands of dollars, and most of the gap is scope, not margin. Get each in writing and line them up; furnace installation cost explains each line.

Line on the quote	What to look for
Equipment	Brand and full model numbers: furnace, plus AC coil and thermostat if included
Size	Input BTU/h, and a copy of the heat loss calculation
Venting and condensate	New venting or chimney liner; where the condensate drains
Other work	Gas line, electrical, duct changes, permit and removal of the old unit, each listed
Warranty and price	Parts and labour terms, who registers the warranty, totals before and after HST, deposit

• New venting or chimney liner$300 to $1,500
• Condensate pump$150 to $350
• Gas line work$300 to $1,200
• Ductwork modifications$500 to $3,000+
• New thermostat$150 to $600
• Municipal permit$75 to $300

Check the TSSA registration

In Ontario, installing or servicing a gas furnace must be done by a contractor registered with the Technical Standards and Safety Authority (TSSA), using certified gas technicians. Check the number with TSSA’s online lookup before you sign; registration is the legal minimum, not a judgement of quality. See TSSA’s guidance on fraudulent fuels workers.

Red flags in a furnace sale

• Pressure to sign today, or a price that expires when the salesperson leaves.
• A size copied from the old furnace, or a price given before anyone has seen the house.
• A vague scope (“supply and install furnace”), a large cash deposit or no TSSA registration number.
• A cracked heat exchanger you are told about but never shown.

Step 6: Decide whether to buy, finance or rent

Typical Ontario furnace rentals run $40 to $80 a month on 10 to 15-year terms: $4,800 to $14,400 over the term before any rate increases, against $4,000 to $6,500 to buy a single-stage furnace outright. Rentals usually bundle repairs, so read the yearly rate increase, the buyout schedule and what happens when you sell. If you finance, compare total cost, not the monthly payment. The rent or buy guide runs the numbers.

Step 7: Register the warranty and keep the paperwork

The manufacturer covers parts for a set term and the heat exchanger for longer; the installer covers labour. Some brands give their longest parts coverage only if the furnace is registered within a set window after installation. Ask who registers it, and keep:

• The invoice with model and serial numbers, install date and total paid
• The warranty registration confirmation and the installer’s labour warranty
• The heat loss calculation, start-up readings and any permit record

A yearly tune-up typically costs $120 to $250; furnace maintenance cost covers what it should include.

Step 8: Install day and the first few weeks

A straight swap in the same spot usually takes one working day, longer if the venting changes or the AC is replaced too. In winter, ask for a morning start. Before the crew leaves, the technician should test gas pressure, temperature rise, combustion and condensate drainage, then show you the readings and how to change the filter.

A faint burning smell on the first few runs is normal as factory coatings burn off. A smell that lingers, water around the base or frequent short cycles are not: have the installer back while the labour warranty applies, and keep snow clear of the outdoor pipes.

Questions people ask

How much should I budget for a new furnace?

Budget from the midpoint of the tier you want, then add the extras your house needs. A single-stage furnace typically runs $4,000 to $6,500 installed before HST, and new venting, a condensate pump, gas line or duct work is priced on top. Remember the 13% HST: a $5,500 job comes to about $6,215. Every tier is broken down in furnace prices in Ontario.

What size furnace do I need for a 2,000 sq ft house?

Rules of thumb put it between about 50,000 and 90,000 BTU/h, too wide to buy from. Newer, well-insulated homes land near the low end. A CSA F280 heat loss calculation sets the right size, and it often comes out smaller than the old furnace.

Is a two-stage furnace worth it in Ontario?

For most detached homes, yes, if comfort matters to you. It runs on low fire most of the winter, so heat is steadier and quieter. Do not expect it to pay for itself on gas: at about 96% AFUE it is close to a good single-stage model.

Can I install a furnace myself in Ontario?

No. Installing, connecting or servicing a gas furnace in Ontario must be done by a TSSA-registered contractor using certified gas technicians. You can change filters, keep vents and outdoor pipes clear and test carbon monoxide alarms, but anything involving gas, venting or combustion is a job for a registered contractor.

When is the best time to buy a furnace?

Spring and early fall, when installers have open schedules and you have time to compare quotes. The worst is a mid-winter breakdown, when you choose under pressure. Past 15 years, price a replacement before it fails. More in the best time to buy a furnace.