Official sources checked on October 23, 2026.
The furnace replacement cost in Ontario for a natural gas furnace runs roughly $2,800 to $10,000 installed in 2026: about $2,800 to $6,000 for a single-stage 95–96% AFUE furnace, $4,500 to $7,500 for a two-stage furnace and $7,000 to $10,000 for a modulating 98% furnace, based on published prices from three Ontario HVAC contractors (January to October 2026). HST at 13% comes on top unless the quote says it is included, and the work must be done by a TSSA-registered fuels contractor.
New venting, a condensate drain, gas line changes and a municipal permit can add a few hundred to a few thousand dollars. There is no Home Renovation Savings rebate for a gas furnace in 2026: that program pays for heat pumps, not furnaces.
In this guide
Furnace replacement cost in Ontario at a glance
Most Ontario homeowners replacing a gas furnace in 2026 will see quotes between $4,000 and $7,500 before HST. The table summarizes what drives the number up or down.
| Item | Typical range (2026) | Notes |
|---|---|---|
| Single-stage gas furnace, 95–96% AFUE, installed | $2,800 – $6,000 | Toronto quotes sit at the top of the range ($4,000 – $6,000) |
| Two-stage gas furnace, 96–97% AFUE, installed | $4,500 – $7,500 | The most common replacement in the sources reviewed |
| Modulating / variable-speed furnace, 98% AFUE, installed | $7,000 – $10,000 | Steadier temperatures, quieter operation |
| New PVC intake and exhaust venting | $200 – $500 | Needed when a condensing furnace replaces an older chimney-vented unit |
| Condensate drain (if none exists) | $100 – $250 | High-efficiency furnaces produce water that must be drained |
| Gas line work (if needed) | $200 – $600 | Only if the gas connection must be modified |
| Municipal permit | $100 – $350 | Toronto: $214.79 flat fee for a furnace replacement in a house (2026) |
| Removal of the old furnace | Often included, or $60 – $500 | Ask whether disposal is in the price |
| HST | 13% | Charged on the taxable amount of the invoice |
Prices summarize published ranges from three Ontario HVAC contractors: a GTA contractor (January 2026), a Toronto contractor (updated October 2026) and a Hamilton-area contractor (updated September 2026). Only one of the three states that its prices are before HST. The Toronto permit fee comes from the City of Toronto stand-alone HVAC permit page (fees effective January 1, 2026). The 13% rate is the Ontario HST listed by the Canada Revenue Agency.
What a new furnace costs by type
The type of furnace is the biggest price driver. A modulating furnace costs roughly twice as much installed as a basic single-stage model, and Toronto quotes run higher than the provincial low end.
| Furnace type (installed) | GTA contractor, Jan. 2026 | Toronto contractor, Oct. 2026 | Hamilton-area contractor, Sept. 2026 |
|---|---|---|---|
| Single-stage, 95–96% AFUE | $2,800 – $4,500 | $4,000 – $6,000 | Not broken out |
| Two-stage, 96–97% AFUE | $4,500 – $7,000 | $5,500 – $7,500 (FAQ: $4,500 – $6,500) | Not broken out |
| Modulating / variable-speed, 98% AFUE | $7,000 – $10,000 | $7,000 – $9,500 | Premium features add $1,000 – $2,000 |
| Typical overall range | Not stated | $4,300 – $7,000 plus HST | $3,000 – $8,500 including standard installation |
Single-stage (95–96% AFUE)
A single-stage furnace runs at full output whenever it fires. It is the lowest-cost option and still meets the federal 95% minimum efficiency. It suits smaller homes and owners who mainly want the lowest upfront price.
Two-stage (96–97% AFUE)
A two-stage furnace runs at a lower setting most of the time and switches to full output on the coldest days. It costs about $1,500 to $2,500 more than a single-stage model in the published ranges, and it is the replacement the Toronto source says it installs most often.
Modulating or variable-speed (98% AFUE)
A modulating furnace adjusts its output in small steps. It is the most expensive tier at $7,000 to $10,000 installed. The extra efficiency over a 96% furnace is small, so the case for it rests mostly on comfort and noise, not on gas savings.
Why your quote may be higher: the extra costs
Two quotes for the same furnace can differ by $1,000 or more because of the work around the unit. These are the line items the sources list separately:
- New PVC venting, $200 – $500: a condensing furnace vents through plastic pipes, usually out a side wall, instead of the old chimney.
- Condensate drain or pump, $100 – $250 if your basement has no drain nearby.
- Gas line changes, $200 – $600.
- Ductwork modifications, $200 – $1,000 for a simple swap; a full duct overhaul can add $3,000 – $7,000.
- Electrical work, $150 – $800.
- Moving the furnace to another spot, $2,000 – $5,000 more.
- Complex installs (finished basement, tight space, venting changes), $500 – $2,500 more on any tier.
- Optional add-ons: a new thermostat ($150 – $450) or a humidifier ($400 – $700 installed).
Location also matters. One Hamilton-area contractor publishes a baseline of $4,000 – $6,500 for the GTA, $4,200 – $6,800 for Hamilton and Burlington, $5,200 – $8,500 for rural southwestern Ontario and $6,000 – $10,000 or more for Northern Ontario. Only one source gives regional figures, so treat them as a rough guide.
Worked example: replacing an old furnace in a Toronto semi
Here is how a realistic quote adds up for a 1,600 sq. ft. semi-detached house in Toronto with a 20-year-old chimney-vented furnace. The owner chooses a two-stage 96% furnace. Each amount sits inside the published ranges above.
| Line item | Amount |
|---|---|
| Two-stage 96% AFUE furnace, supplied and installed | $5,800 |
| New PVC intake and exhaust venting | $400 |
| Condensate drain connection | $200 |
| Removal and disposal of the old furnace | Included |
| Subtotal before tax | $6,400 |
| HST (13%) | $832 |
| Contractor invoice | $7,232 |
| City of Toronto permit, furnace replacement in a house (2026 flat fee) | $214.79 |
| Total cost to the owner | $7,446.79 |
The same job outside Toronto with a single-stage furnace could look like this: $3,500 installed + $300 venting + $150 drain = $3,950, plus $513.50 HST, for $4,463.50 before any permit fee. The gap between the two examples, almost $3,000, comes from the furnace type, the Toronto price level and the permit.
RénoClair tip
Ask every contractor to quote the same furnace type (single-stage, two-stage or modulating) and to state in writing whether HST and the permit are included. A $6,400 quote with HST included is $832 cheaper than a $6,400 quote plus HST.
Who can replace a furnace in Ontario: TSSA rules
Only a TSSA-registered fuels contractor can legally do gas furnace work in Ontario. The Technical Standards and Safety Authority states that “furnaces and fuels-fired appliances must be maintained by TSSA-registered contractors” and that registered contractors must employ TSSA-certified gas technicians (TSSA, “Be Fuels Wise”, March 1, 2024).
- Check the company in the TSSA registered fuels contractor lookup before you sign. TSSA says the tool is updated at the start of each month.
- Ask for the company’s TSSA registration number on the written quote.
- Do not install a gas furnace yourself or hire a handyman without TSSA registration, even for a “simple swap”.
Do you need a permit to replace a furnace in Ontario?
Often, yes: permits are issued by your municipality, and Toronto lists a specific fee for furnace replacement. The City of Toronto stand-alone mechanical (HVAC) permit page (modified August 18, 2026) shows a flat fee of $214.79 for a boiler or furnace replacement in single-family detached or attached homes and townhouses, effective January 1, 2026. Toronto accepts these applications online.
For HVAC permits, Toronto’s guide lists documents such as the type, location and size of equipment, heat loss and heat gain calculations and duct design calculations. Other Ontario municipalities set their own rules and fees, so call your local building department. In most cases the contractor applies for the permit: confirm it in writing.
Efficiency rules: why new gas furnaces are 95% AFUE
Federal rules require most new gas furnaces to reach at least 95% AFUE. According to Natural Resources Canada’s gas furnace regulations page, gas furnaces manufactured on or after July 3, 2019 with an input rate of 65.92 kW (225,000 Btu/h) or less, using single-phase power and without an integrated cooling component, must meet a minimum AFUE of 95%.
Two exceptions keep an 80% minimum: furnaces for relocatable buildings and “replacement non-condensing gas furnaces”. If a quote offers an 80% furnace for a regular house, ask the contractor which exception applies. AFUE (annual fuel utilization efficiency) is the seasonal efficiency rating printed on the furnace’s specifications.
This rule is why many replacements include new PVC venting and a condensate drain: a 95% furnace condenses its exhaust and usually cannot reuse the chimney of an older mid-efficiency unit.
Rebates and a new furnace in Ontario
The Home Renovation Savings program (Save on Energy and Enbridge Gas) lists rebates for heat pumps, insulation, smart thermostats, appliances and other upgrades, but none for gas furnaces.
If you heat with Enbridge natural gas and are open to a heat pump, the Home Renovation Savings heat pump page offers $500 per ton, up to $2,000, for a cold-climate air source heat pump, or $3,000 for a ground source heat pump. Homes heated with electricity, oil, propane or wood get up to $7,500 or $12,000. Pre-approval is mandatory: installations done before approval are not eligible. Our guide to Enbridge heat pump rebates explains the steps.
A new federal heat pump rebate was announced on October 8, 2026 (up to $2,000, or up to $10,000 for households below median income), but its application date and rules were not yet published when we checked. It does not cover gas furnaces either.
Furnace or heat pump: should you switch?
A like-for-like gas furnace is not the only option. A ducted cold-climate heat pump is the main alternative, and it is the equipment Ontario rebates actually pay for. Compare running costs in heat pump vs furnace in Canada and installed prices in heat pump cost in Ontario before you sign a furnace quote, especially if your air conditioner is also near the end of its life.
Buying, leasing or renting: Ontario consumer rules
Ontario restricts how furnaces can be sold at your door. According to the Government of Ontario page on door-to-door sales (updated June 19, 2026), businesses cannot offer or sell furnaces, air conditioners, water heaters, air cleaners and similar products at your home unless you initiated the contact, for example by calling and asking them to come.
- If a technician comes for a repair, maintenance or an energy assessment, the business cannot sign a new contract with you for these products during that visit.
- For these restricted products you still have a 10-day cooling-off period to cancel for any reason once you have a written copy of the contract.
- The same page states that the law prohibits the registration of Notices of Security Interest (NOSIs) for consumer goods.
Before you sign a rental or lease, read how the monthly payment changes over time, what it costs to buy out the furnace and what happens when you sell the house.
After the install: carbon monoxide alarms
A home with a gas furnace must have working carbon monoxide alarms. The Ontario carbon monoxide safety page (updated December 30, 2025) says a house with a fuel-burning appliance, a fireplace or an attached garage needs CO alarms adjacent to each sleeping area and, since January 1, 2026, on every storey, including storeys without bedrooms.
The province also recommends that fuel-burning appliances, chimneys and vents be cleaned and inspected by professionals every year before the cold weather. A furnace replacement is a good time to test or replace your alarms.
Checklist before you sign a furnace quote
- Get at least three written quotes for the same furnace type and efficiency.
- Check each company in the TSSA registered fuels contractor lookup.
- Ask how the furnace size was chosen. Toronto’s HVAC permit guide lists heat loss and heat gain calculations among the documents for HVAC permits.
- Make sure the quote names the model, its AFUE rating and whether it is single-stage, two-stage or modulating.
- Look for venting, condensate drain, gas line and disposal as separate lines, or a clear note that they are included.
- Confirm who applies for the permit and whether the fee is in the price.
- Check whether HST is included or added.
- Ask which manufacturer and labour warranties apply and who registers the furnace with the manufacturer.
- If you consider a heat pump instead, get pre-approval from Home Renovation Savings before any work starts.
Common mistakes
- Comparing a single-stage quote with a two-stage quote as if they were the same product.
- Signing at the door: for furnaces, that sale is restricted in Ontario unless you invited the business.
- Assuming an “all-in” price includes HST and the permit.
- Waiting for a mid-winter breakdown, when you have the least time to compare quotes.
Once the new furnace is running, keep it efficient with a simple routine: our guide on how often to change a furnace filter and which MERV to buy explains the official intervals.
Replacing the water heater at the same time? Our guide to water heater rental vs buying in Ontario compares 2026 rental rates, buyout prices and a 15-year cost example.
Weighing a heat pump against a like-for-like furnace? The Ontario heat pump rebate guide lists the Home Renovation Savings amounts by fuel type, and the pre-approval steps come before any installation.
A new gas furnace also brings a safety rule: Ontario requires a carbon monoxide alarm next to the bedrooms and, since January 1, 2026, on every storey of a home with a fuel-burning appliance. See our guide to the carbon monoxide detector law in Ontario before the installer leaves.
To estimate the installed price before rebates, use our heat pump cost calculator (low, typical and high, with the detailed budget as a PDF).
Frequently asked questions
What is the furnace replacement cost in Ontario in 2026?
Most gas furnace replacements cost about $4,000 to $7,500 before HST. The full range in published Ontario contractor prices is roughly $2,800 for a basic single-stage furnace to $10,000 for a modulating 98% furnace.
How much does a new furnace cost in Toronto?
One Toronto contractor publishes $4,300 to $7,000 plus HST for a high-efficiency gas furnace fully installed, and up to $9,500 or more for a modulating unit. Add the City of Toronto permit fee of $214.79 (2026) if it is not included.
Is HST included in furnace prices?
Not always. Ontario HST is 13%, and only one of the three price sources we reviewed states that its prices are before HST. Ask each contractor to write it on the quote.
Do I need a permit to replace my furnace in Ontario?
Usually, yes. Toronto charges a $214.79 flat fee for a furnace replacement in a house (2026); other municipalities set their own rules, so check with your building department or ask your contractor to confirm.
Who is allowed to install a gas furnace in Ontario?
Only a TSSA-registered fuels contractor, using TSSA-certified gas technicians. You can verify a company in the TSSA online lookup.
Is there a rebate for a new gas furnace in Ontario?
Not through Home Renovation Savings: its rebates cover heat pumps, not gas furnaces. Enbridge gas-heated homes can get up to $2,000 for a cold-climate air source heat pump with pre-approval.
Can I still buy an 80% efficiency furnace?
Only in limited cases. Since July 3, 2019, most new gas furnaces made for Canada must reach 95% AFUE; the 80% minimum applies to replacement non-condensing furnaces and furnaces for relocatable buildings.
Can a company sell me a furnace at my door in Ontario?
No, unless you contacted the business first. Ontario restricts door-to-door sales and leases of furnaces, and you have a 10-day cooling-off period for these contracts once you receive a written copy.
How much does it cost to replace a gas furnace in Ontario?
Most gas furnace replacements cost about $4,000 to $7,500 before HST, depending on efficiency and extras. A basic single-stage unit can start near $2,800 and a modulating 98% furnace can reach $10,000; Toronto adds a $214.79 permit fee (2026) if the quote does not include it.
What extras can raise a furnace replacement quote in Ontario?
Published contractor prices list PVC venting at about $200 to $500, a condensate drain at $100 to $250 and a gas line at $200 to $600, plus ductwork changes from about $200 to $1,000 (a full duct overhaul can add $3,000 to $7,000). Ask for each item on the quote.
Do I need a carbon monoxide alarm if I have a gas furnace in Ontario?
Yes. Ontario requires a carbon monoxide alarm in a home with a fuel-burning appliance, adjacent to each sleeping area and, since January 1, 2026, on every storey. See the carbon monoxide detector law in Ontario.
The bottom line
Budget about $4,000 to $7,500 plus HST for a typical gas furnace replacement in Ontario in 2026, more for a modulating unit, in Toronto or in Northern Ontario, and less for a basic single-stage furnace. Get three comparable quotes from TSSA-registered contractors, check what is included (venting, drain, permit, disposal, HST) and look at the heat pump rebates before you decide, since a gas furnace itself gets no Home Renovation Savings rebate.
Sources
- TSSA, Be Fuels Wise: Hire Registered and Certified Professionals (March 1, 2024), checked October 23, 2026
- TSSA, Registered fuels contractor lookup, checked October 23, 2026
- Natural Resources Canada, Gas furnaces (Energy Efficiency Regulations), checked October 23, 2026
- City of Toronto, Stand-alone Mechanical (HVAC) permit (modified August 18, 2026; fees effective January 1, 2026), checked October 23, 2026
- Government of Ontario, Door-to-door sales and home service contracts (updated June 19, 2026), checked October 23, 2026
- Government of Ontario, Carbon monoxide safety (updated December 30, 2025), checked October 23, 2026
- Home Renovation Savings, Heat pumps, checked October 23, 2026
- Canada Revenue Agency, GST/HST rates, checked October 23, 2026
- Published installed prices from three Ontario HVAC contractors (GTA, January 2026; Toronto, updated October 2026; Hamilton area, updated September 2026), checked October 23, 2026
