Furnace installation cost in Ontario: what you pay for beyond the box
Most of the gap between two furnace quotes is not the furnace. It is the venting, ductwork, gas line, drainage and permit work your house needs around it, and whether each quote includes that work.
Base price: a single-stage gas furnace typically costs $4,000 to $6,500 installed, before 13% HST. Two-stage and modulating tiers are in furnace prices in Ontario.
On this page
- Add-ons and their typical prices
- What the installed price usually includes
- Special situations that change the job
- Check a quote you already have
- Installation day, step by step
- TSSA registration: who is allowed to do the work
- How to compare line items across quotes
- Furnace and AC in one visit
- Questions people ask
Add-ons and their typical prices
These line items turn a $5,000 job into an $8,000 one (typical Ontario ranges, before HST):
- New venting or chimney liner$300 to $1,500
- Condensate pump$150 to $350
- Ductwork modifications$500 to $3,000+
- New thermostat$150 to $600
- Municipal permit$75 to $300
- Gas line work$300 to $1,200
Heat pump electrical work ($500 to $2,500) and a panel upgrade ($2,000 to $4,500) apply only if you add a heat pump; see heat pump prices.
What the installed price usually includes
In most Ontario quotes, and in the furnace ranges on OntarioFurnacePrices.ca, the base price already includes standard labour and removal of your old furnace. Installers rarely publish a separate labour rate, and the split between equipment and labour varies by company, brand and job, so this guide does not pretend there is one fixed figure. What you can compare is scope: what is included, and what is priced on top.
- The furnace, sized for your home, with the manufacturer's parts warranty
- Standard labour for a like-for-like swap in the same location
- Reconnecting the existing supply and return ductwork
- Reconnecting the gas line, usually with a new shut-off valve
- Reconnecting reusable PVC venting and running the condensate line to a nearby floor drain
- A new filter, thermostat wiring and start-up
- Combustion and safety checks: gas pressure, temperature rise, venting and flame safety
- Removal and disposal of the old furnace
If one of these is missing from a quote, ask whether it is excluded or simply not written down.
Special situations that change the job
Most of the gap between a simple swap and an expensive one comes from a few situations. If one describes your home, expect it on the quote:
-
Switching from oil or electric heat to gas
Raises the price: Gas line +$300 to $1,200
A gas line has to run to the furnace, and the utility has to connect the house if it has no gas service yet. An old oil tank must also be removed properly; home insurers often ask about oil tanks.
-
Orphaned water heater
Raises the price: Liner +$300 to $1,500
When an old mid-efficiency furnace shared a chimney with a gas water heater, the new condensing furnace vents through the wall. The water heater is left alone in a chimney sized for two and often needs a liner to vent safely.
-
Mid- to high-efficiency conversion
Raises the price: Condensate +$150 to $350
A condensing furnace needs PVC intake and exhaust pipes to an outside wall and a drain for its condensate. Venting falls in the $300 to $1,500 range; with no floor drain nearby, a pump is added.
-
Attic or crawlspace furnace
Raises the price: More labour
Horizontal furnaces in tight spaces take longer to swap and may need a second technician. In an unheated space the condensate line needs freeze protection.
-
Ductwork changes
Raises the price: +$500 to $3,000+
From a new plenum or a bigger return air drop to reworking runs that never heated the upstairs well. Ask for duct work to be listed separately.
-
Municipal permit
Raises the price: +$75 to $300
Requirements differ between municipalities and by scope. Ask whether your job needs one and who arranges it; normally the installer does.
-
Vent location
Raises the price: Longer vent run
The exhaust has to clear windows, doors, the gas meter and air intakes by distances set in the CSA B149.1 gas code. If the old exit point no longer works, the run gets longer.
Worked example: replacing an older mid-efficiency furnace
Picture a 1970s bungalow with a mid-efficiency furnace from the mid-2000s, a gas water heater sharing the chimney, and no floor drain near the furnace. A fair quote for a single-stage replacement could stack up like this:
| Line item | Typical range | Why it is there |
|---|---|---|
| Single-stage furnace, installed | $4,000 to $6,500 | Equipment, standard labour, removal of the old furnace |
| New PVC intake and exhaust | $300 to $1,500 | A condensing furnace cannot reuse the old metal vent |
| Chimney liner for the water heater | $300 to $1,500 | The water heater is now alone in a chimney sized for two |
| Condensate pump | $150 to $350 | No floor drain close enough for gravity drainage |
| Municipal permit | $75 to $300 | Where the municipality requires one |
| Total before HST | $4,825 to $10,150 | Against $4,000 to $6,500 for a simple swap |
| Total with 13% HST | $5,452 to $11,469 | What you would actually pay |
Illustrative only, built from the typical ranges on this page. It is not a quote for any home.
Nothing in that list is padding. Each item answers a real problem in that house, which is why one furnace can cost very different amounts on the same street.
Check a quote you already have
Pick the furnace type, tick the extras on your quote and enter its total to see where it sits in the typical range for that scope.
Furnace quote checker
Estimates update as you change the inputs. Nothing is sent anywhere.
Typical price for this scope
Before 13% HST, midpoint $5,250
Enter your quoted total to see where it sits.
The range updates as you pick the furnace type and extras.
Ductwork changes can run past $3,000. If your quote includes major duct work, a higher total can still be fair.
Get the real number for your home: a free, no-obligation quote.
Planning check only: it compares your number with typical Ontario installed ranges for the same scope, and cannot see your home, the model or the warranty.
Installation day, step by step
A like-for-like replacement is usually done in one working day; conversions, new venting and duct changes can stretch it to two.
Shut-off and protection
Gas and power to the furnace are turned off, floors are protected and the venting and ductwork are checked against the quote.
Old furnace out
Gas, venting, wiring and ducts are disconnected and the old furnace is carried out for disposal.
New furnace in
The furnace is set level and connected to the supply and return ducts. The gas line is reconnected and leak tested.
Venting and condensate
PVC intake and exhaust pipes are connected or run to the outside wall, and the condensate line goes to a drain or a pump.
Wiring and thermostat
Power, thermostat and any AC or humidifier connections are wired, and a new filter goes in.
Start-up and checks
The technician measures gas pressure, temperature rise and combustion, tests the safety controls, then walks you through the filter, the shut-off and the warranty paperwork.
TSSA registration: who is allowed to do the work
In Ontario, gas work is regulated by the Technical Standards and Safety Authority (TSSA). Installing or replacing a gas furnace must be done by a TSSA-registered contractor, with the hands-on work done by certified gas technicians. Ask for the contractor's TSSA registration number before you sign, and confirm it with TSSA.
A safety rule, not a price feature
A quote far below the others deserves a second look on this point. And whoever installs it, the Ontario Fire Code requires working carbon monoxide alarms outside sleeping areas in any home with a fuel-burning appliance, and since 2026 on every storey as well.
How to compare line items across quotes
Ask every installer the same questions and note the answers on each quote:
Questions to ask each installer
- Which exact furnace model and capacity is on the quote, and how was it sized?
- Is new venting included, and will the water heater need a chimney liner?
- Where will the condensate drain, and is a condensate pump included?
- Are ductwork changes included, and what exactly do they cover?
- Does this job need a permit, and is it in the price?
- Is removal and disposal of the old furnace included?
- What labour warranty do you give, separate from the manufacturer's parts warranty?
- Is the total before or after 13% HST?
- What is your TSSA registration number?
Furnace and AC in one visit
If your central air conditioner is about as old as the furnace, replacing both together typically runs $8,000 to $15,000 before HST. One crew, one set of disconnections and an indoor coil matched to the new furnace's blower are the reasons to do it in one visit. See furnace and AC prices, compare every tier on the furnace prices page, or estimate your home with the furnace cost calculator.
Get an itemized price for your home
A free in-home estimate checks venting, condensate, ductwork and gas line on the spot, so the quote you get lists what your house actually needs.
Free, no obligation. About a minute to request.
Questions people ask
Does furnace installation cost include removing the old furnace?
In most Ontario quotes, yes. Removal and disposal of the old furnace is normally part of the installed price, along with standard labour, reconnection and start-up. If a quote lists disposal as an extra, ask why, and check whether your other quotes include it.
How much is labour to install a furnace in Ontario?
Most installers price the job as one installed figure rather than an hourly labour line, and the split between equipment and labour varies by company and job. Compare totals for the same scope: a single-stage furnace typically costs $4,000 to $6,500 installed, before HST, with extras on top.
Do I need a permit to replace a furnace in Ontario?
It depends on your municipality and the scope of work. Some require a permit for a furnace replacement or for duct and venting changes; where one is needed it typically costs $75 to $300. Ask your installer whether your job needs one and who arranges it. The gas work itself must be done by a TSSA-registered contractor.
Can I install a gas furnace myself in Ontario?
No. Connecting a gas furnace is regulated gas work in Ontario and must be done by a TSSA-registered contractor using certified gas technicians. Manufacturer warranties also normally assume professional installation. What you can do is clear a path to the furnace and move stored items away from it before installation day.
Why do furnace installation quotes vary so much?
Mostly scope. One quote may include new venting, a chimney liner, a condensate pump and a permit while another leaves them out. Equipment tier, brand, access and the length of the installer's labour warranty explain most of the rest. Line the quotes up item by item before you compare the totals.
What does a mid-efficiency to high-efficiency conversion add?
On top of the furnace's installed price, expect new PVC venting ($300 to $1,500), often a chimney liner if a gas water heater stays on the old chimney ($300 to $1,500), and a condensate pump where there is no floor drain nearby ($150 to $350). The worked example on this page totals $4,825 to $10,150 before HST, permit included.