A furnace is usually the most expensive single appliance in a house, and the quotes homeowners get for the same house can be thousands of dollars apart. Most of that spread is explainable: the size and type of furnace, the brand, what the installer includes, and whether the venting, ducts or gas line need work. This guide sets out typical 2026 installed prices around Hamilton, Burlington and Haldimand, before HST, and what drives each number up or down.
None of the numbers below is a quote. The right furnace and the right price for your house depend on a home visit and a heat-loss calculation.
Typical installed prices
- Standard high-efficiency gas furnace (single- or two-stage, 96% AFUE): $4,500 to $8,000
- Variable-speed or modulating furnace: $6,500 to $11,000
- Furnace and central air conditioner together: $8,000 to $14,000
- Furnace with a heat pump instead of an AC (hybrid): $8,000 to $14,000 for the heat pump side, plus the furnace
- Propane furnace: similar to natural gas, plus any tank or regulator work
- Oil furnace replacement: $6,000 to $10,000, and often a reason to look at a heat pump instead
Those figures include removing the old furnace, the new unit, connecting it to the existing ducts and gas line, new plastic venting, a condensate drain, a basic thermostat and start-up. Use the HVAC cost calculator to adjust for your house size and equipment level.
What makes one quote higher than another
The type of furnace
Every new gas furnace sold in Canada must be at least 95% efficient, so the difference between a cheap and an expensive furnace is mostly about how it runs. A single-stage furnace fires at full output every time. A two-stage furnace spends most of its time on a low fire, which is quieter and gives more even heat. A modulating furnace adjusts in small steps to match the heat loss almost exactly. Furnaces with variable-speed blower motors use much less electricity for the fan, which matters if you run the fan continuously for air cleaning or have air conditioning.
Brand and warranty
Most brands sold in Ontario are built by a handful of manufacturers, and mid-range models from well-known brands are reliable. Premium brands and top-tier lines cost more and often come with longer parts warranties, sometimes conditional on registration and yearly maintenance. Labour warranties are set by the installer, not the manufacturer, so compare those separately.
Size
A larger furnace costs a little more, but the bigger issue is getting the size right. An oversized furnace short-cycles and wears faster. The guide to what size furnace you need explains how sizing should be done.
Venting and the chimney
Replacing an old mid-efficiency furnace that vented up a chimney is where hidden costs appear. The new furnace vents out the side wall in plastic pipe, and if a gas water heater shared the chimney, it may now be alone in a flue that is too large for it. The fix, a chimney liner or a power-vented water heater, adds $500 to $1,500 or the cost of a new tank. A good quote raises this up front.
Ductwork, gas line and electrical
If the new furnace has a different footprint, the plenums need to be rebuilt. Undersized returns, a common problem in older Hamilton houses, may need a new return run, which helps any new furnace or AC work properly. Moving the furnace, or upsizing the gas line, adds cost. These are worth paying for when they solve a real problem, not when they are padding.
Season and timing
Quotes in a January cold snap are no higher in principle, but you have less time to compare. Replacing an old furnace in spring, summer or early fall gives you the chance to get two or three quotes and pick an install date.
Rent, finance or buy
Many Ontario households rent their furnace. Rentals typically cost $60 to $120 a month for 10 to 15 years, and the total paid is often well above the purchase price. Financing through the contractor or the manufacturer is common too; compare the interest rate with a line of credit. Our guide to renting or buying works through an example.
How to compare furnace quotes
- Ask each contractor for a heat-loss calculation, and compare the sizes they recommend.
- Get the exact furnace model numbers in writing so you can look them up.
- Check what is included: removal, venting, chimney liner, thermostat, permits, condensate pump, and disposal.
- Compare the labour warranty and whether the installer registers the manufacturer’s warranty for you.
- Ask who does the work: their own TSSA-certified technicians or subcontractors.
- Watch for pressure tactics. Since 2018 Ontario has banned door-to-door sales of furnaces, and contracts signed at home carry a 10-day cooling-off period.
Rebates and incentives
Ontario rebates now focus on heat pumps, insulation and air sealing, not on gas furnaces themselves. If you are replacing a furnace and an air conditioner together, pricing a heat pump in place of the AC can open up a rebate under the Home Renovation Savings Program. Read heat pump rebates in Ontario before signing, because the job usually has to be registered before installation.
When to replace rather than repair
A furnace that is 15 to 20 years old, needs a costly repair, breaks down every winter or has a cracked heat exchanger is usually worth replacing. The guide on how long a furnace lasts explains the warning signs.
Getting a quote
When you are ready, send one request and we pass it to one licensed contractor who works your area. They visit, size the house and quote. Ask them to include a heat pump option if your air conditioner is also near the end of its life, and see furnace installation for what the job involves.
Questions people ask
How much is a new furnace in Hamilton?
Most high-efficiency gas furnaces cost $4,500 to $8,000 installed, before HST. Modulating and variable-speed models run $6,500 to $11,000.
Is it cheaper to replace the furnace and AC together?
Usually yes. A combined job typically costs less than two separate installs, and the indoor coil, blower and outdoor unit can be matched properly.
Why do furnace quotes vary so much?
Different furnace types and brands, different sizing, and different scopes: one quote may include a chimney liner, return duct and thermostat while another leaves them out. Compare model numbers and inclusions line by line.
Are there rebates for a new furnace in Ontario?
Not generally for gas furnaces on their own. Rebates under the Home Renovation Savings Program focus on heat pumps, insulation, windows and air sealing.