Replacing a furnace: where the money goes
Furnace replacement cost in Canada typically runs from a few thousand dollars for a straightforward swap to noticeably more when ductwork, venting or electrical work comes along. The efficiency tier, the size of the unit and the condition of the house decide where a job lands, and a written quote is the only reliable number.
How much does a new furnace cost in Canada?
Prices vary by region and year, and they have moved a lot in recent years with equipment and labour costs. As a broad guide, a like-for-like replacement of a standard gas furnace has typically landed in the low thousands of dollars installed, while premium units with variable output or complex venting can cost considerably more. Treat that as a range for orientation, not a quote.
What changes the figure is rarely the metal box alone. The same furnace can be a simple afternoon job in a house with good access, or a long day involving new venting, a new gas line connection and a condensate drain. Two quotes for the same model can differ for those reasons.
What drives furnace replacement cost?
Four items account for most of the spread.
- Efficiency tier. High-efficiency condensing furnaces recover more heat from exhaust gas, which means plastic venting and a drain, and a higher purchase price.
- Capacity. The unit should match the heat loss of the house, not the size of the old one. Many old furnaces are oversized for a home that has since been re-insulated.
- Blower and controls. Variable-speed blowers and multi-stage burners cost more and run quieter, with steadier room temperatures.
- Site conditions. Venting changes, ductwork repairs, a relocated unit or an electrical upgrade each add labour.
Labour and permit rules are regional, so a quote from a local licensed contractor is worth more than any national average.
Is a high-efficiency furnace worth the extra?
A worked comparison, with assumptions stated: an 80 percent furnace turning 100 gigajoules of fuel into heat delivers 80 gigajoules to the house. A 96 percent unit would need roughly 83 gigajoules for the same delivery, so it saves about 17 gigajoules a year. Multiply that by your delivered gas price and divide the price premium by the result to get a simple payback. If the answer is a decade or more, ask whether you will still own the home and whether the unit will last that long.
High-efficiency furnaces also tend to be sealed-combustion units, which draw air from outside and avoid pulling heated indoor air up the flue. For the lifespan side of the decision, see heating system lifespans.
Should you replace the furnace with a heat pump or boiler instead?
A furnace replacement is a natural decision point for looking at other systems. A cold-climate heat pump can supply most of the heat in many Canadian homes, sometimes alongside a gas furnace as backup, as covered in the guide to hybrid dual-fuel systems. Whether it makes sense depends on electricity and gas prices, the house, and available programs. Start with heat pump vs furnace.
If the house already has hot-water heating, the question is boiler replacement rather than furnace, a choice discussed in boiler vs furnace.
Federal, provincial and utility programs for heating equipment come and go and change their terms. Check the Government of Canada energy-efficiency pages, your provincial energy ministry and your utility before signing, because some programs require approval before the work starts.
When comparing quotes, ask for the model's rated efficiency, the heat-loss calculation used to size it, the warranty terms on the heat exchanger and parts, and what is included for venting, permits and old equipment removal.
What does a quote usually include?
A clear quote lists the model and rated efficiency, the size in input and output capacity, venting and flue materials, the thermostat, the condensate handling, the permit and inspection, disposal of the old unit, labour and taxes. Anything marked as an allowance or an extra should be explained in writing. Ask whether duct cleaning, a carbon monoxide detector and a humidifier connection are included, since these are sometimes optional.
Get at least three quotes from licensed contractors and compare line by line. The cheapest bid often leaves out something the others have priced. Ask each firm how they calculated the size, and be wary of anyone who simply matches the old unit. A new furnace is a rare chance to match equipment to the house you have today.
For context on why a heat-loss-first approach matters, look at the Drake Landing homes, where very low heat demand shaped every equipment choice.
Quick answers
How long does a furnace replacement take?
A straightforward swap is commonly done in a day. Changes to venting, ductwork or gas piping can extend the job.
Do I need a permit to replace a furnace?
Most jurisdictions require a gas or mechanical permit and an inspection. Your contractor should know the local rules, and your municipality can confirm.
Can I save money by buying a smaller furnace?
Right-sizing saves money, but undersizing risks cold rooms on the coldest days. The size should come from a heat-loss calculation for your house.