Quick answer
Buy from whoever will install and service it. A big-box store sells the appointment; a subcontracted local dealer quotes, installs and holds the TSSA registration and the labour warranty. Compare the two quotes line by line on model number, labour warranty term and who answers a no-heat call. A direct contractor quote for a high-efficiency furnace typically lands at $4,500–$7,500 installed.
Whether you should buy a furnace from a big-box store or a contractor matters less than it sounds, because a local HVAC company installs it either way. The store sells the appointment and takes the payment; a dealer under contract to the store measures, quotes and does the work. The real choice is whether you want a retailer standing between you and the company that will be in your basement. Decide it by comparing two written quotes on the same lines.
How retail furnace programs work
A retail program is a referral arrangement. You book a consultation at the service desk or online, the lead goes to a dealer contracted for your postal code, and that dealer's salesperson visits, sizes the furnace and prices it. The dealer's crew installs it, and the store handles payment or financing and keeps a program fee. Stores do not typically employ gas technicians of their own.
That makes four questions worth asking before you sign:
- Which company is installing, and is it the name on the TSSA fuels contractor registration? Check it yourself; verifying a TSSA licence takes a few minutes.
- Who holds the labour warranty, the store or the dealer, and what happens to it if the dealer leaves the program?
- Whose name goes on any permit, and who registers the manufacturer's warranty?
- Whose phone rings on a no-heat call at 2 a.m. in January: a call centre that opens a ticket, or the company that installed the furnace?
What to compare line by line
Two furnace quotes are comparable only when the same items appear on both. Put them side by side and check:
- Full model numbers for the furnace, coil and thermostat. A description such as 96% two-stage is not a model; the number tells you the staging, the blower motor type and the input.
- BTU input, and how it was chosen. Matching the old furnace's size is not sizing; ask whether a heat-loss calculation was done.
- Labour warranty term in years, in writing, and the company that owes it.
- What is included: venting changes, condensate drain, gas piping, thermostat, removal of the old unit, and a chimney liner if the water heater is left alone on the chimney.
- After-hours service: who answers, and whether an evening or weekend visit carries a surcharge.
- Financing: the rate, the term, the total cost of borrowing, what happens when a deferred-interest period ends, and whether there is a prepayment penalty.
If a model number does not appear in the manufacturer's regular literature, compare the specifications instead: stages, blower type, AFUE and input. Our guide to comparing HVAC quotes has a fuller checklist.
Where the price difference comes from
The furnace and the labour cost the same through either door; the difference is what sits on top. A retail program adds the store's fee, and promotions such as no interest for a year are paid for by a lender fee that ends up in the price. A direct quote carries neither. That does not make the store dearer every time, since retailers run real promotions, so compare totals against the published band:
- High-efficiency gas furnace, installed, direct quote: $4,500–$7,500
- Financing example: a $5,000 furnace over 10 years is roughly $60–$75 a month, depending on the rate
- Diagnostic visit if you are still deciding between repair and replacement: $90–$150, credited toward the repair
A quote well above that band for the same specifications should come with an explanation: a liner, a long vent run, duct changes. One more check on the fine print: no current Ontario program pays a rebate for a gas furnace on its own, so a rebate line on a furnace quote is a store or manufacturer promotion, not government money. Typical ranges for other work are on our pricing page.
The verdict: buy from whoever is accountable afterwards
Choose the quote that names the installer, lists full model numbers and puts the labour warranty in writing; if both do, choose the one whose phone is answered by the people who did the work. A store program suits a buyer who wants the retailer's financing or its complaints desk as a backstop and is comfortable with the dealer it assigns. A direct contractor suits a buyer who wants one company to quote, install, register the warranty and come back when something fails.
Either way, Ontario's Consumer Protection Act gives you a 10-day cooling-off period on an agreement signed in your home. Nobody should be selling furnaces at your door uninvited: that practice has been banned in Ontario since 2018.
ZK Mechanical is owner-operated: Zobir, a TSSA-licensed gas technician, runs the company, quotes are free and written, and financing through our lending partners has no prepayment penalty. See furnace installation or ask for a written quote to set beside the store's.