How to hire an HVAC contractor in Ontario

To hire an HVAC contractor in Ontario, read their reviews and look at past work, check the company on TSSA's list of registered fuels contractors for any gas, oil or propane work, and check the person doing the work on the Skilled Trades Ontario public register for air conditioning and heat pumps. Get two or three written quotes for the same job, and make sure the written estimate is part of your contract. A furnace or air conditioner can't be sold to you at your door unless you contacted the business first.

Shortlist and read the reviews

Start with contractors who list your kind of job (a furnace, a central air conditioner, a heat pump, a boiler, duct work), work in your town, and answer no-heat calls in winter if you need that.

When you read reviews:

• Look for recent reviews that name the equipment, the job and how it went. "Great service" tells you little.
• Read the low ratings. If the business answered a complaint fairly, that's a good sign. Watch for the same problem coming up again and again: no-shows, surprise charges, a system that never worked right.
• Check the count and the dates. A handful of recent reviews says more than many from years ago.
• On Zulma Atlas, each contractor's page shows the services they publish and the towns they serve, and has reviews from homeowners. A business that has claimed its page can answer reviews.

Look at their past work

• Ask for photos of a similar install: the furnace room, the outdoor unit and the line set, not only the box.
• Ask for a reference from a job like yours in the last year, and call them: was it on time, on budget, and does it heat and cool evenly?
• For a heat pump, ask how many cold climate heat pumps they put in last year. A heat pump is less forgiving of bad sizing and placement than a furnace.

Check the registration and the certificates

Gas, oil and propane. In Ontario, only TSSA-registered contractors and certified fuel technicians may install, service or maintain a fuel-burning appliance such as a furnace, a boiler or a water heater. Search the company on TSSA's Authorized Heating Fuel Contractors list by name, authorization number, city or postal code, and ask the technician which TSSA certificate they hold.

iSources: TSSA, "Protecting Ontarians from Fraudulent Fuels Workers" (23 March 2026) and "Authorized Heating Fuel Contractors".

Air conditioning and heat pumps. Residential Air Conditioning Systems Mechanic and Refrigeration and Air Conditioning Systems Mechanic are compulsory trades in Ontario. The person working on your system needs a Certificate of Qualification, a Provisional Certificate of Qualification or a Registered Training Agreement, and should appear on the Skilled Trades Ontario public register. Search the person who will do the work, not just the company.

iSource: Skilled Trades Ontario, "Residential Air Conditioning Systems Mechanic" and "Refrigeration and Air Conditioning Systems Mechanic".

Refrigerant. Anyone who buys or handles refrigerant in Ontario needs an Ozone Depletion Prevention (ODP) card. The card alone does not allow them to work on or fix the equipment, so ask for both.

iSource: Government of Ontario, "Certificate to handle refrigerants" (updated 7 April 2026).

Ask the right questions

• Who will do the work, and which TSSA certificate or trade certificate do they hold?
• Do you carry liability insurance? Can I see proof?
• Will you do a heat loss calculation, room by room, before you size the system?
• What's included: the equipment, labour, the thermostat, removing the old unit, permits?
• Does this job need a permit? Will you pull it and book the inspection?
• Which rebates or loans does this qualify for, and who applies?
• What warranty do you give on parts and labour, and does the maker's warranty need registering?
• When can you start, and how long will we be without heat or cooling?

Compare quotes on the same job

• Ask each contractor to quote the same equipment size and scope, in writing.
• Compare the total, including HST, not only the price of the unit.
• A quote far below the others can leave out the line set, the electrical work, the permit or removal of the old unit. Ask what's missing.
• A quote far above can be sized bigger than your home needs. A system that is too big turns on and off too often and wears out sooner.
• For typical prices, see our furnace replacement cost guide.

Permits

In Toronto, replacing a furnace or boiler in a house, or adding a cooling system, needs no building permit. Installing a new heating system or changing the one you have does. Other cities set their own rules, so ask your contractor or your city's building department.

iSource: City of Toronto, "When Do I Need a Building Permit?".

Your rights on price and contracts

• Any home renovation or repair contract worth more than $50 must be in writing.
• If a written estimate is part of the contract, the final price can't be more than 10% over it unless you agree to new work or a new price.
• Keep the deposit to no more than 10%, and never pay the full amount before the work is done.
• If you sign at home, you have 10 days to cancel for any reason.
• Furnaces, air conditioners, air cleaners and purifiers, water heaters and duct cleaning can't be sold or rented to you at your door unless you contacted the business first.

iSources: Government of Ontario, "Your rights when starting home renovations or repairs" (updated 6 August 2026) and "Door-to-door sales and home service contracts" (updated 19 June 2026).

After you hire: keep track of the job

• Before work starts: keep the signed contract, the estimate and the heat loss calculation.
• During the job: if the plan changes, get the new price in writing before the extra work. Note the permit number and the inspection date.
• At the end: run the system with the contractor in heating and cooling mode, and ask how to change the filter. Ask for an itemized invoice, the warranty on parts and labour, and the model and serial numbers of the furnace, air conditioner or heat pump.
• Register the warranty with the maker if it needs registering. Some makers shorten the warranty if you don't.
• Keep it all together: the invoice, warranty, permit and rebate papers are what you'll need for a warranty claim, a rebate or a future sale.
• Set a reminder for the filter and a yearly service before the heating season.

Red flags

• They knock on your door offering a new furnace, air conditioner, water heater or duct cleaning.
• They can't give you a TSSA registration you can find, for gas, oil or propane work.
• They size the system from the square footage alone, with no heat loss calculation.
• They want cash only, or full payment up front.
• They won't put the price in writing.
• They push a rental or a financing plan before giving you a price to buy.

Help with the cost

Home Renovation Savings, from Save on Energy and Enbridge Gas, pays up to $7,500 for a cold climate air source heat pump and up to $12,000 for a ground source one, set by its size. The model must be on Natural Resources Canada's list. Toronto and Durham Region also lend money for heat pumps, repaid on the property tax bill. Check what your town offers on its Atlas HVAC page.

iSource: Save on Energy, "Home Renovation Savings".