Quick answer
An HVAC installation contract should name the equipment by brand, model number, efficiency rating and BTU size, list every part of the scope (venting, gas line, electrical, thermostat, removal), and give start and finish dates. In Ontario it must also show the total price, payment terms, your cancellation rights and the contractor's legal name and address. If a line is missing, ask for it before you sign.
What should an HVAC installation contract include? Enough detail that a stranger could read it and know exactly what is being installed, by whom, for how much and by when. A one-line contract that says 'supply and install 96% furnace' leaves the model, the size, the venting and the clean-up open to argument. The test is simple: if a line item matters to you, it should be on paper before any money moves.
The equipment lines every HVAC contract should name
- Brand and full model number of each piece: furnace, coil, condenser or heat pump, thermostat. A series name alone ('two-stage 96%') is not a model number, and the same series is sold with different blower motors and gas valves.
- Efficiency rating: AFUE for a furnace (the federal minimum for gas furnaces is 95%) and SEER2 for an air conditioner or heat pump (13.4 is the minimum for a split AC).
- Input size in BTU per hour for the furnace and tonnage for the cooling side, with a note on how the size was chosen. A size copied from the old nameplate is a guess.
- Scope of work, item by item: venting and where it terminates, gas line changes, electrical connection, condensate drain or pump, thermostat and wiring, sheet-metal transitions, removal and disposal of the old unit.
- What is excluded. A chimney liner for the water heater left on the old flue, duct repairs, asbestos tape on old ducts and drywall patching are the usual surprises.
- A start date and a finish date, not 'approximately two weeks'.
What Ontario's Consumer Protection Act requires in writing
Ontario's Consumer Protection Act, 2002 requires a written agreement, with a copy handed to you, when a contract is signed in your home or when the work or the payment happens after the signing. Most furnace and air conditioner installs are both. The agreement has to disclose the items below, and gaps in that disclosure can extend your right to cancel.
- The contractor's legal name, business address and phone number, plus the name of the person who sold you the job. A trade name and a cell number are not enough.
- A fair description of the goods and services, which is where the model numbers and scope do double duty.
- The total price including HST, and the payment terms: deposit, any progress payment, balance on completion, and for financing the interest rate and total cost of borrowing.
- Delivery, start and completion dates.
- A statement of your cancellation rights, including the cooling-off period that applies to agreements signed at home.
Two rules are worth knowing before you sign. Where a contract includes an estimate, the final bill cannot run more than 10% over it unless you agree to the change in writing. And the 10-day cooling-off period on an agreement signed at home starts the day you receive your written copy, not the day of the sales visit.
The paperwork that should be attached to the contract
- The company's TSSA fuels contractor registration number, and the gas licence class (G2 or G1) of the technician who will fire the appliance. Our guide on how to verify a TSSA licence explains the lookup.
- A certificate of liability insurance naming the company, and a current WSIB clearance certificate showing the account is in good standing.
- Warranty terms split in two: the manufacturer's parts warranty, including who registers it, and the contractor's own labour warranty with its length in years. The difference is set out in labour warranty versus parts warranty.
- Who files any rebate. Heat pump rebates run through the Home Renovation Savings Program, approval comes before the install, and the installer has to be on the program's participating-contractor list. No current Ontario program pays for a gas furnace on its own, so a contract promising a furnace-only rebate deserves a question.
- Who obtains any permit the municipality requires, and who files the notification with the Electrical Safety Authority when new wiring or a new circuit is part of the job.
Payment terms, change orders and checking the total
The contract should tie payments to events you can see: a deposit on signing, the balance when the equipment is running and commissioned. It should also say how extras are handled, which means a written change order with a price, signed before the extra work starts. How much deposit an HVAC contractor should ask for covers the deposit side. To check that a contract total is in a normal range, compare it with the published bands for this area:
- High-efficiency gas furnace, installed: $4,500–$7,500.
- Furnace and air conditioner replaced together: $7,500–$11,500.
- Three-ton cold-climate heat pump, installed: $9,500–$15,000.
A total far below the band usually means something on the scope list is missing; a total above it should come with a reason you can read, such as a new vent route or duct rework. The pricing page shows what moves a job within each band.
What you should be handed on install day
A finished job comes with paper too. Ask for the commissioning sheet with the combustion readings, gas pressure and temperature rise the technician measured, the warranty registration confirmation, the manuals, and the paid-in-full invoice showing the model and serial numbers. Those are the documents a future buyer's inspector, an insurer or a warranty claim will ask for.
ZK Mechanical writes the price, model numbers and scope down before work starts, and quotes are free. If you have a contract from another company on the table and something on this list is missing, ask them to add it; a contractor who intends to do the work as described has no reason to refuse. For a written quote on furnace installation in Burlington, Oakville, Hamilton or the west GTA, call (647) 801-1252 or request a quote.