Quick answer
In practice, yes. Furnace warranty documents make maintenance by a qualified technician a condition of coverage and exclude damage caused by neglect, and the manufacturer can ask for service records before approving a major claim such as a heat exchanger, inducer motor or control board. Any TSSA-licensed contractor's tune-up counts. You do not have to buy the installer's plan or the manufacturer's branded service.
You need annual maintenance to keep your furnace warranty in the way that counts: when an expensive part fails, the claim goes more smoothly with service records behind it and can be refused without them. Nobody checks each year whether you booked a tune-up. The question only comes up at claim time, which is the worst moment to discover a gap.
What furnace warranty documents say about maintenance
Warranty certificates say the furnace must be installed and maintained according to the manufacturer's instructions, and the owner's manual in turn calls for a yearly inspection by a qualified service technician. The same certificates exclude failures caused by improper maintenance: dirty filters, blocked airflow, neglected condensate drains. Wording differs between Lennox, Carrier, Trane, Goodman and the other brands, so read the certificate for your model.
Records are requested on the big claims. A heat exchanger, an inducer motor or a control board is costly enough that the distributor may ask the contractor filing the claim for the installation date, the serial number and the service history. The classic refused claim is a heat exchanger that cracked from overheating on a furnace that ran for years with a plugged filter and a temperature rise above the rating plate.
Parts coverage is also only half the bill. Labour is a separate promise, usually from the installer, with its own terms; labour warranty versus parts warranty explains the split.
What counts as proof of furnace maintenance
- A dated invoice or service report from a licensed heating contractor, one for each year.
- The technician's name and TSSA gas licence number on the report.
- The furnace model and serial number, so the report is tied to that unit.
- Readings taken that day: temperature rise, gas pressure, combustion numbers and flame signal.
- A list of what was cleaned, tested and replaced.
What does not count: a receipt for filters, a sticker on the cabinet with no date, or your own cleaning, however careful. Keep the reports for the whole warranty term and photograph each one, because the claim may come a decade after the first visit.
What a furnace warranty does not require
The warranty does not require you to buy a maintenance plan from the company that installed the furnace, and it does not require the manufacturer's branded service. The condition is a qualified technician, and in Ontario that means a TSSA-licensed gas technician working for any registered contractor. You can change service companies whenever you like and the record still counts.
Maintenance is one of several conditions. Registration deadlines, do-it-yourself gas work and non-approved parts can each end coverage on their own. Those are covered in what voids a furnace warranty and whether you have to register your furnace warranty.
Rental furnaces, extended plans and new-build homes
- Rented furnace: the rental company owns the equipment and its contract sets out who services it. Read that agreement, not the manufacturer's certificate.
- Extended or third-party protection plans: these are separate contracts and often have stricter maintenance terms than the factory warranty. Check them line by line.
- New-build home: the builder's warranty and the furnace manufacturer's warranty run side by side, and the maintenance condition on the furnace applies from the first winter.
When to book the tune-up, and what it costs
Book it in early fall, before the first cold week. A standalone furnace tune-up from a licensed contractor takes 45–90 minutes and costs $120–$250. A maintenance plan that bundles the furnace and air conditioner visits typically costs $150–$350 per year, which is worth it only if you would book both anyway.
The visit protects the furnace as well as the paperwork. The technician measures the temperature rise and compares it with the range printed on the rating plate; a reading above that range is the early sign of the overheating that cracks heat exchangers. Correcting it, with a new filter, a blower speed change or a cleared return, is the reason manufacturers write the maintenance condition in.
If you have missed a year or two, start now. A gap is not an automatic refusal: the manufacturer looks at whether the failure was caused by neglect, and a recent report with clean readings is good evidence that it was not. What you cannot do is create the record after the part has failed.
ZK Mechanical's TSSA-licensed technicians service every major brand, whichever company installed the furnace; ask for the licence number and the readings on your report. To book a furnace tune-up in Burlington, Oakville, Milton, Hamilton or Mississauga, call (647) 801-1252 or pick a date through the contact page.