Under the Tarion warranty, HVAC in a new Ontario home falls under the two-year coverage for defects in the heating, plumbing and electrical delivery and distribution systems — the furnace, the ductwork, the venting and the distribution of heat around the house. That is longer than the one-year general coverage most buyers know about and shorter than the seven-year structural coverage, and the two-year clock is the one people miss. If something about the heating or cooling has never been right, the deadline that matters is the end of your second year of possession.
Tarion administers Ontario's statutory new home warranty, and since 2021 the Home Construction Regulatory Authority has licensed the builders themselves. The warranty is with your builder; Tarion backs it and steps in when the builder does not.
What the Two-Year Warranty Covers Mechanically
Defects in the work and materials of the heating delivery and distribution system, plus violations of the Building Code's health and safety provisions. In practice that reaches most of what goes wrong mechanically in a new house.
- Ductwork that leaks at the joints, was never sealed, or runs uninsulated through an unconditioned attic or a garage ceiling.
- Supply runs and returns installed differently from the mechanical drawings, so a bedroom never receives the air it was designed to get.
- Venting or combustion air installed incorrectly, or clearances that do not meet code.
- A ventilation system installed but never balanced or commissioned, or ducted to the wrong rooms entirely.
- Condensate drainage run without a proper trap or without slope, so it backs up or spills.
- Gas piping and connections that do not meet code, which is a health and safety item rather than a comfort complaint.
The one-year warranty is broader — defects in work and materials generally, Building Code violations and fitness for habitation — so first-year claims can include a great deal that would not survive into year two. Use the first year generously and write everything down.
The Forms and the Deadlines, in Order
There are four windows and they are strict. Tarion's process runs on forms submitted inside defined periods, and an item raised after its window closes is considerably harder to pursue.
- The 30-day form, submitted within the first 30 days of possession. This is your move-in list, and it should include comfort complaints such as an upstairs that will not warm up.
- The year-end form, submitted during the last 30 days of your first year of possession. This is the important one and the most commonly missed.
- The second-year form, submitted at any point during the second year of possession, which is where heating and ventilation defects live.
- The major structural defect form, covering years three through seven for structural claims only.
- The emergency procedure, which is separate from all of the above. A total loss of heat is treated as an emergency: contact your builder first, and if you cannot reach them or they do not respond, contact Tarion directly.
Put the year-end and second-year dates in a calendar during the week you move in. No builder is required to remind you that a window is closing.
The New-Build Complaints That Are Actually Warranty Items
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Most of the comfort problems dismissed as just how new houses behave are warrantable defects. We hear the same handful in every new subdivision — the Orchard and Alton Village in Burlington, the newer pockets of Waterdown, Joshua Creek in Oakville, Binbrook and the Meadowlands in Ancaster.
- A second floor running 3–4°C hotter in summer and colder in winter than the main floor, which is usually dampers nobody ever balanced or a return undersized for the upper level.
- One bedroom over the garage that never reaches temperature, fed by a long uninsulated duct run through the garage ceiling.
- A furnace short-cycling through the shoulder season, often because the unit was selected by rule of thumb instead of a heat loss calculation.
- A ventilation unit humming away in the basement that nobody has ever adjusted, with the house sitting near 50% relative humidity in January and the windows streaming.
- A humidifier installed with the bypass damper still sitting in its summer position from the day it went in.
- Registers whistling under pressure, or a duct booming each time the blower starts.
Documenting these with dates, measured temperatures and photographs is what turns a complaint into a claim. A written report from an independent licensed contractor carries far more weight than a description typed into a form.
Book an Independent Inspection at Month 20
Month 20 is the sweet spot. It leaves four months to file the second-year claim and for the builder's mechanical trade to come back, and it is late enough that a full heating season and a full cooling season have exposed whatever is wrong. A proper visit measures airflow at the registers, checks static pressure across the furnace, verifies the ventilation system is balanced and actually running, inspects venting and duct sealing, and produces something in writing you can attach to a form.
The same visit is useful for the things Tarion does not cover, such as filter access, thermostat configuration and whether the builder-grade equipment is worth upgrading. Builder-grade HVAC upgrades covers what is worth changing and what is genuinely fine, and an Oakville new home's first year walks the season-by-season version of the same story.
Tarion's Warranty and the Manufacturer's Warranty Are Different Things
Tarion covers the installation; the manufacturer covers the equipment. Your furnace almost certainly carries a parts warranty from Lennox, Carrier, Trane, Goodman or whoever built it, and that term is usually far longer than two years. It typically requires online registration within 60 to 90 days of installation to secure the extended term, and it generally covers parts only rather than the labour to fit them.
- Register the equipment yourself. Do not assume the builder or the mechanical contractor did it — call the manufacturer with the serial number and confirm.
- Keep the model and serial numbers and the installation date somewhere other than a sticker in a damp basement.
- Most manufacturers expect documented annual maintenance by a licensed contractor and can decline a claim where there is no service history.
- Labour sits outside the parts warranty. A ten-year parts term still leaves you paying a technician to diagnose and install the part.
- Ontario's Building Code requires whole-house mechanical ventilation in new homes, which is why nearly every recent build has an HRV in the basement. Treat it as code-required equipment rather than an optional extra.
Understanding HVAC warranty coverage sets out what parts, labour and workmanship warranties each actually pay for, because homeowners routinely assume the longest number they have seen applies to everything.
Tarion publishes the forms, the deadlines and the builder directory, and reading the coverage description on their own site beats relying on what the sales office said eighteen months ago. When you want a written, independent read on how the mechanical system actually performs before your second-year deadline closes, that is a visit we do, and the scope is described on our HVAC inspection page.
Frequently asked questions
Does Tarion cover my furnace?
The installation of the heating system is covered — defects in the work and materials of the heating delivery and distribution system fall under the two-year statutory warranty. The furnace as a manufactured product also carries its own parts warranty from the manufacturer, which usually runs much longer but generally excludes labour.
How long is the Tarion warranty on HVAC?
Two years for defects in the heating, plumbing and electrical delivery and distribution systems, running from the date of possession. The broader one-year warranty covers defects in work and materials generally and Building Code violations, so anything noticed early should be raised in the first year rather than saved.
Is no heat in a new home a Tarion emergency?
A total loss of heat is treated as an emergency under Tarion's process. Contact your builder first using the emergency contact they provided at closing, and if you cannot reach them or they fail to respond within the timeframe, contact Tarion directly. Keep a written record of every attempt to reach the builder.
Does Tarion cover an oversized furnace or a hot second floor?
Often yes, when it can be shown to be a defect in the work rather than a preference. An unbalanced system, an undersized return, uninsulated ducts in unconditioned space, or equipment selected without a proper heat loss calculation are all arguable defects. Measured evidence from an independent contractor is what makes that case.
Do I still have a manufacturer's warranty on a new home furnace?
Yes, and it is separate from Tarion. Check whether the equipment was registered within the manufacturer's window, since the extended parts term usually depends on registration inside 60 to 90 days of installation. Keep annual service records too, because most manufacturers can decline a claim where maintenance cannot be shown.