Comparison Checklist
Furnace age and expected lifespan
Repair cost vs replacement cost
Energy efficiency gains
Safety concerns
Comfort and reliability
Rebate eligibility
| Option | Best For | Watch For | Fit |
|---|---|---|---|
| Furnace repair | Systems under 15 years old with a single, clear failure like ignitor, blower motor, or flame sensor. | Repeated repairs on the same system, cracked heat exchangers, or discontinued parts. | Best when the furnace is reliable overall and the repair cost is under 40% of replacement. |
| Furnace replacement | Furnaces over 18 years old, systems with rising repair bills, or homes with comfort and efficiency complaints. | A proper replacement quote should include sizing, ductwork review, venting, thermostat, and commissioning. | Best when the long-term cost of keeping the old furnace exceeds replacement value. |
| Heat pump conversion | Homeowners exploring electric heating, reducing gas bills, or qualifying for federal Greener Homes or provincial rebates. | Cold-climate heat pumps still benefit from a backup furnace or electric strip heat below -20°C in Ontario. | Worth quoting alongside furnace replacement for homes with central ductwork. |
The 50% rule and when it breaks down
A common guideline says to replace when a repair costs more than 50% of a new furnace. But that rule ignores system age, part availability, safety risk, and comfort.
A $600 ignitor repair on a 10-year-old furnace is different from a $600 blower repair on a 22-year-old unit with a history of breakdowns.
Toronto-specific factors that affect the decision
Toronto homes often have compact mechanical rooms, shared venting, older ductwork, and mid-efficiency furnaces that cannot be replaced with the same venting type.
Replacement in these homes may require venting changes, electrical updates, or ductwork modifications that affect the total project scope.
What a proper furnace quote should include
Equipment model and efficiency rating, installation labour, venting and drainage, thermostat setup, old equipment removal, permit if required, and commissioning.
GTA HVAC Pros reviews these details by phone before recommending repair or replacement.