Published prices for an AC service call in Ontario are $120–$250. The most common repair, a capacitor or contactor, is $150–$450; refrigerant leaks run $250–$1,800, depending on how big the leak is.
These figures come from Ontario HVAC contractors’ own price guides. An older system on R-22 refrigerant costs more to recharge, which is often when a replacement or a heat pump makes sense.
The service call
The diagnostic visit is usually charged separately, and some contractors waive it if you go ahead with the repair.
Published service call prices
CAD · before HST · published prices
- Diagnostic / service callFrom a Hamilton HVAC contractor’s 2026 price guide
- $120–$250
- Diagnostic service call (waived if the repair goes ahead)From a Halton HVAC contractor’s 2026 price guide
- $120–$180
- After-hours, weekend or holiday premium, addedFrom a Hamilton HVAC contractor’s 2026 price guide
- $50–$150
- After-hours emergency diagnosticFrom a Halton HVAC contractor’s 2026 price guide
- $220–$280
Common repairs
An AC that hums but won’t start is often the capacitor; one that runs but doesn’t cool may be low on refrigerant from a leak.
Published repair prices
CAD · before HST · published prices
- Capacitor or contactorFrom a GTA HVAC contractor’s price guide
- $150–$280
- Capacitor replacement (the most common AC repair)From a Halton HVAC contractor’s 2026 price guide
- $250–$400
- Contactor replacementFrom a Halton HVAC contractor’s 2026 price guide
- $300–$450
- Refrigerant leak or fan motorFrom a GTA HVAC contractor’s price guide
- $250–$600
- Refrigerant top-up and leak diagnosisFrom a Halton HVAC contractor’s 2026 price guide
- $350–$650
- Major refrigerant leak repairFrom a Halton HVAC contractor’s 2026 price guide
- $700–$1,800
Repair or replace?
A big refrigerant leak on an old outdoor unit can cost a good share of a new one. The air conditioner cost guide has replacement prices, and a heat pump that also heats is worth pricing at the same time.
Prevent the next one
A spring tune-up cleans the coil and tests the capacitor before it fails on a hot day.
Published tune-up prices
CAD · before HST · published prices
- Furnace, AC or heat pump tune-upFrom a GTA HVAC contractor’s price guide
- $175
- Annual furnace tune-upFrom a Halton HVAC contractor’s 2026 price guide
- $140–$220
- Annual AC tune-upFrom a Halton HVAC contractor’s 2026 price guide
- $130–$200
Questions people ask
How much does AC repair cost in Ontario?
Published prices: $120–$250 for the service call, $150–$450 for a capacitor or contactor, $250–$1,800 for refrigerant leaks and recharges, before HST.
Is it worth fixing an old air conditioner?
A capacitor or contactor almost always is. A major refrigerant leak on an old unit often isn’t; compare it with a new AC or a heat pump.
Where these prices come from
These figures are from Ontario HVAC contractors’ own published price guides, one of them in Hamilton, checked October 23, 2026. We don’t name them: we’re a referral service and don’t promote individual contractors. They’re ranges, not quotes, before HST and before rebates. Rebates are from the Home Renovation Savings Program’s own page, linked above.