How-to · 20 minutes · easy
Test your AC in April or early May. If something's wrong, you have time to fix it cheaply. If it dies on the first 32°C day in July, you're paying emergency rates AND sweating through 48 hours.
What you'll need
Always step 1. A clogged filter ices the indoor coil within hours of running.
Walk to the outdoor condenser. Remove leaves, branches, grass clippings within 2 ft. Spray the coil gently with a hose from the outside in to clear pollen and dust.
There's a grey weatherproof box mounted on the wall near the outdoor unit. Open it; flip the disconnect to ON.
Switch from HEAT to COOL. Set the thermostat 5°F below current room temperature. Mode: AUTO, fan: AUTO.
Within 60 seconds you should hear the outdoor unit start. Within 5 minutes, the supply registers should blow noticeably cold air.
Hold a kitchen thermometer at a return grille for 30 seconds, note temperature. Hold it at a supply register, note temperature. The supply should be 14–18°F colder than the return after 15 minutes of running. Outside that range = call for service.
When to stop and call
If the AC won't start, the temperature differential is wrong, you hear unusual noises from the outdoor unit, or there's ice anywhere on the line set, book a tune-up. (416) 258-2460.
Open 24/7
Most GTA calls get same-day service. Call, text, or request a fixed quote — we'll come back with a real ETA.
Mississauga, ON · Greater Toronto Area and up to 2 hours out — London, Kitchener, Barrie, Kingston, Niagara.
(416) 258-2460 · 24/7