Before you book an AC technician, run through this checklist. You might solve the problem yourself — or at least help the technician diagnose it faster when they arrive.

1. Check the thermostat setting

Make sure it's set to "Cool" mode and the temperature is set lower than the current room temperature. Sounds obvious, but it's the most common call our technicians get.

2. Clean or replace the air filter

A clogged filter is the #1 cause of poor cooling. Most filters should be cleaned every 2–4 weeks during heavy use. Remove the front panel, slide out the filter, rinse it under running water, let it dry completely, and reinstall.

3. Check the outdoor unit

Make sure the outdoor unit isn't blocked by furniture, plants, or debris. The condenser needs airflow to work. Also check that the fan is spinning when the AC is running.

4. Check for ice on the coils

If you see ice forming on the indoor unit, turn the AC off and run it in fan-only mode for 30 minutes to let the ice melt. Ice usually forms due to a dirty filter or low refrigerant.

5. Check the circuit breaker

If the AC isn't turning on at all, check your electrical panel. A tripped breaker is an easy fix.

6. Check the remote batteries

Replace the remote batteries. A weak signal can cause erratic behaviour.

7. Check for refrigerant leaks

If the AC runs but doesn't cool, and the filter is clean, you likely have a refrigerant leak. This requires a professional. Book an AC technician — they'll diagnose and refill the gas.