Common Air Conditioning Issues and How to Identify Them

Even a reliable air conditioner can run into problems over time. Some are simple fixes; others need a professional. Here's how to tell the difference.

Dirty air filters

Signs: low airflow, poor air quality, higher energy bills. A clogged filter makes the system work harder. Check and replace filters regularly, especially during heavy use.

Frozen evaporator or condenser coils

Signs: ice on the coils, insufficient cooling. Turn the unit off to thaw, check for dirty filters, and if it recurs, get refrigerant levels checked professionally.

Refrigerant leak

Signs: bubbling or hissing noises, a sudden drop in cooling, higher bills. Refrigerant should only ever be handled by a licensed technician.

Thermostat problems

Signs: won't turn on, short cycling, not reaching set temperature. Check settings and batteries first before assuming it needs replacing.

Electrical issues and circuit breakers

Signs: won't turn on or stops suddenly, tripped breaker, unusual noises. Try resetting the breaker; if it keeps tripping, have a technician check the wiring.

Fan problems

Signs: low airflow, unusual noises, unit running but not moving air. Often a worn belt, debris or a failing motor.

Water leaks

Signs: water near or leaking from the indoor unit. Usually a blocked drain line or pan, or coils that have frozen and melted. Left unfixed, this can lead to mould.

Unpleasant odours or strange noises

Usually dirty filters, mould or a mechanical fault. Replace filters and clean coils first; if it persists, get a professional to check for mechanical issues.

Running constantly or short cycling

Often a thermostat issue, low refrigerant, or a system that's the wrong size for the space. Worth getting the sizing checked if the basics don't fix it.