Before you call anyone out, work through this list — the first few fix a surprising number of “broken” aircons.
- Mode: check the remote shows Cool (a snowflake), not Fan, Dry or Heat.
- Temperature: set it lower than the room temperature, e.g. 24 °C.
- Remote and timer: replace the batteries and check no timer or sleep setting is switching it off.
- Filters: clogged filters choke the airflow. Clean them.
- Outdoor unit: is its fan spinning? Clear leaves, plants and anything blocking it.
- Power: check the circuit breaker and the isolator next to the outdoor unit.
- Doors and windows: close them, and the curtains on the sunny side.
- Give it time: a hot room can take 15–30 minutes to cool, longer on a 35 °C afternoon.
- Size: if it has never coped on hot days, the unit may be too small — check the size guide.
- Error code: a flashing light or code on the display points to a fault. Note it down for the technician.
When to call a technician
Call a technician if you see ice on the pipes or the indoor coil, hear hissing or bubbling, see oily marks on the pipe joints, the outdoor unit isn’t running, or the breaker trips. These point to a refrigerant leak, a faulty capacitor, fan or compressor, or a control board problem.
Why is my aircon blowing warm air?
Most often the wrong mode or temperature is set, the filters are clogged, or the outdoor unit isn’t running. If those are fine, a refrigerant leak or a faulty outdoor component is likely — call a technician.
Why is my aircon running but not cooling enough on hot days?
Dirty filters or coils, an outdoor unit in direct sun with poor airflow, or a unit too small for the room. Clean the filters, clear the outdoor unit and compare the room size with the unit’s BTU.
Can low gas stop my aircon cooling?
Yes. An aircon doesn’t use up refrigerant, so low gas means a leak. It should be found and repaired, not just topped up — see regassing.