Troubleshooting · Published 7 September 2026 · By the Trubair technical team
The most common cause of poor cooling. Clogged filters starve the coil of air, reducing cooling and sometimes causing the coil to freeze. Clean them first.
Check the remote is set to cool rather than fan or dry, the set temperature is below room temperature, and any timer is not switching the unit off.
If the outdoor coil is covered in dust or surrounded by clutter, it cannot release heat. Cooling capacity drops sharply on hot days.
Refrigerant does not get used up. If it is low, there is a leak that needs locating and repairing before the system is recharged.
A weak or failed capacitor can stop the compressor or outdoor fan from starting, so the indoor unit blows air that is not cold.
Restricted airflow or low refrigerant can cause ice to form on the indoor coil. Switch to fan mode to thaw it and book a check.
Sometimes the unit simply is not large enough for the room, or years of wear have reduced its performance. A load calculation shows whether replacement makes sense.
If cleaning the filters and checking the settings does not help, switch the unit off and book a repair visit. Running a struggling system can turn a small fault into a costly one.
Book a service and we will take care of everything.
