Air conditioner not cooling: what to check and when to get help
An air conditioner that runs but does not cool is often affected by something simple, such as the wrong mode, a clogged filter or blocked airflow. If those checks change nothing, the cause is usually inside the system, for example the refrigerant circuit or a component, and needs a qualified technician.
How this usually shows up
- The AC is on but the room stays warm
- Air from the unit is only slightly cool or warm
- The outdoor unit is not running
- The unit switches on and off repeatedly
- Ice on the indoor unit or the pipes
What may be happening
These are possibilities, not a diagnosis. Someone needs to see the problem to know which applies.
- Wrong settings
- The unit may be in fan, dry or heat mode, or the set temperature may be close to the room temperature.
- Dirty air filter
- A clogged filter restricts airflow and can reduce cooling. In bad cases the indoor coil can freeze.
- Blocked airflow at the outdoor unit
- Leaves, dirt or objects around the outdoor unit make it harder for the system to release heat.
- Power or tripped breaker
- Part of the system may not be getting power, for example the outdoor unit.
- A fault inside the system
- Possibilities include a refrigerant leak or low refrigerant charge, a failed fan or compressor, or a control fault. These need specialist diagnosis.
- A unit that is too small for the space
- A unit that is too small for the room, or a room with a lot of sun or heat, may struggle in hot weather.
What you can safely check
- Check the mode is set to cool and the temperature is set clearly below the room temperature.
- Replace the remote control batteries if the unit does not respond.
- Close windows and doors in the room.
- Only if your unit's manual describes user filter cleaning: switch the unit off with the remote and follow the manual exactly. Let the filter dry fully before refitting.
- Look at the outdoor unit from a distance. Check that nothing is blocking the air around it and that the fan is turning when the unit is on.
- If the unit has no power at all, note whether its breaker looks switched off, and tell us. Please do not keep switching it back on.
- Note what you see and hear, and take a photo or short video. It helps whoever looks at the unit.
- Do not open the unit or its panels.
- Do not handle refrigerant, gas kits or refrigerant pipework. This is specialist work.
- Do not spray water on the electrical parts of the unit.
- Do not keep resetting a breaker that trips.
When to get professional help
- The filter is clean and the settings are right, but the air is still not cool.
- There is ice on the indoor unit or on the pipes.
- The outdoor unit does not start, makes unusual noises or the breaker keeps tripping.
- You notice a burning smell, smoke or sparking, or water near electrical parts. Keep clear, switch the unit off with its remote or normal off switch only if that is safe, and call 112 if there is any danger.
- The system has been losing cooling gradually over time.
How BB Cyprus can help
Send BB Cyprus a request with what the unit is doing, the brand if you know it, and a photo or short video. We review it, phone you back and tell you the appropriate next step. You get a written quote before any work starts.
This is part of our air conditioning work.
BB Cyprus, also known as Bits&Bobs Cyprus, handles home repairs and property maintenance in Nicosia, Limassol, Larnaca. You do not need to know which trade you need.
Related problems
This page is general information, not a diagnosis. Every property is different, and electrical, refrigerant and pressurised-system work should be done by a qualified professional.