Air-con not cooling, just blowing air! 5 common causes and easy basic checks you can do yourself

Thailand is hot all year round, so when you switch on the air-con and only get circulating air instead of the cold blast you're used to, it's frustrating. An air conditioner that doesn't cool, or only blows air, is one of the most common home problems. But before you rush to call (and pay) a technician, check the causes and do some basic checks yourself first.

5 common reasons your air-con isn't cooling

An air conditioner that doesn't cool can have many causes, from small things to internal faults. The most common are:

• Clogged dust filter: thick dust build-up blocks the flow of cold air
• Wrong mode on the remote: you accidentally pressed Fan or Dry mode instead of Cool mode
• Outdoor compressor not running: the compressor doesn't cycle, or something is obstructing the condenser unit
• The unit hasn't had a deep clean for too long: the indoor evaporator coil is covered in stubborn dirt
• Refrigerant leak: a leak in the refrigerant pipes stops the temperature dropping

3 steps to check it yourself

You can check and fix a non-cooling air conditioner with these basic steps:

• Check the mode on the remote control: see whether the remote's screen shows the snowflake symbol (Cool mode), and set the temperature to 23-25°C
• Remove and wash the dust filters: open the front panel, take out the air filters, rinse them clean, let them dry completely and put them back — this often makes the air-con noticeably colder straight away
• Inspect the outdoor condenser: go and check whether the outdoor condenser fan is spinning normally, and whether leaves or other things are blocking the airflow

Precautions and signs you should call a specialist

You can do basic checks yourself, but if there's a problem with the electrical system or internal mechanism, never take it apart or repair it yourself, for safety. If you notice signs such as unusual noises, a burning smell, refrigerant leaking, heavy dripping water, or ice forming on the unit, contact an experienced air-con technician to inspect and fix it with proper equipment.