Air Conditioner Problems: What is Common & When to Service

Like any appliance, air conditioners can develop issues over time, particularly in heavily used or neglected systems. While some problems — such as dirty filters or improper settings — can be easily corrected, others might call for expert servicing to stop more damage or a system breakdown. This guide will go over the most common air conditioner problems, how to troubleshoot them and when it’s best to call a technician.

Common Air Conditioner Problems

Although they are built to be dependable, air conditioners can have issues, particularly if they have not been serviced recently. Among the most often occurring AC unit problems are those relating to general maintenance, airflow or power. Below are a few common air con issues to consider before calling for help:

Disrupted Airflow

Poor airflow is often caused by blocked vents, closed louvres or furniture obstructing the indoor unit. Check that nothing is preventing air from circulating freely and that the fan settings are correct. Adjust the swing/louvre function if airflow feels uneven.

Air Con Not Blowing Cold Air

If your unit is running but not cooling, the cause may be low refrigerant levels or a dirty filter affecting the mode settings. Set the mode to 'COOL' and ensure the temperature is currently lower than the room temperature. If that's all fine, it's a good idea to get a technician to check the internal components or refrigerant. (Learn more about why your Fujitsu air conditioner is not cooling.)

Air Conditioner Not Turning On

If your air conditioner is not working because it doesn’t power on, check both the remote control batteries and the isolation switch near the outdoor unit in case it has been turned off. Another reason may also be a blown fuse or tripped circuit breaker. Book a service call if everything seems to be in order but the unit still won't turn on.

Dirty or Blocked Filters

An often occurring problem is a dirty or blocked air filter. Dust accumulation over time can restrict airflow, lower efficiency and even cause the unit to turn off. Maintaining seamless operation of your system is basically dependent on routinely cleaning or replacing filters. (Read more about how often to clean an air conditioner filter.)

Specific AC Unit Problems

Although most general air conditioner problems are easy to fix, some are more technical and might call for professional help. These usually include the internal parts of your unit, and if they’re not looked at, they could cause long-term damage or affect performance and efficiency. If your system is still not operating as it should be, there are some other issues that it could be:

Refrigerant Leak

Should a refrigerant leak exist, your air conditioner may not be cooling but blowing warm air and running longer cycles, or it could stop cooling altogether. Among the signs are hissing noises, ice buildup on the coils or a clearly diminished cooling capacity. If you suspect you have a refrigerant leak, we recommend you call a qualified technician to find the leak and fix it safely.

Drainage Problems

Condensation generated by your air conditioner should drain away via a hose or pipe. Should the drain line be blocked or misaligned, water can back up into the unit and cause leaks, mould growth or even damage to electrical components. Common red flags are musty smells or watermarks around the indoor unit. If you suspect you have a drainage problem, we recommend you call a qualified technician.

Sensor Issues

Usually found near the evaporator coil, most air conditioners feature a temperature sensor to assist system control. Should the sensor fail or become displaced, it could lead to irregular cycling or cause the unit to lose its ability to keep the set temperature. This might be a challenge for you to identify, so give a technician a call to take a look and if it is, then it should be an easy fix.