Why your aircon isn’t cold — common AC issues and how you can fix them

If your air conditioner is not cold, there could be several reasons affecting its performance, ranging from minor issues like incorrect settings to more serious mechanical failures. Understanding the possible causes can help you troubleshoot the problem efficiently.

One common reason is incorrect temperature or mode settings. Sometimes, the aircon might be set to fan mode instead of cooling mode. In such cases, the air conditioner will only circulate air without cooling it. To fix this, ensure that the mode is set to “Cool” and the temperature is lowered to around 23–25°C for optimal cooling.

Dirty Aircon Filter

Dirty or clogged air filters cause poor cooling performance in an aircon. Carry out routine aircon cleaning at least once every quarter. Unplug your air-con, take off the front cover grille, and remove the filter. Soak it in soapy water for 5 to 10 minutes. Rinse and let it dry,

If you have indoor pets, especially dogs and cats with long hair, you may need to clean the filter more often than every three months, even if you don’t have allergies. Pet hair can clog a filter – and eventually the indoor coil – faster.

Better yet, examine the aircon filter on a monthly basis to see if cleaning is necessary. Replace the aircon filter if dirt can no longer be washed or brushed off, if filter particles come loose, or if it has many holes.

Dirty Aircon Condenser Coils

It’s a good idea to brush dirt and debris off evaporator and condenser coils on a yearly basis, or at the start of the hot months. Use a fin comb (the this can be purchased from air conditioner wholesalers) to straighten the aluminum fins and prevent them from bending and blocking airflow. If the air-con coils are located outdoors, keep the area around them clean, and trim any foliage to ensure adequate airflow.

Aircon Compressor

Sometimes, the problem lies with the compressor, which is responsible for circulating refrigerant through the system. If the compressor is faulty, the aircon will struggle to cool the air effectively. A malfunctioning compressor typically requires professional repair or replacement.

Faulty Thermostat Sensor

In some cases, a faulty thermostat sensor may cause improper temperature regulation. If the sensor is misaligned or damaged, the aircon might stop cooling too soon or not function efficiently. Checking if the sensor is positioned correctly near the evaporator coil and adjusting it if necessary can resolve this issue.

Aircon Capacity Too Small

Another factor to consider is whether your aircon is too small for the room size. If the unit’s BTU capacity is too low, it will struggle to cool a large space effectively. Ensuring that your air conditioner has the appropriate capacity for your room size can help maintain a comfortable temperature.

Blocked Air Vents

Additionally, insufficient airflow due to blocked vents can impact cooling performance. Obstructed air vents or closed doors may disrupt proper air circulation, making it harder for the aircon to distribute cool air evenly. Keeping air vents clear and allowing proper ventilation can help improve cooling efficiency.

Electrical Problems

Lastly, electrical or internal component issues such as a faulty capacitor, damaged wiring, or an internal board failure can cause the aircon to stop cooling. If none of the above solutions work, it is best to contact a professional aircon technician for a thorough inspection and repair.

Noisy Aircon

Are you bothered by a noisy air-conditioner? Some air-con noises are perfectly normal, such as a sudden thumping noise when you turn on the unit, or a buzzing sound when the fan starts up. Other noises may require professional service to check out.

A screeching sound can indicate a compressor glitch, a loose belt, or worn out bearings, while frequent popping or cracking noises may point to a problem in the air ducts.

A hissing sound that lasts for a few seconds means the refrigerant is expanding, so it’s not a cause for concern. But loud or frequent hissing is a serious problem – there may be excess pressure inside the compressor or a leak in the internal valve. When it doubt, it’s always best to call a trained technician.

This article was originally published in Home & Decor.