Aircon Not Cold? Same-Day Diagnosis in Singapore

Why Is Your Aircon Not Cold?

When your aircon is running but not cooling the room, something is preventing the refrigeration cycle from working properly. As a trusted provider of aircon servicing in Singapore, we see this issue regularly. Here are the most common causes our technicians find in Singapore homes, from the simplest to the most serious.

1. Dirty Air Filter

The most common and easiest fix. A clogged filter blocks airflow over the evaporator coil, reducing cooling capacity. If you have not cleaned your filter in the past month, this is likely your problem.

DIY check: Remove the front panel and slide out the filter. If it is visibly covered in dust, rinse it under running water and let it dry before replacing.

2. Low Refrigerant Gas

If your aircon is blowing slightly cool but not cold air, it may be low on refrigerant gas. This happens when there is a slow leak in the piping or joints. Signs include ice forming on the copper pipes and the compressor running continuously.

Fix: A gas top-up restores cooling. If gas depletes again quickly, leak detection is needed to find and seal the source.

3. Dirty Evaporator Coil

Even if the filter is clean, the evaporator coil behind it can accumulate dirt over time, forming an insulating layer that blocks heat absorption. A chemical wash is needed to clean the coil thoroughly.

4. Blocked Condenser Coil (Outdoor Unit)

The outdoor condenser needs to release heat. If it is clogged with dirt, leaves, or debris, the system cannot expel heat effectively and cooling performance drops. Our technicians clean the condenser as part of our diagnostic process.

5. Faulty Thermistor Sensor

The thermistor monitors room temperature and tells the aircon when to cycle on and off. A faulty thermistor can give incorrect readings, causing the unit to stop cooling before the room reaches the set temperature. Learn more about aircon thermistors.

6. Compressor Failure

The compressor is the heart of your aircon system. If it fails, the unit will blow air but with no cooling effect. Compressor issues are usually indicated by unusual noises, frequent tripping of the circuit breaker, or the outdoor unit not running at all.

7. PCB Board Malfunction

The Printed Circuit Board (PCB) controls all electronic functions. Inverter error codes, blinking lights, or random shutdowns often point to a PCB issue. Check our guide on AC light blinking for brand-specific error codes.

When to Call a Professional

If you have cleaned the filter and checked the remote settings but your aircon is still not cold, it is time to call a professional. Our technicians use systematic diagnostic checks including pressure gauges, multimeters, and thermal imaging to pinpoint the exact cause — not guesswork.

Most cooling issues can be resolved in a single visit. WhatsApp us at +65 9456 0875 for same-day service.

Our Diagnostic Process

1. Visual inspection of indoor and outdoor units
2. Filter and evaporator coil check
3. Gas pressure measurement using manifold gauges
4. Electrical testing of compressor, capacitor, and PCB
5. Thermistor verification
6. Clear diagnosis and upfront pricing before any repair

All repairs come with our 90-day workmanship warranty. View our complete pricing guide for transparent costs.