Aircon Not Cold? Here’s What Could Be Causing It

If your aircon is blowing air, but the room still isn’t cooling — something in the system isn’t working right. Cooling issues don’t fix themselves. And if it’s left unchecked, it often leads to bigger repairs or a full breakdown.

Common Reasons an Aircon Isn’t Cooling Properly

1. Low refrigerant levels

Cooling requires gas. If your system is short on refrigerant (often due to a leak), it won’t cool the air effectively — no matter how long it runs.

2. Dirty evaporator coil

If the indoor coil is choked with dust, heat can’t be absorbed properly. The system runs, but cooling output drops sharply.

3. Clogged air filters

Blocked filters restrict airflow. Less air passes through the coil, which means less cooling reaches the room.

4. Faulty compressor

If the compressor is weak or not activating, refrigerant won’t circulate — and the entire cooling cycle breaks.

5. Frozen evaporator coil

Low gas, airflow blockages, or airflow imbalance can cause the coil to freeze — halting cooling altogether.

6. Electrical or PCB faults

If the outdoor unit isn’t engaging due to a relay, capacitor, or control board fault, the system can’t cool — even if the fan is blowing.

7. Thermostat misreading the room

If the sensor is faulty or exposed to external heat (like sunlight or appliances), it may fail to activate cooling correctly.

8. Blocked vents

Even if the system is cooling, obstructed vents or duct issues can stop cold air from reaching your space.

9. Wrong unit size

If your aircon isn’t sized correctly for the room — especially in open-plan spaces — it may never be able to cool it properly.

What You Can Check First

• Filters: Clean or dusty?

• Thermostat: Set to “cool”?

• Outdoor unit: Running normally or silent?

• Cold air: Ever comes out, or always warm?

These quick checks can help you rule out surface-level issues.

Why It Matters

Weak cooling doesn’t just affect comfort. It stresses the system and can hide deeper faults.

If left unchecked:

• Compressor may wear down

• Gas leaks can worsen

• Energy usage goes up

• Repairs get costlier later

When to Book a Diagnostic

✅ System is running, but not cold

✅ Filters are clean, but no cooling

✅ Outdoor unit isn’t activating

✅ You’ve already serviced it recently, but problem remains

Let us assess what’s really going on — and advise what’s worth fixing.