If your air conditioner is not cooling, leaking water, smells bad, or making unusual noise, this troubleshooting page helps you quickly identify the most likely cause and choose the correct fix path.
In Kuala Lumpur’s hot and humid climate, aircon issues are most often related to airflow restriction, internal dirt buildup, drainage problems, or coil condition. Electrical and refrigerant issues also occur, but less frequently.
This page is designed to help you avoid the wrong service and start with correct diagnosis.
Start here — diagnosis first
If you are not sure what the real issue is, always begin with troubleshooting.
Correct diagnosis helps prevent unnecessary repairs and repeat problems.
From here, you can:
- identify the symptom
- understand the most common causes
- move to the correct repair or cleaning solution
Common aircon problems (by symptom)
Cooling & airflow issues
- Aircon Not Cold — the unit is running but the room stays warm or cools very slowly
- Weak Airflow — air comes out, but the volume feels low
- Ice on Coil — ice or frost appears on the indoor unit
- Blowing Warm Air — warm air instead of cold air
- High Electric Bill — sudden increase in electricity usage with poor cooling
Water & drainage problems
- Water Leaking — visible water leaking from the indoor unit
- Indoor Unit Leaking — water coming from the unit body or drain pan
- Water Dripping — continuous dripping during operation
- Drain Pipe Clogged — blocked drainage line causing overflow
Smell, mould & hygiene
- Bad Smell — musty or sour smell when the aircon is running
- Mold Issue — recurring smell or visible mould growth inside the unit
Noise, vibration & shutdown
- Making Noise — rattling, buzzing, clicking, or grinding sounds
- Vibration Issues — shaking, humming, or imbalance
- Overheating Shutdown — unit stops after running for some time
Electrical & control issues
- Not Turning On — no response when switching on
- Trips Breaker — breaker trips when the aircon starts
- Remote Not Working — remote control does not respond
- Error Codes — error code shown on the indoor unit display
Refrigerant & outdoor unit
- Gas Leak — cooling performance gradually drops over time
- Outdoor Unit Not Running — outdoor fan or compressor not operating
Note: Refrigerant does not normally “run out”. If gas is low, a leak check is required before refilling.
Safe checks before calling a technician
Before booking a service, you can safely check the following:
- Confirm the unit is in COOL mode and temperature is set lower than room temperature
- Clean and fully dry the indoor air filters
- Make sure the outdoor unit has clear airflow and is not blocked
- If ice is visible, switch the unit OFF and allow it to fully defrost
Do not open panels or touch wiring. Electrical symptoms require professional inspection.
When to stop troubleshooting and book service
Stop troubleshooting and contact a technician if you notice:
- burning smell, sparks, or repeated breaker trips
- outdoor unit not running or very loud abnormal noise
- persistent leaking, icing, or no cooling after basic checks
- error codes that return after reset
These symptoms indicate faults that should not be ignored.
Recommended fix paths (based on diagnosis)
Depending on the symptom and diagnosis, the correct service may include:
- aircon repair for cooling, leaks, noise, or electrical faults
- chemical wash for bad smell, weak airflow, or internal dirt buildup
- full servicing for maintenance-related performance issues
Diagnosis always comes before choosing the service.
Need help in Kuala Lumpur?
If you need assistance, message us with:
- your KL area
- aircon type (wall-mounted or cassette)
- main symptom from the list above
- how long the issue has been happening
This helps route the correct technician and reduces unnecessary work.