Living in Malaysia means we use air conditioners every day. If your aircon is running but the room is still warm, itโs frustrating โ and usually fixable. Below are the 10 most common causes your aircond might not be cooling, explained in simple language, with easy steps you can try right now. If you want a quick professional check, book a trusted aircond service in Malaysia with AC Fix. (They can diagnose the problem and give a clear quote)
How to use this guide
Read the short cause list first. Try the easy fixes (like cleaning the filter) before calling a technician. If you see ice, hear loud noises, or smell gas, stop and call a trained technician right away.
1. Thermostat is set wrong
What you see: Unit runs but temperature wonโt drop.
Why: The remote might be on FAN only or the temperature is set too high.
Try this: Put mode to COOL and lower the set temperature by a few degrees. Replace remote batteries if needed.
2. Dirty air filter
What you see: Weak airflow or musty smell.
Why: Dust and dirt block the filter so cold air canโt get through.
Try this: Remove the filter, wash with water, dry fully, and reinstall. Do this every 1โ3 months.
3. Blocked outdoor unit (condenser)
What you see: Leaves, trash, or plants near the outdoor box.
Why: The outdoor unit must release heat; if blocked, the system canโt cool well.
Try this: Clear at least 50 cm around the unit and remove debris.
4. Low refrigerant (gas leak)
What you see: Gradual loss of cooling and sometimes ice on pipes.
Why: The system has lost refrigerant and canโt make cold air.
Try this: Donโt try to refill gas yourself. Contact a licensed technician to locate leaks and recharge safely.
5. Frozen evaporator coil
What you see: Ice on the indoor coil or vents; long run times but no cool air.
Why: Poor airflow or low gas causes the coil to freeze.
Try this: Turn off the AC to thaw. Clean filters and get a technician if it happens again.
6. Fan or compressor failure
What you see: Loud buzzing, humming, or the outside unit not running.
Why: The fan or compressor may be damaged or not receiving power.
Try this: Power down the unit and call a professional โ these parts need expert repair.
7. Wrong mode (Fan, Dry, Auto)
What you see: Air is moving but not cold.
Why: Modes like FAN or DRY donโt run the compressor the same way COOL does.
Try this: Set to COOL and fan to AUTO or MEDIUM.
8. Room is too hot or poorly sealed
What you see: Sun beating in through windows, open doors, or many heat sources.
Why: Hot air keeps entering the room faster than the AC can cool it.
Try this: Close curtains during midday, keep doors closed, and seal big gaps.
9. Unit is old or too small for the room
What you see: AC runs long but never reaches the set temperature.
Why: An underpowered or very old unit canโt handle the room size or heat load.
Try this: Consider replacing with a correctly sized, energy-efficient model.
10. Electrical or control board problems
What you see: Error codes, tripped breakers, or sudden shutdowns.
Why: Wiring, fuses, or the control board might be faulty.
Try this: Check the breaker; if itโs fine, call a certified electrician or AC technician.
Quick maintenance tips (do these now)
- Clean or replace filters every 1โ3 months.
- Keep the outdoor unit clear of debris.
- Use curtains or blinds to cut direct sunlight.
- Turn off heat-producing devices when possible.
- Schedule a full service (chemical cleaning) yearly in humid areas.
Before you decide on repairs or replacement, compare quotes โ you can also check aircond service at AirCond Care for a second opinion.
When to call a technician
Call a technician if:
- Ice keeps forming, or you suspect a refrigerant leak.
- The outdoor unit wonโt run or you hear loud mechanical noises.
- You see electrical issues like tripped breakers or error codes.
Professionals protect your warranty and handle dangerous tasks safely.
Frequently Asked Questions (FAQs)
Q: How often should I service my aircon in Malaysia?
At least once a year; every 6 months is better if you run it daily or live in a dusty area.
Q: Can I refill refrigerant myself?
. Refrigerant must be handled by licensed technicians.
Q: Why does my AC freeze?
Usually from poor airflow (dirty filter) or low refrigerant.
Q: Will a bigger AC always cool faster?
A correctly sized AC is best. Too big can short-cycle and cause problems; too small will run constantly.
Q: Why is my outdoor unit hot after running?
Itโs normal for the condenser to be warm as it releases heat, but it shouldnโt be extremely hot to touch.
Q: Does closing doors help?
Yes โ sealing the room keeps cool air in and reduces workload on your AC.
Q: When should I replace the unit?
Consider replacement if itโs over 10 years old, breaks often, or uses much more electricity than before.
