- Why is my aircon running but not cold?
- What can I check myself before calling a technician?
- Does a dirty filter really make the aircon not cold?
- Which symptom points to which cause?
- How do I know if the aircon needs a gas top-up?
- Decide before the next hot afternoon
Why is my aircon running but not cold?
An aircon that runs but is not cold is either not being asked to cool (wrong mode or setting), cannot move enough air (dirty filter, grimy coil, blocked outdoor unit), or cannot move enough heat (low refrigerant, failed capacitor, tired compressor). The first group costs nothing to check.
Cheapest first:
- Remote on Fan or Dry mode, or set temperature too high.
- Flat remote batteries.
- Filters clogged with dust.
- Outdoor unit blocked or baking in afternoon sun.
- Doors open, sun through glass.
- Evaporator coil coated in grime.
- Refrigerant low because of a leak.
- Capacitor, PCB or compressor fault.
What can I check myself before calling a technician?
Check the remote, the filters and the outdoor unit; those three cover the common aircon not cold complaints without tools. Daikin Malaysia's first question for a unit that does not cool the room well is: "Is the temperature and the operation mode properly set by the remote controller?"
Switch off at the isolator before opening any cover, then rinse, dry and refit the filters. Outside, clear anything pressed against the outdoor unit. If the unit is dead rather than weak, check the breaker and batteries.
Does a dirty filter really make the aircon not cold?
Yes. A filter loaded with dust starves the indoor coil of airflow, so the coil gets very cold but the room does not; in bad cases the coil ices over and the air turns warm. Daikin Malaysia recommends cleaning air filters every 2 weeks (troubleshooting page, 2025-09).
Clean filters but weak or musty air means the grime is on the coil. Aircon Hero lists a full chemical service on a wall-mounted unit at RM198 for one unit, RM168 each for two and RM148 each for three or more, with a 1-month service warranty (aircond service page).
Which symptom points to which cause?
Airflow problems feel weak at the vent; refrigerant and electrical problems feel like normal airflow that is simply not cold. That one distinction decides whether you clean first or book a diagnosis; the table below maps the common patterns to a next step.
| Symptom | Likely cause | DIY or technician |
|---|---|---|
| Weak airflow, slightly cool | Dirty filter or coil | DIY: clean filters first |
| Normal airflow, not cold | Low refrigerant or capacitor | Technician |
| Cold for a while, then warm | Coil icing, from a dirty filter or low refrigerant | DIY: clean the filter; technician if it repeats |
| Outdoor fan runs, compressor silent | Capacitor or compressor | Technician |
Electrical faults are quoted after inspection; see common aircon faults, costs and when to call a technician.
How do I know if the aircon needs a gas top-up?
Low refrigerant shows as normal airflow that never gets properly cold, often with frost on the outdoor pipe. Refrigerant is not used up, so a low reading means a leak; a top-up without a leak check buys time, not a repair. A technician confirms it with gauges and a leak detector.
Aircon Hero lists a gas top-up at RM158 for a 1 to 1.5 HP unit, plus RM28 per additional 0.5 HP or RM48 per additional 1 HP, with top-up charged at RM2.50 per psi. Read when a gas top-up is the right fix.
Decide before the next hot afternoon
Do the free checks: mode, batteries, filters, outdoor unit. If it is still not cold, book a diagnostic visit; if the airflow is weak or musty, book a chemical service. Prices are on the Aircon Hero price list, same-day slots across Klang Valley on aircond service near me. WhatsApp +60 18-355 5162 or email [email protected].
Frequently Asked Questions
Sources: Troubleshooting - Daikin Malaysia (2025-09)
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