Still not cold after a service? Here is the honest diagnosis in order — why a filter-wipe isn’t a chemical wash, why gas doesn’t ‘wear out,’ and how to avoid the top-up scam.
This is the query behind most frustrated aircon searches in Malaysia: “kenapa aircond tak sejuk walaupun dah servis” — why is it still not cold when I just had it serviced? The honest answer is uncomfortable: either the “service” you paid for was a shallow filter-wipe that never touched the real problem, or the actual fault was never diagnosed in the first place. A unit that stays warm after a service almost always has one of a handful of causes — a coil that is still clogged, refrigerant escaping through a leak, a tired compressor, or a room the aircon was never big enough to cool. What it is not is refrigerant that “ran out” on its own. Let us work through it in the order a good technician would, so you know what should have been checked. Start with our general aircon repair hub if you have other symptoms too.
Before diagnosing, separate two different complaints that feel the same. Weak airflow is when little air comes out at all — usually a clogged filter or blower. Weak cooling is when plenty of air comes out but it is not cold — a heat-transfer or refrigerant problem. Feel the air at the vent: strong but warm points one way (cooling fault); a feeble trickle points another (airflow fault). Then feel the two copper pipes at the outdoor unit — on a properly cooling system one is cold and one is warm. These thirty-second checks tell a technician, and you, whether to look at cleanliness, refrigerant, or the compressor, and they are exactly the checks a real diagnosis starts with rather than reaching for a gas bottle.
“Not cold” has a short list of real causes. A proper diagnosis runs them roughly in this order — cheapest and commonest first:
| Cause | Tell-tale sign | Honest fix |
|---|---|---|
| Clogged filter | Weak airflow; easy to see when you slide it out | Wash the filter — free |
| Dirty coil & blower | Airflow ok-ish but never cold; musty smell | Proper chemical wash |
| Low refrigerant (a leak) | Ice on the pipes, hissing, cools then fades | Find & repair the leak, then re-gas |
| Weak / failing compressor | Outdoor unit runs but no real cooling; age | Test; repair or replace decision |
| Faulty capacitor / fan | Outdoor fan not spinning properly | Replace the part |
| Undersized unit / hot load | Cools a bit but never wins against the room | Right-size or reduce heat load |
Notice where “top up the gas” sits: only under a confirmed leak, and only after the leak is fixed. Anywhere else on this list, gas is not the answer.
The commonest reason an aircon is still warm after a “service” is that the service was the wrong depth. A cheap RM30–RM40 job typically means washing the filters and wiping the cover — useful upkeep, but it does not touch the mould-and-dust layer caked onto the evaporator coil and blower, which is what actually blocks the cooling. That layer only comes off with a chemical wash, where the coil, fan and drainage are flushed with a proper cleaner. If your unit was “serviced” and is still warm, the honest question to ask is whether a real chemical wash was done or just a filter rinse. In plenty of cases, the correct chemical wash restores full cooling on its own — no gas, no parts.
Here is the single most profitable myth in the aircon trade: that refrigerant “wears out” or gets “used up” and needs regular topping up. It does not. An air conditioner is a sealed system — the same refrigerant circulates round and round for the life of the unit, the way coolant sits sealed in a fridge you never “refill.” So if your aircon is genuinely low on gas, it is not because the gas expired; it is because there is a leak letting it escape. Topping up without finding and fixing that leak is pouring water into a bucket with a hole: it cools for a few weeks or months, then fades, and you are called back for another paid top-up. A top-up is not a repair — it is a symptom being sold to you on repeat.
Because these two get deliberately confused at your expense, here is how to tell them apart honestly:
| Sign | Points to a clean (chemical wash) | Points to a refrigerant leak |
|---|---|---|
| Smell | Musty, damp, sour | No particular smell |
| How it lost cooling | Slowly, over many months | Faded after a recent re-gas |
| Ice | Rare | Ice forming on the pipe or coil |
| Drainage | Dripping water inside | Dry |
| Proof required | Visibly dirty coil / blower | Pressure-gauge reading you can see |
The golden rule: never pay for gas without seeing the pressure gauge, and never accept a top-up without the leak being found. If the coil is filthy, you need a wash, not gas. If the gas is truly low, you need a leak repair, not a repeat top-up.
When the coil is clean and the gas is correct but the room still will not cool, attention turns to the outdoor unit. A failing compressor — the pump at the heart of the system — can run without producing real cooling, and a worn start capacitor can leave the compressor or outdoor fan unable to do its job. These are diagnosed by testing, not guessing, and they matter for your wallet: a capacitor is a modest part, while a dead compressor on an older unit is the point where replacing the whole aircon often makes more sense than repairing it. An honest technician tests before condemning, and tells you plainly which side of that line your unit is on.
A unit that is both warm and dripping is usually not two faults but one story: it is badly clogged. The same mould-and-dust build-up that blocks the coil’s cooling also blocks the drainage tray, so the unit stops cooling and starts overflowing. A proper chemical wash that flushes both the coil and the drainage typically fixes both at once. One caution before you blame the aircon for a wet ceiling: what looks like an aircon leak can be a building leak entirely unrelated to the unit — our aircon leak vs pipe leak guide shows how to tell, and if the water is coming from the unit above yours, the neighbour dripping guide covers responsibility.
Sometimes the aircon works perfectly and still loses — because it was never big enough for the room, or the room throws too much heat at it. A unit rated for a small bedroom cannot cool a large open-plan living area, a west-facing room baking in the afternoon sun, or a space packed with people and electronics. The tell is a unit that runs constantly, cools a little, but never reaches the set temperature. The fixes are practical: right-size the unit for the space, cut the heat load with curtains or by sealing gaps, or add capacity. Choosing the correct type and size in the first place is covered in our aircon types guide — because no amount of gas or cleaning will make an undersized unit win against a hot room.
One more misdiagnosis worth naming: on a humid day the copper refrigerant pipe can “sweat” — condensation forming on the pipe’s surface — and drip, which owners sometimes read as a cooling fault or a gas problem when it is neither. It usually points to worn or missing pipe insulation rather than anything wrong with the cooling itself. It is a small fix, but it is a good example of why a proper look beats a guess: the same wet patch can be pipe sweating, a drainage overflow, or a building leak, and each has a completely different cure. Our aircon leak vs pipe leak guide untangles which is which before anyone spends.
The right fix for “not cold” depends on the actual cause, so the cost does too (market estimate 2026, indicative Klang Valley):
| Fix | Indicative price | When it’s the answer |
|---|---|---|
| Filter wash | Free / part of a service | Weak airflow from a clogged filter |
| Chemical wash | RM130/unit (our flat offer) | Dirty coil & blower — the commonest cause |
| Capacitor replacement | RM120 – RM280 | Outdoor fan or compressor won’t start properly |
| Refrigerant leak find & repair | RM300 – RM800 | Confirmed leak — fix it, then re-gas |
| Compressor | Quoted after inspection | Tested-weak compressor on an older unit |
A bare gas top-up is often pitched at RM80–RM200 — but if there is no confirmed leak, that is money spent on a symptom. Fix the cause and you fix it once.
The “not cold” complaint is where the gas-top-up scam does its best business, so a few habits pay for themselves. Insist on a diagnosis before a price — a technician who reaches for gas before checking the coil and the gauge is guessing at your expense. Ask to see the pressure-gauge reading before agreeing to any refrigerant charge. Be sceptical of “too cheap” service ads that recoup their margin on surprise add-ons. And choose a contractor who quotes a flat, all-in price up front, so there are no mid-job surprises. If the honest fix is a wash, that is what you should be charged for — not a phantom top-up. The same principle runs through our chemical service guide.
ClickBina diagnoses and fixes aircons that will not cool across Kuala Lumpur and Selangor — checking the coil, the airflow and the pressure gauge before anyone mentions gas, and telling you plainly whether you need a clean, a leak repair, a part, or simply a better-sized unit. No fake top-ups, no scare tactics, one flat price. Whether it is an overdue chemical wash or a genuine repair, it is one team and one WhatsApp thread, and you can plan the budget with our free cost tools. Send us a photo of the unit and tell us what it is doing — we reply within the hour with the honest cause.
Tell us what you need — we reply within the hour.