5 Signs Your Aircon Needs Replacing

The common advice is to replace an aircon after a certain number of years. That is a rough guideline, not a rule. A well-maintained unit in a lightly used room can last well beyond typical expectations. A poorly maintained unit in a room with heavy heat load may struggle much sooner. The signs below are more reliable than counting birthdays.

What matters is the pattern: how often the unit needs repair, how much each repair costs relative to a new unit, and whether the unit still does its job. A single expensive repair on an otherwise healthy system is different from a string of repairs on a system that keeps finding new ways to fail.

One repair in a year is normal. Two related repairs — for example, a capacitor followed by a compressor issue — might be coincidence. But three or more different repairs within a year suggests the system is deteriorating broadly, not failing at one point. When multiple components start going, the next failure is rarely far behind.

Track what has been repaired and when. If the list grows every quarter, each new repair is buying less time. At some point, the cumulative repair spend over the past year approaches or exceeds a significant fraction of a new installation cost. That is the practical crossover point.

Units running on R22 refrigerant are living on borrowed time. R22 is being phased out globally, and supply in Singapore has been declining. Topping up R22 is increasingly expensive, and finding replacement parts for R22 systems is harder each year. If your unit uses R22 and develops a leak, the cost of repair plus gas top-up may not make economic sense.

Newer systems run on R32, which is more efficient and more readily available. Switching from R22 to R32 usually requires new piping as well as a new unit, so this is not a like-for-like swap. Factor in the full installation cost when comparing against another R22 repair.

An aircon that has been regularly serviced should maintain roughly stable efficiency. If electricity bills climb over successive billing periods with no change in usage or tariff rates, the unit is working harder to produce the same result. This is especially true if the compressor runs continuously without cycling off — a sign that it can no longer match the room's cooling demand.

Comparing your current unit's energy label with what is available on the market can be revealing. The efficiency gap between a unit from a decade ago and a current five-tick inverter model is large enough that the electricity savings alone can offset a meaningful portion of the replacement cost over the system's life.

A general service or chemical wash should restore most of a unit's cooling performance if the issue is dirt-related. If the unit has been serviced, the coil is clean, the gas charge is correct, and the room still does not cool properly — the compressor itself may be losing capacity. A compressor that cannot maintain adequate discharge pressure will underperform regardless of how clean the rest of the system is.

This is the point where a diagnostic visit matters more than another service. Measuring the compressor's amp draw and comparing it to the rated value tells a technician whether the compressor is still performing within spec. If it is not, the choice is between a compressor replacement and a full system replacement — and for older units, the latter is usually the better investment.

The outdoor unit sits exposed to rain, humidity, and in coastal areas, salt air. Over time, the condenser coil fins corrode and lose their ability to release heat efficiently. Surface corrosion on the casing is cosmetic, but corrosion on the coil fins or copper tubing is functional damage that cannot be reversed with cleaning.

If the condenser coil has significant fin corrosion — fins crumbling when touched, white powder on copper joints, or visible pinhole leaks — the outdoor unit is near end of life. Replacing just the outdoor unit is possible in some cases, but if the indoor units are similarly aged, a full system replacement avoids the risk of mismatched components and staggered failures.