How often should you top up aircon gas in Singapore?

Aircon gas top-up is not like filter cleaning or routine servicing. A sealed refrigerant system is not supposed to lose gas during normal operation.

That means there is no normal calendar interval for topping up gas as preventive maintenance. If refrigerant pressure is dropping, the system needs a reason, not a schedule reminder.

The better question is not how often. It is why pressure dropped and whether the cause has been fixed.

From the room side, weak cooling often gets simplified to low gas. When a top-up temporarily restores cooling, it can look like the problem was solved even if the underlying leak is still there.

That short-term improvement leads some homeowners to believe top-up is a recurring maintenance item. In reality, repeated top-ups often mean the same cause is being paid for repeatedly.

This is also why case studies around repeat top-up loops are useful: they show how a leak path can hide behind temporary cooling improvement.

A gas top-up can be legitimate when it is part of a confirmed repair path. If a leak was identified and repaired, restoring refrigerant is part of bringing the system back to proper operation.

It may also be part of work on the refrigerant side of the system where charge restoration is expected after the repair process.

The difference is that in these cases, top-up is not routine maintenance. It is a step within a specific repair scope tied to diagnosis.

If cooling improves after a top-up and then fades again, especially with the same complaint pattern, the top-up is likely acting as a temporary refill instead of a lasting fix.

If different contractors keep recommending top-up without explaining a leak path, that is another sign the diagnosis is not being closed properly.

At this point, the right next step is leak-focused diagnosis and repair planning, not another scheduled refill.

Treat gas top-up as a diagnosis-linked action, not a maintenance interval. Ask what checks are being used to confirm low refrigerant pressure and what likely cause is suspected.

If this is not the first top-up recommendation, ask for leak tracing and a cause-based explanation before approving more refrigerant work.

Keep routine maintenance and refrigerant diagnosis separate in your mind. General servicing can be scheduled. Gas top-up should be justified.