Recurring gas top-ups stopped after pinhole leak found at flare joint

What we found

Recurring gas loss at regular intervals points to a slow leak rather than compressor failure. We pressure-tested the system to find the leak path instead of topping up again.

• System pressure dropped steadily during the hold test — confirming an active leak somewhere in the refrigerant circuit
• Leak detection at the indoor flare connection showed gas escaping at the joint where the copper pipe meets the indoor unit
• The flare joint had a visible gap — it had not been properly sealed during the original installation
• Compressor pressures and electrical readings were within normal range — the compressor was not failing

The indoor flare connection had never been properly sealed when the unit was first installed. A small gap at the joint allowed refrigerant to escape slowly. Each gas top-up temporarily restored the charge, but the gas leaked out through the same gap within weeks. The compressor was in good working condition — it was simply running on insufficient gas each time the charge dropped.

What we did

GOOD NEWS — the compressor was not failing. The recurring gas loss was caused by a pinhole leak at the indoor flare joint. We repaired the joint, sealed it properly, and recharged the system. No major parts were needed.

After the flare joint was repaired and the system recharged, cooling returned and held. The client no longer needed repeat gas top-ups. The compressor and all other components continued operating normally.

What we learned

Why gas top-ups keep failing — the leak that top-ups cannot fix.

• Pressure-testing the sealed system identifies where the gas is escaping. Once the leak is repaired and the system is recharged, the gas level holds and the top-up cycle stops.
• A gas top-up restores cooling temporarily by replacing the lost refrigerant. But if there is a leak in the system, the gas escapes again through the same path. The cooling fades, the top-up is repeated, and the cycle continues.
• Flare joints are the most common leak point on split-system aircons. The indoor and outdoor connections rely on a tight mechanical seal. If the flare was not properly formed or tightened during installation, it can develop a slow pinhole leak that loses gas over weeks rather than days.