Coastal unit losing gas again: salt ate through the pipe fitting
Refrigerant does not get used up. Topping up twice in one year means it is leaking out somewhere. Near the sea, the outdoor pipe joints are the first suspect, because salt air thins metal slowly and the leak shows up only as cooling that keeps fading.
By Team Snowflake | Reviewed 10 Mar 2026
Case summary
Samsung Wall-mounted5 years oldCondoSouthern Islands, Singapore
- Concern
- The owner feared an internal compressor leak, which would mean replacing the whole system.
- Found
- Salt-air corrosion had thinned the pipe fitting at the outdoor unit pipe joint, allowing slow refrigerant seepage
- Key check
- Inspected outdoor pipe joints for corrosion damage and tested with leak detector fluid before just topping up gas
- Result
- We replaced the corroded fitting, resealed the joint, recharged the system, and pressure-tested it. The pressure held steady this time, so the gas stayed in. The cycle of repeated top-ups stopped, and the owner avoided a needless system replacement.
What we were told
The aircon has been topped up twice this year and is losing cooling again. The unit faces the sea. A previous contractor keeps refilling the gas and saying everything looks fine, but it never holds for long.
What we checked
Two top-ups in one year with the same fault returning points to a leak, not normal use. A sealed system does not consume refrigerant, so if it keeps running low, gas is escaping somewhere. The seaside exposure made the outdoor pipe joints the first place to look, since salt attacks the exposed metal there.
Gas pressure read low again, confirming the unit was still losing refrigerant.
The indoor coil and its pipe joints were clean, with no sign of leakage. That moved the search outdoors.
The outdoor pipe fitting had visible surface corrosion and pitting, the typical mark of years of salt exposure on coastal units.
Leak detector fluid brushed onto the corroded fitting bubbled up, confirming the gas was seeping there.
What we found
Salty coastal air had slowly corroded the fitting at the outdoor pipe connection over the years. The corrosion thinned the metal wall until gas could seep out through it. Each top-up brought the cooling back for a while, but the leak kept going because the corroded fitting itself was never replaced. The earlier contractor had treated the symptom and missed the cause.
What fixed it
The compressor is sound. The leak is the corroded fitting at the outdoor pipe joint, and that fitting needs replacing. Once the new fitting is installed and the joint sealed, the system should hold its gas normally again. A protective coating on the exposed outdoor fittings can slow future corrosion, which matters for a unit this close to the sea.
Outcome
We replaced the corroded fitting, resealed the joint, recharged the system, and pressure-tested it. The pressure held steady this time, so the gas stayed in. The cycle of repeated top-ups stopped, and the owner avoided a needless system replacement.
What this case teaches us
A repeat gas leak has a source, and near the sea it is usually outside
- Gas that needs topping up twice a year is leaking, not being used up. A top-up alone treats the symptom, so the loss comes back.
- For units facing the sea, ask the technician to inspect the outdoor pipe joints for salt corrosion before anyone refills the gas.
- A corroded fitting can be replaced on its own. That is a far smaller, cheaper job than swapping a compressor or the whole system.
Related reading
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