LG CH38 error in Bukit Panjang: a loose fitting, not corrosion
CH38 on an LG system flags refrigerant pressure below normal, and repeated occurrences usually point to an active leak. Gradual fading over several months, on a nine-year-old cassette, invited an easy assumption: the unit was simply old and due for full replacement.
By Team Snowflake | Reviewed 11 Jul 2026
Case summary
LG Cassette9 years oldCondoBukit Panjang, Singapore
- Concern
- The homeowner expected a quote for a full system replacement, assuming a nine-year-old unit fading like this was simply worn out.
- Previous advice
- Homeowner expected a quote for full system replacement, assuming the unit's age was the cause
- Found
- A loose flare-nut connection at an outdoor pipe joint, not corrosion
- Key check
- A pressure test confirmed low refrigerant, then each outdoor connection was checked by hand. One flare-nut fitting turned slightly and had worked loose, with no staining or corrosion anywhere on it
- Result
- Cooling returned to normal after the retightened joint held and the recharge settled. The CH38 code cleared and did not return. No parts were replaced, and the system was not swapped out.
What we were told
The unit had been cooling less well for a few months, not suddenly, just a slow fade. The CH38 code came on, and the age of the unit made a full system replacement feel like the obvious next step before any other cause was checked.
What we checked
A gradual fade with a CH38 code usually means a leak. Age alone does not say where. Rather than assume the unit had reached the end of its life, the pipe connections were checked first: a leak can come from ordinary wear on a fitting just as easily as from corrosion.
A pressure test confirmed refrigerant had dropped below the normal range, matching the CH38 code.
Every outdoor pipe connection was checked closely for corrosion: staining, green marks, or pitting.
One flare-nut connection could be turned slightly by hand, showing it had worked loose, while the fitting itself showed no staining or damage.
The indoor unit joints and the rest of the piping tested tight and dry, narrowing the leak to that single loose connection.
What we found
The flare-nut connection had gradually worked loose over years of ordinary vibration and the everyday expansion and contraction of the pipework as the system cycled on and off. There was no corrosion or staining anywhere on the fitting: this was a mechanical loosening, not a material failure. A small, steady gap had opened at the joint, enough to let refrigerant escape slowly and trigger the CH38 code as pressure dropped.
What fixed it
Because the joint itself was sound and only loose, the fix was to retighten the flare-nut connection to the correct fit and recharge the system, rather than replace any parts. Full system replacement was not needed: nothing had failed, and nothing had corroded. We also advised checking the same style of connection on other outdoor units of similar age, since ordinary loosening from vibration can happen anywhere a fitting was never revisited.
Outcome
Cooling returned to normal after the retightened joint held and the recharge settled. The CH38 code cleared and did not return. No parts were replaced, and the system was not swapped out.
What this case teaches us
A fading LG unit is not always corrosion, or the end of its life
- A CH38 code means low refrigerant, not automatically corrosion. Ask whether the leak point was actually found before agreeing that an older unit needs full replacement.
- A fitting can work loose from years of ordinary vibration and everyday temperature cycling alone, with no corrosion or staining anywhere on the joint.
- A loose fitting is a straightforward, cheaper repair. Ask where exactly the leak was traced before approving a quote for a full system swap.
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