Quoted $2,000 for Compressor: Turned Out to Be a Pipe Leak
Aircon case in Bedok, Singapore: cooling loss traced to refrigerant leak at corroded outdoor unit connections — compressor was functional after targeted diagnosis checks.
Case Details
| Unit | LGWall-mounted |
|---|---|
| Age | 5 years old |
| Location | HDBBedok, Singapore |
| Reported | Previous contractor diagnosed compressor failure and quoted over $2,000 for replacement. System is only five years old. A second opinion was requested before committing to that cost. |
What We Checked
- Refrigerant pressure was critically low — well below the range needed for the compressor to operate.
- Outdoor unit pipe connections showed corrosion and green oxidation.
- Bubble test confirmed an active leak at the gas line connection on the outdoor unit.
- Indoor unit flare joints showed no signs of leakage.
- LG error code CH35 was active, indicating low-pressure protection — the compressor was shutting down to protect itself, not because it had failed.
The Diagnosis
The compressor was not faulty. It had shut down because refrigerant pressure was too low for safe operation — a built-in safety mechanism. The actual cause was a gas leak at the corroded outdoor unit pipe connections. The previous contractor appears to have tested the compressor while the system was low on gas, found it would not start, and concluded it had failed. A compressor cannot run without adequate refrigerant. Once the leak was sealed and the system recharged, the compressor started and operated normally.
What Fixed It
We explained that the compressor was protecting itself from running without sufficient refrigerant. The fix was to seal the gas leak at the outdoor connections, recharge the system, and test the compressor under normal operating conditions. We welded the corroded connection, recharged the refrigerant, and confirmed the compressor ran with normal current draw and pressure readings. No compressor replacement was needed. We recommended monitoring the welded area for any future corrosion given the pipe condition.
The leak was welded, the system recharged, and the compressor started immediately — running normally at full capacity. Over $2,000 was saved by avoiding an unnecessary compressor replacement.
Why This Happens
Why gas leaks get misdiagnosed as compressor failure.
- When refrigerant is too low, the compressor cannot build pressure. This can look like compressor failure to a technician who does not check for leaks first.
- A compressor that will not start due to low gas is protecting itself — it is not broken.
- Proper diagnosis requires checking for leaks before concluding the compressor has failed.
- If the compressor runs normally once refrigerant is restored, the original diagnosis was wrong.
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