Clicking Sound Then Shutdown: Cracked Blower Catching on Housing
Aircon case in Woodlands, Singapore: airflow traced to cracked blower wheel catching on fan housing triggering motor lock protection after targeted diagnosis checks.
Case Details
| Unit | LGWall-mounted |
|---|---|
| Age | 5 years old |
| Location | HDBWoodlands, Singapore |
| Reported | The aircon made a clicking sound and then stopped, showing an error code. A previous contractor had diagnosed the main board as faulty and quoted replacement. A second opinion was requested before committing to a new board. |
What We Checked
- CH10 error was present — the unit attempted to start, clicked, then shut down.
- The fan motor received power normally and attempted to spin.
- Manual rotation of the blower wheel revealed resistance at one specific point in the rotation.
- Closer inspection showed a crack in the blower wheel — the cracked section was flexing outward and catching on the fan housing.
- The fan motor spun freely once the blower wheel was removed, confirming the motor itself was undamaged.
The Diagnosis
The blower wheel had developed a crack, likely from material fatigue over several years of continuous use. During rotation, the cracked section flexed outward just enough to make contact with the inner wall of the fan housing. This contact caused the motor to stall, triggering the CH10 motor lock protection. The clicking noise was the cracked section striking the housing on each attempted rotation.
What Fixed It
We recommended replacing the blower wheel only. The fan motor tested fine once the obstruction was removed, and the PCB was functioning correctly — it was doing exactly what it should by shutting down the motor when it detected a lock condition. Replacing the PCB would not have resolved the issue. We sourced a replacement blower wheel compatible with the unit model.
The new blower wheel was installed and the unit started normally — CH10 cleared, airflow returned to full strength, and no further clicking or motor lock events have occurred.
Why This Happens
Why motor lock errors are often mechanical, not electrical.
- A motor lock error means the motor was unable to rotate — but the cause is often physical obstruction, not motor or PCB failure.
- Blower wheels can develop hairline cracks over time, especially in humid environments. The crack allows a section to flex outward and catch on the housing during rotation.
- Manually spinning the blower wheel with the unit powered off is a simple diagnostic step that can reveal physical contact points before any electrical testing.
Related Reading
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