Clicking sound then shutdown: cracked blower catching on housing
An LG unit showed CH10, a fan motor lock, and clicked once before shutting down. A previous contractor blamed the control board and quoted a board replacement. The motor itself tested fine, so the question was what kept binding the fan.
By Team Snowflake | Reviewed 24 Mar 2026
Case summary
LG Wall-mounted5 years oldHDBWoodlands, Singapore
- Concern
- Previous advice was that both the control board and fan motor needed replacing
- Previous advice
- Previous contractor diagnosed control board fault
- Found
- Cracked blower wheel catching on fan housing triggering motor lock protection
- Key check
- Manual rotation of blower wheel revealed a crack and physical contact with housing at one point in the rotation
- Result
- We fitted the new blower wheel and the unit started normally. CH10 cleared, airflow came back to full strength, and no further clicking or motor lock events have occurred since.
What we were told
The aircon made a clicking sound, then stopped and showed an error code. A previous contractor had called the main board faulty and quoted a replacement. The owner wanted a second opinion before paying for a new board on one contractor's word.
What we checked
A clicking noise followed by a motor lock error pointed to something physically blocking the fan, not a dead board. A board fault would not produce a repeated click. So we checked the moving parts first, before touching any electronics.
CH10 was showing. The unit tried to start, clicked once, then shut down.
The fan motor was getting power normally and tried to spin, so power supply was not the problem.
Turning the blower wheel by hand showed drag at one spot in the rotation, not even resistance all the way round.
A closer look found a crack in the blower wheel. The cracked section bent outward and caught on the fan housing.
With the blower wheel off, the motor spun freely on its own, which ruled the motor out as the fault.
What we found
The blower wheel had cracked, likely from material fatigue over several years of use. As it turned, the cracked section bent outward just far enough to touch the inner wall of the fan housing. That contact stalled the motor, which set off the CH10 motor lock protection. The click was the cracked section hitting the housing on each attempt to spin. The board read a stalled fan and shut the unit down to protect the motor, exactly as it was designed to do.
What fixed it
We advised replacing the blower wheel only. The motor tested fine once the obstruction was gone, and the control board was working correctly. Replacing the board would have cost more and left the cracked wheel in place, so the fault would have returned. We sourced a replacement blower wheel that matched the unit model.
Outcome
We fitted the new blower wheel and the unit started normally. CH10 cleared, airflow came back to full strength, and no further clicking or motor lock events have occurred since.
What this case teaches us
A motor lock code can point to a jammed fan, not a dead motor
- CH10 means the fan stopped turning. It does not say why. A cracked blower wheel rubbing the housing stops the fan just as a failed motor would.
- A click before shutdown is a mechanical clue. It often means something solid is striking a part on each rotation.
- Ask which part to replace, not just whether to replace. Here the wheel cost far less than the board the previous contractor quoted.
Related reading
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