Clicking Sound Then Shutdown: Cracked Blower Catching On Housing

• •Concern: Previous advice was that both the PCB and fan motor needed replacing
• •Previous advice: Previous contractor diagnosed PCB fault
• •Key check: Manual rotation of blower wheel revealed a crack and physical contact with housing at one point in the rotation

A clicking noise followed by a motor lock error suggested something was physically obstructing the fan. We checked the mechanical components before testing any electronics.

• •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 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.

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 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.