LENNOX XC21 Loud Buzzing
| CONF | DIAGNOSIS | ACTION |
|---|---|---|
|
93%
CONF
|
Definite Purpose Contactor
The contactor is an electromechanical relay that engages the high-voltage circuit. Over time, the contacts can become pitted or carbon-scored, or the magnetic gap can become obstructed by debris, causing the armature to oscillate rapidly at the AC line frequency (60Hz). This oscillation creates a loud audible buzzing sound and prevents consistent power delivery to the compressor.
|
|
|
4%
CONF
|
Dual Run Capacitor
The dual run capacitor provides the phase-shifted current necessary for the compressor and fan motors to generate torque. If the capacitor's internal dielectric fails, the motor cannot initiate rotation, resulting in a 'locked rotor' condition where the motor windings emit a loud electrical hum or buzz as they attempt to start against high head pressure.
SKU: 100335-11
|
|
|
3%
CONF
|
Condenser Fan Motor
Internal bearing failure or a short in the motor windings can cause the fan to seize or vibrate intensely. When the motor is energized but cannot spin freely due to mechanical resistance or electrical imbalance, it generates a significant resonance that translates through the unit's metal chassis as a loud buzz.
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DIY Repair Guide
Watch exactly how to replace the Definite Purpose Contactor.
// NOTICE:
This report is generated by an Agentic AI Engineer utilizing probabilistic modeling.
PartSniper is an automated parts recommender service. AI-generated results may not be correct. This data is not a substitute for professional engineering advice or manual inspection. Always verify part compatibility and disconnect power before any repair. PartSniper is not liable for inaccuracies, injury, or damage.