Andersen Noisy Contactor / Coil Hum

Charger makes a loud buzzing or chattering noise when starting or during charging.

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Safety Warning

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

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Possible Causes

Worn or loose output contactor, Low control voltage to contactor coil, Mechanical vibration of contactor against backplate, AC hum transmitted through enclosure

How to Fix / Troubleshooting

Safety first: Buzzing contactors can indicate impending failure. Turn off the charger at the consumer unit if the noise is excessive or changes suddenly.

User steps:

  • Note when the noise occurs (only at start, or continuously during charge) and report this to your technician.

For a technician:

  • With power isolated, open the unit and inspect the contactor mounting screws and anti‑vibration pads; tighten or replace as needed.
  • Check coil voltage during operation to ensure it matches the contactor specification.
  • If the contactor chatters or hums excessively despite correct voltage and mounting, replace the output contactor assembly.
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Repair Difficulty

Medium 3/5

Required Part

Output Contactor Assembly
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