Moen Backfeed or Miswired Switch Circuit

Moen garbage disposal makes a humming noise even when the wall switch is off

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.

Possible Causes

Shared neutral or hot miswired in junction box, Incorrectly wired multi-way switch, Faulty wall switch leaking current, Induced voltage from nearby wiring causing motor hum

How to Fix / Troubleshooting

Safety first: Turn off the breaker feeding the disposal. Do not use the sink until wiring is corrected.

Verify switch function:
- Have a qualified electrician test the wall switch and outlet wiring.
Correct wiring:
- Ensure the disposal is wired to a properly switched hot with dedicated neutral and ground.
Do not operate until fixed:
- Leave the breaker off until the wiring fault is resolved to avoid shock or fire hazards.

Repair Difficulty

Professional Required 5/5

Required Part

Wall Switch / Electrical Wiring

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