Vent, Valve & Volt
Garbage disposal hums but won't spin, or won't turn on

You can fix this

Likely cause: something loose in the chamber

A rattle or a metallic racket is usually a hard object riding around the grinding chamber. Fish it out with tongs. A deep grinding from the motor itself is one for a plumber.

Why this happens

InSinkErator's first check for a metallic or rattling noise is a foreign object in the grind chamber, especially around the outer edge of the shredding disk. This Old House says spoons, coins and rings are frequent offenders. For a loud vibrating noise, InSinkErator says to make sure the plumbing connections are tight and that the lower mounting ring has not come unlocked from the mount. Family Handyman says a grinding noise from the motor points to a failing disposal.

How to fix it

  1. Turn the switch off. Then, with dry hands, unplug the disposal or turn its breaker off.
  2. Shine a flashlight into the chamber and look around the outer edge of the disk, where the small teeth are.
  3. Lift out anything you find with tongs or pliers. Do not put your hand in.
  4. Take the tools out of the sink and keep everyone clear of the drain opening. Then restore power, run cold water and test.
  5. Whole unit shaking? Switch it off and cut the power again, then check that the pipe connections are snug and that the disposal is still locked onto its mount under the sink. If it hangs loose, call a plumber.
  6. If a piece of metal you find looks like part of the disposal itself, stop using it. CPSC announced a recall in 2017 of certain 3/4 and 1 horsepower disposals, sold under several brand names from December 2015 through March 2017, because a metal component inside can break off and come out during use. CPSC says to stop using a recalled unit right away and contact the recalling company for a free replacement. Check your brand, model and serial number against the notice on cpsc.gov.

When to stop. If the chamber is clear and it still grinds loudly, or you smell burning, stop using it and call a plumber. This Old House lists unusual noises and burning smells as reasons to call a professional.

If this does not fix it, tell the plumber

  • The kind of noise: rattle, metal on metal, vibration or grinding.
  • What you found in the chamber, if anything.
  • Whether the unit is loose on its mount.
  • The brand and model from the label on the unit.

Build the full list: what to tell the plumber.

Start this troubleshooter over

References (every fact above comes from one of these pages)
  1. InSinkErator: Garbage disposal is making an unusual noise
  2. This Old House: How to repair a garbage disposal
  3. Family Handyman: Why is my garbage disposal humming?
  4. CPSC: Anaheim and Moen recall garbage disposals due to impact hazard
  5. Moen: How to unjam a garbage disposal

FourHome is our sister brand. Browse all FourHome replacement faucet and shower parts on the FourHome Amazon store. We earn from purchases made through this link.