When a garbage disposal gets clogged, it usually won't spin, but that's not a hard-and-fast rule. Debris can clog the shredder ring, forcing unprocessed food between the ring and the flywheel and effectively preventing water from going down the drain even if the flywheel still spins. Water backing out of a clogged garbage disposal could mean the disposal itself needs to be cleared, and it could also mean there's a clog in the waste pipes.
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Wherever the clog happens to be, don't try to bust it with a conventional drain cleaner. Most fast-acting drain cleaners contain caustic sodium hydroxide or some type of acid, and both can corrode the garbage disposal and give you skin burns if any water splashes on your body. Moreover, they generate heat, which is bad for the plumbing pipes. Using a drain cleaner is easy, but the tried-and-true clog-busting methods used by plumbers are almost as easy, and they're safer.
The Rotor Won't Spin
If you hear a humming sound, or no sound at all, when you turn on the garbage disposal, debris has gotten caught between the shredder ring and the flywheel. You need to remove the debris, and there's a standard procedure for that:
- Unplug the garbage disposal or turn off the breaker.
- Use a garbage disposal wrench to spin the flywheel. The wrench is basically a 1/4-inch hex wrench, and it fits into a slot on the underside of the canister. Use the wrench to move the flywheel back and forth until it spins freely.
- Plug in the garbage disposal or turn the breaker back on and press the red reset button, which is located on the side or underside of the canister.
- Turn on the water, then turn on the garbage disposal. Let it run for about a minute to completely clear the debris that was blocking it.
If your model doesn't have a slot for a garbage disposal wrench, you can fix the garbage disposal with a broom handle. With the disposal unplugged, insert the handle through the mouth of the disposal, hook it onto one of the impellers and use the handle as a lever to spin the flywheel back and forth.
The Sink Only Drains When the Garbage Disposal is On
When water backs up in the sink until you turn on the garbage disposal, that's usually a sign that fats and starches have collected in the shredder and the gap between the shredder and flywheel. An easy, ecological and safe way to handle this is to fill the garbage disposal with ice, then add salt to lower the melting point and supercool the gunk on the flywheel.
Let the mixture sit for about an hour, then turn on the water and the garbage disposal. The chopped-up ice and salt will flush away the hardened material and clear the clog. It's a good idea to add baking soda or a few chopped up oranges or lemons to deodorize the garbage disposal at the same time.
Clearing Standing Water
If the sink is full of water, you can usually get it to drain by using a sink plunger. Seal the plunger around the garbage disposal opening and pump vigorously until the water starts to drain. You can then use a flashlight to check for clogs inside the garbage disposal. If you see anything large, retrieve it with salad tongs, not your hands.
If the clog persists, you probably have to clear out the p-trap and pipes, which will require a little plumbing know-how. It's easy to do, but it's a bit messy, so you may want to call a plumber at this point.
Chris Deziel is a contractor, builder and general fix-it pro who has been active in the construction trades for 40 years. He has degrees in science and humanities and years of teaching experience. An avid craftsman and musician, Deziel began writing on home improvement topics in 2010. He worked as an expert consultant with eHow Now and Pro Referral -- a Home Depot site. A DIYer by nature, Deziel regularly shares tips and tricks for a better home and garden at Hunker and Family Handyman.