How to Troubleshoot a Garbage Disposal

May 6, 2019 6:31 PM

My garbage disposal won't turn on, and the sink won't drain properly because of it. How do I figure out what's wrong and whether a replacement is needed?

The sink does drain eventually -- right now it's dirty with crud that should have been washed down the drain, but otherwise empty.

The disposal is an InSinkErator CNTR333. I'm not sure how old it is -- definitely more than three years, maybe much more (it could be thirty years old for all I know). It's similar to the one linked, but only 1/2 horsepower rather than 3/4.

I tried resetting it and right afterward it turned on for 2-3 seconds -- but it sounded very faint, like the engine was turning on but the blades weren't spinning. I think that's what the instruction videos call "humming." After 2-3 seconds, it died again. I tried to reset it again, but this time the red button wouldn't stay depressed at all.

I've seen instruction videos for how to try unclogging the disposal if it just hums, but since it's not even humming for the most part, I haven't tried that yet.

I also am not sure if it's an issue with the switch rather than the disposal, but since it was able to turn on briefly after a reset, I'm a little dubious that the switch is the problem.

Is there any other trouble-shooting that I can or should do? Or is it time to order a new disposal?

If it's time for a new one, any recommendations on make/model, pricing, or where to buy it?

posted by rue72 to Home & Garden (13 answers total)

Best answer: It should have come with a kinda pencil-length hex-wrench tool that you can put in the center of the bottom to turn the mechanism by hand. If it turns all the way around and still buzzes weakly, it's probably time for a new one (there's not much that can go wrong with them).

I helped my mom get a new one a couple of years ago, I think it was about $100? Plus installation, which, you can call a plumber and tell them what you need (or what you have) and they can bring something similar with them. They'll see if they can fix your current one, while having a new one in the truck in case they can't.
posted by rhizome at 6:37 PM on May 6, 2019 [2 favorites]

Best answer: Rhizome has it. There should be a zig-zag-ish metal hex tool used to break loose the motor. Those tend to get lost over time. If you have a set of allen wrenches, there should be one that will fit the bottom of the disposer, though it will be more difficult to use.

If a disposer is locking up repeatedly, it’s probably best to replace it. Though, of it isn’t run semi-regularly, it will often stick like this.

You can get a good, inexpensive model down at Lowes or Home Depot.

Installing a disposer DIY is actually pretty easy, especially if you’re replacing one. You can use the existing mounts for the new one.
posted by Thorzdad at 6:47 PM on May 6, 2019

Best answer: We had issues with our garbage disposal (same brand) and I sent my husband to Lowes to get a new one. He returned with a new one for $100 and a little tool for unsticking the motor (like others have said, its an Allen Wrench kinda thingy. Very unimpressive) for $7 or something.

15 minutes later he drove back to Lowes to return the new disposal.

There are very few house projects that have come in so wildly under budget and under time like this one.

It’s worth the $7 try! Hope it works out for you - and if not, replacement isn’t terribly difficult I think, or you can call in a plumber / handyman to install for you (the bulk of the installation work is done if you’re just replacing!)
posted by kellygrape at 6:56 PM on May 6, 2019

Best answer: Here is the tool you need from Amazon.

And the same tool from Home Depot.

Plug it into the bottom of the disposer and rock it back and forth. You may hear some grating if something hard is stuck in there, like a piece of broken glass. Once you free it up, hit the reset button again, turn it on and you should be good to go.

You can also look inside with a flashlight to see if a fork or spoon is stuck in there. Remove the rubber splash guard to get a better view by pulling up on it. You can fish around in there if you have small hands but first make sure the switch is off.

The slow draining is likely because food particles have clogged up the drain holes in the grinder. Once you get it spinning again, the food particles should wash away.
posted by JackFlash at 7:39 PM on May 6, 2019 [1 favorite]

Best answer: Trick a plumber taught me - stick a broom handle in the disposal and use it to force it to turn a few full turns. Then try turning it on again. Often, that’s all you need to do.
posted by MexicanYenta at 7:46 PM on May 6, 2019 [6 favorites]

Response by poster: Thanks, everybody!

I just tried the broom trick that MexicanYenta recommended and it worked! The disposal is working again and the sink is finally clean.
posted by rue72 at 7:59 PM on May 6, 2019 [1 favorite]

Response by poster: Thanks again, MexicanYenta -- I'm going to have to remember that trick.
posted by rue72 at 8:02 PM on May 6, 2019 [1 favorite]

As an FYI, the allen wrench linked above does essentially the same thing as the broom-handle trick, without needing to stick anything down the disposal.
posted by Aleyn at 8:58 PM on May 6, 2019

Not only that, it's made to engage the quick lock ring that attaches and detaches the disposal when you need to replace it. That's why they include one in the box with the new disposal. It's a multi-purpose tool!
posted by JackFlash at 9:05 PM on May 6, 2019

Please don't put anything in the disposal and attempt to force turn it while the switch is on. This is incredibly dangerous.

You can try to loosen it up with the broom handle trick while the power is off but never, ever, put any object down the drain when the power to the unit is on and it is not rotating.
posted by seanmpuckett at 4:46 AM on May 7, 2019 [3 favorites]

Mod note: Couple comments deleted - don't turn the power on if there's a non-food object in there.
posted by LobsterMitten (staff) at 7:12 AM on May 7, 2019 [1 favorite]

Uh, yeah, I assumed that it was understood that you don’t use the broom with the power on. Guess I should have mentioned that part.
posted by MexicanYenta at 3:18 PM on May 7, 2019

Response by poster: Hahaha -- no, I figured. Hopefully we all figured!

I told my coworkers about fixing the disposal and they were scandalized. Then they said they would never put their hand into the disposal to unclog it, either. I dunno, maybe this is another one of those subcultural dichotomies, like "sit or stand" -- manually unclog or no? ;)
posted by rue72 at 3:43 PM on May 7, 2019 [1 favorite]