How to fix a garbage disposal – 5 common problems and the best solutions

See how to fix a garbage disposal that is humming or simply not working as it should. These are the 5 most common problems and fast solutions.

water running through a garbage waste disposal in a sink
(Image credit: Getty)

Is your garbage disposal jammed, clogged, leaking, or humming but not working? Then you need to know how to fix a garbage disposal so you can get it back into action, dealing with part of your household waste quickly and efficiently.

There are lots of common garbage disposal problems that come up frequently but the good news is that many have quick-fix solutions you can apply yourself. In other words, not every fault requires you to call in a pro, saving both time and money.

We’ve put together this troubleshooting guide so you can spot what’s gone wrong with your garbage disposal and sort the problem out in double quick time.

How to fix a garbage disposal

You should fix your garbage disposal as soon as you spot an issue because there are several things that can go wrong from it not working. Whether it's a clog, jam or leak underneath.

These are the issues that are most often encountered with garbage disposals and what you can do yourself to sort them out. 

1. If your garbage disposal is not working at all

If the garbage disposal isn’t working at all, there are two things you need to try. The first is pushing the reset button at the bottom of the machine. 

‘Sometimes the garbage disposal will automatically shut off due to overheating or some other problem, and pressing the reset button will often solve a garbage disposal that won’t turn on,’ says Jake Romano of John The Plumber.

The second approach is to make sure it has power, says Leonard Ang, CEO of iPropertyManagement. ‘Is it plugged in properly? Is the circuit breaker on? Does the external wiring appear to be in good shape?’

2. If your garbage disposal is humming

If you turn on the disposal switch and the garbage disposal makes a humming noise, the problem is a different one. ‘If it just hums, your disposal is jammed,’ says landlord and rehabber in the greater Sacramento region Robert Taylor of The Real Estate Solutions Guy. Note that a jammed garbage disposal will likely still drain.

To fix a garbage disposal that’s jammed, you need to rotate the blades to free whatever is blocking them. First, unplug it or turn off the circuit breaker, then look on the bottom of the disposal for the hex-shaped socket. 

‘New disposals will often include an Allen wrench with the disposal,’ says Robert. ‘It may be under your sink or taped to the disposal. It is shaped something like an “S”.  If you don’t have the original tool, you can use a quarter inch Allen wrench instead.’

Put the wrench into the socket and rotate the grinder back and forth to dislodge anything stuck so the disposal works again, or you can remove the item. Be safe, though and always use pliers or tongs to remove an object that jammed the disposal.

Don’t have an Allen wrench? ‘You can also use a broom handle,’ explains Robert. ‘Insert the broom handle down through the top of the garbage disposal. Then, attempt to rotate the disposal blades back and forth until you can remove the jammed object.’

3. If your garbage disposal whirs and spins 

Another scenario is when it whirs and spins but the water doesn’t go down, or only goes down slowly. If that happens, it’s probably clogged. 

If that’s the case, your best bet to unclog a garbage disposal is using tongs or pliers to remove a blockage if you can see it, or a plunger to loosen a buildup. If the latter doesn’t work, baking soda and vinegar could clear the clog.

Note that if your efforts haven’t cleared the clog there could be a blockage in the P trap under the sink rather than in the garbage disposal. ‘P traps can become clogged due to objects falling into the line and sometimes need to be cleared,’ says Robert Taylor. ‘Most P traps can be removed using a large wrench. You should have a bowl underneath the drain to catch any water when you remove the P trap.’

If that’s not the issue, it’s probably a drain line clog and you might want to call in a plumber at this stage.

4. If your garbage disposal is not grinding well

It might not be an outright fix but if your garbage disposal is not grinding well then you won't be able to use It properly. 

More water is one answer. ‘When running your disposal, turn on the water and run your disposal until you don’t hear anything being ground up,’ says Robert Taylor. ‘Now, shut off your disposal and then the water. This extra bit of water will help flush out any bits of food that may still be sitting in the disposal’s drain line.’

Secondly, pay attention to what you’re grinding. That’s no to waste such as coffee grounds, eggshells, grease, potato peel, bones, nuts, pits, and pasta, oats and rice.

5. If your garbage disposal is leaking

Leaks coming from below the disposal? Check the pipe connections which may need tightening. 

Why is my garbage disposal not working?

To understand why a garbage disposal isn’t working, let’s review how it should work. ‘The garbage disposal mainly consists of a motor with a shredding mechanism that spins to chop up waste, and a drain line,’ explains industrial maintenance professional Jake Brandon, founder of JBBrandon.

‘There are two main reasons why your disposal is not working: a jam in the disposal itself or a clog downstream in the drain line,’ he continues. ‘Inappropriate waste in the disposal accounts for the majority of jams from spoons, rings, or other objects. Your dishwasher and garbage disposal use the same drain line, therefore, if you put things like grease in your disposal, you can back up your drain line.’

How to prevent future issues? ‘Don’t put the wrong things down your garbage disposal,’ cautions Jake. ‘Grease, potato peels, cooked rice and pasta can eventually become a big problem.’

What does it mean when your garbage disposal just hums?

If your garbage disposal just hums, you can be sure about one thing. ‘The buzzing or humming sound made by your garbage disposal indicates that electricity is being supplied to the appliance, but the blades are not spinning,’ says Imani Francies, a home maintenance expert with Insurance Providers.‘The humming sound might indicate that the motor is blocked or stuck, preventing it from grinding.’

Sarah Warwick
Freelance Editor

Sarah is a freelance journalist and editor writing for websites, national newspapers, and magazines. She’s spent most of her journalistic career specialising in homes – long enough to see fridges become smart, decorating fashions embrace both minimalism and maximalism, and interiors that blur the indoor/outdoor link become a must-have. She loves testing the latest home appliances, revealing the trends in furnishings and fittings for every room, and investigating the benefits, costs and practicalities of home improvement. It's no big surprise that she likes to put what she writes about into practice, and is a serial house revamper. For, Sarah reviews coffee machines and vacuum cleaners, taking them through their paces at home to give us an honest, real life review and comparison of every model.