Leaky Garbage Disposal: Repair or Replace?

Determining the cause of your leaky garbage disposal is the first step in helping you decide if you’re up for the fix-it job or would rather simply have your unit replaced.

Depending on the source of your leak, you could be looking at a quick afternoon project or something much messier. Either way, a leaky garbage disposal is a problem you’ll want to take care of sooner rather than later to avoid additional repairs and cost. 

Disposal leaks can range from a few occasional drops to a daily steady trickle. To test a garbage disposal for leaks, turn it on and run water through it. The water load should be great enough so that any leaks are readily apparent.

The International Association of Certified Home Inspectors (InterNACHI) recommends closing the drain and filling the sink with water. Then, with the disposal on, release the stopper and allow the entire sink to drain. Examine the bottom of your sink to look for any leaks.

Leaky Garbage Disposal? Safety First!

Your garbage disposal is a work-horse. When it’s working properly, you don’t give it a thought. But when it needs attention, always remember safety first. 

The mix of electricity, water and grinding mechanisms used by your disposal can make for a lethal combination. Before getting your hands dirty, do this first:

1. Disconnect all power to the unit: Unplug the disposal, turn OFF the power breaker and ensure no one has access to the switch. 
2. Prepare for a mess: Place a small garbage can or bucket under the sink to collect any leaking water. 
3. Get the right tools: Most garbage disposals can be disassembled with a few simple tools. To get started, you shouldn't need more than a couple screwdrivers (both Philips and flathead), a plumber's wrench or adjustable wrench, a needle nose pliers and some plumber's putty.

Typically, garbage disposals last years before the blades wear down or the motor burns out. Newer disposals are generally made better and last longer. You can expect lower end disposals to last around 8 years and higher end units to last up to 15, with an average garbage disposal life span of about 12 years, according to InterNACHI.

If you can get away with a $10 - $15 repair, you’re in luck. Garbage disposals run up to $200 or more to replace. However, the closer you are to the end of your disposal’s life, the more sense it makes for you to bite the bullet and just upgrade. 

We’ve listed the possible sources of leaks below in order of ease of repair. The farther down the list, the more likely you’ll want to replace your unit rather than tackle the repair job.

Carefully observe the source of the leak. Just because there’s water dripping from the bottom of your disposal, it doesn’t mean that’s where it started. It may have dripped down from above. Once you’ve pinpointed the source, if it’s the top of the disposal where your unit meets the sink, it could be either a leaky sink flange or a leaky gasket.

Leaky Sink Flange

The sink flange is the top piece of your garbage disposal. It’s where the sink drain and garbage disposal meet. It’s a common source of leaks – and an easy fix.

The vibrations of the working disposal tend to loosen the mounting bolts and stress the plumbers putty holding it in place. If the bolts are loose, tighten them down. There should be three.

If the plumber’s putty is shot, you’ll need to remove the unit from the sink and replace the putty. Always test your repair before walking away to ensure the leak has been sealed. 

This video will take you step-by-step on how to find and repair garbage disposal leaks.

Watch the Video

Leaky Garbage Disposal Gasket

If the source of the leak is the rubber seal mounted to the flange, you’re probably looking at a leaky mounting gasket – another easy fix. Rubber gaskets often develop leaks as they age, or if they’re not evenly locked on all three sides.

Mounting gaskets are inexpensive and are usually easy to find at your local hardware store - but one size does not fit all. Save yourself a hassle and make a note of your unit’s model number so you can make the right match.

Again, as with the leaky sink flange above, replacing your gasket will mean unmounting your disposal. Don't forget to test your repair before walking away. 

If you’ve determined your disposal is leaking from the side, you could be looking at a problem with one of the drain lines (a simple fix), or a crack in the body of your disposal (time to buy a new one). 

Cracks can appear on the exterior or interior over time. If there are no visible cracks on the unit’s exterior, take a look at your drain lines. 

Leaky Drain Lines

The drain lines are another common place for leaks. There are two of them: A small line connects your unit to a dishwasher. A larger pipe connects your unit to your house’s sewer line.

Both tend to get knocked around, and loosened, when grabbing something stored under your sink. Fixing these types of leaks can be as simple as realigning the two lines and tightening down the hose clamps, screws and retaining bolts. 

If leaking persists, check for a cracked hose or a worn gasket. They can be replaced inexpensively. Be careful not to over tighten the new gasket. 

Leaky Garbage Disposal Body

As your garbage disposal ages, it will tend to develop cracks along the body of the unit along the outside or inside lining due to the constant jarring when in use.

If this happens, you'll begin to notice water leaking through the body itself, or along the disposal’s seams. In this case, you’ll need to replace your disposal. 

Finally, if the source of your leaky disposal is the bottom of your unit, you’re probably out of luck. The odds of an easy fix are small. Typically, a garbage disposal leaking from the bottom means a problem with the reset button or a broken seal inside the unit. In either case, unless you’re a pro and have the time to spare, the best solution is to buy a new disposal. 

The exception here is if your unit is still under warranty. If it is, you may be able to have the unit fixed or replaced for you.

Chances are, if you have your garbage disposal for long enough, you’ll have to deal with a leak. If you let it go without repair, you’re gambling with other problems too.

According to the National Association of Plumbing, Heating and Cooling Contractors, The most common plumbing breakdown during the holidays is blamed on the garbage disposal.

You can prolong the life of your garbage disposal by following a few best practices:

• Always run cold water, not hot, when the disposal is in use.
• Avoid over-loading your disposal. Add food material in batches. 
• Avoid grinding fibrous material such as potato peels, onion peels, rice, etc.
• Perform regular inspections on your unit to spot leaks before they become a problem.
• Never pour bleach through the disposal or down the drain.