5 Causes of a Garbage Disposal Leak

garbage disposal mouth
  • 1-6 hours
  • Intermediate
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Even though a garbage disposal leak is a pretty simple fix, there are still other factors that make the process somewhat complicated.

For one, there are several different places within the system that can actually spring a leak, so one of the most difficult parts of fixing a leaky garbage disposal is figuring out where the leak has sprung. Between all the multiple inlets, outlets, rings, connections, and seals, you could spring a leak at any given time.

Here are the five most common causes of garbage disposal leaks to help you troubleshoot your own unit.

1. Sink Flange

The uppermost portion of the garbage disposal is a sink flange. This is the part where the disposal meets the sink drain. It can leak for a different reasons.

Firstly, the mounting bolts that secure it in place may not be tight enough. There are three of them, and they should all be tightened securely.

Another reason could be the plumber's putty has failed. In order to replace the putty, you will need to loosen the retaining bolts. Once you've created a gap, force some new putty in between the flange and the pipe. Then re-tighten the bolts to hold the putty in place.

2. Dishwasher Connection

dishwasher hose

Some garbage disposals are also connected to the drain pipe of the dishwasher. This connection helps get rid of any of the leftover food that is removed from plates and pans as they go through the washing cycle.

Leaks can occur in the hose where the disposal connects to the dishwasher unit. They can also occur if the clamp on the hose is not secure enough.

In order to fix this, you should tighten the clamp down on the hose or replace the section of cracked hose.

3. Discharge Pipe

On the bottom of the garbage disposal is the discharge pipe that goes into the drain of the sink. It is connected through a flange and a seal. Either of these components can loosen with regular use or fail altogether given enough wear and tear.

Tighten the flange with a plumber's wrench to make sure that is not the problem. If the bottom unit still leaks, you will need to replace the seal that is located between the discharge pipe and the retaining nut.

4. Crack in Body of Disposal

pipes attached to garbage disposal under a sink

As your food waste disposal system gets older, it grows susceptible to cracking along its interior shell. When the shell cracks, water will start to emerge from the seams.

If the inner shell of the garbage disposal is cracked, the entire disposal unit will need to be replaced.

5. Knocked Loose

The bulk of most garbage disposal systems, including pipes and seals, is located under the kitchen sink. Since people use the rest of the area under their sinks for storing items, it's not uncommon that someone bumps into the garbage disposal pipes while reaching for something else in close proximity.

If the disposal is hit hard enough, it can actually move and shift so it no longer sits right. The pipes can be moved, the seals can be pressed in an awkward position, or the retaining bolts can loosen. Make sure nothing has been knocked out of place. Then, check to see where the water is coming from and tighten up the bolts. If this does not fix the leak, then you will need to replace the putty or the sealing ring.