Close up shot of a kitchen sink drain

Is Your Garbage Disposal Unit Leaking?

Many of us rely on our garbage disposal unit on a daily basis, but it can be prone to leaks and other issues. A garbage disposal will typically leak from one of three general locations; they are the top, the bottom, and the pipe connections. In this article, we will look at this problem in more detail and offer some useful advice on how to detect and fix the problem.

Initial Investigations

Take a look under the garbage disposal unit with a flashlight. Look for any signs of puddles, condensation, a musty odor, and accumulations of water nearby. When a garbage disposal leaks, it’s typically caused by a component that has become loose or worn. If you discover that your unit is leaking, you may be able to figure out the cause and fix it yourself, depending on the complexity of the problem. Sometimes the cause is a leak in the sink or the p-trap, so check the four key areas below to confirm your suspicions.

4 Common Garbage Disposal Leaks

Start by turning off the garbage disposal unit and remove the power supply. Then fill the sink around halfway with water and add some food coloring to the water. This will make a leak easier to identify when you venture under the unit. Generally speaking, a garbage disposal unit would be leaking from one of the following four specific locations:

  1. The Drain Line Connection

This is the line connected to the right side of the garbage disposal unit. It’s a PVC plastic pipe or a curved metal pipe that connects the unit to the main drain pipe. Pay close attention to the screws. These are used to fasten the drain line to the disposal unit and to the drain line. If these have become loose, it may introduce strain on the drain line connection, which could be the cause of the leak.

The Probable Causes

A leaking drain line connection is usually caused by the screws that secure the disposal. Another possible cause is that the rubber gasket in the mounting assembly has failed and water is escaping. Remove all the screws, take out the drain line, and then check the rubber gasket for any obvious signs of wear and tear.

How to Fix it

It may be possible to fix a drain line connection leak by simply tightening the connectors of the pipe and disposal unit. Try detaching and reattaching the pipe if it doesn’t work the first time. If the problem persists, you can try to replace the screws and/or the rubber gasket in the mounting assembly. Another option is to tighten the pipe clamp with a screwdriver, and if this doesn’t fix the issue, it’s time to contact your local plumber.

2.The Sink Flange

There is a sink flange located near the top of the garbage disposal unit. This makes the connection between the top of the sink and the disposal. Look for any signs of colored water dripping around the top or bottom of the flange ring. If you cannot see any signs, you can feel around the flange for any feelings of wetness.

The Probable Causes

The sink flange is held in place with bolts and plumber’s putty. Over time, the putty can deteriorate, or the bolt could loosen or corrode. This will break the watertight seal between the sink and the flange and cause a water leak.

How to Fix it

Start by unscrewing the bolts and check them for signs of corrosion. If the bolts have rusted, they must be replaced with new bolts. Now, you can remove the flange, scrape away the putty and reapply some fresh putty. Once you’ve allowed some time for the putty to dry, you can turn the water back on and check the seal. If the water leak persists, it’s time to contact your local certified plumber for advice.

3.The Dishwasher Hose Connection

This is located on the side of the garbage disposal unit. It’s the flexible PVC pipe that connects the dishwasher to the disposal. To check for this particular leak, you will need to run your dishwasher while looking at the disposal. Pay close attention to the hose and accompanying connections for signs of leaks. This usually occurs where the dishwasher hose connects to the disposal unit.

The Probable Causes

In many cases, the screws holding the hose connection to the disposal unit have become loose. This can happen due to lateral movement in the disposal unit, or they may have simply rusted over time. Another possible cause is that the drain hose and/or clamp may be leaking.

How to Fix it

Try to tighten the screws with a screwdriver on the metal clamps that connect the hose to the disposal unit. If the screws will not tighten, they should be replaced with new ones. If the hose or clamp is the source of the leak, they will need to be replaced with new units. If this cannot fix the problem, it’s time to contact a local plumber and get some professional help.

4.The Reset Button

On the underside of the garbage disposal unit, you will find the reset button. This deactivates the disposal unit if the motor overloads or the system jams for some reason. If this is the source of the leak, you should see a slow and constant drip of colored water.

The Probable Causes

If the source of the leak seems to be the actual reset button, this could be a failed seal located somewhere inside the disposal unit. Another possible cause is that the garbage disposal is simply too old, and it is starting to fail.

How to Fix it

Even if a single seal has worn inside the disposal unit, this is a sign that it is probably time to replace it with a new model. It’s highly likely that other internal seals are going to fail soon, and it makes better sense economically to replace rather than repair. If you need a new garbage disposal unit installed in your home, contact your local certified plumber for expert help.

By Giovanni Longo President Flood Brothers Plumbing
Giovanni Longo is a 3rd generation master plumber who has been practicing his craft and trade in the greater Los Angeles area for well over a decade and a half. A plumbing and hydraulics-engineering innovator, Giovanni’s particular world-class expertise focuses on dealing with challenging sewer system designs as well as resolving complex commercial and residential draining issues. As a certified Flood Mitigation expert, he is also well versed in a wide variety of water damage and remediation solution.