Why Is My Garbage Disposal Leaking From the Bottom?

Before anything else, dry off the unit and the area below it, then watch where the water first shows up. InSinkErator's own support page for leaks treats this as a real diagnostic step: for a leak that looks like it's coming from the bottom, the company says to "confirm it's not leaking from somewhere else (such as the mounting assembly) and dripping down to the bottom."

A leak at the mounting assembly, where the disposal attaches to the sink flange, is a different and usually simpler fix than a leak out of the unit's body. Water from the mounting assembly just runs down the outside of the unit on its way to the floor, which can look exactly like a bottom leak if you don't catch it at the source.

If the water really is coming from underneath, InSinkErator separates that from a leak through the wall of the container body itself. For the wall case, the company's guidance is the same: "confirm it's not leaking from the top of the garbage disposal at the mounting assembly and dripping down through the wall," and if that's ruled out, contact the manufacturer for further help.

A leak through the housing wall usually points to a failed internal seal, since that's what is supposed to keep water inside the grinding chamber. Once that seal has gone, the fix is replacing the part that failed, not just tightening something.

InSinkErator's own method for finding a hard-to-locate leak is simple: lay newspaper flat across the bottom of the cabinet under the sink, fill the sink with the stopper in, let it sit, then drain it and watch for wet spots. After that, run the water and the disposal together and check again.

This tells you where the leak actually starts before you spend money on a part. If you still can't tell after that test, that's the point to call it in rather than keep guessing.

Fixr's cost guide prices a minor leak repair, usually a gasket or seal, at $60 to $100 including labor, or less than $10 if you replace the part yourself. A full garbage disposal replacement averages $500, and can run up to $600 for a high-power model.

Which one you need depends on where the leak actually is. A mounting assembly leak is often just a loose connection or a worn gasket at that joint. A true leak through the body or at the motor joint is a sign the unit itself has failed.

If water is pooling anywhere near the outlet the disposal is plugged into, unplug it at the wall or shut off its breaker before you do anything else. Don't run the disposal again until you know where the water is coming from.

Call to get connected with a local plumber who serves Eden Prairie once you've confirmed it's a true leak and not just water running down from somewhere else.