Garbage Disposal Humming, Jammed or Leaking: Fix or Replace?

A garbage disposal is one of the few appliances in your house that you can often fix yourself in about ten minutes, and one of the few where a repair attempt can also cost you a hand if you do it wrong. The difference is entirely in the diagnosis.

Here is what each symptom actually means.

It hums but does not turn

The motor is getting power and the grinding plate is jammed. This is the most common disposal problem and usually the easiest fix.

1. 1Turn the disposal off at the switch, then unplug it or shut off the breaker. Not optional. Every disposal injury story starts with somebody skipping this step.
2. 2Look in the chamber with a flashlight. Bones, a bottle cap, a spoon, a fruit pit — something is wedged against the impellers.
3. 3Remove it with tongs or pliers. Never your hand, even with the power off.
4. 4Find the hex wrench that came with the unit — usually clipped to the underside or taped nearby. Insert it into the socket in the centre of the bottom of the disposal and work it back and forth until the plate spins freely.
5. 5Press the red reset button on the bottom of the unit.
6. 6Restore power and test with cold water running.

If it hums again immediately, something is still jammed or the motor bearings have gone. If it works, you are done — that repair cost you nothing.

It does nothing at all

No hum, no click. Work through it in order, cheapest first.

• Press the reset button on the bottom of the unit. Disposals trip their own thermal overload constantly and this fixes it more often than anything else.
• Check the breaker. Kitchen circuits trip.
• Check the switch. If the disposal is on a switched outlet under the sink, test that outlet with something else.
• If power reaches the unit and it still does nothing, the motor or the internal switch has failed. That is a replacement.

It leaks

Where it leaks from determines whether it is worth fixing.

• From the sink flange at the top. The plumber's putty seal has failed. Fixable — the unit gets dropped, the flange is re-sealed and reinstalled.
• From the dishwasher inlet or the discharge tube. A hose clamp or a gasket. Cheap fix.
• From the bottom of the unit itself. The internal seal has gone and water is running through the motor housing. This is not repairable. Replace it, and do it promptly, because water in the motor is also an electrical problem.

It smells

Not a mechanical failure. Food residue is coating the chamber walls and the underside of the splash guard, which almost nobody cleans.

1. 1Run ice cubes and a handful of coarse salt through it with cold water — the ice scours the chamber.
2. 2Pull the rubber splash guard up (most lift out) and scrub the underside. This is where the smell actually lives.
3. 3Finish with citrus peels ground with cold water.
4. 4Skip bleach. It is hard on the seals and does not solve the residue problem.

What kills disposals early

• Hot water while grinding. Hot water melts fats so they flow down the line and re-solidify further along. Cold water keeps them solid so they get ground and flushed. Always run cold.
• Grease and oil. Not the disposal's job. They belong in the trash.
• Fibrous vegetables — celery, corn husks, onion skins, artichoke. The strands wrap the impellers.
• Starchy foods in volume — pasta, rice, potato peels. They expand and form a paste in the trap.
• Coffee grounds. They accumulate in the trap and cause slow drains. Everybody does this and everybody should stop.
• Bones and pits. A disposal is not a rock crusher.
• Not running enough water. Run cold water for fifteen to twenty seconds after the grinding stops so everything clears the line.

Repair or replace?

Practical rule: if the unit is more than about eight to ten years old and the fault is anything other than a jam or a top-flange leak, replace it. Disposals are not expensive relative to the labour of repeatedly nursing an old one, and a leaking or failing motor is on borrowed time regardless.

Replace immediately if it leaks from the housing, if the motor is seized, if it trips the breaker every time, or if it has become noticeably louder and rougher than it used to be.

If you are replacing it

• Match or upgrade the horsepower. A half-horsepower unit is minimum for a family kitchen; three quarters is the sweet spot.
• Continuous feed is the standard type; batch feed uses a stopper as a switch and is worth considering if there are small children in the house.
• Sound insulation is the upgrade people notice most day to day.
• Check the dishwasher inlet knockout. New disposals ship with it in place, and forgetting to knock it out is the number one DIY installation mistake — the dishwasher will not drain.
• Support the weight during install. Disposals are heavy and the mounting ring will not hold itself.

Get it handled

If the disposal is leaking from the body, tripping the breaker, or you would simply rather not be under the sink with a wrench, Wright Way Services handles disposal repair and replacement across Newnan, Peachtree City, Sharpsburg, Senoia and the rest of Coweta and Fayette County. Call (770) 301-4638.