Garbage Disposer Repair

A garbage disposer, also known as a garbage disposal, is often treated like a mechanized goat and ends up needing repair. This Fix-It Guide on garbage disposer repair tells how a garbage disposer works, what often goes wrong, how to identify a garbage disposer problem, and what parts and tools you will need to fix it. It then gives simple step-by-step instructions for how to service the disposer flywheel, how to stop leaks in garbage disposer hoses and seals, and how to service worn disposer impellers. This Fix-It Guide also refers as necessary to electrical cord repair and motor repair.

How Does a Garbage Disposer Work?

A garbage disposer is a small appliance with a motor that grinds waste from food preparation into liquid for washing down the drain.

Impellers attached to the motor turn a flywheel to cut and grind food in the chamber into waste small enough to flush down the drain and into the sewer or septic system. If a dishwasher is nearby, a line from the dishwasher attaches to the garbage disposer so debris from the dishwater can be caught by the disposer. The entire disposer unit is attached to the bottom of the sink using a flange, ring, and mounting bolts. It is plugged into an under-sink electrical outlet for power.

With minimal maintenance, a garbage disposer can outlive a goat. Simple maintenance includes ensuring that a disposer’s enemies–grease, large items, hard items, and fibrous foods–be eliminated from its diet.

What Can Go Wrong with a Garbage Disposer?

How can you tell when something your garbage disposer ate disagrees with it? The unit will either become clogged or make extraneous noise. What causes these problems? The flywheel may be jammed. Hoses and seals can leak. The impeller can become worn. The motor can fail. Fortunately, they all can be fixed.

Fix-It Tip

If the disposer won’t start after unjamming, wait at least 10 minutes for the motor to cool fully, then press the reset button, if there is one, on the underside of the unit and try again.

How Can I Identify a Garbage Disposer Problem?

Not sure where to start looking?

  • If the unit doesn’t work at all, make sure power is on to the outlet and test the electrical cord. Test the motor with a multimeter and service or replace it if it is faulty.
  • If the unit does not turn, check the flywheel for jamming and service if needed (see below).
  • If the disposer leaks water, check and service or repair loose or worn hoses and seals (see below).
  • If the disposer turns but doesn’t grind up waste, check the impellers for wear and replace if needed (see below).

What Do I Need for Garbage Disposer Repair?

Though there are motor and impeller replacement kits for most popular garbage disposers, you’ll probably need to get them from the manufacturer or aftermarket supplier. Here are some tools for removing and repairing garbage disposers:

  • Hex wrench (check for one in a pouch attached to or near the disposer)
  • Screwdrivers
  • Multimeter (for testing the motor)


Never use chemical drain openers on a garbage disposer. The chemicals can damage plastic and rubber internal parts that protect the motor from moisture.

What Are the Steps to Garbage Disposer Repair?

Before working on the disposer, unplug it under the sink, or, if it is wired directly into the house, trip the circuit breaker or remove the fuse at the main electrical service panel.

Garbage Disposer Repair

Insert the hex wrench into the bottom and turn to rotate the flywheel.

Service a garbage disposer flywheel:

  1. Look for a six-sided (hex) hole at the center of the bottom of the disposer.
  2. If you find such a hex hole, look for a hex wrench, usually stored in a pouch on or near the disposer. If you don’t find one there or have one in your toolbox, you will need to purchase one. Don’t use a screwdriver or other tool because it can damage the hex hole.
  3. To free the flywheel, insert the hex wrench in the hex hole and rotate it in a circle in both directions.

Stop leaks in garbage disposer hoses and seals:

  1. With your hand, feel various locations around the disposer to identify the source of the leak.
  2. As needed, tighten fittings to eliminate the leak.
  3. If you find leakage from the bottom of the garbage disposer, it is probably leaking through the flywheel seal and into the Motor. Detach the disposer from the drain system and disassemble the unit. Then you can replace the seal, or take the unit to a repairman for service.

Service worn garbage disposer impellers:

  1. Unplug the garbage disposer from the electric receptacle or turn it off at the circuit breaker box.
  2. Remove all hose fittings connected to the disposer. Remove the disposer by twisting it to free it from the support ring. (Some units must be unscrewed from the ring.)
  3. Carefully remove the garbage disposer from under the sink, being aware that it is heavy.
  4. To service worn impellers on many models, dismantle the unit and remove the flywheel lock nut and flywheel.
  5. Remove the impellers or sharpen them in place, depending on the model. If the impellers cannot be sharpened, the flywheel assembly will need to be replaced as a unit.

Fix-It Tip

If you are buying a replacement garbage disposer because the last one couldn’t stand up to its diet, consider buying a heavy-duty model. Better units can handle more types of waste, because they usually have stainless-steel grind/impeller assemblies, as well as heavy-duty motors. There are safety differences as well. Heavy-duty models usually have a jamming-prevention system to reverse the grinding direction, or they use some other mechanism to clean obstructions.