When the garbage disposal hums, leaks or quits

Kitchens in Rosemead's ranch homes are compact, and the disposal gets used hard. Most of the time, problems come down to a jam, a tripped reset or simple old age.

Freeing a jammed disposal

When a disposal hums but does not turn, the grinding plate is jammed. Turn off the switch and unplug the disposal or switch off the breaker. Look at the bottom center of the unit for a hex socket.

Insert the hex wrench, often stored under the sink, and work it back and forth until the plate turns freely. Then use tongs or pliers, never fingers, to pull out whatever caused the jam from above. Wait a few minutes, press the red reset button on the bottom, restore power and run cold water while switching it on.

When it does nothing

If it makes no sound at all, check the reset button first; the motor's thermal overload may have tripped. Then check the wall switch, the outlet under the sink, and the breaker.

If the outlet is dead, check a GFCI nearby; see tripped breakers and dead outlets.

Leaks

Leaks from disposals come from three places. At the top, where it meets the sink flange, the plumber's putty or mounting gasket has failed. At the side, the dishwasher hose or drain elbow connection is loose.

At the bottom, the unit's internal seals have failed, which means the disposal needs replacing. Put a dry paper towel under the unit and run water to find which.

When replacement is the answer

Other signs: rust, constant jams, loud grinding or a motor that trips again and again.

Choosing a replacement

Disposals are rated by horsepower. A 1/3 or 1/2 horsepower unit suits light use. A 3/4 horsepower unit handles most households well and jams less.

Continuous-feed units run while the switch is on; batch-feed units only run with the stopper in place, which is safer around children. Look for stainless grinding parts and sound insulation. If your sink has a dishwasher, the new unit needs the dishwasher knockout removed.

What a replacement involves

We shut off power, disconnect the drain and dishwasher line, and drop the old unit off its mount. We check the sink flange for leaks and reseat it if needed. Then we mount the new unit, connect the drain so it slopes properly to the wall, and knock out the dishwasher plug if your dishwasher drains through it.

We test with water running and check every joint. See minor plumbing.

What not to put in

Disposals handle soft food scraps. They struggle with:

• Grease and oil, which clog the drain downstream
• Fibrous foods like celery, corn husks and artichokes
• Starchy foods like pasta, rice and potato peels in large amounts
• Eggshells and coffee grounds, which build sludge
• Bones, fruit pits and anything non-food

Run cold water during and for about 15 seconds after grinding.

Odors

A smelly disposal often has food stuck under the splash guard. Pull back the rubber and scrub it. Grinding ice cubes and a few lemon peels helps clean the chamber.

For drain clogs below the disposal, see under-sink leaks and supply lines.

Switch and outlet safety

An air switch on the countertop, a push button that sends air through a tube, keeps the switch away from the wet sink and is an option where a wall switch is far away. The outlet under the sink should be GFCI protected, either at the outlet or upstream. Keep cleaning chemicals away from the disposal cord.

Septic and older drains

Rosemead homes are on city sewer, but older cast-iron drain lines under slabs can be partly blocked with scale. A disposal sends more food solids into those lines, so use plenty of water.

Keeping it running

Keep grease, fibrous peels, eggshells, rice and coffee grounds out of it.

When you want it done for you, our plumbing repairs page lists the jobs we take and what to send for a quote. More on the houses themselves: repair notes for postwar Rosemead homes.

Need a hand with this?

Call or text (310) 628-9399, Mon–Sat 8:30 AM–7 PM. A photo is usually enough for a free estimate.

Call or text for a free estimate