How to Fix the Four Most Common Garbage Disposal Problems Yourself
Garbage disposal service calls are among the most common plumbers respond to, and a significant percentage require nothing more than pressing a reset button or unjamming the grinding plate with a hex key — tasks that take two minutes and cost nothing except the $150 to $200 service call fee. Here is how to handle the four most common problems before reaching for the phone.
Problem 1: The Disposal Doesn’t Run at All
When you flip the switch and hear nothing, the overload protector has tripped. Find the red or black button on the bottom of the unit under the sink and press it firmly until you feel it click. This reset button pops out when the disposal motor overheats. If it won’t stay in when pressed, let the motor cool for five to ten minutes before resetting. If it trips again quickly after resetting, investigate for a jam before resetting again.
Problem 2: The Disposal Hums But Doesn’t Spin
A humming disposal with no spinning indicates a jam. Turn off the disposal immediately to prevent overheating and motor damage. Insert a 1/4-inch Allen key into the hex fitting in the center of the disposal bottom and work it back and forth to manually turn the grinding plate and dislodge the jam. Once you feel the plate moving freely, press the reset button, run cold water, and turn it on.
Problem 3: The Disposal Leaks
Leaks come from three locations: the flange where the disposal mounts to the sink drain, the side port where the dishwasher drain connects, or the main body. Flange leaks at the top are fixed by tightening the mounting ring or re-plumbering the sink flange. Dishwasher port leaks require checking and tightening the hose clamp on the dishwasher drain connection. Leaks from the main body indicate a cracked unit that requires replacement rather than repair.
Problem 4: The Disposal Drains Slowly
A slowly draining disposal indicates a partial blockage in the drain pipe below, not a disposal malfunction. First run water and disposal for 30 seconds to flush material through. If still slow, disconnect the P-trap under the sink and clean it out — food debris accumulates here most commonly. If cleaning the P-trap doesn’t resolve it, the blockage is further down the drain line and requires a plunger or drain snake.
