You drop food scraps in the disposal and press the switch. Nothing happens. Or it hums but doesn't spin. Or it works but you have a puddle under the sink. Here are the 7 most common disposal problems and how to fix each one.
Most disposals have a red reset button on the bottom of the unit. If the motor overheats or jams, the overload protector trips and the button pops out. The disposal won't run until you press it back in.
Fix: Unplug the disposal (or turn off the breaker). Wait 30 seconds. Press the red reset button on the bottom. It should click in. Turn power back on. Test.
If it trips again immediately: There's a jam or a motor problem. Don't keep resetting it — unplug and troubleshoot.
A piece of food (fibrous stuff like celery, corn husks, or potato skins) or a foreign object (a ring, a utensil, a bone) is stuck in the impeller. The motor tries to turn but can't.
Fix: Unplug the disposal. Use a flashlight to look down the drain. If you see the obstruction, remove it with pliers (never your fingers). If you can't see it, insert an Allen wrench (usually 1/4") into the hole at the bottom center of the disposal and turn it back and forth to free the impeller. Once it turns freely, remove the wrench. Reset. Test.
The wall switch or the switch on the disposal itself may be bad. If you hear a click when you press the switch but nothing happens, the switch may be open.
Test: Bypass the switch. With power off, locate the wire nut where the switch connects to the disposal. Connect the two wires directly (use a wire nut, not your hands). If the disposal runs, the switch is bad.
Fix: Replace the switch ($10-20). If it's a wall switch, replace the switch plate. If it's the switch on the disposal, replace the switch assembly.
Some disposals are controlled by an air switch on the counter (a pneumatic button) instead of an electrical switch. If the air hose is disconnected, cracked, or the air motor is bad, the button does nothing.
Test: Check the air hose connection at the back of the disposal. Make sure it's tight. Listen for a hissing sound when you press the button — if there's no hiss, the hose is disconnected or the air motor is bad.
Fix: Reconnect or replace the air hose ($10-20). If the air motor is bad, replace the motor assembly ($50-100) or switch to an electrical switch.
The motor burns out from overloading or from running jammed. If you hear a humming sound when you press the switch but the impeller doesn't turn, the motor may be seized.
Test: After clearing any jam and resetting, if the disposal hums but doesn't spin, the motor is likely failed. A tech can test the motor windings for continuity.
Fix: Replace the motor or the entire disposal. A new disposal runs $100-300. If the motor is bad and the disposal is more than 5 years old, replacement is usually the better call.
Disposals leak at two common points: the mounting ring (where the disposal attaches to the sink flange) and the drain connection (where the disposal connects to the dishwasher or drain pipe).
Find it: Run water into the disposal. Look for drips at the mounting ring (top) and at the drain connection (side). Check the sink flange gasket — if it's compressed or cracked, it leaks.
Fix: Replace the sink flange gasket ($5-10). Tighten the mounting ring. Check the drain connection — make sure the hose clamp is tight. If the drain pipe is cracked, replace it.
Simple but common: the disposal is unplugged, the breaker is tripped, or the GFCI outlet is tripped.
Fix: Check the breaker panel. Reset the GFCI outlet (if your sink area has one). Make sure the disposal is plugged in (if it's a plug-in model). Test the wall switch with another device to confirm it's live.