Disposal Won't Turn On
Updated February 20, 2026
Flip the switch and get nothing -- no hum, no sound? That is electrical, not a jam. Tripped reset, tripped breaker, or bad switch are all quick fixes. Burned-out motor means replacement.
Overview
Key question: does the motor make any sound? Humming means jammed -- different problem. Complete silence means no power reaching the motor. Almost always one of three things: tripped thermal overload (reset button), tripped breaker, or bad wall switch. All quick and free. Fourth possibility is a burned-out motor, which means replacement. Working through the checks in order takes under 10 minutes.
Symptoms
- Complete silence when you flip the switch -- no hum, no vibration, nothing
- Was working, then stopped mid-use -- typically after a jam or heavy load (overload tripped)
- Other things on the same circuit are also dead -- tripped breaker
- Works sometimes, does not work other times -- loose wire or failing switch
- Faint click from the switch but no motor response -- switch makes contact but power is not reaching the unit
Common Causes
- Tripped thermal overload -- small red or black reset button on the bottom. Trips when the motor overheats from a jam, overload, or prolonged use. Single most common cause. Five-second fix.
- Tripped breaker -- disposal is typically on a dedicated 15 or 20 amp circuit, or shares with the dishwasher. Look for a breaker in the middle position or slightly offset from the others.
- Faulty wall switch or loose wiring -- switch contacts wear out over years. Wire connections behind the plate loosen from vibration. Fails completely or works intermittently.
- Plug bumped loose -- disposals plug into an outlet under the sink. Storing and removing items can bump the cord loose. Hardwired units can have loose wire nuts in the junction box.
- Burned-out motor -- ran jammed for too long and the windings burned out. No sound at all, does not respond to reset. Needs replacement.
What You'll Need
How to Fix It
-
Press the Reset Button
First thing to try, fixes it more often than anything else. Bottom of the unit: small red or black button. If tripped, it will be popped out slightly. Press firmly until it clicks. Try the switch. Runs normally? That was the whole problem.
Tip: Pops back out immediately? Motor may still be hot. Wait 10-15 minutes, try again. Still will not stay in? Motor may be burned out. -
Check the Circuit Breaker
Electrical panel: find the breaker for disposal, kitchen, or dishwasher. Tripped breaker sits in the middle or slightly offset. Reset: flip fully to OFF first, then ON. Test the disposal. Trips again immediately? Short circuit in the disposal, wiring, or switch -- stop resetting.
Warning: Breaker tripping repeatedly means an electrical fault. Do not keep resetting. Call an electrician. -
Check the Power Connection Under the Sink
Under the sink: is the cord firmly plugged in? Gets bumped loose when you store or remove things. GFCI outlet? Press RESET. Some kitchens have GFCI protection upstream in a different location (near the sink or in the garage) even if the disposal outlet does not have visible buttons.
Tip: Non-contact voltage tester near the outlet slots tells you instantly whether there is power. Confirms if the issue is the supply or the disposal itself. -
Test the Wall Switch
Outlet has power but disposal does not respond? Wall switch may be bad. Breaker off. Remove the plate and unscrew the switch. Check all wire connections. Multimeter: test continuity with switch ON -- should get continuity between the brass terminals. No continuity? Switch is bad. $2-5 replacement.
Warning: Breaker off before touching the switch or any wiring. Verify with a voltage tester before touching anything. -
Determine If the Motor Is Burned Out
Reset stays in, breaker is on, outlet has power, switch is good, but still nothing? Motor is likely burned out. Confirm by plugging a lamp into the disposal outlet. Lamp works but disposal does not? Motor has failed. Cannot be repaired economically -- replacement time.
Tip: Disposals last 8-15 years. In that range with a dead motor? Replacement is the right call. Consider upgrading to 3/4 HP or 1 HP if the old unit was underpowered. -
Replace the Disposal (If Motor Is Burned Out)
Manageable DIY for most homeowners. New unit mounts to the existing flange (most use a universal 3-bolt system). Power off, disconnect drain, twist off the old unit, install new one in reverse. Different brand? Mounting ring may need to change too. Reconnect, restore power, test. 30-60 minutes.
Tip: InSinkErator uses a proprietary mount. Waste King uses universal 3-bolt. Replacing InSinkErator with InSinkErator? Existing mounting ring works with the new unit.
When to Call a Pro
Call a plumber or electrician if the breaker trips repeatedly (electrical fault), if you are not comfortable with wiring, if you want professional installation for the replacement, or if the problem is in the wall wiring. Disposal replacement is a common service call, 30-60 minutes.
Prevention Tips
- Clear jams with the Allen wrench, not by running the motor against a stuck flywheel. Stalled motor burns out within minutes.
- Humming but not grinding? Off immediately. Leaving it running trips the overload or kills the motor.
- Feed waste gradually with cold water. Do not stuff the chamber.
- Run it regularly even with nothing to grind. Idle disposals seize from corrosion.
- Keep under-sink items organized so nothing bumps the power cord loose.
- Know where the GFCI outlet is if your disposal is on a protected circuit. Quick reset when it trips.