Do this now
Switch it off at the wall and keep your hand out of it. Then flip the switch once and listen: a hum means it is jammed, silence means it has no power.
Garbage disposal not working: whether it hums or is silent decides the fix
Updated
That one sound splits the whole problem. A hum means the motor is getting power and the flywheel cannot turn, because something is wedged against it. That is a jam, and it is free to clear with the hex wrench that came taped to the unit. Dead silence means no power is reaching the motor at all, which is almost always the reset button on the underside, and after that the breaker or the switch. Work out which sound you have before you do anything else, because the two fixes have nothing in common.
- 01
Switch it off, and understand why that is not enough
Off at the wall switch, and if you can reach the plug under the sink, pull it. The blades in a disposal are not sharp and they are not what hurts people. The flywheel is under motor torque, and a jam that frees itself while your hand is in the chamber is the injury this appliance is known for.
Never put your hand into the grinding chamber, switched off or not. Everything below is done with a wrench, a torch and tongs.
- 02
Flip the switch once and listen. This is the test
One second is enough. A hum, a buzz, any sound at all with no grinding means power is arriving and the motor is stalled. Complete silence means it is not. Turn it straight back off either way, because a stalled motor left humming is how you turn a free fix into a new unit.
- 03
If it was SILENT: press the reset button underneath
Reach under the sink and feel the bottom of the unit for a small button, usually red, in the centre or just off it. If it has tripped it will be standing proud, and it clicks in. This is the single most common cause of a dead disposal and most people do not know the button exists.
- 04
If it is still silent: breaker, then GFCI, then the switch
Check the breaker panel. Check any GFCI outlet under the sink or nearby, because kitchen outlets are commonly protected and a trip kills the disposal while the lights stay on. If power is definitely arriving and it is still silent, the switch or the motor has failed and that is where your part of this ends.
- 05
If it was HUMMING: put the hex wrench in the bottom
There is a hexagonal socket in the dead centre of the underside of the unit. The wrench that fits it came with the disposal, usually taped to the side or clipped to the mounting. Push it in and work it firmly back and forth. You are turning the flywheel by hand to break whatever is wedged against it, and you will feel it let go and spin freely.
- 06
Get the object out, and never with your fingers
Torch in one hand, tongs or long-nosed pliers in the other. It is usually a bottle cap, a bone chip, a fruit stone or a piece of cutlery, and it is usually sitting against the outside edge of the chamber where the flywheel meets the wall. If you cannot see anything, run the wrench again and look once more.
- 07
Press reset, run cold water, then switch on
A stalled motor will normally have tripped its own reset while it was humming, so press the button before you test. Start the cold tap first and leave it running, then switch the unit on. It should sound normal within a second or two.
- 08
If it hums again straight away, stop
Either the object is still in there, or the motor is failing. Running it repeatedly to find out which is the thing that decides it for you, and not in your favour.
What it costs
| Cost | Source | |
|---|---|---|
| Freeing a jam yourself with the wrench that came with the unit | Free | |
| A replacement jam wrench, if yours has gone | Sold as a disposal jam wrench | |
| A plumber freeing a jam, described as 45 to 60 minutes work | $75 to $175 | |
| A disposal that will not switch on | $70 to $550 | |
| Unclogging a disposal or the drain below it | $70 to $200 | |
| Loose or broken impeller blades | $130 to $330 | |
| Repair, national average | $175, most falling between $100 and $250 | |
| Replacing the unit, fitted | $200 to $550 | |
| Minimum call-out for a diagnostic only | $70 to $130 |
Every figure here is published by the source named beside it. We do not average them into a number of our own.
Where to stop
Clearing a jam is genuinely a homeowner job and the tool for it came in the box. These are the versions where it is not.
- Anything involving your hand inside the chamber
- There is no version of this that is worth it. If it cannot be reached with tongs through the opening, it is worth the call-out.
- The unit is hardwired rather than plugged in
- You cannot isolate it by pulling a plug, so every step above happens with the breaker off, and anything beyond the reset button becomes electrical work.
- It is also leaking
- That is a different fault with a different answer, and where it leaks from decides whether it is a gasket or a new unit. Work through the leaking guide first, because a cracked housing makes the jam irrelevant.
- The other side of the sink fills when you run it
- The disposal is fine and the drain is blocked downstream of it. That is a clogged kitchen sink, not a disposal fault, and HomeGuide prices unclogging at $70 to $200 separately.
- A burning smell, or repeated jams on ordinary food
- HomeGuide puts loose or broken impeller blades at $130 to $330. A unit that jams on things it used to handle is telling you the flywheel or the shredding plate is going.
Why it happened
A disposal does not have blades in the way people imagine. It has a spinning plate with two blunt swivelling lugs that fling food against a grinding ring, and it works by impact rather than by cutting. That design is why it is so easily stopped: anything that is hard and small enough to wedge between the plate and the wall of the chamber stops the plate dead, and the motor sits there stalled, humming. It is almost never food that does it. It is bottle caps, a teaspoon that went in with the washing up, fruit stones and bone chips. HomeGuide describes exactly this: a jammed disposal hums without grinding when a small object gets stuck in the grinding chamber.
What stops it happening again
Cold water running before, during and for a good twenty seconds after is the whole discipline, and the run-on at the end is the part everybody skips. It carries the ground waste out past the trap instead of leaving it to settle in the bend. The other half is knowing what actually jams these, which is not food scraps but hard small objects, so the useful habit is looking in the sink before you flip the switch rather than after.
- The part
- Keep the hex wrench where you will find it. Taped to the inside of the cupboard door above the unit is better than in the drawer it will migrate out of.
- How often
- Cold water on every use, and a look into the chamber with a torch whenever it sounds different from normal.
Want the rest of the house covered?
One email a month, timed to the systems you actually have. The same kind of thing as the tablet: small, cheap, and it stops the call.
Also asked
- Why is my garbage disposal humming but not spinning?
- The motor is getting power and the flywheel is jammed on something, usually a hard object wedged against the edge of the chamber. Switch it off, put the hex wrench that came with the unit into the socket in the centre of the underside, and work it back and forth until the plate turns freely.
- Where is the reset button on a garbage disposal?
- On the bottom of the unit, usually a small red button in or near the centre. If it has tripped it stands proud of the housing and clicks back in. A tripped reset is the most common reason a disposal is completely silent.
- What size Allen key does a garbage disposal use?
- Most take a quarter inch hex wrench, and one shipped with the unit, normally taped to the side of the housing or clipped to the mounting bracket. Replacements are sold as garbage disposal jam wrenches if yours has gone missing.
- How much does it cost to fix a jammed garbage disposal?
- Free if you do it yourself with the wrench. HomeGuide puts a plumber at $75 to $175 for the same job and describes it as removing the unit, freeing the flywheel and extracting the object in 45 to 60 minutes.
- Is it safe to put my hand in a garbage disposal?
- No, and not even with the power off. A flywheel under motor torque that suddenly frees itself is what injures people. Use a torch and tongs through the opening, and turn the flywheel with the wrench from underneath.
- My disposal is silent and the reset button did not help. What now?
- Check the breaker, then any GFCI outlet under the sink or nearby, since kitchen circuits are commonly protected and a trip kills the disposal while the lights stay on. If power is definitely reaching it, the switch or the motor has failed. HomeGuide puts a disposal that will not switch on at $70 to $550 depending on which it turns out to be.
- Why does my disposal keep jamming?
- Repeated jams on ordinary food usually mean the flywheel or the shredding plate is wearing out rather than that you are doing something wrong. HomeGuide prices loose or broken impeller blades at $130 to $330, against $200 to $550 to replace the whole unit fitted.