A garbage disposal that hums but refuses to grind is one of the more puzzling kitchen problems a homeowner can encounter. The motor is clearly receiving power (that steady buzz makes it obvious) but nothing is spinning.
It’s nerve-wracking, but the good news is that a humming disposal usually isn't a dead one; it's a jammed one, and, in many cases, the fix takes under ten minutes without calling anyone.
In this brief article brought to you by Mr. Rooter Plumbing, we give you a quick rundown on what causes the problem, how to fix it safely, and when it makes more sense to hand it off to a trained plumber.
What That Hum Is Telling You
A humming sound means the motor is receiving power and trying to run, but something is blocking the flywheel and impellers from spinning. Think of it like a car engine revving in park with the wheels locked. Power is flowing, but nothing is turning.
Three things most commonly cause this:
- Food debris buildup is the most frequent culprit. Hard food scraps (like fruit pits, bone fragments, and dense vegetable pieces) wedge between the flywheel and the grinding ring and lock everything in place.
- A foreign object like a fork, a bottle cap, a small piece of broken dishware, or even a cherry pit can drop into the disposal unnoticed and jam the works completely.
- A tripped internal overload protector shuts the motor down automatically when it overheats (usually from running too long or working too hard against a stubborn jam). The motor receives power but cannot run until someone resets it.
Not comfortable working on a jammed disposal? Our plumbing repair service is available around the clock. Call Mr. Rooter to get in touch with a live representative at any time of the day – or night.
How to Safely Unjam and Reset a Garbage Disposal
Before you bring in a plumber, try resetting the garbage disposal installation yourself if you’ve got the tools and confidence. These steps work for most standard disposal units:
- Turn off power to the unit. The wall switch goes to the off position before anything else happens; Do NOT tinker with the unit with the switch on!
- Unplug the disposal. Reach under the sink and unplug the unit from the outlet. If the disposal is hardwired, then switch off the circuit breaker at the electrical panel. Do NOT work on a disposal with live power running to it!
- Look inside with a flashlight, never a hand. Tongs, needle-nose pliers, or a wooden spoon work well for removing foreign objects. Again, do NOT stick your hand in there!
- Use the Allen wrench slot at the bottom. The bottom center of the disposal unit has a small hex socket. Insert an Allen wrench and work it back and forth in both directions to manually rotate the flywheel and break up whatever is causing the jam.
- Press the reset button. This resets the overload protector and allows the motor to run again.
- Restore power and test. A successfully cleared disposal will spin freely and quietly.
If humming continues after all of these steps, the jam may be too severe to clear manually, or the motor itself may need professional attention. The plumber team at Mr. Rooter is always happy to help.
When Repairs Become Burdensome
Frequent jams, leaks from the bottom, grinding or rattling sounds on a clear unit, and a motor that refuses to respond to a reset are all signs that your garbage disposal installation has reached the end of its useful life.
An aging and unreliable disposal is a problem worth solving once and for all. Contact Mr. Rooter Plumbing today and ask about our prices, fees, and availability.
