Quick Answer:
Turn off power to the disposal, dry the area, and look for obvious damage. Inspect the disposal housing for cracks and check nearby plumbing and the water supply line to make sure the leak isn’t coming from those fittings. If you see cracked plastic or burned components, or if water is near wiring, stop and call a professional.
Why This Happens
An electrical surge can damage the disposal motor, overload internal seals, or weaken plastic parts. That damage can let water escape from the unit itself, the mounting area, or nearby plumbing. Many leaks that appear to be the disposal are actually from the sink flange, the drain connection, the dishwasher hose, or a nearby water supply line. Two specific patterns to watch for are a worn or displaced sink seal—often a cause of a Disposal flange seal failure—and leaks that only show when you run hot water.
Step-by-Step What to Do
1. Cut the power
- Switch the disposal off at the breaker or unplug it. Do not rely on the wall switch alone.
- Keep the power off while you inspect so you don’t risk electric shock if water is present.
2. Contain and dry
- Wipe up standing water with towels and use a bucket to catch drips.
- Dry the floor and the area under the sink so you can see where water is coming from.
3. Visual inspection of the unit
- Look closely at the disposal housing for cracks, splits, or melted plastic—this helps determine if the unit itself leaked or failed. Inspect around the motor and the lower housing seams.
- Check the electrical cord and any nearby wiring for scorch marks or melted insulation.
4. Check the mounting and drain connections
- Examine the sink flange, gasket, and mounting bracket for gaps or looseness.
- Inspect the discharge pipe, hose clamps, and the dishwasher connection for loose fittings or worn gaskets.
5. Verify the source — plumbing vs disposal
- Have someone run cold and then hot water while you watch under the sink. Note whether the leak starts only when water runs and whether it happens with hot water. This will help you determine if it’s a plumbing issue or a disposal issue; leaks that appear only with hot water can point to a failing seal or connection. If useful, check for patterns like Disposal leaks only when hot water used.
- Also check the nearby water supply line and shutoff valve—verify the leak isn’t coming from that valve or hose.
6. Minor fixes you can try safely
- Tighten loose hose clamps and drain couplings after the unit is powered off and the area is dry.
- If a gasket is visibly displaced and you have a replacement on hand, you can swap it—only after power is off and you are comfortable with basic plumbing work.
7. When to stop
- If you see a cracked or melted housing, burned wiring, persistent tripping breaker, or you find water contacting wiring, leave the power off and call a professional.
What Not to Do
- Do not ignore electrical hazards if water is near wiring; professional help is appropriate if unsure.
- Do not run the disposal to “test” it if the area is wet or you smell burning.
- Do not pour chemical drain cleaners into the unit to try to stop a leak—those can damage seals and make repairs harder.
When to Call a Professional
- If the housing is cracked, melted, or shows burned components.
- If breakers trip when you try to run the disposal, or if wiring looks damaged or wet.
- If you can’t locate the leak source, the leak persists after tightening fittings, or you’re uncomfortable working near electricity and water.
Safety Notes
- Always cut power at the breaker before working under the sink.
- Avoid touching electrical connections or wires with wet hands. If wiring is wet, keep power off and call a pro.
- Wear gloves and eye protection for inspections. Use a flashlight rather than a hand-held lamp that could fall into water.
Common Homeowner Questions
- How quickly should I shut off power? — Immediately; don’t risk electrical shock if water is present.
- Can I keep using the disposal if it leaks a little? — No. Even small leaks can cause electrical hazards or worsen damage; stop using it until fixed.
- Will an insurance claim cover a disposal damaged by a surge? — That depends on your policy and whether you have surge protection; check with your insurer.