First steps: turn it off and protect the cabinet
If your garbage disposal is leaking, stop using it until you know where the water is coming from.
- Turn the disposal switch off, and if you can reach the plug safely and the area is dry, unplug it. If the disposal is hardwired, turn off its circuit at the breaker. If water is near the motor, plug, or switch wiring and you cannot do this safely, leave it alone and call a licensed plumber or electrician.
- Do not keep running the disposal to test the leak. Never put your hand into a disposal.
- Place a shallow pan under the unit and dry the cabinet floor. Do not leave soaked towels against particleboard.
Water and electricity are a serious combination. If in any doubt, do not proceed.
Is the leak really from the bottom?
A disposal has several connections above its lower body, and water from them can run down and look like a bottom leak.
Moen describes a simple paper towel test for new installations that works for older units too:
- Dry the disposal, pipes and cabinet.
- Wrap dry paper towels around the sink flange at the top, the drain discharge elbow on the side, and the dishwasher connection.
- Stop the sink, fill it with water, and release it.
- See which towel gets wet first.
If you also need to trace other leaks in the cabinet, see how to find and fix a leak under the sink.
Causes
- Failed internal seal. Water comes from the bottom or lower body. This often means replacing the unit.
- Cracked or corroded housing. Age and corrosion can cause the body to leak.
- Loose sink flange or mounting. Water leaks where the disposal meets the sink and runs down.
- Leaky discharge elbow or gasket. Water appears at the side pipe or where it joins the trap.
- Dishwasher hose connection. Water drips when the dishwasher drains.
- Loose bottom plate screws. On some models, screws on the discharge elbow plate can be snugged up a little. Follow your model’s instructions.
Fixable leaks
If the leak is higher up, repair may be reasonable:
- Discharge elbow or gasket. Check that the gasket is in place and seated, and tighten the elbow’s screws gently.
- Dishwasher hose clamp. Tighten or replace the clamp or hose.
- Sink flange. The flange may need to be removed, cleaned, and resealed, following the manufacturer’s instructions.
- Trap connections. Tighten slip nuts and replace worn washers, as described in the under-sink leak guide.
Bottom leak: when to replace
If the test shows the top and side connections are dry and water comes from the lower housing or the bottom, the internal seal or casing has probably failed. In that case, replacement is generally more practical than repair. Replacing a disposal involves electrical and plumbing connections, so if you are not comfortable with both, hire a professional.
Can you reseal a garbage disposal?
Generally not the internal seals. Those are inside the sealed housing and are not designed to be serviced. You can reseal external connections such as the sink flange and replace gaskets, but a leak from the body itself usually means a new unit.
Can I run the dishwasher if the disposal is leaking?
It is better not to. On many setups the dishwasher drains through the disposal, so running it can send more water through the leaking connection and into the cabinet. Pause the dishwasher until you have found and fixed the leak, or hand-wash in the meantime if the sink can drain properly without the disposal leaking.
Lifespan and cost
Disposals do not last forever; many are commonly said to last around ten years or so, depending on the model, usage and care. Cost varies widely by unit, labor and region. A simple replacement with a similar model is usually less than a full upgrade, but get quotes. Ask whether the price includes removing the old unit and any new electrical or plumbing parts.
Reduce future problems
- Run cold water when using the disposal, and for a short time afterward.
- Avoid grease, fibrous scraps and large bones.
- Do not use harsh chemical drain cleaners in a disposal.
- Look under the sink regularly for damp spots.
For a broader view of what else can go wrong, see kitchen sink plumbing problems and how to fix them and why a kitchen sink leaks from the bottom.
When to call a pro
- Water is near the disposal’s electrical parts
- You are not sure where the leak starts
- The unit is leaking from the housing
- You are not comfortable replacing the disposal
- The cabinet floor is soft or moldy