Symptoms
- Puddle appears in the cabinet only during or after disposal use
- Cabinet floor is damp near the disposal
- Musty smell developing in the cabinet
- No leak when the sink is used without the disposal running
Likely causes
- CommonLeak at the sink flange or mounting ringA failed putty seal or loose mount lets water escape where the disposal meets the sink.
- CommonLeak from the disposal housing itselfA worn internal seal can leak specifically under the vibration and pressure of running.
- PossibleLoose discharge tube connection to the trapVibration during operation can work a loose fitting further open.
- PossibleDishwasher hose connection leaking only under flowA marginal connection may only leak when water is actually moving through it.
What to do
- Dry the entire area under the sink completely with towels.
- Run the disposal briefly with water and watch closely, using a flashlight, to catch the leak as it starts.
- Trace the water back to its highest point of origin, since water often runs along pipes before dripping.
- Check the sink flange, mounting ring, discharge tube connection, and dishwasher hose in that order.
- Tighten fittings, redo the putty seal, or replace a cracked gasket depending on what you find.
- If the leak traces back to the disposal housing itself, plan to replace the unit.
Tools and parts
- Flashlight
- Towels
- Screwdriver
When to call a pro
If you can't pinpoint the source or it turns out to be the housing itself, a plumber can diagnose and fix or replace it efficiently.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.