Sink flange leak troubleshooting
Garbage Disposal Leaking From the Top (Sink Flange Fix Guide)
If your garbage disposal is leaking from the top where it meets the sink, the problem is usually a loose mounting ring, failed sink flange, or plumber’s putty that has dried out. This guide walks you through how to confirm a top leak and the exact steps to tighten, reseal, or replace the flange so you can stop the drip.
Tip: Keep a flashlight and paper towels handy so you can see exactly where water shows up as you test.
How to Tell If the Leak Is Coming From the Top
Before you start pulling anything apart, make sure the leak is really coming from the top of the disposal and not from a side hose or the bottom of the unit.
Signs of a top / sink flange leak
- Cabinet is wet directly under the sink drain opening.
- You see water tracking down the outside of the disposal from the top ring.
- Leak shows up when you fill the sink and let water sit, even with the disposal turned off.
Quick test to confirm
- Dry the disposal and cabinet area completely with a towel.
- Place dry paper towels around the top of the disposal and on the cabinet floor.
- Fill the sink halfway with water, then remove the stopper without running the disposal.
- Watch the top mounting ring and paper towels. If they get wet first, you have a top leak.
Tools and Supplies You’ll Need
Fixing a garbage disposal leaking from top is usually a DIY job if you’re comfortable working under the sink and following basic safety steps.
- Flathead screwdriver and Phillips screwdriver
- Adjustable wrench or socket set (for mounting bolts)
- Plumber’s putty or a replacement sink flange kit (as needed)
- Bucket or pan and old towels
- Non-contact voltage tester (optional, for extra safety)
Always shut off power to the disposal at the wall switch and the breaker panel before loosening any mounting parts.
Step-by-Step: Tightening a Loose Mounting Ring
Many “garbage disposal leaking from top” problems come from a mounting ring that has slowly loosened over time. Start with these simple checks:
- Turn off power at the switch and breaker. Confirm the disposal cannot turn on.
- Place a towel and small pan under the disposal to catch any remaining drips.
- Look at the metal mounting ring where the disposal meets the sink drain.
- Use a flashlight to check for visible gaps or moisture at the top joint.
- Locate the three mounting tabs or screws that hold the disposal to the sink flange. Tighten them evenly a quarter-turn at a time.
- Once snug, refill the sink, let water run through the disposal (power still off), and check for leaks around the top.
If the leak stops after tightening, dry everything off, run a few more test cycles, and you’re done. If water still seeps out around the top or through the flange, move on to resealing.
Resealing or Replacing the Sink Flange
When tightening doesn’t solve a garbage disposal leaking from top, the plumber’s putty or flange gasket has likely failed. Resealing takes a bit more time but can usually be done with basic tools.
1. Remove the disposal from the mounting assembly
- Support the bottom of the disposal with one hand or a small box.
- Rotate the mounting ring counter-clockwise until the disposal drops free from the sink flange. Set the disposal on a towel in the cabinet.
- Unplug the power cord or disconnect the hard-wired connection if you need more room.
2. Lift out the old sink flange
- From above the sink, remove the drain stopper and look at the metal flange.
- Loosen any visible screws on the upper mounting ring from below the sink.
- Push up gently from underneath and lift the flange out of the sink opening.
- Scrape away old plumber’s putty or gasket material from the sink surface.
3. Install new putty or flange gasket
- Roll a rope of fresh plumber’s putty roughly the thickness of a pencil.
- Press the putty around the underside lip of the new or cleaned flange.
- Set the flange into the sink opening and press down firmly and evenly.
- From below, reinstall the mounting hardware, tightening screws in a star pattern so the flange squeezes the putty evenly.
- Wipe away any excess putty that squeezes out inside the sink.
4. Reattach the disposal and test
- Lift the disposal back into place, lining up the mounting tabs with the ring.
- Twist the mounting ring clockwise until it locks fully into the flange.
- Reconnect the power and any drain or dishwasher hoses you removed.
- Fill the sink, then release the water while you watch the top of the disposal for leaks. Turn the disposal on briefly to confirm everything stays dry.
When It’s Better to Replace the Disposal
If you’ve resealed the flange and your garbage disposal still leaks from the top, or the unit is more than 8–10 years old, replacement often makes more sense than more gasket and putty experiments. Cracked housings, rusted mounting hardware, and repeated leaks are all signs it’s time for a new unit.
Popular Replacement Option: InSinkErator Badger 5 (1/2 HP)
A compact 1/2 HP disposal that fits many existing Badger-style mounts. It’s a common upgrade when older units start leaking around the flange or housing.
- Designed to fit many standard InSinkErator mounts
- Good everyday power for typical kitchen scraps
- Simple under-sink replacement for older units
For more replacement ideas and specs, you can also check the product picks on the main garbage disposal help page.
Related Leak Guides
If your tests point to a different leak source, use the dedicated guides below so you’re not chasing the wrong problem.
Quick FAQs About a Garbage Disposal Leaking From the Top
Is it safe to use the sink if the disposal is leaking at the top?
You can usually run limited water while a bucket catches drips, but long-term leaks can damage cabinets and nearby electrical connections. Fix or temporarily cap the leak as soon as you can.
Can I just caulk around the top of the disposal?
Caulk might slow the drip for a short time, but it doesn’t fix failed putty or loose hardware. For a lasting repair, the sink flange needs to be properly tightened and sealed with plumber’s putty or the correct gasket.
Do I need a plumber to fix a sink flange leak?
Many homeowners can handle a garbage disposal leaking from top with basic tools and careful step-by-step work. If you’re not comfortable disconnecting wiring or the mounting hardware is badly rusted, calling a licensed plumber is a good idea.