Why Is My Garbage Disposal Leaking From the Bottom? (It Is Not the Reset Button)

You reached under the kitchen sink for the dish soap and the cabinet floor was wet. Flashlight up: nothing dripping at the sink drain, nothing at the trap, but a slow bead of water forming on the bottom of the disposal, right around the little red button, then letting go onto the cabinet floor. This is one of the most common plumbing calls we take in Pasadena kitchens, and it has one of the shortest honest answers in the trade. Here it is, and then the parts that actually matter: how to be sure, what to do tonight, and what replacement involves in an older Pasadena house.

The short answer: a bottom leak means the unit is done

If water is coming out of the bottom of the disposal body, whether from the seam, the motor housing, or the red reset button, the seal between the grinding chamber and the motor has failed. On every consumer disposal we install or pull out of Pasadena kitchens (InSinkErator Badger and Evolution, Moen, Waste King, the big-box house brands) that seal is molded into the housing. It is not sold as a part and it is not serviceable. InSinkErator’s own support pages say the same thing. The fix is a new unit.

The reset button is not what failed. It is simply the lowest opening in the casing. Once water gets past the internal seal and into the motor compartment, it finds the lowest hole and exits there. Poking the button, tightening anything, or wrapping the bottom in tape changes nothing except how long the motor sits wet.

Make sure it is really the bottom (a five-minute check)

Water runs downhill, so a leak from higher up on the disposal can look like a bottom leak by the time you see it. There are only three places a disposal leaks from, and two of them are cheap fixes:

• Top, at the sink flange. The plumber’s putty under the flange dried out, or the mounting ring worked loose. Water shows up on the top edge of the unit first. Fixable in under an hour.
• Side, at the dishwasher inlet or the discharge tube. A hose clamp that let go, or the flat rubber gasket behind the two-bolt discharge elbow. Also fixable, and often just a gasket.
• Bottom, from the housing or reset button. Internal seal. Not repairable.

To tell them apart: towel everything dry, lay a piece of dry cardboard or a paper towel on the cabinet floor, run the faucet for thirty seconds with the disposal off, then run the disposal for ten seconds. Look for the highest wet spot, not the lowest drip. One more tell: a failed bottom seal usually weeps even when nothing is running, because the grinding chamber holds a little standing water all the time. A flange leak only shows up when water is going through the sink.

Can I keep using the sink until it is replaced?

Yes, with two rules. Use the sink for water; do not run the disposal, and do not run the dishwasher, because on most Pasadena kitchens the dishwasher drains through the disposal and will push a full cycle’s worth of water out of the failed seal. Put a shallow pan under the unit and check it daily.

The reason not to wait long is not the disposal, which is already finished. It is the cabinet floor. Particleboard sink bases from 1960s through 1990s kitchens swell within days and never flatten out again; we replace more sink-base floors than disposals some months, and that is carpentry work on top of plumbing work. In prewar bungalows the cabinet floor is often solid fir and forgives a lot more, but the subfloor under it does not, and a slow leak that runs for a season is how dry rot starts in a spot nobody looks at. A wet motor can also trip the breaker or GFCI, which in an older kitchen sometimes takes the refrigerator with it.

Why disposals in Pasadena tend to die at the bottom

A typical disposal lasts eight to twelve years. Builder-grade 1/3 horsepower units sit at the bottom of that range, and there are a lot of them in Pasadena kitchens because they were the cheapest thing on the shelf during the 2015 to 2019 flip years. Those units are now hitting the end of their life, which is why we are seeing so many of these calls.

Local water shortens that life. Pasadena Water and Power delivers a blend of local groundwater and imported water, and it runs hard (the exact number is in PWP’s annual water quality report). Scale builds on the impeller plate and works at the seal every time the unit spins up. Running the disposal without water, and feeding it fibrous scraps like celery and artichoke leaves, accelerates the same wear. Our spring plumbing checklist covers the habits that stretch a unit’s life; by the time it is leaking from the bottom, that advice is for the next one.

What replacement involves, and where old Pasadena kitchens complicate it

On a standard mount with the same brand, a swap is about an hour: pull the old unit off the mounting ring, hang the new one, reconnect the discharge tube and dishwasher hose, plug it in. Different brand means a new sink flange and putty, and that is still a short job. Three things turn it into a longer one, and all three are common in houses built before 1960.

• Drain height. In a lot of 1920s through 1950s Pasadena kitchens the trap arm enters the wall higher than a modern layout expects, or the original drain was never lowered when a disposal was first added decades ago. A taller replacement unit can leave the discharge outlet below the trap arm, and water does not drain uphill. Measure from the bottom of the sink to the trap arm before you buy anything, or, better, let whoever is installing it look first. Our standing advice: do not buy the unit before someone has seen your drain.
• Power. Newer kitchens have a switched receptacle under the sink and the disposal plugs in. Many older ones have the disposal hardwired straight into a box, or wired into the same circuit as half the kitchen. If a receptacle is being added or replaced under the sink, current California electrical code requires GFCI protection there, and that is electrical work, not a plumbing swap.
• The dishwasher knockout and the air gap. Every new disposal ships with the dishwasher inlet plugged. Forget to knock the plug out and the first dishwasher cycle floods the cabinet; we get called to “fix” brand-new disposals for exactly this. And under California Plumbing Code section 807.3 a dishwasher cannot connect to a disposal without an approved air gap fitting, the little chrome cylinder at the back of the sink. If your kitchen has never had one, a disposal swap is the moment to add it.

On permits: Pasadena’s published list of work exempt from a plumbing permit covers stopping leaks and repairs that do not replace or rearrange fixtures. A like-for-like disposal swap is treated in practice as an appliance replacement rather than permitted plumbing work. Adding a circuit, moving the drain, or doing this as part of a larger kitchen remodel is different, and the Building & Safety Division at (626) 744-4200 will tell you in one phone call. If you are already pulling a permit for something bigger, the same sequence we describe for water heater replacement applies: permit first, then the work.

What it costs, honestly

The unit is the predictable part. At retail in Pasadena, a 1/3 or 1/2 horsepower Badger-class disposal runs roughly $100 to $140, and a 3/4 to 1 horsepower Evolution-class unit runs roughly $250 to $350. We do not quote labor from a chart, because the drain height and the wiring decide whether this is a one-hour visit or half a day, and we would rather look than guess. What we will say: a straight swap on an existing mount is one of the least expensive service calls we make, and it is the wrong place to economize on the unit itself. Buy the 3/4 horsepower. The 1/3 horsepower unit is the one that put you under the sink with a flashlight in the first place.

One opinion a lot of installers will not volunteer: if you are replacing a disposal in a household where someone has trouble reaching a wall switch or bending under the sink, ask for an air-switch button mounted on the counter. It is a small add-on during a swap and a real nuisance to add later. It is the kind of detail we build into aging-in-place kitchens as a matter of course.

Questions Pasadena homeowners actually ask about leaking disposals

If your disposal is dripping from the bottom, the decision is already made; what is left is doing the swap without a second visit. Request a free estimate and tell us the house’s age and whether the disposal plugs in or is hardwired, and we will come prepared. Handyman Connection of Pasadena, 110 S Rosemead Blvd Suite G, Pasadena, CA 91107, (626) 744-0402, CSLB License #992200. We serve Pasadena, Altadena, South Pasadena, Arcadia, San Marino, Sierra Madre, La Cañada Flintridge, Eagle Rock, Highland Park, Monrovia and Temple City.