Dishwasher Leaking From the Bottom? Find the Source First

Water on the floor under a dishwasher usually comes from one of five places: the door gasket, too many suds from the wrong detergent, a loose drain or supply hose under the tub, a failed pump seal, or a cracked tub or float. Turn off the water and the breaker, dry everything, then run a short cycle and watch where it shows up first.

Most leaks are slow and you notice them as a warped floor or a swollen toe-kick. Don’t let it go. Water under a built-in dishwasher soaks the subfloor and the cabinet next to it.

Common causes

Door gasket. If water is at the front corners, check the rubber seal around the door. Food stuck on it, or a torn spot, lets water out every cycle.

Wrong detergent or rinse aid overflow. Hand dish soap foams up in a dishwasher, and the suds squeeze past the door seal. A little spilled rinse aid can do the same.

Loose or cracked hose under the tub. The inlet line from the hot water valve and the drain hose to the disposal both run under the dishwasher. A loose clamp or a cracked fitting drips during the fill or drain.

Pump or motor seal. A slow leak dead center under the machine, often during the wash part of the cycle, is often a pump seal.

Float switch stuck. The float tells the dishwasher when to stop filling. If it’s stuck down, the tub overfills and spills out the front.

Bosch and Miele leak trays. Bosch dishwashers have a tray underneath with a float. If it fills, the dishwasher shows E15 and stops. Water in that tray means there’s a real leak somewhere. That code and others are on our Bosch codes page.

Dishwasher not level. If the front sits lower than the back, water reaches the door seal and gets out.

Safe checks you can do

1. Shut off power at the breaker and the water valve under the sink.
2. Wipe the door gasket. Clean it with warm water and look for tears or flat spots.
3. Check your detergent. Use only dishwasher detergent. If you used dish soap, run a rinse cycle with a cup of vinegar to break up the suds.
4. Check the float. Most are a small plastic dome in the front corner of the tub. Lift it and let it drop. It should move freely.
5. Pull the kick plate. With a flashlight, look for drips on the fill valve, the hose connections, and under the pump.
6. Check level. Front-to-back and side-to-side.

Don’t pull the dishwasher out of the cabinet yourself unless you’re comfortable disconnecting water and electrical. It’s easy to crack the supply fitting doing it.

When to call a pro

Book us when the drip is under the tub or around the pump, or at a hose connection that’s hard to get to, or if you see an E15 or similar leak code. Standing water in the tub as well? Our dishwasher not draining page covers that. We replace gaskets, pumps, valves and floats with OEM parts. Details on dishwasher repair.

Need a tech? Call (415) 585-5900 or text us, or book online. We’re licensed & insured and EPA certified, and we serve homes across the San Francisco Bay Area. Same-day service available. The $219 service call is free if you have us do the repair.

FAQ

Why is my dishwasher leaking only sometimes?

Intermittent leaks usually mean suds, an overloaded front corner deflecting spray at the door, or a fitting that only drips under full pressure during the fill.

Can I run my dishwasher if it’s leaking?

Better not. Even small leaks soak into the subfloor and cabinets. Close the supply valve under the sink until it’s repaired.

What causes a Bosch E15 error?

Water in the leak protection tray under the dishwasher. Something is leaking internally, and the float shuts the machine down.

Is a leaking dishwasher worth repairing?

Most leaks come from gaskets, hoses, valves or pumps, which are reasonable repairs. A cracked tub usually isn’t.