The short answer
On a Bosch dishwasher, water reaching the floor from the machine usually comes down to water in the base pan tripping the leak float rather than anything deeper in the machine: once the float lifts, the machine latches into a protective state and runs its drain pump instead of starting a cycle. That keeps it an owner check first, not a service call. Start here: look for water in the base pan, because a Bosch latches on its base-pan float and runs its drain pump until the pan is dry.
What you are seeing
- A damp patch on the floor at the front of the machine
- A drain pump that runs on its own with nothing selected
- Water appearing only during the fill rather than throughout the cycle
- Not this fault: Condensation on the door front, which is venting rather than leaking
- Not this fault: Water only after the sink is used, which is a drain-hose problem
- Body: Bosch builds this dishwasher as a stainless tub that dries by condensation rather than with a heating element, sealed by a single-piece door gasket, with an integrated drain pump and a base-pan float that latches the machine into a continuous drain. That architecture decides which of these you see first.
- Also check note: If these fit better, the fault is a different one.
Likely causes, in order
- Water in the base pan tripping the leak float — Why this rank: The Bosch base-pan float latches the machine into a continuous drain, so the first sign of a leak is a pump that will not stop rather than water on the floor.
- A failed sump or pump seal — Why this rank: The Bosch sump and pump seals sit under the tub where a leak reaches the base pan without ever showing at the door.
- A leaking or tripped inlet hose — Why this rank: The Bosch inlet hose carries its own safety valve at the tap end, so a tripped hose looks like a machine that will not fill.
- A hardened or displaced door gasket — Why this rank: The Bosch gasket is one continuous piece pushed into a channel and pulls out at the top corners before it hardens.
- A weeping fill valve — Why this rank: A valve that no longer closes fully lets a slow trickle into the tub between cycles.
- Body: Ranked for a Bosch dishwasher specifically.
What to check, in order
- Body: The order follows the ranking, and the ranking follows the platform. First: listen for a drain pump running with nothing selected. It goes first because the Bosch base-pan float latches the machine into a continuous drain, so the first sign of a leak is a pump that will not stop rather than water on the floor. Second: dry under the machine, run a cycle and look for a damp line at the front underside. With the first check clean, this is what the Bosch platform makes next most likely. Third: dry both ends of the inlet hose and check them again after a cycle. Only after those three is it worth reaching for a hardened or displaced door gasket: it costs more to get at, and it does not explain the first three coming back clean.
Checks you can make
- Listen to the machine with the door shut and nothing selected. A drain pump running on its own means the base-pan float has tripped and there is water under the tub. — Tools: none — Time: about five minutes
- Dry the floor completely, lay dry paper towel across the full width under the front of the machine and at each corner, and run a cycle. Where the towel wets first is where to look. — Tools: paper towel — Time: about forty minutes
- Slide the machine out on a towel and look along the floor under the tub for a damp line. On this platform a leak reaches the pan without ever appearing at the door. — Tools: towel, flashlight — Time: about twenty minutes
- Body: Stop at the first step that would need a meter on live terminals or a sealed assembly opened.
Before you open anything
Safety
Switch the machine off at its breaker, or unplug it, before removing any panel. Unplug the appliance or switch off its breaker before removing any panel. A capacitor can hold a charge after the power is off. Work with the floor dry and stand on something dry. Water on the floor is part of the electrical hazard, not separate from it.
When to call
The line is not difficulty, it is what the next step costs and risks. Call when: the machine has latched into a protective drain and there is water under the tub water has reached the junction box or the floor covering under the cabinet
Nearest pages
What this page omits
This is generalized information: it ranks causes for the Bosch dishwasher range as one platform, not for a single model. Where a page exists for your specific model it is the more specific one and takes precedence over this. The narrower pages below cover the other presentations of this symptom.
Entries: - [Bosch Dishwasher: Will Not Drain](/blog/bosch-dishwasher-drainage-failure) - [Bosch Dishwasher: Door, Latch or Seal Fault](/blog/bosch-dishwasher-door-seal)
Related pages
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
