Gaggenau Dishwasher E15 (Leak / Anti-Flood)

Gaggenau Dishwasher E15: what it actually is

On Gaggenau dishwashers, E15 corresponds to the dishwasher’s leak-protection (“water protection”) system being activated. In Gaggenau’s own documentation, the “water protection system activated” fault instructs you to turn off the tap (water supply) and contact service with the fault code. (Gaggenau)

What’s happening inside the machine (real mechanism, not marketing):

• There is a base tray (bottom pan) under the tub.
• A float + microswitch (or similar sensor) in that base tray detects water.
• When water is detected, the control logic blocks filling and often runs the drain pump to prevent a flood.

That’s why people see E15 + constant pumping and the dishwasher “won’t start” or “won’t stop draining.”

First-principles: E15 is a symptom, not a root cause

E15 only tells you one thing with high confidence:

• Water reached the base tray (or the float/sensor is stuck/false-triggering).

So the job is to answer two questions:

1. Is there actually water in the base tray right now?
2. If yes, where did it come from? (internal leak, oversuds overflow, backflow, or external drip into the tray)

What you should do immediately (safe + aligned with the manual)

• Turn OFF the water supply (“tap”) feeding the dishwasher. (Gaggenau)
• Power the dishwasher down (switch off / breaker).
• Do not keep resetting and rerunning cycles; if the base is wet, it will retrip quickly.

Gaggenau’s manual language is explicit: “water protection system activated → turn off tap → call customer service and mention the fault code.” (Gaggenau)

How E15 typically gets triggered in the field (ranked by probability)

1) A real internal leak into the base tray

Common leak zones on this platform (high-level, but real):

• Door seal / door corners: misalignment, torn gasket, debris on the seal, door not closing square.
• Sump / pump area: seals, clamps, or plastic housings seep under pressure during wash.
• Inlet/fill path: slow seep at the fill connection or valve area, especially during fill.
• Drain path: small drips at drain hose connection points.

2) Oversuds / wrong detergent

If someone used dish soap or too much detergent, foam can migrate where it shouldn’t and trip the base sensor. This is one of the most common “sudden E15” stories.

3) Drain backflow or sink plumbing events

If the sink/disposal backed up, was plunged aggressively, or the drain hose routing is wrong (no high loop), water can behave unpredictably and contribute to overflow conditions that end in the base tray.

4) False trigger (stuck float / contaminated switch)

Less common than a real leak, but it happens: the float can stick due to residue, or the switch can be intermittent.

A technician’s diagnostic method (how to pinpoint the source quickly)

Step A: Identify when E15 appears

This narrows leak location dramatically.

• E15 appears immediately / during initial fill
  • Suspects: inlet/fill connections, valve area, water supply connection seep.
• E15 appears mid-wash (after it’s been spraying)
  • Suspects: door seal, spray arm/deflector issues, pump/sump leaks under pressure.
• E15 appears near the end / around draining
  • Suspects: drain connection drips, backflow events, hose routing issues.

Step B: Confirm whether the base tray is wet

If you can safely remove the toe-kick panel (power OFF first), you can often visually confirm water in the base with a flashlight. If you’re not comfortable, skip this and treat it as an active leak.

Step C: Clear the water only to verify

Drying the base tray can temporarily clear E15, but it does not fix the cause. The moment the leak repeats, E15 returns.

This is why “tilt the dishwasher and it works again” is a trap: it’s a reset, not a repair.

What “real fix” means for E15

A proper fix is one of these:

• Repair the leak source (seal/hose/pump/sump/fill component).
• Correct oversuds and fully flush the system.
• Correct drain routing / address backflow.
• Free/replace a stuck float/switch if it’s genuinely false-triggering.

Until the underlying cause is resolved, E15 is expected to recur.