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Bosch E15 fault codewhat it means and how to fix it

Stop — call an engineerDishwasherAll Bosch dishwashers; shown as E15, E:15, F15, E:31-00 or E:3100Last reviewed

The water protection system has activated — there is water in the base of the machine. Turn the tap off and call service. Do not tilt it, whatever else you read.

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What E15 means

Bosch give E15 as the water protection system being activated, and Siemens put it more plainly still: the dishwasher is signalling that there is water in the floor tub. A float in the base tray has been lifted by water that should have stayed inside the machine. The official instruction is two lines long and that is all of it — turn off the water tap, call customer service. This page exists mainly to address what you will find everywhere else, because almost every result for this code tells you to tip the machine backwards to about 45 degrees, drain the tray, and let the float drop. It does clear the code. Three things Bosch actually say make it a poor idea. First, the only official statement about tipping one of these machines says the opposite: always transport the dishwasher upright, to prevent residual water getting into the machine’s controls and damaging the appliance. The water you would be sloshing around is the water Bosch are warning about. Second, every version of the trick starts by unplugging the machine, and Bosch state that the water damage protection system will not function unless the power supply is connected — so the procedure switches off the protection that is currently reporting the problem. Third, Bosch’s water damage guarantee on AquaStop runs for the service life of the appliance, but only if the machine is connected to the power supply and has been installed according to their instructions. Tipping an unplugged machine to defeat its float is difficult to square with either condition. The float dropping is not a repair. Water got into that tray from somewhere, and that somewhere is still there.

What causes it

Causes of the Bosch E15 fault code, most common first
CauseWhat is actually happeningHow likely
Internal hose or connection leakingA perished hose or a clip that has let go, dripping into the base tray. Common, and one of the more affordable outcomes once located.Common
Door seal failed at the lower cornersWater running down inside the door and collecting underneath rather than escaping where you would notice it.Occasional
Sump or tub leakingA split or a failed seal at the bottom of the tub. More serious and the reason the diagnosis has to come before any price.Occasional
Excess foam overflowing the tubWashing-up liquid in the detergent compartment generates enough foam to escape the tub and reach the base without anything having broken.Occasional
Float or sensor stuckThe protection reporting water that has already gone. Real, but a conclusion reached after a leak is ruled out, not a reason to reset and carry on.Rare

Can you fix it yourself?

What it costs to fix

Typical repair cost

£90–£280

A hose or clip repair is typically £90 to £170. Sump or tub work is £160 to £280 because substantially more has to come apart. If AquaStop itself has failed and caused damage, Bosch’s own guarantee may apply — worth raising with them before you pay anyone.

Typical UK prices including parts and labour, updated August 2026. Your quote may differ.

What other owners found

Nobody has shared what worked for them on this code yet. If you have had it, you would be the first — and it genuinely helps the next person.

Common questions about Bosch E15

Everyone says to tilt it 45 degrees. Why not?

Because Bosch say three things that cut against it. They instruct owners to always transport the dishwasher upright to stop residual water reaching the controls. They state the water damage protection system will not function unless the power is connected, and the trick begins with unplugging. And their lifetime AquaStop water damage guarantee requires the appliance to be connected to the power supply and installed to their instructions. Beyond all that, it drains the tray without fixing the leak that filled it.

Is there an official reset for E15?

No. Bosch publish a reset — off, unplug or pull the fuse, wait two minutes, restore power — but they attach it to the general "a technical fault is present" entry, not to this code. E15 has its own entry and its entire content is turn off the tap and call customer service.

My machine shows E14, not E15. Is that different?

Not in what it means or what you should do. Siemens and Neff manuals give E:14 and E:15 the same meaning — the water protection system has activated — with the same instruction. In the long display format E:14 appears as E:30-00 and E:15 as E:31-00. There are two codes here rather than one, and both are telling you the same thing.

Bosch’s own UK page does not mention turning the water off. Should I?

Yes. This is a genuine inconsistency worth knowing about. The Bosch UK web page for E15 never mentions the water supply and instead suggests inspecting the base and ordering parts. Every other Bosch source — the GB manual, the EU manual, Bosch US and Siemens — leads with turning off the tap. On a flood code, follow the manual.

My machine shows E:31-00 or E:3100 instead. Same fault?

Yes. Those are the same code on newer display generations, and F15 is the same again. If your display alternates between E:31 and 00, that is this page.

There is no water on the floor. Is it a false alarm?

Unlikely, and the dry floor is the whole point. The tray catches the leak before it reaches your kitchen. A dishwasher sits sealed under a worktop and usually runs overnight, which is exactly why the float exists.

Can I at least mop the base out myself?

Be careful if you do. Bosch warn that the plastic housing on the supply hose contains an electric valve and must never be immersed in water, and that the supply hose itself contains electric power cables and must never be cut. There is mains voltage in places you would not expect around the base of these machines.

Written by

Fault Code Check editorial team

Updated

Reviewed by

Appliance technical reviewer

Qualifications to be displayed on appointment

Last reviewed

Sources and how we verified this

We establish the facts from the sources below and then write the explanation ourselves. We do not copy manufacturer wording and we do not host their manuals.

  • Manufacturer technical and service documentation
  • Manufacturer support portal

Checked by Appliance technical reviewer (Qualifications to be displayed on appointment) on 5 August 2026.

Read our full verification process