E15 means water has reached the base tray of the dishwasher and tripped the Aquastop anti-flood float. The machine has shut down deliberately to stop a leak becoming a flood. Tilting the machine to empty the tray will clear the code — but the code will come straight back unless you find where the water came from.
What E15 means
Bosch dishwashers have a shallow tray in the base of the machine with a polystyrene float sitting in it. Under normal conditions that tray is dry. If any water escapes inside the cabinet, it collects in the tray, the float rises, and a microswitch tells the control board to stop everything and run the drain pump continuously.
You will usually hear that pump droning away and see E15 on the display. The machine will not accept a new programme until the tray is empty and the float has dropped again.
It is tempting to treat E15 as a fault to be reset. It is not — it is the machine reporting that water is somewhere it should not be. Clearing the tray without finding the source risks a genuine flood and, in a fitted kitchen, damage to the cabinets and floor around it.
Clearing the code
- Switch off and disconnect
Turn the dishwasher off at the wall socket and close the water supply tap under the sink. Do not skip this — you are about to tip a machine that has water in it and mains wiring inside it.
- Pull the machine out
Slide it clear of the cabinet, taking care not to strain the hoses. Put towels down around and under it.
- Tilt to drain the tray
Tip the dishwasher backwards to roughly 45 degrees and hold it there for a minute or two. Water will run out of the base at the back or the sides. Let it fully drain — you may need to repeat this a couple of times.
- Stand it upright and leave it to dry
Leave the machine standing for a few hours, ideally overnight, so the float and its switch dry out completely. Rushing this step is the usual reason the code reappears immediately.
- Reconnect and test with an empty machine
Plug it in, open the tap, and run a short programme with nothing inside. Stay with it and watch the floor. If E15 returns during the cycle, there is an active leak.
Where the water is coming from
| Source | How likely | What to look for |
|---|---|---|
| Perished door seal | Common | Water running down the inside of the door or onto the floor at the front |
| Split or loose hose clip inside the cabinet | Common | Damp along the side panels or under the tub |
| Leaking spray arm bearing or seal | Occasional | Drips from the centre of the tub floor |
| Overfilling due to a faulty inlet valve | Occasional | Water level higher than the base of the door |
| Excess foam from the wrong detergent | Occasional | Suds visible in the tub; happens after hand-wash liquid is used by mistake |
| Cracked sump or tub | Less common | Persistent leak with no visible hose fault |
| Failed float switch | Uncommon | Tray genuinely dry but code persists |
Finding the leak
With the machine pulled out and running an empty cycle, work methodically:
- Check the door seal first. Run a finger around the whole gasket. Look for splits, hardened sections, food debris holding it open, or a section that has come out of its channel. This is the most common single cause.
- Watch the base during fill. If water appears within the first minute or two, suspect the inlet side — the fill hose connection or the valve.
- Watch during the wash phase. Water appearing once the spray arms start usually points to a hose clip, the sump seal or a spray arm bearing.
- Consider detergent. If someone has put washing-up liquid in the machine, foam will force water past seals that are otherwise fine. Run a rinse cycle with no detergent and see whether the fault clears for good.
If you have drained and dried the machine thoroughly and E15 still shows on an empty tray, the float may be stuck in its guide or the microswitch may have failed. Both are inside the base and need the machine dismantled.
When to call a professional
Call an appliance engineer if the leak is not obvious after an inspection, if it comes from the sump or tub rather than a hose, or if the code persists with a genuinely dry base. A cracked tub is usually the point at which replacement makes more sense than repair on an older machine.
Stop and call a qualified appliance technician or electrician if you find scorched or melted wiring, smell burning, see water that has reached electrical components, or if the fault returns immediately after a repair. Never bypass a safety device — thermal fuses, door interlocks and flood switches fail for a reason, and defeating one converts a broken appliance into a fire or flood risk.
