Bosch [E18] fault codewhat it means and how to fix it

E18 is a water inlet problem, and it is the code where Bosch are most generous with instructions — the manual runs to eleven steps and expects the owner to work through them. The causes they name are all outside the machine: the supply hose kinked, the water tap turned off, the tap jammed or furred up, and the filter in the water supply blocked. The genuinely useful part is that Bosch publish a number to test against rather than a vague instruction to check the flow. Their specification is that the flow rate must be at least ten litres a minute with the water supply open. That is measurable with a two-litre jug and a watch: if it takes longer than about twelve seconds to fill, you are below what the machine needs, and the problem is your supply rather than your appliance. One warning applies whenever you handle a Bosch inlet hose and it is easy to get wrong, because it does not look like an electrical component. Bosch state that the plastic housing on the supply hose contains an electric valve and must never be immersed in water, and that the hose must never be cut through because it contains electric power cables. A damaged one is replaced, not repaired or shortened to fit a new kitchen.

1. 1

   Check the tap is fully open — right off and right on again, rather than judging by how the handle sits.

2. 2

   Look at the hose along its length for kinks, particularly where it disappears behind the machine.

3. 3

   Close the tap, unscrew the hose at the tap end into a bowl, and clean the gauze filter in the connector until light passes through it.

   Never cut, shorten or immerse a Bosch inlet hose. Bosch state the plastic housing contains an electric valve and the hose contains electric power cables.
4. 4

   Do the flow test while the hose is off. Time a two-litre jug from the fully open tap — Bosch require at least ten litres a minute, so anything slower than about twelve seconds a jug is below specification.

5. 5

   If the flow is fine, reconnect finger tight plus a quarter turn, straighten the hose so nothing is crushing it, and run a short programme while watching both ends.

6. 6

   If the flow is poor, the fault is in your plumbing rather than the dishwasher. Check any isolation valve on the run and any inline filter or softener before calling an appliance engineer, who cannot help with this.