Bosch E27 dishwasher: what it means & what to check

Stop using it for now. Carrying on with this fault risks further damage or a leak. Switch it off at the wall until it has been looked at.

What E27 actually means

The dishwasher has measured the electricity coming into it as too low to run safely, so it has stopped itself.

Bosch dishwashers monitor the incoming mains voltage, and E27 is flagged when it drops below roughly 170V. That is a problem with the electricity supply rather than with the dishwasher, so the machine halts the cycle rather than risk running the pumps and heater on an inadequate supply. In our experience this one is often misread as a board fault, and the machine itself turns out to be perfectly healthy once it is fed a proper supply.

What E27 looks like on a Bosch dishwasher

Most people find this page having searched for what the machine is doing rather than the code itself. On a Bosch dishwasher, E27 usually shows up as one or more of these:

Dishes coming out cold and wet
Not drying the load
Water not heating up
No function at all
Dead — nothing lights up
Lights flashing and nothing happening
Programme won't start
Dishwasher tripping the electrics

Recognise any of those? That is this fault, and the rest of this page explains what causes it and what you can check yourself.

What usually causes it

A long, thin or coiled extension lead between the socket and the dishwasher
A generator, inverter or off-grid supply that cannot hold its voltage under load
A genuine dip in the incoming mains supply to the property
Poor or loose connections in the socket or house wiring feeding the appliance
A worn or damaged plug or socket causing a voltage drop at the connection

What you can safely check yourself

Work through these in order. Anything beyond this — panels off, testing parts, anything to do with the wiring — is an engineer's job, and not one to attempt with the machine plugged in.

Take the dishwasher off any extension lead or multi-way adaptor and plug it straight into a wall socket
Watch whether lights dim or other appliances misbehave at the same time — that points at the house supply, not the dishwasher
Turn it off at the wall for a minute, then back on, and see whether the code returns straight away or only under load
If you are running from a generator or inverter, try the machine on a normal mains socket instead

Common questions about Bosch E27

What does E27 mean on a Bosch dishwasher?

The dishwasher has measured the electricity coming into it as too low to run safely, so it has stopped itself. Bosch dishwashers monitor the incoming mains voltage, and E27 is flagged when it drops below roughly 170V. That is a problem with the electricity supply rather than with the dishwasher, so the machine halts the cycle rather than risk running the pumps and heater on an inadequate supply. In our experience this one is often misread as a board fault, and the machine itself turns out to be perfectly healthy once it is fed a proper supply.

Can I fix Bosch E27 myself?

There are 4 checks you can safely do yourself first.

Take the dishwasher off any extension lead or multi-way adaptor and plug it straight into a wall socket.
Watch whether lights dim or other appliances misbehave at the same time — that points at the house supply, not the dishwasher.
Turn it off at the wall for a minute, then back on, and see whether the code returns straight away or only under load.
If you are running from a generator or inverter, try the machine on a normal mains socket instead.

This sometimes clears with those checks. If it comes back, it needs looking at properly.

How much does it cost to repair Bosch E27?

£66 including VAT for an engineer to come out and diagnose it, or £84 in total including VAT if it is put right on the visit and no parts are needed. Any parts needed are quoted on site before we fit them — you decide. Every repair carries a 90-day workmanship guarantee.

Tried the checks and it's still showing E27?

This sometimes clears with the checks above. If it comes back, it needs looking at properly. Then it wants someone who can open it up.

What it costs, before you call: the price is the same whatever the fault turns out to be — £66 including VAT for an engineer to come out and diagnose it, or £84 in total including VAT if it is put right on the visit and no parts are needed. Any parts needed are quoted on site before we fit them — you decide. Every repair carries a 90-day workmanship guarantee.

Our own engineers, not a call centre. We cover Nottinghamshire, Derbyshire and Leicestershire — most dishwasher faults are seen same day or next day.

Call 0115 648 0929 Book online — postcode and number is all we need

Outside our area? The explanation above still stands — take it to a local engineer and tell them the code. Knowing it saves them time and you money.

Other Bosch dishwasher codes

All Bosch fault codes and repairs →

What this looks like when it happens

Repairs we cover near you

Written by the engineers at ASAP Repairs, 0115 648 0929. We repair these machines for a living in Nottinghamshire, Derbyshire and Leicestershire.

Bosch E27 error — dishwasher