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E27

Also shown as E9001, E:27, E 27 depending on how new the control board is.

Bosch dishwasher error code E27

The mains voltage reaching the machine is too low for it to run.

Cycle will not run

The machine is protecting itself and will not start. Worth knowing before you call anyone: this is often a house wiring problem rather than an appliance fault, and a technician who arrives to a healthy dishwasher will still charge for the visit.

What to check yourself

  1. Step 1. Check what else is on the same circuit

    A dishwasher sharing a circuit with a microwave, a kettle or a space heater can see the voltage sag every time the other appliance kicks in. If the code appears at predictable times of day, that is the pattern.

  2. Step 2. Take it off any extension lead or power strip

    A dishwasher should be plugged straight into its own outlet. Extension leads and strips drop voltage under load, and a long thin one drops a lot.

  3. Step 3. Ask whether the whole house is affected

    Look for lights dimming when large appliances start, or other equipment behaving oddly. A supply problem across the house is a job for the utility or an electrician, not an appliance technician.

What a technician will look at

Described so you know what you are paying for, not as steps to repeat.

  • Have the outlet and circuit checked

    An electrician can measure the voltage at the outlet under load, which settles in ten minutes whether the fault is the house or the machine.

When to call a technician

Call an electrician before an appliance technician. If the voltage at the outlet is correct under load, then the fault is inside the machine and the appliance visit is justified.

What the repair costs

RepairPart onlyFitted by a technician
Moving the machine to its own outlet-Free
Electrician checking the circuit-$100 to $250
Control board replacement, if the machine is at fault-$300 to $550

A new machine of the same class runs $500 to $1,500. Once a quote passes about a third of that on an older appliance, the repair stops making sense.

Questions people ask

It only happens in the evening.
That fits a shared circuit or a supply that sags at peak demand. Note the times before calling anyone: it turns a vague complaint into something an electrician can actually chase.

Which machines this applies to

Applies to

All Bosch dishwashers. Machines with newer electronics show E9001 for the same fault.

Last checked

2026-08-04