White Knight E09 tumble dryer: 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 E09 actually means

The machine has measured the mains voltage reaching it and decided it is outside the range it is allowed to run on, so it has halted.

E09 is logged by the control board as a voltage error, and it is one of the few codes on these Vestel-built White Knight washer-dryers that is deliberately shown to the owner rather than hidden in the service menu. The board monitors incoming supply throughout the cycle and, if it reads too high or too low, it stops rather than risk running the motor and heater on a supply that cannot sustain them. On the WK-AT and WK-ATBIWM machines that usually means the cycle stops part-way, often with a wet load still in the drum.

What E09 looks like on a White Knight tumble dryer

Most people find this page having searched for what the machine is doing rather than the code itself. On a White Knight tumble dryer, E09 usually shows up as one or more of these:

Not drying
Blowing cold air
Clothes still damp at the end
Takes hours to dry
Drum not turning
Won't spin
Hums or buzzes but nothing moves
Turns one way only

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

The machine is plugged into an extension lead, multi-way adaptor or a socket shared with other heavy appliances
A genuine dip or spike in the household supply, or a loose connection at the socket or plug
A poor connection where the mains cable enters the machine
A fault on the main control board's voltage-sensing circuit, so it misreads a perfectly good supply

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.

Turn the machine off at the socket, leave it a minute, then switch back on and see whether the code returns
If it is running through an extension lead or a multi-way adaptor, plug it straight into a wall socket instead
Check whether lights or other appliances in the house flicker or misbehave at the same time — if so the problem is the supply, not the dryer
Note whether the code appears at the same point in every cycle or at random; it helps whoever attends

Which White Knight models show E09

E09 means the same thing on all 3 of these models. If yours is not listed, the explanation above still applies — the code is set by the control board, not the model number.

WK-AT75WDW · WK-AT7WM148W · WK-ATBIWM814W

Common questions about White Knight E09

What does E09 mean on a White Knight tumble dryer?

The machine has measured the mains voltage reaching it and decided it is outside the range it is allowed to run on, so it has halted. E09 is logged by the control board as a voltage error, and it is one of the few codes on these Vestel-built White Knight washer-dryers that is deliberately shown to the owner rather than hidden in the service menu. The board monitors incoming supply throughout the cycle and, if it reads too high or too low, it stops rather than risk running the motor and heater on a supply that cannot sustain them. On the WK-AT and WK-ATBIWM machines that usually means the cycle stops part-way, often with a wet load still in the drum.

Can I fix White Knight E09 myself?

There are 4 checks you can safely do yourself first.

Turn the machine off at the socket, leave it a minute, then switch back on and see whether the code returns.
If it is running through an extension lead or a multi-way adaptor, plug it straight into a wall socket instead.
Check whether lights or other appliances in the house flicker or misbehave at the same time — if so the problem is the supply, not the dryer.
Note whether the code appears at the same point in every cycle or at random; it helps whoever attends.

This one usually needs an engineer once you have tried them.

How much does it cost to repair White Knight E09?

£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 E09?

This one usually needs an engineer once you have tried the checks above. 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 tumble dryer 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 White Knight tumble dryer codes

All White Knight 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.

White Knight E09 error — tumble dryer