On checking the internet there is no need to strip down the back of the machine to take out circuit board to replace fuse to fix F11 problem.
First make sure machine is turned off.
Second press & hold temperature button .
Thirdly press the on button & hold at the same time as the temperature button.
Fourthly release the 2 buttons at the same time .
Fifthly press the soil button .
Sixly turn machine off then back on & F11 message saying fault F11 phone Dyson 087etc disappears entirly.
If it does not work right away keep trying as I had to make about a few attemts .
It does work so I`ve saved the £85.00 callout charge .
Found this sollution on this same Questions & Answers page.
Craig
Craig Foylan
October 2007