The Dyson CR01 washing machine error code f11 is one of the many next-to-useless codes that I talk about in my error codes (useful or not?) article.
F11 means “no motor action”, which means the motor isn’t turning or at least the control pcb isn’t getting any indication that the motor is turning. This fault could be equally observed by just looking through the door glass and seeing the drum isn’t turning. The motor not turning could be caused by many different things as described in my troubleshooting article Washing machine won’t spin or drum won’t go round.