its a service code to say the heater has failed.
Power off, remove back cover. Heater is located at bottom of drum. Disconnect wiring, undo central mounting nut and prise it out of its rubber seal - may require some effort. Replace heater, use sealant when refitting rubber seal.
Check out this site for spares : www.4directelectricals.co.uk
Check out this site for info: www.2ndwave.co.uk/manual.html
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix washing machines.