E3 indicates a heating fault.
Either the safety thermostat (if fitted), screwed in at the bottom rear, has tripped or the pcb in the door is at fault.
Unplug the appliance, take it out and take the right hand side panel off.
Check to see if there is a thermostat screwed up into the underside of the tub on the rear right side. If there is, test the thermostat to see if it's open circuit, if it is you'll need to change it.
If not there or if it's ok check the heater.
If it's all ok there then you are left with the main control board in the door.
paul, March 2012