My smeg dishwasher has stopped working?

It's a model number DWF1 2 and I've had it just over 5 years.It stopped recently with 1" of water remaining in it, the 'eco' light flickering on and C11 showing in the indicator panel (this changes to C1 when the door is closed).
The letter C could be an E or L (the segments appear dimly lit) but there are no references to any of these codes in the manual. No programmes can be selected.
Can anyone help?