Hi John, I am here to help if I can.It might need reconfiguring.i have technical info for these hobs but L is not shown.Try thsi:
Switch off appliance at mains.
Reconnect mains.
Press and hold minus button.
Continue pressing minus button with fingure of left hand.
With right hand finger press keys 1 to 4 in turn.
1 is front right2 rear right,3 rear left, 4 front left.
This must be done quickly,otherwise it will not work.After each press of a key a bleep will be heard.
Multiple bleeps mean start again.
Once successful C will be displayed in each element display.
Place a pan of water on one of the elements.Press the plus button for the corresponding element.Wait for the C to change to a dash.
Repeat for each element.When all are complete,the unit will switch off.You have reprogrammed it.
If you still have problems, tell me the model number and I will go higher to find the fault.All the best.
FOXY, September 2008