The display is showing the letter L for all four rings when I turn on the hob

Alan, September 2009

This works! But the control reverts back to the L display when turned on again SO to fix it permanently so that the display does not come up with the 4 L's whenever it is turned on follow this procedure:
Turn on and press lower right plus and central minus together to change to 0's and now press LEFT plus and central minus to finish the process. This switches off the Lock system.

Lilah Clarke, January 2015

press the bottom right + and the central - at the same time less than 3 seconds after the L showing.

HTH, November 2009