The clock on the front of my Leisure Rangemaster 110 has stopped working ?

Replace it.

https://www.amazon.co.uk/Leisure-A097268-Rangemaster-Clock-Timer/dp/B009LMDXH0

http://www.espares.co.uk/product/es470358/oven-clock-assembly-timerprogrammer

Check you are buying the exact model you need.

Obviously, isolate the cooker before starting work

do NOT rely on memory as to which wires and which screws and which bits go where and the orientation; make notes and take photos.

If in doubt get a techie out

XXX
September 2016