More then likely it will be your FSD (flame safety device) solenoid that cost about £100 if they still make them for your cooker. I've had an engineer look at mine and I cant get spares anywhere as one of mine has failed and the other is temperamental. Just getting by with beans on toast. Looks like a new cooker for me but hopefully your cooker is not obsolete??!!
Jajemiley, April 2011