Rbc127rin/1

Recently cleaned this oven the 4 hob burners to the right hand side worked ok before the clean commenced. However the two left hand burners back and front will not stay alight and hand cleaned the spreaders and crowns and wiped the hon top with a damp cloth as it was fairly clean. I did remove all the knobs also any ideas thanks..

Mod edit: the appliance in question is a Rosieres Bocuse 120cm dual fuel range cooker.
Don