We have a 2004 Abbey with the oven, grill and hob having one igniter buton, lately this has not been working all the time. Does this have a 9v battery somewhere or does it work off of the 12v caravan electrics?
Depending on which model of cooker it is, it may have a 12v spark ignitor pack behind the cooker, or a 1.5v unit supplied by an AA size battery , usually located in the storage compartment at the base of the cooker.
If it is the 12v pack you have, then no, the oven has to come out (or complete cooker) which of course means breaking a gas union, which in turn means having a qualified engineer to do it.