Hi Dave, as you look at the grill is it a mesh and have disc shapes in it.I have had the grill fault where it lights and then after a few minutes pops and goes out.The mesh on the grill has a small tear in it.If yours has,the grill unit will have to be replaced with a new unit.This will have to be done by the relevant gas engineer.Stoves have a web site so you can book a call with them or their agent.All the best.
FOXY
October 2008