solved problem by changing expansion vessel. prop?support boiler, take off panel, undo 4 top screws holding top plate drill out 6 pop rivets and take out several screws to remove top side plate to gain access to vessel. drain down to level below boiler, undo copper pipe, change vessel, replace both fibre washers. refill check for leaks replace side with self tapping screws. fire up
Grahame Sells, December 2010
