I am having problems with HW for about 2 weeks now. Completely out of the blue boiler went on lockout when hot tap or shower turned on one morning. If reset was pressed 2 or perhaps 3 times all would work well, sometimes for the rest of the day. Other times if hot water tap not used until later in day would lock out again. Then would have to reset 2/3 times and all well. Have had engineer out from national gas supplier who said gas pressure too low at 2.1, increased to 3.6 and I had resultant bill for £190 but later same day still had same problem. Two other engineers have subsequntly been out - second engineer suggests replacing electroders, third engineer says that's not the problem. Now process of elimination, could be a circuit, which would be approx £150 plus labour or could be a stuck diaphragm or even something with metre in garage. Any positive help with this would be gratefully received.
