i need help, my boiler broke down a month ago, all fault finding pointed to main pcb, replaced that and now if water is used to run bath or CH is used for a time, i get the 4 flashes per second fault, it seems to overheat but with cover off to test the overheat switch it refuses to go into fault, have tried turning gas pressure down in case this was causing the overheat, but is still same, if anyone knows what is causing this it would be much appreciated, or should i bite the bullet and go straight to getting a new boiler ?
