So heres my latest problem with my boiler - the pressure is fine 1.5 bar, the radiators, pump, etc have all been bled so there is NO air trapped in the system and still when you have a shower or bath the boiler goes off along with the pilot light. To restart the boiler you have to press the 'red' button in which works fine then goes off again. I have had a engineer round and he says it sounds like the reset button is faulty, however i thought the reason why the boiler cuts out is because its getting to hot ? the boiler isnt making any rattling sounds and the pressure remains the same regardless of the pilot being lit or not . im confused as i spoke to another engineer and he told me over the phone it sounds like the heat exchanger will need to be replaced - any help would be greatly appreciated as this boiler is swallowing all my money !!!!!!