S
stu32
I have a Potterton Suprima 40 boiler which makes a noise which I can only describe as the sound of a steam train moving! The sound is consistent and remains within the boiler without transferring to the rest of the pipe work. The sound starts up shortly after the gas has ignited, it starts quietly at first before building up and then remaining until the boiler is switched off. It is still heating the hot water ok although some of the radiators don't seem to be getting as hot as they usually do. I have bled the radiators and no air was found, the sound in the boiler doesn't sound like air either. Any ideas? 
