Just removed a radiator from a system that has an header tank,cwc and copper cylinder. The radiator does not tee off to another. I capped off the rad pipes and filled the system back up. when full there was quite a loud vibrating noise from the cylinder and cw tank.We run off a bit of hot water and the noise stopped The header tank is situated abive the cw tank in the loft space. Does anyone know what caused the noise and will there be any probs regarding circulation with these capped off pipes. Thanks for any advice