Having cleared out my CH system, and bled all the radiators clear of air before firing up the gas boiler, I have found that when I switch on the boiler and really fire it up, the pipes leading up into the airing cupboard really begin to rattle - sounds like the Water hammer scenario!
Is this normal? Is the system trying to clear the air?
Never had this issue when I cleared the system previously. Is it beacuse the gas is too fierce?