Hi Simonjones I have a problem regarding water hammer I have done all that I can possible think off fitted tee piece on mains pipework in roofspace with 28mm pipework with stopend fitted also fitted prv on incoming mains change floatvalve on tank and pipework is well clipped but problems keeps happeing would be grateful of any other tips
Look at fitting an equlibrium valve instead of a standard part 2. Part 2 float operated valve will still oscillate under high pressure conditions. Although you have fitted a PRV the static pressure will creep up in the pipework when there is no draw off so a slow draw from the cold water cistern like a toilet valve can still cause the valve in the loft to oscillate.