noisy c/h

[rogersarthur]

hi, can anybody help, when i turn on a hot tap theres a buzzing noise. been advised to fit a " shock arrester" but they 're for water hammer ?? i think
p/s it's a worcester bosch combi'[/u]

 

[plummerman]

A shock arrestor is for single appliance use when you've got water hammer,(i.e cold main to tanks, toilet etc) they are designed to absorb pressure fluctation when outlets open and close. But they ain't suitable to be connected to a boiler

Are you on a water meter by any chance? If so has the RGI fitted a mini expansion vessel on the cold inlet pipework to boiler to take up expansion/backpressure when taps are closed?

It's more than likely there's just muck in a seatin on a ball valve or loose seating on a tap causing resonance