Water Hammer and screeching

[Jimdiychancer]

Fitted Worcester greenstar 28i junior combi now WC has a problem initially was the pipes were banging, now it a screeching noise.

Heating eng fitted new water float valve at installation.

Tried turing down pressure.

Called alt plumber who says mini expansion vessel needed with this boiler.

Original installer says no onlyfive small rads.

Any thoughts?

 

[transam]

He means a mini expansion vessel on the mains water supply , not the heating circuit so the rads have nothing to do with it

If you have a water meter it is probably a boiler manu requirement

maybe ??