Water hammer sound since new install

[finchy01]

Had a call back from a customer reported what sounds like water hammer early in the morning and evenings. Trouble is its an Unvented system and also only seems to be happening on the hot. I'm guessing it could be an expansion vessel issue but would be surprised as it's all brand new. My thought was stopgap but they say it's only happening on the hot. Any other thoughts?

TIA

 

[townfanjon]

If the vessel is conected by a hose , bin it and replace with 22mm copper . Check cylinder temp isnt too high . Did you set the ex vessel pressure ? Is it connected into the multibloc ?

 

[finchy01]

Straight into the combi valve with 22mm cooper. I haven't been back yet to check vessel pressure but was just looking if it could be any different. I was actually thinking of changing to a felxi hose in case it's sudden pressure with no allowable movement.

 

[townfanjon]

The hoses cause loads of grief , internal bore is too small . Also check pressure to the cylinder , if its over 3 bar " happy days " set ex vessel at 3 bar . If its under, reduce the ex vessel to same or a "nats" under .