DavecUK As the pump has suddenly started doing this, and when under no load it’s relatively quiet
There’s a second video Dave, where the OP just draws water from the group under no load. to me, sounds quiet - but only goes to 6 bar, whereas, under load, it goes to 6 bar ok-ish, then as it goes to 9bar starts making noises and the needle flickers sort of thing.
Link to both videos for convenience:
Mack21 Vid without PF (pump stops at 6 bar):
Mack21 pump is suddenly making quite a lot of noise