Manifold water hammer

[OwenF]

I’ve installed a cold and hot water manifold and am gradually commissioning runs as they are completed.

 

When opening the manifold I get awful water hammer. My guess is that this is air in the line travelling up and escaping through the rubber seal of the manifold tap. (FYI manifolds are located at FF level and so far I’ve been commissioning GF)

 

I had thought about putting a AAV on the manifold (a la UFH systems) but on reflection this probably wouldn’t help air trying to get past the rubber seal.

 

My questions

- is this something others with manifolds have experienced?

- is it likely to cause damage (E.g if lines needing to be drained and re-filled multiple times)?

- is there anything I can do to stop it?