Regulating a manual & automatic air vent valve from Emmeti

[Time Machine]

I'm using a manual & automatic air vent valve from Emmeti. It has 2 caps, a gray one that suppose to be automatic and a black one (on the top) that is manual.

I could understand if I suppose to let the grey cap (auto) closed all the time. Does one know how it works?

Thanks.

 

[milleniumaire]

I appreciate this is an old post, but I've just found a soaked carpet underneath the bathroom UFH manifold because one of these so called automatic air vents is leaking and probably has been since the heating came back on a couple of weeks ago!
What a piece of junk - failed after only a couple of years!

 

[Lou]

(Just bumping a few older threads, they will drop off what is new soon)

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