Vaillant Atmotec exclusiv - no pressure

[Newbie101]

Hi, I'm in an Airbnb in Austria and the boiler has lost pressure. YouTube seems to suggest it's an easy fix....but I can't find the valves that are used in the videos. Any clues from the photo?!

 

[Deleted member 120897]

It could be the white knob, although the arrows would be the wrong orientation. Keep looking. Does the bnb host know?

 

[EvilDrPorkChop]

It could be the white knob, although the arrows would be the wrong orientation. Keep looking. Does the bnb host know?

Think that's the discharge.

 

[Deleted member 120897]

Think that's the discharge.

I wondered that, but wasn’t sure, as it appears connected to the return?