Newbie help - repressurising a Greenstar 25si boiler - no key system

[benmango]

As above, I'm having trouble establishing what needs doing to top up the pressure on our Greenstar 25si boiler. It has recently lapsed into the lower red section.. All the online guides refer to using a white key but the underside of our boiler doesn't have the holes or key to do this.

Instead we have 2-3 black valves on pipes underneath the boiler. I shall upload pictures of these shortly to demonstrate. Anyone have any ideas what I need to do?

 

[stani]

Picture 3.
Open 1 of the black valves fully.
Open the other slowly, you will hear water flow,
Watch the pressure gauge start to rise, close this valve at approximately 1.5 bar.
Then fully close the other valve.

 

[Rickster123]

No need for the key. Turn both black knobs on the silver loop. Softly softly or it'll shoot up too quick!

 

[benmango]

Thank you all very much - so simple a solution in the end, but equally I didn't want to rush in there twisting valves and do something wrong. Thanks all again!