Which valves do I turn to top up boiler with water?

[Simon373]

Hi, here is a photo of the valves. Which ones do I need to open in order to top up the boiler please? I presume it’s the ones connected to the braided hose. But why does it have 2 taps on each end?

thanks

 

[moonlight]

The two taps on the top nearest the braided flex. The other two taps are to isolate the boiler

 

[Simon373]

The two taps on the top nearest the braided flex. The other two taps are to isolate the boiler

Great, thanks very much!