Valve leaking when filling boiler

[Rjp90]

Hi,

I have drained the central heating system to decorate. Upon refilling the boiler (headline vizo 24) water is leaking from a valve hilighted on the attached image. The water is coming from the screwdriver slot. Can anyone advise what is the purpose of this valve. I'm assuming this is not suppose to leak. Would a simple part swap resolve this issue. Any advise would be apriciated.

 

[leesparkykent]

maybe its the original filling loop position and what is leaking is a non return valve?

 

[jtsplumbing]

Remove it and cap it off its not required.