rd537i expansion vessel valve(?) leaking

[MrSPV]

Hi

Can anyone tell me what is involved in fixing a leak that appears to be coming from a small screw on a fitting above the expansion vessel? Should I just tighten it or is it symptomatic of something more serious? See attached photo.

Thanks
Mike

 

[Madrab]

Automatic air vent .... over time they can start to leak. You can turn it down tight just now as it's usually just needed to vent the boiler on filling but ideally a new AAV would be fitted.

Nothing to be overly concerned about but I would get it replaced sometime in the near future

 

[ianmcd]

Just tighten the little black plastic bit down it will be fine

 

[MrSPV]

Thanks everyone, that seems to have done the trick.