Hot water tank cold water inlet leak (Name of part)

[aaad1]

Hi all,

Noticed a small crack and occasional leak by the cold water inlet to the hot water tank and up stairs.

I'm unsure what this part is called and if I can just buy a screw for the pipe seperately from B&Q or have to replace the whole black part (unsure of the name). You can see the small crack on the black part on the 3rd picture.

p.s. Ignore the green tomatoes, they're ripening in the cupboard where it's warm.

Thanks

 

[Notch7]

It looks like a pressure reducer / limiter to me

Is it what looks like a crack in the gold coloured body in LH picture

 

[aaad1]

It looks like a pressure reducer / limiter to me

Is it what looks like a crack in the gold coloured body in LH picture

I have added a 4th picture to highlight the crack. There was a couple of drips of water underneath this plastic part.

So this is a pressure reducer?
If I turn off the cold water lever (just before this section - can see it on picture 1 and 3), it would be safe to undo and change either the screw cap or the whole pressure reducer?
Thanks

 

[oldbuffer]

Looks like (part of) the combination valve for an unvented hot water cylinder. If so, can only be worked on by someone with a G3 qualification with current accreditation to an approved G3 scheme.