Correct way to install a plug socket off this fused connection unit?

[Participant]

Hi all

I want to put a plug socket in my airing cupboard next to this FCU (which switches the boiler). It'll be for a cordless vacuum cleaner.

Is it safe / correct to just take a spur off that grey cable before the FCU? Or should I take from the switched output?

Thanks.

 

[Participant]

Neither without more info.

Do you know where the spur is fed from? A socket circuit? It's own circuit? It's hard to tell from the photo but what size is the cable feeling it? (The grey cable)

Thanks, I think it's 2.5mm T&E but I don't know what fuse is in there and what circuit it's on. Will check.

 

[Participant]

Hi all. Here are some more pics and answers to some of the questions above:

The supply cable is 2.5mm^2 T&E:

The cable goes under the floor so I can't trace it:

Here's the fuse board; they're all RCD protected but I'm not sure which circuit the boiler is on?! Should I switch each off so I can figure it out?

The FCU is fused at 3A:

Not sure where to go from here.