Combi from immersion circuit FCU in airing cupboard - RCD?

[Leighloz]

Looking to take advantage of the scrappage scheme to replace current creaking boiler with a combi. Have a quote. Also got a question.

Combi is going in to bathroom airing cupboard where hot water tank currently is. There's a dedicated immersion heater circuit from the cu in twin core and earth (2.5mm2) that's been lying dormant for years- installer suggests using this supply for the combi.

Existing immersion heater circuit is from the non-RCD protected side of the CU and terminated in a FCU (but nothing connected to load and no fuse at the mo - supply is live) . There's space to move across the immersion heater MCB to the RCD protected side of the CU.

When the corgi (and apparently NIC/EIC registered) man comes to rip out the old tank and install the new combi, do I need to make sure he moves the MCB in the CU to the RCD protected side given that we're in a bathroom? Do I need to worry about anything else with this set up?

Is there an issue with location of the FCU in the cupboard given that door to airing cupboard not accessible from bath? Bath also has an electric shower on outside airing cupboard wall over bath so distance as crow flies (through walls) between shower and FCU short, but human arms unable to get anywhere near without punching thru marine ply.

I just want to make sure he does it properly, but I think building control will be involved anyway given mains pressure plumbing/gas installation, so presumably they will check?

Cheers for any advice as to what to look out for or ask.

Leighloz

 

[ban-all-sheds]

Combi is going in to bathroom airing cupboard where hot water tank currently is.

I assume the installer has checked that you'll get a good enough flow rate from the incoming water supply there?

Existing immersion heater circuit is from the non-RCD protected side of the CU and terminated in a FCU

That's handy.

There's space to move across the immersion heater MCB to the RCD protected side of the CU.

Why would you want to do that?

When the corgi (and apparently NIC/EIC registered) man comes to rip out the old tank and install the new combi, do I need to make sure he moves the MCB in the CU to the RCD protected side given that we're in a bathroom?

It's not in the bathroom, it's in a cupboard. You need to make sure he doesn't move it.

And you need to make sure he doesn't move the old cylinder into his van.

Is there an issue with location of the FCU in the cupboard given that door to airing cupboard not accessible from bath?

No.

I think building control will be involved anyway given mains pressure plumbing/gas installation

No.

so presumably they will check?

No.

 

[Leighloz]

I assume the installer has checked that you'll get a good enough flow rate from the incoming water supply there?

Yes. 20 l/min from sink or bath taps. Boiler rated at 13 l/m deltaT35.

There's space to move across the immersion heater MCB to the RCD protected side of the CU.
Why would you want to do that? .

Because working in bathroom - all needs to be connected via RCD - I thought. But I guess not if he's classed as working in a cupboard (that just happens to be in a bathroom).

And you need to make sure he doesn't move the old cylinder into his van. .

Nah.... Xmas drinks fund. I read it on here.


Fab. Thanks for clarifying.

 

[ban-all-sheds]

Because working in bathroom - all needs to be connected via RCD - I thought. But I guess not if he's classed as working in a cupboard (that just happens to be in a bathroom).

Even if he classes it as the bathroom he's not doing anything to the existing circuit - just connecting an appliance to it.

But then he is NICEIC, so you're starting out with someone who will be hard-of-thinking when it comes to grasping what the regulations really say.

 

[Leighloz]

Apparently changing the off and onable bits of the CH system is notifiable, so part P relevant, but given that he can self certify I guess I won't see the man from the council with his clipboard.

Thanks for all your help...

Leighloz

 

[flameport]

Boiler rated at 13 l/m deltaT35.

Just like most/all combi boilers then - prepare to be disappointed compared to the previous hot water cylinder.

 

[Leighloz]

Currentlyonly getting 9l/min out of my bath hot tap with my vented cylinder,so 13 l/m will be better!

Leighloz