Worcester Boiler and UH1 ufh wiring help please

[Matchermike]

Good morning.

I have wired a new conversion with the assistance of our electrician but am a little stuck wiring the boiler and our jg ufh system.

We have a jg uh1 wiring center which we have wired for mains on the downstairs ring. Our boiler is on separate supply.

We have installed 1.5mm twin and earth between boiler and uh1 to act as boiler enable. This all seems correct as per jg diagram.

I understand our worcester bosch greenstar heatslave ii 25/32 has a loop installed between live and switched live. We should remove this and wire our boiler enable to this. At the uh1 we wire to the volt free boiler enable contacts.

Now our electrician suggests both uh1 and boiler should be on same supply. The heatmiser uh1 guide says to power uh1 from boiler fused spur but jg makes no reference to this and just says fused spur. Is this essential?

Worcester technical also suggested volt free contacts can not be wired to their boiler. Confused?!

Is my wiring logic sound?

Appreciate any advice.

Thanks
Mike

 

[Dan Robinson]

It all needs to be on the same supply.

 

[Dean744PiN5]

the volt free is just that you provide the voltage required (this allows for both boilers with 24v or 240v switching), in this case it will come from the live supply at the boiler to the wiring center and then back in to live return.

 

[Matchermike]

Thanks for the quick replies.

so my wiring logic for boiler enable is sound.

To rectify the supply issue. Does putting boiler and ufh socket ring on same rcd work? Or do i have to take down boards and put cable between uh1 and boiler fused spur?

Thanks
mike

 

[Dan Robinson]

It needs to be on the same fused spur.

 

[Matchermike]

Thanks for the reply. Boards off tomorrow then!

I'll put a socket faceplate on the existing spur at the uh1 and add a new box running 4mm from the existing boiler spur.

This will mean 4mm from board to boiler switch and onto uh1 switch

Thanks
Mike