Combi boiler wiring - C1 or C2?

[Pretty Mouth]

A combi boiler is wired into a plug, which is plugged into a single socket. The Nest receiver, controlling the heating (heat link I think they call it), is wired into a separate plug, which is plugged into a socket on another circuit.

So 2 circuits interlinked, a minimum C2.

However, could this also create a 'widowmaker', where unplugging either of the plugs, while the other is still energised, would leave the pins live?

 

[James]

It is only a problem if the supply from the heat link is looped to the relay in the heat link.

if the heat link supply is only used to power the unit and the boiler is connected Only to the volt free contacts (relay) then it is not a danger.
however a sticker to remind service people to isolate at both supply’s would be a good addition.

 

[Pretty Mouth]

It is only a problem if the supply from the heat link is looped to the relay in the heat link.

if the heat link supply is only used to power the unit and the boiler is connected Only to the volt free contacts (relay) then it is not a danger.
however a sticker to remind service people to isolate at both supply’s would be a good addition.

Thanks @James . Looking closely at the wiring diagram, I see what you mean now. Possibly no code. I'll have to go back for a closer look.

 

[littlespark]

Isn’t there something in the manual that says it all needs to be isolated from one point?

How difficult would it be to rewire the receiver into the wiring centre?

 

[brianmoooore]

It's the Nest receiver that has two supplies, not the boiler, so that's where the warning label is needed.

 

[Pretty Mouth]

Isn’t there something in the manual that says it all needs to be isolated from one point?

How difficult would it be to rewire the receiver into the wiring centre?

Not difficult at all - it's gonna happen, along with a tonne of other remedials. Just wanted to ask really