Honeywell BDR91 to Nest wiring

[Nesthelp2019]

I am trying to upgrade my existing Honeywell BDR91 to the third generation Nest but would like a bit of help with the wiring before I jump in. This is how things are currently connected:

https://imgur.com/rrt3jdx

So the live and neutral wires coming from a fused spur are in one side of a connector block along with the live and neutral wires going to the boiler. In the other side of this connector block are the live and neutral going to the relay.

The earth wires are just in connector blocks.

Then the grey and black wires going to the boiler are connected to A and B in the relay.

As I understand it when connecting the Nest:

N = N
L = L
A = 2
B = 3

There is no space in the new Nest box for the connector block with the live and neutral wires connected so I am a little unsure of how to proceed.

 

[CBW]

Put all L’s to L and all N’s to N if you can, if not then just add something like this to help:https://www.toolstation.com/corgi-wiring-unit/p63297 and your other 2 are switch lives, appears to be extra low voltage (probably 24v).

 

[muggles]

If you use the search function at the top of the forum page, you'll find that this question has been answered four times already