Replacing Honeywell BDR91 receiver with Dryton Wiser Kit 1 (One Channel) Hub

[Pav950]

Hello,

Currently have Baxi EcoBlue +28 Combi Boiler with thermostat (Honeywell CMR927). Trying to replace receiver BDR91 to Drayton Wiser Thermostat kit 1 (One Channel) Hub. Never done anything like that before and after reading several posts kind of understood that I have to transfer wiring from an old received to a new hub in a similar manner. However looking at wiring of my Honeywell BDR91 (please see photo attached) I am getting confused as L1 & L2 are linked together and i am not sure how to transfer those into the new Drayton wiser wiring? Please could someone advice how shall i safely wire a new hub?

Thank you very much in advance for any advice.

Many thanks
Pav

 

[RandomGrinch]

I am getting confused as L1 & L2 are linked together and i am not sure how to transfer those into the new Drayton wiser wiring?

Ignore the link wire in your BDR91, it is completely superfluous - your existing setup would work perfectly well without it.

You would transfer N in BDR91 to N on the Wiser back plate
L to L
Black wire in A to terminal 1
Grey wire in B to terminal 3
And the green/yellow earth wire to the earth terminal on the back plate.

Don't add any additional link wires.

Post a picture of the wiring when you are finished, if you would like some reassurance!

 

[Pav950]

Thank you very much RandomGrinch. Will do like you suggest. Why you think the link was there on the first place? Was it like for extra safety?

 

[RandomGrinch]

Why you think the link was there on the first place? Was it like for extra safety?

No idea!
There is no safety reason for it.
Both the L1 and L2 terminals are linked together internally.

Some boiler controls are connected with cables that have fewer cores. In that case, an extra link wire may be needed to connect between L2 and A, to provide the switched live for the boiler.
Your installer may have left this spare link wire in place, just in case it was needed in the future!

 

[Pav950]

Yeah, that make sense. Thank you so much once again!