Change Honeywell BDR91 to Hive receiver

11 Jun 2017
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United Kingdom
Hi can anyone help? I would like to change my BDR91 to a Hive receiver. My boiler is a Vaillant Ecotec 837. In my BDR91, there is a cable from the boiler and a feed from a fused switch. I’ve seen posts where there are only the cables from the boiler, so is it as simple as this?:

The two blue wires in N into Hive N
The black wire in L(1) into Hive L
The brown wire in L(2) into Hive L
The grey wire in A into the Hive Com (1)
The black wire in B into the Hive heating on (3)



  • BDR91 wiring.jpeg
    BDR91 wiring.jpeg
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X2 blue wires in BDR91 N to N on Hive
X2 Brown wires in BDR91 L to L on Hive

What you need to establish is whether the grey and black wires operate on 24v side of boiler or 230v side, get this wrong and it could be costly.
You've got the idea Ailsworth DIYer. As you have figured, for a single channel Hive..

The blue wires go to N go the the Hive N
The brown wires in L & L go to the Hive L
The grey wire in A goes to the Hive Com (1)
The black wire in B goes to the Hive heating on (3)

Wire it this way (without any additional links) and it doesn't matter if it's 230V or 24v, because the mains supply to power the Hive and the switching circuits are kept separate exactly as they are presently are at the BDR91.

Tidy the wiring up though. There shouldn't be so much of the copper visible poking out of the terminals.

From what you have said, I assume you have the combi version of the Vaillant which doesn't have a hot water cylinder.
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