Hive multizone with system boiler

[Poppy1011]

Hi, would be grateful for wiring advice for my Hive multizone set up.

I have a Worcester Bosch Greenstar 35Cdi system boiler and separate hot water tank with multizone thermostats (upstairs and downstairs). The boiler uses 230v mains switching. The boiler is currently connected to 2x Center BDR91 relay boxes, which in turn connect wirelessly RF to the two battery-powered EHE0200361 programmable timer/thermostats in each zone. There's also a separate Honeywell hot water electronic timer.

I want to replace this with my Hive set up. I have purchased a dual channel Hive Heating and Hot Water thermostat, plus a secondary multizone (single channel) thermostat.

The two existing receivers are currently wired exactly the same - fixed live and neutral (blue and brown wires), black wire to A, grey wire to B, earth unused.

For the single channel Hive receiver, I think this is simply a case of wiring up the L and N, and then black to 1-Common and grey to 2-NO (Heating On).

But for the dual channel receiver, there is no Common - do I connect the black to 4-NO and grey to 2-NC (Heating off)? On some threads I read that I would need to create a link between Live and NC - is this the case?

Many thanks in advance for any advice you can offer

(by the way I don't intend to hook up the hot water control to the Hive as the existing hot water timer works fine and is located some distance away so will be a pain to move the wiring).

 

[MeldrewsMate]

For the single channel Hive receiver, I think this is simply a case of wiring up the L and N, and then black to 1-Common and grey to 2-NO (Heating On).

Yes, that will open the associated zone valve (for the upstairs zone). The zone valve will create a boiler demand once it's open.

But for the dual channel receiver, there is no Common - do I connect the black to 4-NO and grey to 2-NC (Heating off)? On some threads I read that I would need to create a link between Live and NC - is this the case?

No. The dual zone receiver connects its L terminal with its terminal 4 for CH=ON, and its terminal 3 to L for HW=ON, therefore one of your cores (black or white in your photo for receiver two) will be permanent live (and be unused in your new configuration), the other will drive open the downstairs zone valve, so you should connect this to the dual receiver terminal 4.

If convenient, the unused core can be reconfigured to open the hot water zone valve, and then be connected to terminal 3.

As always, if you are not competent to make electrical changes then you must entrust this work to a qualified electrician.

 

[Poppy1011]

Thanks a lot.
So just to confirm, for the dual receiver, assuming I don't want to reconfigure the hot water, I simply wire the black or grey wire to terminal 4, and leave the other wire unconnected?

And no need for a link between L and Com for the single channel receiver? I got this from a similar thread which suggested a link between these two

 

[Poppy1011]

Sorry to bump - can I check that the black wire goes to terminal 4 only, and the single channel receiver doesn't need a link between L and Com>

The Hive is basically just a switch. With the single channel version, terminals 1 (common) and 3 (heating on) are wired straight to the switching contacts, so just like any switch. A light switch for example, you need one connection for the live supply, and another connection to supply the device being switched. In the case of Hive, terminal 1 has the the live supply to one side of the switch, and terminal 3 connects the other side of the switch to (in your case) the motorised valve.

The dual channel version needs extra terminals for controlling the hot water, so the common contact of the switch is wired internally to the live terminal instead of being connected to an external terminal, meaning no link is required as it is already there inside the Hive.

 

[stem]

For your installation, for the single channel:

Brown wire in L goes to Heatlink L
Blue wire in N goes to Heatlink N
Black wire in A goes to Heat link Common (1)
White wire in B goes to Heat link Heating on (3)

Do not add any links, your system doesn't need it.

The dual channel uses terminal (4) for the heating on. But I don't know if that is the white or black without knowing what is on the other end of each. It depends on how the original installer has wired it up. For the single channel with voltage free switching, it doesn't matter which way around they go. When there is just a live supply you need to get the right wire.

 

[Poppy1011]

Thank you so much, it's all set up and working fine now