Another Hive thread! Connecting to a Greenstar 30si combi.

[abzthemanc]

Another hive thread!

Hi all wanting to replace my current digital timer/thermostat with a hive V2. I have a Worcester Bosch Green Star 30si Combi boiler.

My current setup is as shown in the attached image.

The thermostat is in my landing and boiler is in the garage.

The boiler connects to a fused switched spur and to the thermostat.

If I understand correctly I'm missing a wire from the Ns which would need to go into the Hive. If this is the case then I'm missing a wire in my current cable which I believe is 5 core (earth, black, blue, brown, grey).

Can anyone advise what steps I would need to take to get the Hive working? I'm likely gonna put the receiver next to the boiler as the wire to existing stat is separate and goes through the wall and too much faff to replace.

Thanks in advance!

PS the LS to Com wire does change from Black to brown as there are two separate wires connected at the spur via a connector.

 

[stem]

For a single channel Hive.

The black/brown wire going from the boiler Ls (Live Supply) to existing thermostat 'Com' connects to both the Hive (L) and (1) Common
The grey wire going from the boiler Lr (Live Return) to existing thermostat 'No' connects to the Hive (3) Heating On 'No'

As you have figured, you will need to add a neutral wire for the Hive (N) usually this would come from the boiler Ns (Neutral Supply) as below:



However if you have to open up a room sealed enclosure to access the boiler terminals, this should only be done by a Gas Safe engineer. If this is the case, you can run a new cable to connect the N on the 'load' side of the fused spur to the Hive instead.

 

[abzthemanc]

Thanks for the reply and advice!

If I understand correctly the diagram below should suffice.

If I was to change wiring at the boiler, Id need an additional wire in my current 5 core flex (is there such a thing as a 6 core?!) so I could connect the Ns to N on the Hive receiver. The alternative as you mention is to simply add another neutral from the Load in the fused spure to Hive (as shown below).

I'm trying to understand the difference between the neutral (N) on the boiler and Neutral Supply (Ns)... since we will be connecting to Neutral at the spur, are they essentially the same thing?

 

[EFLImpudence]

I'm trying to understand the difference between the neutral (N) on the boiler and Neutral Supply (Ns)... since we will be connecting to Neutral at the spur, are they essentially the same thing?

Yes, the same thing.

Your diagram is possibly confusing you because it does not show the supply side of the FCU nor the supply cable.

 

[EFLImpudence]

You should have the thermostat L connected to a propler L, not LS. Obviously at the same place from which the N is taken.


Edit - or connect N to NS as Stem has shown.

 

[abzthemanc]

You should have the thermostat L connected to a propler L, not LS. Obviously at the same place from which the N is taken.


Edit - or connect N to NS as Stem has shown.

Thanks, based on boiler manual all wiring to a thermostat goes from Lr, Ls, Ns. I guess since the Hive says it should be connected to a permanent live, is that the reason you say I should not be using the Ls? What is the impact of using Ls instead?

 

[EFLImpudence]

No, I was just saying they should be connected at the same place - it will be the same cable, after all - then I saw Stem's diagram.

 

[abzthemanc]

Got you, that makes sense...

Stem's diagram is the idea scenario. However my problem is that my current cable is missing the extra wire I need to connect to Ns, it only has 4 wires + earth.

 

[EFLImpudence]

Either use a second cable or get some 4-core flex.