Greenstar 28i Junior Combi Boiler

[nyc6699]

Hi all, Can you clarify the following for me please for a single channel hive connection into the boiler. I’ve read similar posts but not quite the same set up.

Picture 1 is inside the boiler.
Picture 2 is the single channel.

Is it LS on the boiler to 1 (common) on the hive and LR to 3 (heating on) on the hive.

Is it only 2 wires or do I need to find a live from somewhere.

Many thanks and appreciate any help.

 

[CountryFan]

Is it LS on the boiler to 1 (common) on the hive and LR to 3 (heating on) on the hive.

Yes

Is it only 2 wires or do I need to find a live from somewhere.

No, it’s 4 wires. What do you think permanent live and permanent neutral mean? Also, on that boiler, you may need to safety check afterwards if the cover forms part of the combustion circuit.

 

[RandomGrinch]

It would be:

Ls (Live supply) from boiler to L on the Hive receiver backplate.
Ns (Neutral supply) to N on the Hive.
Lr (Live return) from terminal 3 on the Hive.
Earth, to earth.
A short link wire would be added between L and terminal 1 on the Hive.
You would need a four core flex to wire as above.

Is that a picture of your boiler?
There seems to be some flex already connected to the Lr and Ls terminals?

 

[kidgreen61]

You need a permanent live & neutral into the Hive which you can take from the boiler, then connect Ls to T1 & Lr to T3.
I use 4 core cable

 

[RandomGrinch]

You need a permanent live & neutral into the Hive which you can take from the boiler, then connect Ls to T1 & Lr to T3.
I use 4 core cable

Wouldn't you use a five core cable, if you are connecting Ls and Lr separately to T1 and T3?

 

[nyc6699]

Many thanks everyone and very much appreciated.

 

[trojanhawrs]

Wouldn't you use a five core cable, if you are connecting Ls and Lr separately to T1 and T3?

Doesn't need an earth, just there as a tether. Can get away with 3 core if need be.

 

[RandomGrinch]

Doesn't need an earth, just there as a tether. Can get away with 3 core if need be.

Agreed, the Hive doesn't need an earth (although try arguing on the electrics forum about all points, or outlets requiring a connection!).

My point is; as the oversleeving of a green/yellow core as a live conductor, is now explicitly banned in the regs, and finding a flex without a green/yellow earth core is difficult; you necessarily have to have a 4 core flex.
Or as has been suggested above, keeping Ls and Lr separate, and not using a link on the Hive, then that would require a 5 core flex.

If we suggest using a 3 core flex, naturally a DIYer will pick up a standard cable. Of course it would still work, but I would prefer to give advice that was compliant with the regs

 

[trojanhawrs]

My point is; as the oversleeving of a green/yellow core as a live conductor, is now explicitly banned in the regs, and finding a flex without a green/yellow earth core is difficult; you necessarily have to have a 4 core flex.

I didn't know that, thought if it's insulated it's a non issue if sleeved. Which reg is that?

 

[RandomGrinch]

I didn't know that, thought if it's insulated it's a non issue if sleeved. Which reg is that?

It came in with amendment 2 of BS7671:2018, so only recent, although considered poor practice before.
I can't find the exact phrasing at the moment, so will look again later.

Edit: 514.4.2

18th Edition Amendment 2 – electricaltesting.co.uk

electricaltesting.co.uk

 

[ericmark]

Doesn't need an earth, just there as a tether. Can get away with 3 core if need be.

Not since 1966 when the rules changed, there has to be an earth terminated to all fixed equipment, including lights, only the pendent for the light can be without an earth.

And yes I do find the word terminated to be a problem with some class II equipment since often no tether terminal included. But I did not write the book.

Seem to remember mothers boiler was a Greenstar Junior and removing the front cover did not break any room seals. It was open to bottom so clearly no seal.

The idea is line is taken from the boiler, so if the boilers protective device opens (the fuse blows) then the thermostat supply can't by-pass the protective device. Personally I would only modify central heating in the summer, so I have time to correct anything which goes wrong.

The 17th Edition said

411.3.1 A circuit protective conductor shall be run to and terminated at each point in wiring and at each accessory except a lampholder having no exposed-conductive-parts and suspended from such a point.

the 14th

D.6 At every lighting point an earthing terminal shall be provided and connected to the earth-continuity conductor of the final sub-circuit.

wording has changed, but meaning is the same, an earth needs running even if not used.