Current boiler diagram and looking to go Nest.

[jmac80]

Hello all

Spent a while earlier popping off faceplates etc and this is exactly what i have on my current heating system..
obviously i'm no spark/plumber so please excuse the diagram, I would just like a little help to better understand why the system is wired this way.

What confuses me instantly is that everything I read about adding roomstats/programmers to my worcester combi requires the mains from 3a switch going to boiler then from boiler back to programmer etc.. like this pic in the manual for my boiler:

For a nest setup would I need to get a new cable put in to the boiler..?

Thanks

 

[jackthom]

Are the mains supply, programmer and boiler all fairly close together?
If it's reasonably easy to run a new 3 core flex from the 3A spur to the boiler that's what I would be happier doing.
As the heatlink doesn't need an earth connection you could use another 3 core flex to connect Live, Neutral and Switched Live (LR) back from the boiler to the heatlink.

 

[jmac80]

Are the mains supply, programmer and boiler all fairly close together?
If it's reasonably easy to run a new 3 core flex from the 3A spur to the boiler that's what I would be happier doing.
As the heatlink doesn't need an earth connection you could use another 3 core flex to connect Live, Neutral and Switched Live (LR) back from the boiler to the heatlink.

Hi mate
Yes they are all right next to each other, Is heat resistant 0.75mm flex cable adequate or would it need to be more like 1.5mm flex?
Cheers

 

[jackthom]

Heat resistant flex is good and 0.75 mm will be perfectly happy.

In case there's any doubt about the wiring, LR goes to Terminal 3 in the heatlink and you'll need a short wire link between Live and terminal 2.

If you use the green/yellow wire for the LR connection make sure it has a brown or red sleeve at both ends to show it is no longer an earth wire.

 

[jmac80]

Heat resistant flex is good and 0.75 mm will be perfectly happy.

In case there's any doubt about the wiring, LR goes to Terminal 3 in the heatlink and you'll need a short wire link between Live and terminal 2.

If you use the green/yellow wire for the LR connection make sure it has a brown or red sleeve at both ends to show it is no longer an earth wire.

Thanks again
I shall do another diagram to make sure we are all on the same boat
It's actually 5 core heat flex I have here.. got some 1.5mm and 0.75mm.

Cheers

 

[jmac80]

Heat resistant flex is good and 0.75 mm will be perfectly happy.

In case there's any doubt about the wiring, LR goes to Terminal 3 in the heatlink and you'll need a short wire link between Live and terminal 2.

If you use the green/yellow wire for the LR connection make sure it has a brown or red sleeve at both ends to show it is no longer an earth wire.

Hi
So would this be it?
I was hoping to keep the earth cable as the future plan is to add a wiring junction box and 3 x 2 port valves and 2 more nests for them areas.

Thanks

 

[Echo the husky]

Spot on!

 

[jmac80]

Not sure how I managed to post this in the Electrics outside of UK forum but can a moderator please move this post to the normal UK electrics forum?

Thanks

+++++++++
no, its plumbing and heating
+++++++++

 

[jmac80]

Not sure how I managed to post this in the Electrics outside of UK forum but can a moderator please move this post to the normal UK electrics forum?

Thanks

+++++++++
no, its plumbing and heating
+++++++++

Lol ok.. round and round i go.. thanks

Actually.. to be honest it's more electrics question.. it's about wiring up a system not plumbing it in for water.

 

[muggles]

it's about wiring up a system not plumbing it in for water.

Indeed, but very few electricians can competently wire up heating systems - it's best left to heating engineers who actually understand how the system works

 

[jmac80]

Indeed, but very few electricians can competently wire up heating systems - it's best left to heating engineers who actually understand how the system works

Ok mate
Thanks

 

[jmac80]

Indeed, but very few electricians can competently wire up heating systems - it's best left to heating engineers who actually understand how the system works

Wondering can anyone suss this one out..
It's the final system I want to have with 3 x 2 port zone valves, also a honeywell 10way wiring box / junction box..

Here is the blank plan... and also the info on the zone valves I have...

And this is from the zone valve manual:

can anyone do a rough sketch on the blank one posted above on where the wires terminate then I can redo the diagram and upload?

Thanks

 

[jackthom]

Would take me too long.
How about..
Boiler Live to Honeywell 1
Neutral to 2
Earth to 3

All three valves...greys to Honeywell 1 Live
.......Blues to 2 Neutral
....Yellow/greens to 3 Earth
.....Orange all to 7
......Browns individually to 4,5,6.

Then each heatlink gets Live and Neutral from Honeywell 1 & 2
A short link required from Live to 2 in each heatlink.
3 from each heatlink to go individually to Honeywell 4,5,6

Honeywell 7 goes to LR in boiler.

Have I left anything out?

 

[jmac80]

Would take me too long.
How about..
Boiler Live to Honeywell 1
Neutral to 2
Earth to 3

All three valves...greys to Honeywell 1 Live
.......Blues to 2 Neutral
....Yellow/greens to 3 Earth
.....Orange all to 7
......Browns individually to 4,5,6.

Then each heatlink gets Live and Neutral from Honeywell 1 & 2
A short link required from Live to 2 in each heatlink.
3 from each heatlink to go individually to Honeywell 4,5,6

Honeywell 7 goes to LR in boiler.

Have I left anything out?

Thanks so much, I shall draw that up then upload

James

 

[jackthom]

The Honeywell terminals 1&2 in particular will get a bit crowded but they're usually fairly roomy.

You could link a single flex for L&N from one heatlink to the next if it's easier.