Nest S plan wiring using Wago wiring centre

[trickymicky69]

Hi,
I am in the middle of having a new heating system installed
There will be a new 2 core cable ran for the nest heatlink which will be hard wired to the thermostat on terminals t1 and t2
Being an S plan system there are two valves - one for CH and one for HW
There is a newly installed fused spur at the boiler location
Worcester manual says remove link if not using their thermostat (I’m not, so will remove)

I can figure out how to wire an s plan using a Wago wiring centre with no issues

Where my brain fails to work properly is how it would tie in with the nest connections at the heatlink

Thanks

 

[CBW]

The heating on and hot water on go to the browns of corresponding motorised valves, but the hot is also via the cylinder thermostat.

 

[ianmcd]

the nest heatlink which will be hard wired to the thermostat on terminals t1 and t2

the nest T1 &T2 go directly from the nest receiver to the nest thermostat, you can do this within the Wago wiring centre if you want but they are simply that , they do not join with anything else

 

[trickymicky69]

So am I better off wiring the heatlink through the wiring centre or straight to the heatlink?

 

[trickymicky69]

For the valves

 

[ianmcd]

So am I better off wiring the heatlink through the wiring centre or straight to the heatlink?

Doesnt make any difference, whatever is easiest, it is simply a low voltage power supply

 

[ianmcd]

For the valves

T1 &T2 have absolutely nothing to do with any valve they are a low voltage supply to the thermostat to save you using the USB power cable

 

[RandomGrinch]

Where my brain fails to work properly is how it would tie in with the nest connections at the heatlink

Have you had a look at the Nest installation guide?

 

[trickymicky69]

So if I am understanding correctly…..
Neutral live and earth from fused spur into wiring centre
Neutral and live for boiler from neutral and live in wiring centre plus earth if required
Link wire removed from boiler (as per manual)
T1 and T2 wired to two core and onto thermostat 12v connection
L,2 and 5 on heatlink are linked with jumper wire
Both orange wires to valves into live on wiring centre
Both green wires to earth on wiring centre and one earth to terminal on heatlink
Brown wire from water valve to cylinder thermostat
Com connection to terminal 6 on heatlink
Brown wire from heating valve to terminal 2 on heatlink
Brown wire from water valve to terminal 5 on heatlink

Is that correct?

 

[muggles]

So if I am understanding correctly…..
Neutral live and earth from fused spur into wiring centre
Correct, 3a fuse

Neutral and live for boiler from neutral and live in wiring centre plus earth if required
Earth is always required. Depending on the model you may also need a pump overrun connection

Link wire removed from boiler (as per manual)

 Correct

T1 and T2 wired to two core and onto thermostat 12v connection
Correct, preferably using a 0.75mm² shielded flex such as CY https://www.electriccable.co.uk/RWDcycableTECC.php Shielding to be earthed at heat link

L,2 and 5 on heatlink are linked with jumper wire
 Correct

Both orange wires to valves into  switch live on wiring centre

Both green wires to earth on wiring centre and one earth to terminal on heatlink
Correct

Brown wire from water valve to cylinder thermostat Normally Open terminal

Cylinder thermostat Com connection to terminal 6 on heatlink

Brown wire from heating valve to terminal 3 on heatlink

Is that correct?

 

[trickymicky69]

Thank you

 

[trickymicky69]

How would I know if my boiler has pump overrun?
It’s a brand new Worcester green star 4000 24kw system boiler

 

[muggles]

System boiler will deal with pump overrun on its own, so you don't need to account for that.

 

[trickymicky69]

Great, thank you