Nest wiring

[Tysonboy]

looking to instal a nest thermostat to my Worcester 28cdi boiler, I have no other thermostats connected just have a digital timer.
Do anyone have any photos or wiring diagram to help me out.
Thanks

 

[stem]

Fitting a Nest to a Worcester cdi has been covered frequently already on this forum. If you use the search facility you will be able to locate them. There's an example here.

If your model of boiler is the type that involves opening up a room sealed compartment to access the wiring terminals (some are, some aren't) then it's not a DIY job, it should be done by a Registered Gas Installer, who can ensure that it is properly sealed up again afterwards.

 

[Tysonboy]

Thanks stem, I have searched but unfortunately can not find anyone that has wired up to my specific model.

 

[stem]

The manual I have for the WB 28 cdi shows the boiler connections as:

Which has the same terminal labelling as the example contained in the link I gave you.

Lr= Live return
Ls=Live supply
Ns=Neutral supply

How is yours different?

 

[Tysonboy]

 

[stem]

OK, so it's not different, three terminals marked Ns Ls & Lr

Which is the same as the original post I referred you to.

So, the wire link is removed

And the instructions to connect the Heat link are therefore also the same.

1. Ls (Ls = Live Supply) This would go to the Heat link (L), and also be linked to the 'Heating Common' (2)
2. Ns (Ns = 'Neutral Supply') so self explanatory
3. Lr ('Live Return') this goes to Heat link (3) "Heating Call for Heat"
4. Earth to earth as applicable.

 

[Tysonboy]

Should I just leave the LCD timer connected or disconnect it

 

[stem]

As it's an integral part of the boiler it will need to be left in place but set to be permanently 'on' 24/7 otherwise it will interfere with the operation of the Nest.