Wiring Nest heatlink to Vaillant ecoTEC 937

[Droler]

Hi,
1st post and I'm a bit of an amatuer (can do basic wiring) so be gentle...
Basically I need to wire a 3rd generation Nest Heatlink to a Vaillant EcoTEC 937. Could someone please relate the Nest instructions to the boiler wiring diagram for me? I'm not sure which Nest instructions I should be following, the left (230v combi) or the right (low voltage combi).

Also when wiring in the power to the Nest unit is it ok to run it from the power cable connection off the circuit board?

Many thanks

 

[Dan Robinson]

Hope you are going to do your 26.9 checks when you. Put that boiler cover back on.

 

[Droler]

Is this something to avoid as a DIYer then?

 

[Dan Robinson]

Well, seeing as you're this far.... you might as well remove the red link wire and follow the second example from the nest diagram, then get the boiler serviced by an rgi.

 

[ben9]

Hi,
1st post and I'm a bit of an amatuer (can do basic wiring) so be gentle...
Basically I need to wire a 3rd generation Nest Heatlink to a Vaillant EcoTEC 937. Could someone please relate the Nest instructions to the boiler wiring diagram for me? I'm not sure which Nest instructions I should be following, the left (230v combi) or the right (low voltage combi).

Also when wiring in the power to the Nest unit is it ok to run it from the power cable connection off the circuit board?

Many thanks
View attachment 106505 View attachment 106507 View attachment 106506

 

[ben9]

@Droler, the boiler looks similar to mine. Googled couple of hours and so far I have found out :Boiler:remove link between 3(RT)&4 and connect to Nest 2(heating on)&3(heating off),
Boiler:L=Nest L
Boiler N=Nest N
Boiler E=Nest E
I think It should work.