Baxi Argenta 32 and Nest Gen3

[Colin Cooper]

Hi all,
I have been trawling the internet trying to get some information on how to connect a nest to my new boiler, i live in Spain and the instructions for the boiler don't seem to be available in English... Baxi didn't either bother to reply!
as i understand it the Baxi have the usense ubit that connects via the R-BUS plug, so i tried that... doesn't seem to do anything
i have addad a couple of pics and would be very gratefull if their is anyone that can help me out here.
Many thanks
Colin

 

[ianmcd]

sorry your post is very confusing what are you actually asking ? are you trying to wire the nest up to the R-bus on your boiler ? that wont work you need to wire it to the Tout

 

[Colin Cooper]

Hi Ian, hehe... it does read a bit confusing i admit! sorry for that.
I'm trying to get my nest working, and just got a bit confused where to connect it to..
ok, so two wires from the Tout plug, where would they go into the heatlink? 2&3 i'm guessing?

 

[Colin Cooper]

Hi Ian, leading on, connected already to the Tout is an outside thermostat, i'm guessing some sort of safety device so the boiler doesn't get to cold?
if i disconnect this and attach the nest, i get a red error message saying "outside temp closed"?
Colin

 

[ianmcd]

That is a weather compensation sensor so connect that back the way it was, what thermostat do you currently have ? sensor

 

[Colin Cooper]

nothing, its a new install... so i purchased the Nest Gen3
Colin

 

[ianmcd]

Do you have underfloor heating by any chance ?

 

[ianmcd]

I like a challenge and now know that you have an oil condensing boiler, try connecting the R-bus terminals to the OT terminals in the nest

 

[Colin Cooper]

no underfloor, yep its a new oil fired boiler... ok, i will try that
Thanks
Colin

 

[ianmcd]

if you dont have any external control , where do the two wires in the R-Bus go to ?

 

[Colin Cooper]

I have tried them into 2&3 and now to the OT terminals ... With no luck
I do know that the RBus is the direct connection for the baxi usense smart controller, so I thought that it was probably the connection, boiler end for the nest...

 

[ianmcd]

I cant see it in your pics, is there a terminal X3 on the pcb ? can you send me a pic of that please

 

[Colin Cooper]

Hi, yes there is, its a 3 pin connector port... one of which has an earth symbol and the other two are blank.... not at my house at the minute, but i know thats there as i have looked at it.

 

[ianmcd]

That is where you need to wire the Nest into but you will have to do more probably insert a link somewhere, send me a pic when you get home and I will try and work it out for you

 

[Colin Cooper]

Hi Ian, Ok thats starting to make more sense now, ... this is a pic of the whole PCB
your help is very much appreciated
Colin