How do you wire a Google Nest to a Evinox 40-10E HIU (E-ON)

[MG2022]

Hello members,

Does anybody know how to wire a nest heat link to an Evinox HIU?

I know I need to replace the room module/thermostat with the nest controller and supply a 12v connection to the heat link. I also know to supply the heat link with a 240v connection for power from the HIU connection.

Looking at the instructions of the heat link I need to connect call-for-heat (Normally Open), common and satisfied (Normally Closed).

The problem I have is that unlike previous versions of the HIU my one has no obvious connections for the above. I have attached the electrical diagram to the HIU - can anyone decipher it at all?

I hoped I could simply use the wires that went to the thermostat, or would that be 'too easy' ?

Really hoping somebody has done this before.

Many thanks

Matt

Evinox Technical Diagram:

Room Module / Thermostat:

 

[ShaunCorbs]

What happens when you link 3 and 4 ?

 

[MG2022]

Hi Shaun,
Bit worried about touching cables to test stuff - are you expecting the heating to come on if I did that? and what is the chance this could break something?
Regards
Matt

 

[Deleted member 120897]

Is there a section in your instructions for a 3rd party thermostat? I’ve found this, but appears different from your instructions.

 

[ShaunCorbs]

Best advice I can give then is to employ an electrician / spark