No current thermostat, how to hook up the nest to a Viallant ecoTEC pro VMW IT 236/5-3 H R6

[User9000]

Hi there,

I have a Gen2 Nest thermostat that we've been using for the last 4 years on an older boiler. Everything was working fine. We've just got our boiler replaced with a Viallant ecoTEC pro and I'm not sure how to hook it up. Before the heatlink was hooked up to the boiler and the thermostat was on a table stand connected to power over USB. I'm looking to do the same thing with the new ecoTEC boiler.

I saw a link of a page where one could do a compatibility check and the first question is about the wires I have sticking out of my wall. Eeeuh, I don't have any wires sticking out of my wall. That cable is lost during the last renovation and it's the whole reason I have a Nest. So, the compatibility check site is not helpful in my case.

Any advice?

[Vladut]

Hi there, thank you so much for reaching out. Indeed the compatibility checker may be confusing but it depends very much which are you using. Can you please try the EU compatibility checker?

[Vladut]

Hi there, just checking in with you. Have you checked my last message?

[User9000]

The compatibility checker only says that it's compatible but how it should be connected is still a big question mark.

[LarisaL]

Hi there! Just to clarify, the serial number of the thermostat display, which can be found on the back of the display when it is off the base, above the QR code, starts with 09A? If yes, then you have a 3rd Gen thermostat and you can check the wiring in the installation guide. 

[Vladut]

Hi there, just checking in with you. Did you manage to check my colleague's last message?