Nest 2nd Generation - Vaillant ecoTec Pro 28 h combi A

[fguitch]

Hi,

I'm trying to install my Nest heatlink by replacing my old thermostat.
Here is some pics

So just to be sure I need to connect Live & Neutral to the respective Live & Neutral terminals of my Heat link.
Black Wire (from 3) goes to 3 on the Heat Link.
Should I also add the Live to 1 on the Heat Link ?

Thanks for your help.

 

[Echo the husky]

Your existing wiring is extremely poor and does not comply with the wiring regulations. The use of the earth wire as the neutral is not allowed. As such, the existing thermostat cable needs to be disconnected from where it is connected, and the Heatlink unit should be mounted near the boiler, and connected to it using a suitable multicore heat resisting flex. To do this requires removing the cover from the boiler so this work needs to be carried out by a gas safe registered heating engineer.

 

[Tay7]

Where is the current thermostat installed? Hallway?

What have you got at the boiler end? This is where the heatlink would normally go and the actual nest would go where your pictures show. You would disconnect the old cable from the wiring centre at the boiler end and re-use it for the 12v feed from the heatlink to the nest (T1/T2). Your third wire would be connected to do the same as it does now i.e. call for heat and you'd lose the jumper wire.

All this depends what you have at the programmer/boiler end.