Baxi Duo Tec & Nest

[Djbx]

Hi all,

I read Stem’s post about installing the Nest with the Baxi - first of all thanks for your post to m the install. I’ve followed the instructions for it, connected it all as was pictured on the duo-Tec boiler. Singed in and all that business, select to turn off the heat and it’s not cutting out at all. On the app and software etc it’s saying all connected and no issue but it’s obviously a disconnect somewhere. I’ve rest the boiler and app/thermostat - no joy.

Wiring diagram in the nest booklet has a loop from port 2 to the live on the heat link. But I saw in someone else’s post that wouldn’t be correct, as we’re connected direct into the L&N in the boiler. If I read that right?

Any assistance would be greatly appreciated, many thanks!

 

[CBW]

If I understand it correctly, you don’t need the link in your situation.

 

[ericmark]

It would seem this is the circuit diagram, there has been a debate on where the neutral should come from, and I have missed out the earth bonding, So it needs 3 core and earth boiler to heat link.

When I fitted it to my system, I found the anti legionnaires software was switching the boiler on when not required, and the geofencing was turning off the boiler when it was required, and the smart programming was adding bits to the schedule.

So I had to disable them all in the software which means the Nest was no longer doing any of the smart functions, which raises the question why fit Nest?

 

[ianmcd]

1&2 from the boiler to 2&3 on the nest
L&N FROM Boiler TO L&N on nest no links

If you dont have enough cores
L&N to L&N
2 from boiler to 3 on nest
Link L&2 on nest

you cant have 1 from the boiler to 2 on nest and have alink or it will never go off