Wiring Nest Thermostat to a Baxi 428 Combi Boiler

[buntonn]

Hello,

I'm trying to install a Nest Thermostat 3rd edition to a new Baxi 428 combi boiler. I have fitted the Heat Link to the wall and put in trunking, but an not sure on the wiring looking at both manuals. I am not sure if I should be following the instructions in the Nest manual for 230v combi boiler or Low voltage/dry contact combi boiler?

This was a brand new central heating install, so no existing thermostat.

From Nest installation manual




From Baxi Boiler installation manual




How my boiler is wired right now


Any help would be very appreciated.

Thanks

[Dickie]

X8 OT on boiler, remove the link, connect two wires to it & OT1/OT2 on Heatlink.
The 3rd generation is supposed to operate on Open Therm.

Open Therm is a two way digital control, with the 0s & 1s jumping back & forward.
240v switching is an On/Off Control only. OT is a ‘Master & Slave’ communication, which can modulate the boiler easier.
HTH

[buntonn]

Thanks for the info, I have attached the wiring layout for open therm, if that helps?

[buntonn]

X8 OT on boiler, remove the link, connect two wires to it & OT1/OT2 on Heatlink.
The 3rd generation is supposed to operate on Open Therm.

Open Therm is a two way digital control, with the 0s & 1s jumping back & forward.
240v switching is an On/Off Control only. OT is a ‘Master & Slave’ communication, which can modulate the boiler easier.
HTH

Wired up as you said and it's working perfect

Thank you!

[Dickie]

X8 OT on boiler, remove the link, connect two wires to it & OT1/OT2 on Heatlink.
The 3rd generation is supposed to operate on Open Therm.

Open Therm is a two way digital control, with the 0s & 1s jumping back & forward.
240v switching is an On/Off Control only. OT is a ‘Master & Slave’ communication, which can modulate the boiler easier.
HTH

Wired up as you said and it's working perfect

Thank you!

Thanks for your expression of gratitude. A wee donation to the charity in my signature would be appreciated. I hope you were like me & enjoyed a wonderful healthy & happy childhood.
Unfortunately, some kids don’t. Thanks.