Nest Gen3 on Firebird Combi 90

20 Jul 2014
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South Glamorgan
United Kingdom
I have a Firebird Combi 90 oil boiler, and Robus RRF10 stat.

I’ve just acquired a Nest gen 3 thermostat. Can I connect this to my current setup and remove the Robus?

I can connect the Next link box to the permanent live and neutral on the right of the combi electrics box. Im not sure where the signal wires will go? Im guessing the grey and black wires under the Room Stat connection block is the key..

Any help would be appreciated. Thank you :)

pics attached
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I’ve used multi meter. Black wire from “Room stat” on boiler goes to T3 on Robus. And Grey wire from boiler “Room Stat” goes to Robus T2
wires in 2&3 on the existing stat go to 2&3 on the nest heat link, that is your heating switching wires, you will also need a permanent live and a Neutral to power the unit
Thank you, thought so. Just to reclarify.

Wire Nest 2 to 1 on the boiler junction box, and Nest 3 to 2 on the boiler junction box?

(Boiler 1 went to old stat 2 and Boiler 2 went to old stat 3)

I can then use the redundant black and grey wire of the old stat to wire into nest T1 & T2 to wall mount where old stat was?

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yes you can do it that way, doesnt matter which way you wire 1&2 from the boiler to nest 2&3 its just a switch will work either way round, you will need to switch any existing CH timer to constantly on though and the nest will over ride it
Thanks again :)

yup the boiler timer is always on override and the old Robus stat was my switch. I’ll do the same with the nest

many thanks again :)

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