Nest and Alpha CB24

[texwatson]

Hi, I'm after some help with my newly purchased NEST thermostat with my Alpha CB24X boiler. I currently have a wireless (battery operated) thermostat which I want to replace with the NEST. Can someone give me guidance with the wiring to the boiler PCB? I do not have the optional clock as mentioned in the Alpha documentation, and I don't have a wired in thermostat/timer.

Installation seems pretty straight forward, I'm competent with basic wiring and electrical stuff, but reading trying the match the NEST and Alpha diagrams are not helping me.

The NEST gives me wiring diagrams for Switched Live, Low Voltage (dry contact), Bolier with zone valves and Boiler with MOMO zone valves... ??? Not a clue what my Alpha is.

Any help (where to stick my wires) would be VERY appreciated.

NEST:

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• texwatson
• 11 Oct 2014
• 1

Alpha:

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• texwatson
• 11 Oct 2014
• 1

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• texwatson
• 11 Oct 2014
• 1

 

[petit_pablo]

Your existing thermostat should be wired into 1 and 2 on your boiler terminals?

You need to put the nest terminals 2 and 3 to these terminals doesn't really matter which way round you do it. Then L-N from the incoming mains.