Connecting Nest E to Alpha E-Tec

[Rod2808]

Hello,

I would like to attach a Nest E thermostat to an Alpha E-Tec boiler. Currently doesn't have a thermostat, hadn't arrived when boiler was installed. Advice from the engineer doesn't match with what's on the Nest Heat Link, he may have been talking about an older model.
Engineer suggested wires from 1 + 2 on boiler, where red wire is currently, to 2 + 3 on Nest. The Nest doesn't have 2 or 3, can someone suggest the correct way to connect them?
The installation instructions mention an OpenTherm installation using a BUS communication wire to terminals 41 and 44. Not sure again if that's the right thing to be doing here.
Thanks

 

[Deleted member 267285]

It’ll be 1 and 2 from boiler to NO and Com on Nest.

 

[ianmcd]

As @Chris_W says, its as simple as that, forget about OT with your set up

 

[Rod2808]

Thanks Chris_W. The company are sending an electrician Friday now but I'll try myself as its so straightforward
ianmcd why shouldn't I use OT? I don't know much about it but it sounds useful, apparently saves a few pennies on gas and stops the boiler turning on and off so often.

 

[ianmcd]

Thanks Chris_W. The company are sending an electrician Friday now but I'll try myself as its so straightforward
ianmcd why shouldn't I use OT? I don't know much about it but it sounds useful, apparently saves a few pennies on gas and stops the boiler turning on and off so often.

if you want to try the OT you use terminals 41 & 44 to the OT terminals on the nest , and remove the red link, but these are actuall OT connections but for the Alpha climate control so might not work, you wont damage anything, give it a try if you want, might work , if it doesnt just use the connection method mentioned earlier

 

[ianmcd]

Sorry meant to add if you want to use the OT you will have to access paramater P7 and select alternative input 1, to tell the boiler you are using a 3rd party OT control

 

[Rod2808]

ianmcd thanks very much. I'll give it a try.