Help!? Replacing Old Sunvic stat w Nest Learning Thermostat 3rd Gen - Heat only system

[Krissyboy87]

Evening all,

Apologies if this has been covered in another thread - I've never called upon a forum before!

We're in the process of upgrading our old heat only boiler with a new Ideal Logic heat only boiler.

So, feels like an opportune time to upgrade our ancient (albeit reliable) Sunvic thermostat with an up to date smart thermostat - the Nest Learning 3rd Gen..

I've checked online for compatibility and it's not all that conclusive We've got solid core copper cables feeding the old stat, so that appears to be a tick, but I just want confidence that it will work with my system - words of confidence (or not) would be greatly appreciated!

I attach pics of our existing system and stat, and cables feeding it

 

[Aquarius]

Good morning Krissyboy,

I don’t see a reason why it wouldn’t work. You have a y-plan system, the thermostat would need the 2 wires joining to the nest thermostat or disconnecting in the wiring center if you intend to use a usb lead for the nest thermostat? the heatlink would go where that black programmer is situated in the cylinder cupboard and wiring appears accessible. Should be straightforward enough.

 

[Krissyboy87]

Good morning Krissyboy,

I don’t see a reason why it wouldn’t work. You have a y-plan system, the thermostat would need the 2 wires joining to the nest thermostat or disconnecting in the wiring center if you intend to use a usb lead for the nest thermostat? the heatlink would go where that black programmer is situated in the cylinder cupboard and wiring appears accessible. Should be straightforward enough.

Aquarius - season's greetings and thank you, that is really helpful!

I have just watched a video on wiring up the Nest to a "y-plan" system and now makes complete sense, lots of familiar parts etc! I am now satisfied that I can proceed to order the device.

Wishing you and yours a great Christmas!

Kris

 

[Aquarius]

Wishing you and yours a great Christmas!

Kris

Same to you, wishing you a merry Christmas too.