How to control heating and hot water tank using Nest 3rd Gen Thermostat and app

[DIYBabe90]

Hi,

I have a Hive controller to schedule hot water and heating in the house. Heating is further controlled using hive thermostat. I have a systems boiler that is connected to a hub that sends signals to hot water tank. Hot water tank is fed by mains (not gravity), installed last year.
I am planning to install Nest 3rd Gen thermostat unit to control both hot water and heating. Can anyone point me on how to go about it? Is nest compatible with my system and can allow me to do what I am planning? Thanks

 

[Deleted member 267285]

Being an unvented cylinder, it falls under part G3 of the building regulations. I’m not 100% sure you can do it under diy.

 

[DIYBabe90]

Being an unvented cylinder, it falls under part G3 of the building regulations. I’m not 100% sure you can do it under diy.

I want to understand the work that is involved here. Appreciate your concern on why I should not do it.

 

[ianmcd]

Yes you can do it the nest receiver simply replaces the existing Hive receiver, no G3 requirement to do it, will require some minor wiring alterations though as they dont use the same backplate

 

[DIYBabe90]

Yes you can do it the nest receiver simply replaces the existing Hive receiver, no G3 requirement to do it, will require some minor wiring alterations though as they dont use the same backplate

Thanks. Where can I find any more details on how to do it?

 

[Deleted member 267285]

Yes you can do it the nest receiver simply replaces the existing Hive receiver, no G3 requirement to do it, will require some minor wiring alterations though as they dont use the same backplate

Well, you learn something new, thanks mate.

 

[ianmcd]

Thanks. Where can I find any more details on how to do it?

Nothing hard google the wiring diagrams for nes and for Hive dual channel, the same wires go to the corrosponding terminal , i.e. HW on to HW on etc but on the nest you will need to make a link between live and 2&5 the rest is a simple swap all the wires are already there

 

[ericmark]

Nest Gen 3 can use Opentherm, and the algorithms are claimed to be better than Hive, however it has no compatable TRV heads so likely better with Hive.

I have Nest Gen 3 mainly as two wires main house to boiler does all, but when Google bought out Nest they dropped support for Energenie TRV's and in Europe failed to market an alternative. In USA they market sensors but they don't work with UK version.

 

[ericmark]

Nest publish wiring diagrams for S and Y Plan, but not C Plan, however I have worked out how to make it work.

 

[DIYBabe90]

Nest publish wiring diagrams for S and Y Plan, but not C Plan, however I have worked out how to make it work.

Thanks. Can you please share your wiring diagram?

 

[ianmcd]

Thanks. Can you please share your wiring diagram?

You do not need a wiring diagram, you do not have a C plan just move the wires from the hive to the nest to exactly the same terminals, if you cant do that then you will need a pro installer , it couldnt be easier

 

[ericmark]

With C Plan power out of com not in, when I go upstairs to PC I will post circuit diagram.

 

[ericmark]

 

[ianmcd]

YOU DO NOT HAVE A C PLAN !!!!!