nest installation issues

[Leesparkykent]

Cheers

So the opentherm is supposed to be able to control both heating and hot water via the one pair connection.
I have a 3 core from boiler spur to wiring centre and 3 core to each stat. Brown on each valve to sw return from each stat. I understand the wiring of what's in place.
I'm trying to figure out best way to achieve 12v at wall stats and not kill the feed to the valves. I think this leaves me with 2 options. Adjust wiring at spur or install heat link in wiring centre cupboard and use 2 legs from the 3 core back to boiler for opentherm. The 2 valves are for both zone use and not domestic hot water

Img[/QUOTE

Cheers

So the opentherm is supposed to be able to control both heating and hot water via the one pair connection.
I have a 3 core from boiler spur to wiring centre and 3 core to each stat. Brown on each valve to sw return from each stat. I understand the wiring of what's in place.
I'm trying to figure out best way to achieve 12v at wall stats and not kill the feed to the valves. I think this leaves me with 2 options. Adjust wiring at spur or install heat link in wiring centre cupboard and use 2 legs from the 3 core back to boiler for opentherm. The 2 valves are for both zone use and not domestic hot water

Img

yes it would normally be installed at wiring centre position so you have access to all the cables.

 

[m82s]

Thank you matey. After all that it's just clicked in the old brain department. I need mains at wiring centre for valves but 12v at the cupboard so it makes sense to stick heatlink in cupboard and achieve both.
To confirm 5 core from boiler delivers mains in to boiler and 2 spare legs back from cupboard heat link for opentherm. Zone valves connected to heat link brown on valve. Remove stats and use 3 core from wiring centre to supply nest 12v at wall

Thanks mate

 

[Leesparkykent]

Thank you matey. After all that it's just clicked in the old brain department. I need mains at wiring centre for valves but 12v at the cupboard so it makes sense to stick heatlink in cupboard and achieve both.
To confirm 5 core from boiler delivers mains in to boiler and 2 spare legs back from cupboard heat link for opentherm. Zone valves connected to heat link brown on valve. Remove stats and use 3 core from wiring centre to supply nest 12v at wall

Thanks mate

That's the one.

 

[m82s]

Well I thought I'd Sussed it but I have not. A single 3 core from boiler won't give the opentherm legs I need plus it wouldn't be right to run opentherm connection within the same cable run as the mains to the wiring centre. Bloody valves!

 

[Leesparkykent]

Well I thought I'd Sussed it but I have not. A single 3 core from boiler won't give the opentherm legs I need plus it wouldn't be right to run opentherm connection within the same cable run as the mains to the wiring centre. Bloody valves!

Well I thought I'd Sussed it but I have not. A single 3 core from boiler won't give the opentherm legs I need plus it wouldn't be right to run opentherm connection within the same cable run as the mains to the wiring centre. Bloody valves!

is the programmer near the boiler or do you have programmable thermostats? You could connect it not using the open therm connections.

 

[m82s]

No programmer exists. Programmable stats x2

I think this leaves me with running a cable which I'd really rather not in a new build or run without opentherm

 

[MRBROWN33]

I’m sure the nest hub should have LV terminals to power the stat. Use the down stairs stat cable to goto the hub, you may need to do some alterations in the wiring Center to get the stat cable to your hub, this will depend on where you have positioned the hub. The back plate on the nest stat should have the LV terminals to connect to and then the stat just plugs onto it. For now put both Brown cables together on the valves with the call cable from the nest hub and disconnect the other stat cable. Hope this helps?

 

[MRBROWN33]

No programmer exists. Programmable stats x2

I think this leaves me with running a cable which I'd really rather not in a new build or run without opentherm

Just out of interest does the programmerable room stats run on batteries?

 

[Eliza Bennett]

Did you try Nest support? They will give you a brief solution.