nest installation issues

m82s · Jan 21, 2018

Leesparkykent said:
To be fair no one knows your an electrician as you haven't stated such on your profile and not in the opening post either.

Cheers buddy. I didn't mean to go off on one. I appreciate all the folk come here expecting to be given free information. I opened a new profile thinking mine had been closed since I have not been active on the forums for about 3yrs. I didn't get a password reset. Yahoo is crap like that and takes ages. I put a brief note in my profile so people would see I'm not here to scrounge info and potentially harm myself or others. I'll add some more info. Here is my profile I set up this afternoon.

If anyone wishes to still help me then I'd be grateful.

Cheers

[ElectriciansForums.net] nest installation issues

Leesparkykent · Jan 21, 2018

m82s said:
Cheers buddy. I didn't mean to go off on one. I appreciate all the folk come here expecting to be given free information. I opened a new profile thinking mine had been closed since I have not been active on the forums for about 3yrs. I didn't get a password reset. Yahoo is crap like that and takes ages. I put a brief note in my profile so people would see I'm not here to scrounge info and potentially harm myself or others. I'll add some more info. Here is my profile I set up this afternoon.

If anyone wishes to still help me then I'd be grateful.

Cheers

View attachment 40355

I'm not 100% but I don't think you can have two nests set up as open therm.

m82s · Jan 21, 2018

Leesparkykent said:
I'm not 100% but I don't think you can have two nests set up as open therm.

I'll cross that bridge when it comes to it I think. To pass regs my house (a bungalow has been zoned into two. The second zone runs the lounge only. I know what people will say about me altering this but that's for another day. The nest is connected to opentherm and without altering the current stats and initial install at all, it appears the nest calls for heat, the boiler fires but the valves don't open due to n/o stat connections.
The stats are wired from the control centre supplying mains at both stats via 3 cores. I can't see how without either altering the wiring at the boiler spur or locating heat link at the wiring centre cupboard I'll achieve 12v at the wall stat. For now I'm happy with running nest via USB if I can confirm isolation of wall stats is ok. Obviously this means some connection altering. I do intend on buying a second nest and remove one stat now if poss as per nest say is possible

Leesparkykent · Jan 21, 2018

The brown of the two port needs connecting to heating on of the heatlink.

m82s · Jan 21, 2018

Leesparkykent said:
The brown of the two port needs connecting to heating on of the heatlink.

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

Leesparkykent · Jan 21, 2018

m82s said:
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

m82s said:
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 · Jan 21, 2018

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 · Jan 21, 2018

m82s said:
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 · Jan 21, 2018

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 · Jan 21, 2018

m82s said:
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 · Jan 21, 2018

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 · Jan 31, 2018

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 · Feb 1, 2018

m82s said:
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 · Feb 6, 2018

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

nest installation issues

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m82s

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