NEST Install advice please.

[sh4d0w]

Hi guys,

I have just picked up a NEST to try out.

We have had endless issues with our Vailiant VR470F and VR81 working over two zones, they just wont work independently.

I know the 470 will do weather compo and modulation and probably offers a better range of settings for my boiler but at the moment we are just that fed up with it we are happy to change.

We have 2 zones - Upstairs and Down and also a 250l Albion water tank. All work off 3 honeywell zone valves.

I want to know if i can run ONE NEST on my UPSTAIRS to just test it out ALONG side my 470F or will this not work? - i know i need two nests, one for each zone.

I would also welcome some views and opinions on the nest vs 470.

Many thanks

 

[Vee]

Am I assuming that you also have the VR61 wiring centre?

 

[Gasmk1]

why not go for the vsmart

 

[sh4d0w]

You are assuming right Vee.

Gasmk1 - Vsmart wont do two zones.

 

[Vee]

You should be able to wire it in via the 240V switched live in the boiler panel. You need to keep the NEST out of the VR61 altogether including the zone valve for the circuit you are trying to control. The Vaillant control system uses ebus and low voltage and you otherwise risk damaging it. Are you qualified to deal with this?

 

[sh4d0w]

Hi Vee,

I am not qualified in any of it!

I have now bought two nests and will completely replace my current stat i guess.

I just need to know how too.

 

[Vee]

In all honesty I think you may do more damage than good attempting this. Whatever made you think this was a DIY job? It may be worth exploring why the current set up doesn't control the two zones. Depending on the control valves and pipework set up it may play a part and the NEST will not resolve this. By the way, NEST is far inferior to the VR470 & VR61 setup you have.

 

[sh4d0w]

In all honesty I think you may do more damage than good attempting this. Whatever made you think this was a DIY job? It may be worth exploring why the current set up doesn't control the two zones. Depending on the control valves and pipework set up it may play a part and the NEST will not resolve this. By the way, NEST is far inferior to the VR470 & VR61 setup you have.

I would love to use my VR470 but it just seems far too complicated! does not do any form of "Smart" functionality, the missus and I dont have a fixed shift pattern so the option to be able to access the stats away from the home would be fantastic, VSmart is just un-smart and doesnt do more than one zone.

My system is about 18 months old and works OK, just Zone2 will not pull for heat unless Zone1 is active, if Zone2 is active on its own the valve will open but no water is called.

Dont have the patience to work it out and i have had 3 plumbers out to have a look and each one has claimed to be a Vlent specialist but all said completely different things two never got back in touch and the 3rd wanted to replace my stat with a Hive!

Had a spark look at it too, he said that it was confusing as the VR61 says that my 2port valve for hot water "Should" be a pump.

I just dont know... i do know that Nest Works! and i have them here now so why not just give them a go.

Unless you want a job in Stockport Vee?

 

[Vee]

The term pump in the VR 61 for the valve is ok as all it is is a switch. The valve is wired into it and the auxiliary switch in the valve is used to fire the boiler or in this your case wired back to the VR61, which will tell the boiler. It stems from the way systems are piped in Germany.

I do like a challenge, but I am not sure I can justify Stockport with the other half.

The best way forward is the remove all Vaillant controls and wire the system as S-Plan+ using the 240V side of the Vaillant connections called RT. I attach a picture of S-Plan +. The thermostats become the relay box of the nest so refer to their instructions. Instead of a channel from a programmer the relay boxes need a permanent live in with a link to the common. If not using the NEST for hot water use a single channel programmer.

 

[sh4d0w]

Thanks for that info Vee, that is pretty much my heating system! but i have the VR61 wiring so no choc block.

Bring your other half for a nice trip up to the manchester markets! 🙂

 

[Vee]

The Vr 61 has got to come out. Free lodgings for the Christmas markets, great, forgot to mention the kids.

 

[tolly]

You cant use ebus and the 230v RT, its one or the other

 

[Vee]

Exactly.

 

[sh4d0w]

Kids can come too! we will fit them in the garden im sure! HAHA.

VR61 to come out, 230V to hive heat link 1 then loop feed to second one then back to boiler im guessing?

 

[Vee]

Nor quite. Use Page 24 of this:
https://nest.com/support/images/mis...Nest-Learning-Thermostat-Install-Guide-UK.pdf