Another Volkera and Nest installation - advice please

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hrgiger

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Hi guys,
We are in the process of having a nest thermostat fitted (3rd gen) to out Volkera Easi heat 29 boiler and our fitter is struggling a bit so thought id ask for some advice.

Can any show me the correct wiring for the heatlink please? so that it controls the boiler properly.
A pic would be great if possible, or a good description of what goes where.

i can then share this with the installer to help him out.

Thanks in advance
Si.
 
Last edited:
I was about to say a similar thing... does you installer turn up with their knuckles dragging on the ground? There's a wiring diagram on Page 26 of the boiler manual, and Nest comes with a manual too. Nest needs to be connected to Live & Neutral for power, and the timer connections for control. If he can't work that out, I wonder what other parts of the installation he's struggled with? Has he calculated the gas supply to check it's up to the job, for example, or is that too difficult for him as well?
 
As far as I can see it's a combi boiler with 24 volt control system so heat link will have 7 wires to heat link.
N = Neutral
L = Line
2 and 3 go to CN5 on boiler 24 volt DC
Earth needs connecting if taking supply to thermostat from heat link.
T1 and T2 go to Thermostat. Unless using wireless option.
As to why Nest Gen 3 rather than Nest e I don't know, suppose it means no batteries to change.

There are with system boilers more complex systems, but as said it has a volt free relay so nothing complex with wiring. So it raises question what is the problem? If you have some thing unusual then OK can see there may be a problem, and I will admit I got the set up wrong first time around, and I saw no reference in the paperwork to using the MiHome Energenie TRV heads which as far as I am aware are the only heads designed to work with Nest. But standard wiring is easy.
 
ianmcd said:
IF you have an installer as you call it , needs help to install a nest then you need another installer, if you are just installing it yourself just say so and you will get the advice that you need , you are installing a switch, nothing magical about it

if he or you can not follow this then you need someone who can

https://nest.com/support/images/mis...Nest-Learning-Thermostat-Install-Guide-UK.pdf
Click to expand...

hi ian, no im not installing it myself, although i may well end up doing if the sparky trying to do it cant. He's an older guy who shall we say isnt to techy.. nothng wrong with his work but just set in his ways, so i thought id ask to aid the process along if i could.

muggles said:
I was about to say a similar thing... does you installer turn up with their knuckles dragging on the ground? There's a wiring diagram on Page 26 of the boiler manual, and Nest comes with a manual too. Nest needs to be connected to Live & Neutral for power, and the timer connections for control. If he can't work that out, I wonder what other parts of the installation he's struggled with? Has he calculated the gas supply to check it's up to the job, for example, or is that too difficult for him as well?
Click to expand...

Hi muggles, wouldnt say he was a knuckle dragger but not far off..lol.. just set in his ways. he just said he hadnt worked on this brand of boiler before so i thought id ask.

ericmark said:
As far as I can see it's a combi boiler with 24 volt control system so heat link will have 7 wires to heat link.
N = Neutral
L = Line
2 and 3 go to CN5 on boiler 24 volt DC
Earth needs connecting if taking supply to thermostat from heat link.
T1 and T2 go to Thermostat. Unless using wireless option.
As to why Nest Gen 3 rather than Nest e I don't know, suppose it means no batteries to change.

There are with system boilers more complex systems, but as said it has a volt free relay so nothing complex with wiring. So it raises question what is the problem? If you have some thing unusual then OK can see there may be a problem, and I will admit I got the set up wrong first time around, and I saw no reference in the paperwork to using the MiHome Energenie TRV heads which as far as I am aware are the only heads designed to work with Nest. But standard wiring is easy.
Click to expand...

Hi eric, thanks for the info, just checking this was meant for my post as you make reference to Energenie TRV heads and its not something i discussed or asked about ?

But if anyone can help me out with the information that would be appreciated and i will pass it on, or ask said may even just do it myself.
all the best
si
 
be carefull this boiler is 24V switching if you get it wrong you will blow the PCB and they are not cheap
 
Nest and MiHome Energenie work together, that's why I talked about MiHome Energenie as they are connected. The whole idea today is to heat centrally but use independently sorry to say don't think Nest is that good as far as this goes, although it does link to the TRV to my mind it's the wrong way around, the Nest thermostat tells the TRV's what heat is required, where Hive the TRV sends a signal to wall thermostat to run for ½ hour when it's too cold.

But it means two completely different bits of software will both control Nest, either Nest's own software or MiHome Energenie software when using phone or tablet, with a PC the MiHome Energenie web page will not control Nest.

I did down load the installation instructions for your boiler, the first thing I did was go to find on this page and look for OpenTherm and ebus to see if the boiler can be controlled that way, I got no results so assume only way to control boiler is return water temperature and off/on. Next I looked for how the boiler is turned off/on and I found the reference to CN5 as the terminal and 24 volt DC, so that's not a problem with Nest as it has volt free contacts.

In the software Nest asks if it is a system boiler or combi boiler so it will be automatic set correct but I will admit it has that many options I did get it wrong when I did it first time around, and I can understand an electrician older than me having a problem setting it up, but the wiring is straight forward, there should be no problem. I am 68 so to not understand how old is this guy, does his white beard make him look like father Christmas?
 
ericmark said:
Nest and MiHome Energenie work together, that's why I talked about MiHome Energenie as they are connected. The whole idea today is to heat centrally but use independently sorry to say don't think Nest is that good as far as this goes, although it does link to the TRV to my mind it's the wrong way around, the Nest thermostat tells the TRV's what heat is required, where Hive the TRV sends a signal to wall thermostat to run for ½ hour when it's too cold.

But it means two completely different bits of software will both control Nest, either Nest's own software or MiHome Energenie software when using phone or tablet, with a PC the MiHome Energenie web page will not control Nest.

I did down load the installation instructions for your boiler, the first thing I did was go to find on this page and look for OpenTherm and ebus to see if the boiler can be controlled that way, I got no results so assume only way to control boiler is return water temperature and off/on. Next I looked for how the boiler is turned off/on and I found the reference to CN5 as the terminal and 24 volt DC, so that's not a problem with Nest as it has volt free contacts.

In the software Nest asks if it is a system boiler or combi boiler so it will be automatic set correct but I will admit it has that many options I did get it wrong when I did it first time around, and I can understand an electrician older than me having a problem setting it up, but the wiring is straight forward, there should be no problem. I am 68 so to not understand how old is this guy, does his white beard make him look like father Christmas?
Click to expand...

Hi Eric,
Thanks for your wonderful advice thats great.

So as the thermostat is being connected wirelessly its a pretty simple install of the following

N = Neutral
L = Live
2 and 3 go to CN5 on boiler 24 volt DC

no need for the earth and T1 and T2

The guy is a wee bit younger than your good self, but just like i said i think he's a bit stuck in his ways and old school,to the point of he muttered he cant see the point of these app controlled devices !!
He's a nice guy so i just wanted to be able to contribute to solving the problem if he couldnt.

thanks
si
 
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