Help with smart thermostat wiring please

[cammy2207]

It is a Minute HE, Vokera. You know anything about these?

 

[stem]

Not really, but a quick search shows the Mynute HE as a system / heat only boiler. They usually have motorised valves in the pipework which are operated by the thermostat, in which case the motorised valves will operate on 230V. [S-Plan or Y-Plan]

It's combi boilers that sometimes have an option to be wired up as 24v or 230V. Whether there is a combi version of the Mynute, or not I don't know. But you will know if you have a combi boiler or S-plan / Y-plan.

 

[cammy2207]

It's not a combi. Does that mean it's more likely to work if it's 230v?

I will be decorating hall in next week or two, that's when i planned to do the switch over.

 

[stem]

For heat only boilers (ie not a combi) the thermostats usually are wired to motorised valves that look something like this.

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• stem
• 1 Apr 2010
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• stem
• 26 Mar 2010
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If you do have a motorised valve (or valves) they operate on 230V.

 

[cammy2207]

...which means there should be plenty power to feed the digital stat? And hopefully at least work the on\off?

 

[stem]

Boilers that have 24v control, only use it for their internal control circuits that are wired to the potential free contact (aka dry contact) of a smart thermostat.

The smart thermostats connected to boilers that use 24v control still need to have a 230V mains supply connected to them to provide operating power.

That is why the contact has to be 'potential free' to keep the 24v separate from the 230V

 

[cammy2207]

Thanks for all your input @stem much appreciated

That will be the c wire then?

 

[stem]

Sorry don't understand what is a C wire?

 

[cammy2207]

No, sorry, just reffetreferr the the 'common' wire needed if you have a 24v system... Not important!

 

[cammy2207]

@stem So it's wired in. After error readings initially from the unconnected dual sensor wires, I was able to access the advanced settings and use only the internal sensor. The device works fine... Manually that is. The problem I had now was the name of the app that accompanies the stat was not stated within the instructions or packaging...i contacted the seller and got the app. Now... The app will not accept my password in the registration process before I can connect it to my router. All correspondence to the app maker and stat manufacturer regarding this have all bounced back from China. So I'm left with a digital thermostat that does the same as my last analogue one and not able to control from my phone or alexa! [rant over!]

Any miracles greatly received!

 

[stem]

Sorry, I can't help you there. I'm better with wires than apps I'm afraid.

I have never installed one of these type of thermostats, I am aware of a few folks who have had difficulties of one sort or another with similar looking Chinese units they picked up from Amazon. I don't know if they managed to get them working in the end or not.

If the app won't accept the password, It would appear that either the app or the password is incorrect, so only the manufacturer would be able to help with that I would suspect.