Boiler wiring question

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Hi,

Background:
Had an extension done last year. The boiler was replaced and moved. Had a Vaillant Ecotec Plus 832 installed. My heating system is 2 zones. One zone for all the Rads in the house and the other zone for the wet UFH in the extension.

Because this was done in the summer I left the plumber to it and didn’t think anything of it.

The plumber reconnected up the existing thermostat which is a wireless Drayton digistat RF1. This has an RF reciever at the boiler.

Issue:
In the last couple of days I’ve bought a Tado Smart Thermostat setup. Installed it myself and everything is working. 1 wire needed moving according to the online instructions.

However, after speaking to Tado they have some concerns about how the boilers power supply is connected.

I have a 230v AC fused plug going direct to the reciever (was Drayton SCR, now Tado Extension kit). From here I have a L, N and E going to the boiler.

Tado say the boiler should have its own power supply and the reciever (Extension Box powered from the boiler or independently. Is this correct? What is the correct way?

Attached is a diagram of the wiring. I have a wiring centre installed to the UFH manifold etc which I haven’t included in the diagram. It’s just the power issue that concerns me.

Many thanks.

6AC9B331-736C-4427-BD5B-0DD3C3628F0A.jpeg
 
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Ok,

Maybe I phrased it poorly. This is what Tado say:

“the power to the boiler should not be supplied through the Extension Kit. If this is the case, we would recommend to ask an electrician to check this and fix this issue, since it can damage the Extension Kit in the long run”

Thanks for the quick answer. Just want to make sure my boiler or tado doesn’t die prematurely!

Cheers
 
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[QUOTE="SensibleDev, post: 4085633, member: 141903"“the power to the boiler should not be supplied through the Extension Kit. If this is the case, we would recommend to ask an electrician to check this and fix this issue, since it can damage the Extension Kit in the long run”
[/QUOTE]
Mmmm. It's not really through the extension kit - just using the terminals as connectors.

Depending on location of the parts, that's how I would have done it.



Perhaps wait and see if anyone else knows something more specific to the Tado.
 
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Mmmm. It's not really through the extension kit - just using the terminals as connectors.
It does indeed sound rather silly. After all, it's only a boiler which is being supplied by the 'onward connections' from those terminals, not a cooker or shower!

Kind Regards, John
 
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The boiler and receiver are all connected to the same 230V supply directly via their terminals. One does not interrupt the other, so the electrical connections are the same as if they were simply going through a junction box, or the wiring centre. What you have complies exactly with Vaillant's boiler instructions, which specifically states that they should be connected to "one common electricity supply" Which comes first or second is irrelevant.

Capture.JPG


Personally I wouldn't have used a "fused plug" for the supply. As a fixed appliance, I would have wired it to a fused connection unit. Maybe that is what Tado are referring to.
 
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Electrically it's the same. Don't worry about it.

You don't need the cable going from 2-zone 1 and back to SCR 1, that could have been achieved with a jumper from L to 1 in the SCR. But if you have 4-core cable anyway, then there is no harm in it.
 
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Surely there must be a minimum - but it is an MI, so... :)
Well, I suppose from the point-of-view of 'protection', there doesn't need to be a minimum - I'm sure that a 1mA fuse would avoid any harm coming to the boiler :)

Or maybe they are advocating the use of one of my 1A fuses?!

Kind Regards, John
 
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Surely there must be a minimum - but it is an MI, so... :)
MI are guidance only and don't have to be followed if they are wrong, which they are in this case. The external fuse is to protect the cable not the boiler which should have its own internal protection. As has been said before how could you comply with this incorrect MI in other countries where FCUs are not available or compliant?
 
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MI are guidance only and don't have to be followed if they are wrong, which they are in this case. The external fuse is to protect the cable not the boiler which should have its own internal protection. As has been said before how could you comply with this incorrect MI in other countries where FCUs are not available or compliant?
Winston - please tell us how you know that the requirement is not imposed by the gas regulations.

If you don't know that it isn't then you don't know that the MIs are wrong, and you must stop saying that they are.
 
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Said this before & I will say it again: How do you know they are wrong?
 

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