Is my Vaillant wiring centre (VR66) wired ok?

[Rystar00]

Hi all,

I was looking at my wiring centre today and noticed that the power supply seems to run directly from the boiler (the second white wire is the power to the VR66)

Looking at the manual it says the VR66 needs a ‘permanent’ power supply.

Is what the plumber done ok?

 

[CBW]

@hertsboilers was this you? @Rystar00 I would say it’s ok unless you plan on often turning your boiler power supply off? Most heating wiring centers are fed from a fused connection unit on the load side, which is permanent unless you turn the switch off.

 

[Rystar00]

Thanks very much for your reply.

Herts Boilers didn’t commission it - Herts Boilers have only serviced it (and done an absolutely brilliant job each time!)

 

[CBW]

@ScottishGasMan might be able to confirm if the wiring of it is acceptable and if that’s what is meant as a “permanent“ supply.

 

[ScottishGasMan]

Well, the wiring centers not much use if the boilers turned off lol, so daisy chaining the supply from spur to boiler to wiring center isn't a problem. That is a permanent power supply. (Fairly certain it's how mine is done)

My only concern would be, that I can see a power cable going into boiler, and what I expect is the power cable going out to the wiring center. But I don't see an eBUS cable (the Vaillant communication cable that connects the boiler to the wiring center)

Cant see the wiring center from the pictures so I'm making assumptions now. But I assume the cable going from the boiler to wiring center is a 5 Core cable, so Live, Neutral and Earth, with the other 2 cores being used for eBUS.

Unfortunately that's not an acceptable way to do it, the eBUS must have its own flex, of at least 0.75mm2 cross section, and the power in a separate flex.

If it's worked all this time then that's great, but I would suggest altering it the next time the boilers worked on, as they can often cause interference being wired in the same cable. Ideally any Extra low voltage wiring would not share a flex with a mains cable.

 

[Rystar00]

Thanks so much Scottish. Really appreciate your expertise.

I attach a picture of the wiring centre and the wiring diagram in the manual. There is only one cable going from the boiler to the wiring centre so looks like it is wired wrongly?

The reason why I’m looking into this is because my Vsmart room stat is constantly disconnecting (even though no issues with power or WiFi). Could this issue be causing the problem?

How would you advise rectifying the power issue? I have a spare plug next to the cylinder. Should I run a new separate power supply off that for the wiring centre (and use the existing cable for the EBUS only)?