Is my boiler wired right?

[rewireIT]

Just looking at my boiler wiring out of interest, and just wondering if it's wired correctly.

So perma lives, neutrals and earths in the right place, but i can't figure out the switch lives to the controller.

If i follow the circuit it seems like the earth of the 4 core is acting as some sort of live to the controller even though the perma live is already there. If i volt stick it, the earth is live at both ends at all times, the black is showing 50v amperage only sometimes and then dead others.

From the wiring diagram i would have assumed the 4 core would go to the switch as L N E and the black would act as the sole switch wire.

What am i missing?

(Ps thanks for your help - i'm trying to get more into the domestic side of stuff having grown sick of site work so this is my first foray into stuff like boilers.)

PPS the controller is not a stat, it's just on/off. Timer/temp etc is built onto the boiler.

 

[brianmoooore]

Just because a wire is green/yellow doesn't necessarily make it an earth, especially if plumbers are involved!
Your controller is wired as 'volt free' , and the green/yellow has been used as a 'live'.
There doesn't appear to be a real earth at the controller, but it does look like there's one at the boiler.

 

[rewireIT]

Just because a wire is green/yellow doesn't necessarily make it an earth, especially if plumbers are involved!
Your controller is wired as 'volt free' , and the green/yellow has been used as a 'live'.
There doesn't appear to be a real earth at the controller, but it does look like there's one at the boiler.

The boiler is definitely earthed.

So could you talk me through the controller and what the '1' and '2' are doing on the boiler? I can't visualise how this works.

I gather the yellow/green is a live and the black is the switch, so what is the brown doing?

In my head, we have perma live in to boiler, out to controller. 240v out from boiler to the controller, button on controller than activates the black, turning the boiler on.

So howcomes the black is sometimes giving voltage sometimes not, when the controller switch isn't being operated?

 

[brianmoooore]

Your boiler wiring diagram shows a link between two terminals at the top. This link has been removed and connected to the green/yellow and black wires, which, at the controller end, are connected to the switch terminals. The blue and brown supply power to the clock of the controller.
A five core cable should have been used, of course.

 

[rewireIT]

Your boiler wiring diagram shows a link between two terminals at the top. This link has been removed and connected to the green/yellow and black wires, which, at the controller end, are connected to the switch terminals. The blue and brown supply power to the clock of the controller.
A five core cable should have been used, of course.

Ah ok that makes sense - so the yellow is power in from the boiler, the switch is operated on the controller then the black switches the boiler on.

Still any idea why i'm getting a voltage reading now and again on the black without operating any switches? It seems to be intermittently going live but only registering 50v.

 

[davesparks]

Still any idea why i'm getting a voltage reading now and again on the black without operating any switches? It seems to be intermittently going live but only registering 50v.

What are you using to measure the voltage? Is it a meter with a high or low input impedance?

Most likely is capacitive coupling (aka ghost voltage)

 

[rewireIT]

What are you using to measure the voltage? Is it a meter with a high or low input impedance?

Most likely is capacitive coupling (aka ghost voltage)

Fluke T90 which the spec sheet says 200kohms input impedance.

 

[davesparks]

Fluke T90 which the spec sheet says 200kohms input impedance.

Interesting, you wouldn't normally expect that tester to display a voltage of it was due to capacitive coupling.

Does that model have the button to lower the input impedance?

What are you measuring the 50V with reference to? Is that 50V to earth, to neutral or something else?

 

[rewireIT]

Interesting, you wouldn't normally expect that tester to display a voltage of it was due to capacitive coupling.

Does that model have the button to lower the input impedance?

What are you measuring the 50V with reference to? Is that 50V to earth, to neutral or something else?

L to N is coming up 50v on the stick. It's the version that is just 'prod and play', without the button.

 

[littlespark]

Is there a fault with the heating, or are you just worried about the workmanship?