Okay, better pictures now at.
That long screw that the earth wire is connected to also has a nut that holds the cover in place.
Mike
*Assuming* there's a single unbroken flex between that switch and the heater (no funky junction boxes between), then:
I would say that your immersion heater is not earthed - except by fortuitous earthing via the pipework and physical coupling to the tank - maybe... And it gets worse:
Having the dual switch makes no sense. I think, looking at it, if your bath/sink switch is switched the "wrong" way, then you will connect neutral to your immersion's earth connection which is a potentially quite dangerous thing to do (slight voltage differences between neutral and earth can cause non trivial currents to flow).
If the live had been routed via the bath/sink switch instead, as is more usual, you'd get a big bang instead.
Also, your immersion is not correctly earthed.
Based on what I can infer (and it's only an inference) from those photos, I'd say the earth in the switch needs to me moved to the same terminal as the incoming earth - the one on the left next to the fixing screw.
But you'd need to verify this to your satisfaction, or call a sparky in pronto.
I would draw three conclusions:
a/ Originally there was a dual element heater, that when it failed was replaced by a single one
b/ The person who wired it and used a CPC as a switched conductor needs dissolving in Aqua Regia to ensure that he never does this again
c/ You urgently need to get the wiring checked / replaced / made safe
Andrew
ps the switch plate needs cleaning as well !!!!
d. OP might also replace the thermostat with one with a secondary overheat manual reset stat while they're in there.
Owain
Pity. If you do open it again, wipe the snot off before taking pic.
But the terminal markings are not which would give a clue as to what the wires are intended to do.
AFAICT the live (brown) is going directly from the on/off switch to the immersion and the switching is being done on the neutral line. The earth cable with the red sleeve is being used as a neutral.
In message , Bill writes
Certainly did - I used to have one.
Could it originally have had two elements in the one case and somebody modified it to take a one element one? Brian
I would agree, there is only one element to the heater.
You cold then link the now empty terminal to the blue next to it to neutralise the bath/sink switch.
I cannot think of any reason why an electrician would wish to oversleeve a green/yellow cable with green/yellow sleeving.
I also cannot think of any reason why an electrician would wish to oversleeve a green/yellow cable with green/yellow sleeving but then finding himself short of a bit of green/yellow sleeving would then decide to use a bit of red sleeving instead of green/yellow sleeving.
Or did I mis-read your post;-)?
OK. So I have read all your posts on this one.
What switch do you use to operate the immersion and what effect does the other switch have on the operation of the immersion heater?
Only 70%?
I am 100% certain that something is wrong
So would I unless the length of the flex from the switch to the immersion is clearly visible in which case there would be no point in using either test. ie no hidden jbs etc.
That's how I saw it too...
I hedge more these days ;-o
Still wonder who wires this stuff up - it's not even like it's a bodge 'cos the bloke was missing a part - this is just silly...
+2
If the blue lead to the heater is long enough to reach, I suggest removing the blue strap from the bottom of the switch in the picture and moving the blue lead to the heater from the top left to the bottom right terminal.
This will mean the bath/sink switch is completely out of circuit, your single immersion heater element is controlled by the on/off switch and your immersion heater is permanently earthed.
If there is now only one immersion element, why not simplify the whole arrangement with a single 20A double pole switch?
Richard
Ah, now that is a much clearer... (and somewhat more worrying!)
Erm, that looks to be a station short of Upminster... (i.e. Barking!)
The arrangement seems to connect live to the heater (via the stat) any time the main switch is on. Then depending on the position of the sink / bath switch, it connects the neutral to either to the other side of the heater, or to the earth connection of the cylinder.
If we assume that the cylinder is connected back to the main earth terminal either via main EQ bonding or via a circuit CPC included in supplementary EQ bonding, then in one position your second switch is creating a neutral to earth fault.
To fix this, it would seem that you want to :
Disconnect all wires from the basin / bath switch - and ignore that henceforth since it serves no purpose with that heater.
Move the green / yellow wire in the immersion flex to join the one connected to the switch chassis.
Connect the neutral wire of the immersion flex to the the N output of the main switch in place of that short link wire (which can be dispensed with)
Very likely - only the person doing the modification either had a bit of a brain fart at the time, or really did not have a clue what was going on!
And here is me avidly reading Adams words expecting an explanation from a pro...
Mike
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.