conductive brick wall????

[PWE]

Hello all, I'm new to this forum.

Has anybody ever come across a conductive type of house brick? I know it sounds crazy.
A heating engineer I was working with got a buzz off the bracket of his boiler he just screwed to a wall. The whole wall was setting the volt pen off. I penetrated the plaster with test lamps and tested between the brick and local water main and was showing 240 volts. I have never come across anything like this before.
I took pictures but not sure how to upload. Posting this via app for iPhone.

 

[static zap]

At that voltage try and find source , lighting , ring main or something from neighbors !

 

[Richard Burns]

Presumably there is an exposed live cable in the wall, possibly where the heating engineer has just screwed the bracket!
If the wall is fairly new then there will be plenty of water in the plaster to conduct.
Presumably there is no RCD in place or you would hope it would have tripped.
Needs sorting quickly.

 

[PWE]

Traced the fault back to the cooker circuit that was back to back with boiler. Which was disconnected. Baffling bit is the brick conducting. Think it is maybe mixed with something. It was bone dry too.

 

[PWE]

The whole wall was showing 240 no matter where I put test lamps on. It was a live to earth short on cooker cable buried in wall. At first I thought he had screwed into cable but he hadn't.

 

[Richard Burns]

If the heating engineer has pierced the cable for the cooker with a screw that has touched the line and nothing else then it is entirely possible to get a voltage showing across a wall,it is a known means of receiving an electric shock.
The current flow should not be large with a dry wall, but could still kill.
If the cooker was disconnected was the circuit isolated?

- - - Updated - - -

The whole wall was showing 240 no matter where I put test lamps on. It was a live to earth short on cooker cable buried in wall. At first I thought he had screwed into cable but he hadn't.

Live to earth short should have tripped the breaker, what else is wrong here?

 

[PWE]

Thanks Richard I didn't know that was common. If I can remember correctly it was high IR reading between live and earth on 3036 fuses. Which would explain no disconnection.

 

[AndyOz]

I witnessed a fault similar on a large high temperature hot water pump. There was reports that the whole boiler house was live and numerous faults were raised over a period of a couple of weeks. As the fault was only there when the pump was running it was not an easy one to find. I remember the feeling of disbelief as my martindale test lamps confirmed that the wall was live. This again was good old rewirable fuses. Shortly after the whole boler house was refurbished, I got the job of the rewire.

 

[Sparks1962]

I had roughly the same thing in a Church some years back, Verger said he got a packet off a metalclad switch in the Vestry, on investigation I could hear a sizzling noise by putting my ear close to the switch. Wiring was in rusty conduit on a damp cement rendered wall, on the switch feed there must have been a nick which had been lying next to the switch box fixing screw. The wall above the switch had a vapour mark above it and was certainly near mains potential. The Church had been wired in the '50's and had little done since. Obviously no CPC pulled in to the conduit with the other conductors.
On investigation the 4 pole ELCB was faulty and the earth electrode cable detached from the rod

 

[R G]

Had a similar fault where a water tank had overflowed and soaked the wall , whole wall became live , turned out a to be a live cable buried by kitchen fitters 10 years before.....

 

[PWE]

Had the same feeling of disbelief Andy haha. Had to do an electrical contact report for H&S department because engineer had reported the "wee tingle". I was just thinking how the hell am i going explain this one. 240 v flowing through a brick wall. I just kept it very short and no one questioned it, probably not wanting to open a can of worms.