exposed mains cable behind boiler

[andyf]

I've recently had a new boiler fitted in a downstairs kitchen. The new position of the flue meant the disturbing of what I believe to be the mains supply to upstairs. This cable was originally just buried under the plaster as it is an oldish house. Now the cable emerges just above the boiler, runs down behind the boiler for about half the boilers length before re entering the plaster and continuing on it's original path.
Although most of the cable is covered by the boiler and the bit visible at the top of the boiler will be covered by a removable box, is this acceptable re building standards or good practice?
The plumber told me it was not live any way but I saw his testing thing flash red as he proded the cable!
Any advice would be appreciated before I pay the bill.
I also wasn't sure whether to post this in the electics or plumbing section. Thanks.

 

[JohnD]

I see two possible problems:


1) the heat of the boiler will
(a) mean that the ability of the cable to carry current before it overheats, will be reduced (as a rule of thumb, halved)
(b) cause the life if the insulation of the cable to be reduced

2) If the cable is not in plain view, someone may unknowingly drill or screw into it, causing damage, possibly danger of electrocution, and possibly danger of a surprisingly big flashbang or fire hazard.

If you believe it to be a supply cable to another flat, you probably ought to notify the electricity supplier and ask them to inspect it. explain that it has been exposed during building works and you are concerned it may be unsafe. (I am sure they will soon tell you if it is alive or dead). I would hope they would come out the same day, within an hour or two. If you don't know who to contact, start with the phone no on your electricity bill (it is their job to know).

Can you post some pics, or at least give a description of the size and colour of the cable, and what it appears to be made of? where does it originate? Is it near your on meter, service head and supplier's main fuse? Some photos showing these bits would be useful.

 

[andyf]

Perhaps I should clarify that the upstairs I mention is my upstairs in my house and that by mains I meant the supply to the upstairs sockets or lights from the junction box. The cable is the thick flattish grey kind,about 15mm x 5mm, the same as what runs betweeen my sockets. I'll go under the floor tommorrow to see if I can locate where it comes out and terminates. The plumber suggested that it may be for the old cooker point which is possible but this was at the other end of the wall.
I don't think there is too much danger of it being drilled etc as the bit exposed above the boiler is perhaps less than a foot from the ceiling but the effects of heat did concern me, though I don't think this area of the boiler gets very hot. Thanks.

 

[jj4091]

Is your consumer/meter unit downstairs & do you have an electric shower upstairs?

 

[andyf]

Looks like the plumber was right. Tested the cable myself with a volt detector and it doesn't appear to be live. Also looked further around under the floor and found the end of a cut off cable of the same size near to where the exposed cable may have entered. Guess that it is the old cooker point supply.
The shower has no electric supply by the way and the consumer unit is downstairs in the garage. The cable is actually thicker than that running between the sockets. Definitely cooker supply size.