The flat upstairs is leaking water into my flat

[mp3wizard]

i think there was a copper pipe coming out the side of the wall, a trickle pipe maybe, that outside wall is no longer, as the new side extension forms the wall, if it is as you say a redundant system, could it be just the last bits of water flowing out of the system, as the damp patch is drying up from what i can see today.

no the only part that is wet is the picture i sent you, the conversion was very poorly done so it wouldn't surprise me if there are interconnected, i'm assuming his radiator still works, so it must be part of the old system like you said right?

 

[JohnD]

it might just be that the leak is clogging up with dirt and scale again, in which case it could start leaking at any time, for example vibration from a slammed door or furniture moved.

If it is a redundant pipe, it needs capping off properly.

 

[mp3wizard]

right, so the part marked in red is the isolation valve, and providing it's an inactive system we can cap it off at that end, is that correct?

 

[JohnD]

that would work, but IMO a better solution would be to remove the "T" to its left and replace with an elbow; or put a stop-end into the "T"

 

[Belboz]

I would take professional advice before doing anything but...

It's possible that the copper pipe with the isolating valve was fitted as a drain off for your upstairs neighbour's CH system. Not a usual way of doing things but entirely possible. The alternative is that it was part of the original CH system feeding the whole house from where the original cyclinder/boiler was (unlikely but possible I suppose)

You may be right about some residual water but it is also entirely possible that the isolating valve has 'failed' and is allowing water to pass through. That may be a small, slow trickle when the CH is off but more if the CH is on. If the professional confirms that the assembly is redundant, he (or she) can make good and remove it. There are several ways of doing this but the upshot will be no more valve to leak.

If it were me, I would replace the T with an elbow and then get rid of the copper pipe and valve entirely.

Of course, it may require a drain down of your neighbour's CH system pro tem (albeit there are other less-aggro methods)

As I said, get a professional in for best advice first

 

[mp3wizard]

thankyou very much for all your help, i think you have certainly saved me from destroying my newly plastered wall!