Scorched pipework on unvented cyl

[Groovejet]

While checking out a bad smell, located in cupboard I came accross pipework that had scorch marks and a shale deposit covering them.

it seems to start from where the earth bonding starts and continues about 2 foot below.

Its a cross between when a pipes been overheated with a blow lamp and a reaction of some sort.

Help appreciated

 

[gigz]

Probably flux residue. It'll eat through the copper. Carefully clean it off with wire wool and a hot damp cloth. Pics would help.

 

[gigz]

Probably flux residue. It'll eat through the copper. Carefully clean it off with wire wool and a hot damp cloth. Pics would help. Is it green in colour ?

 

[Madrab]

If you haven't got wire wool then a rough green scourer and soap would work or alternatively a fine grade sandpaper

 

[Groovejet]

No! It's not flux
It's weird!
Hot,cold feed,balanced c/f,and blow off have got a crust of like iron shale, really crumbly.
Then as the pipes get lower they've turned black /grey , exactly like 40 year old cold pipes go, that really dull ,knackered look!

The flats are only max 10 year old

It all originates from the earth bonding clips. These are in a row of pipes. further away from bonding it gets gradually better

It's quite worrying as it looks like a reaction between metals or something electrical???
Pics are on another phone, could upload 2 moro

 

[Madrab]

Hmm, it almost sounds like the pipes are being anodised.
I know this sounds weird but if there is a low voltage leak then the earthing bonding straps could be sacrificing themselves. Are the clips in good condition or do they look like their 'corroding'? If they are I'd get a spark in to check the main equipotential bonding and the RCD/MCB's just in case and check for a current leak.

 

[muggles]

Sounds more like an electrical issue than a plumbing one, having said that it would be interesting to know what the issue is!

 

[Groovejet]

Yea , you nailed that on the head
It's exactly what's happening, the pipes are sort of acting like a sacrificial annode
The straps are in good condition, so are the cables, the only slight change is the copper bonding cables have discoloured, once again as if they've been left to the elements
I'll get a photo on and tell what the outcome is

Thank 4 help

 

[Madrab]

View media item 65999

 

[Groovejet]

Untitled

• Groovejet
• 5 Sep 2013
• 1

Here's the pic that I promised ,thanks

 

[mfarrow]

The best reference I can find of it is Chinese Drywall which is a phenomenon found in certain chinese drywall imported to the US which emits corrosive acid gas which eats copper pipes, among other things. With global markets the way they are, I wouldn't be surprised if some found its way over here. The US subsidiary of Taylor Wimpey is one of the potential users of this defective material.

Otherwise the flats burnt down at some point and they rebuilt with the old copper. Cowboys!

I'd find out if someone can test this for you. Poisonous gases could be leaching from anywhere.

 

[Madrab]

Yeah, the fact that the earth straps are all shiny kinda rules out the potential for it being an electrical sacrificial process I would think though it could be a form of electrolysis. What you have there is copper oxide which is a form of copper rust. How's it's forming is another story.
Is there a funny smell in the area that the pipes are located? Is that a copper pipe in the middle that isn't affected?

 

[Groovejet]

When I'm back at flats for maintanance ill do double take at pipes and take a photo square on
There are areas where the pipes look like they've been heated to cherry red then cooled and left purple blue heat marks. Thing is these heat scorches are nowhere near soldered joints???

There's also a temp and pressure relief valve located under suspect pipes that's turned that dull black colour

Your right, it looks like ones not been affected!
Too busy looking at problem and missed that!
Will check out

I might not get to-flat until next week now,but will update

 

[Madrab]

OK, if one's not affected then we can rule out anything in the environment that is causing it, corrosive gases etc I would think but check for bad smells. Are you getting discoloured water at all? Is the valve conected with an un-vented hot water cylinder? If, so it may be time to get someone in who's qualified for that type of hot water system to check it hasn't been compromised.

 

[Groovejet]

Yea, the reason for going into the cupboard was a bad smell.
Your good u!

But I located it coming from the pressure relief turn dish, going into a 1 1/4 waste pipe with no air gap .

The corrosion looks too localised to be affected by that.
But saying that its in a closed cupboard, within a meter of each other?
And yes it's a unvented with no heating they have storage heaters

Discoloured water? I ran hot /cold on bath and water ok
But the temperature of water in all flats I've been in will take your skin off, it's rediculous.