Plumbing component failures

[34theletterbetweenB&D]

This is bizarre. Started with a damp patch under a ground floor radiator while the system was out of use late this summer. After some observation it was determined to be the isolator in one of the pipes weeping, ever so gently. Sometime over a month ago, a drain cock in the hot water supply started leaking, That only revealed itself a month ago on making a large enough puddle to sneak out from under the kitchen units. Today heard a slow drop, drop, and after some hunting around it's another draincock, this time on the cold water to the downstairs WC.

 

From the rather confused account of the lady previously occupying the place I reckon most of the plumbing was renewed throughout in 1977. Am I coming up against a 35 year life span of these fittings? Because at this rate I am thinking of getting my friendly plumber in to do the lot...

[Suzie]

It sounds like your water has suddenly got a bit softer and started to dissolve the scale that was blocking the leaks.

[34theletterbetweenB&D]

Good thought, but the supply is mainly from artesian wells in chalk, it's near as hard as it can be; there's no way our water supplier is softening that. And the first two failures were on systems that have always been soft: the feed to both the hot cylinder and c/h header tanks goes through a softener that was part of that 1977 revamp.

 

I am going to have this failed component apart on the bench to inspect its internal state. Should have done that with the first two...

[skipepsi]

Is your system micro bore? all our radiators have leaked, seeped around the spindle retightening needed at odd intervals.

[mikes rail]

There was problems with poor copper pipe years ago and I think it was around the seventys. Place I worked had pipe work from that time that started to spring pin hole leaks. As soon as one was fixed within a few days a new one would start a few feet more down the pipe. In the end whole line had to be replaced.

[jonhall]

Is there a blockage somewhere? Everytime you replace a weak point, the problem moves on the the next weakest point?

 

Jon

[Enterprisingwestern]

Which part of the drain cock was leaking? If it was the washer then you've done well to get 35 years out of it. If it was the actual fitting, then, as others have alluded to, it could be poor quality pipe and fittings, was the original installed by a DIY type plumber using fittings from "non professional" sources, this could be a source of your problem.

Also, technically, copper pipe and fittings are only "guaranteed" to have a life of twenty years.

 

Mike.

[34theletterbetweenB&D]

_{Thanks for the thoughts. It's not microbore piping on the ch, all 15mm and larger, and the workmanship all over is tidy so I don't believe that to be the source of the trouble. Since the failures are so far 'here there and everywhere' (hot water, ch, now cold water) I don't believe there is any blockage, everything works as it should. The cold water feed has plummetted in temperature in the cold spell, and maybe it was that pushed this drain cock in the rising main over the edge.}

[DonB]

We had a leak in a 30(+)-year old section of 1/2" CH copper pipe which was buried in the concrete base of a ground floor bathroom. it corroded at the point where it emerged from the concrete. It was discovered that the wall thickness of the tube was not uniform and was less than a quarter of a millimeter where it leaked. The amount of general corrosion would not have caused a leak to a uniformly drawn tube.

In reply to the OP:-

Does the water softener use Salt (NaCl) in the unit? Is that seeping into the system and causing corrosion? Are you using a corrosion inhibitor in the CH system?

Any chance of stray electrical currents causing electrolytic reactions? Is your system used as part of the Earth tapping / connection for your electric supply?

[Kenton]

A change in provider water pressure ? The wekest seals going first.

 

If the plumbing done DIY were the joints just sealed with plumber's mate - a goo like putty often used to "seal" threads (now usually replaced by PTFE tape. Like normal putty it has a lifetime, becomes brittle and cracks allowing small leakage.

[Mike Bellamy]

There was problems with poor copper pipe years ago and I think it was around the seventys. Place I worked had pipe work from that time that started to spring pin hole leaks. As soon as one was fixed within a few days a new one would start a few feet more down the pipe. In the end whole line had to be replaced.

 

I remember this as my Dad had to replace loads of pipe he had installed - very little help from the manufacturers or merchants who had profitted from this - damn near put him out of business but he survived to carry on until retirement (and still going strong at 86!)

 

Mike

[Donw]

Central Heating systems are best with an anti corosion product such as Fernox. If you consider an iron or steel radiator connected to copper pipe - opportunities for galvanic action. However two of your problems appear to be drain cocks if they are leaking through the plug it may well be the seals have perished. Have you drained the system at all. If you use a drain cock which has been there for some time consider replacing the washers. Similarly the glands on lockshields or rad valves (usually the same item just different tops) can leak often left alone for years then get used and suddenly start leaking.

Aslo in the period around the seventies copper supplies became a problem and some pretty thin pipe was sold. You can get some annoying leaks. I had one that was hard to spot a tiny pin hole in the heating coil that allowed the CH to leak into the hot water. It looked like a faulty ball cock in the tank causing an overflow.

I had one chap wanted to refix all the floor boards after the work to save a bob or two. Youve guessed it put a nail through a pipe. As it was on a joist with little clearance for a fitting I slit a piece of pipe and sprung it over then sweated it on, worked a treat.

Don

[skipepsi]

I must admit my BIL went up in my opinion when he did that, nail through pipe, 'turn water off again dear' how long for , about 10 minutes and sure enough at the end of a long day he had it sorted. Not one swearword or moan just a man doing it himself.

[34theletterbetweenB&D]

Everything is properly bonded and earthed, c/h circuit dosed with a corrosion inhibitor. The component that failed in the rising main was by the looks of it the washer seating, clean cracked through where there was a bubble inside the casting. That at least accounts for why it was a sudden onset problem. We do get constantly varying mains pressure here (top of a hill, pump supply, and end of the supply line) to the extent that once in a while the loft header tank and upstairs WC cisterns will not refill; so a component on the main is going to get regular load variation. (Veolia having recently sold out, I suspect there will have to be a new series of communications with the business that has taken over to ensure that they don't try and economise on running sufficient pumps/pumping rates to maintain adequate supply pressure.)