# Today's little nightmare repair



## futz (Sep 17, 2009)

Got a boiler leak call from a semi-regular customer. Had a look and made a list Friday and did the repair today. It was a bit of a pig to do. 

The boiler is a fairly nice retrofit someone did when the original rotted out - the rot was caused by non oxy-barrier poly-b radiant loop piping.

Here's the boiler and DHW tank. Decent stuff.









Here's the leaky culprit - 1-1/2" Spirovent with a hole in the side. I'm guessing it's a sand hole in the casting that took a while to show up, or a speck of iron/steel in the brass that rusted through.









The SS heat exchanger is to isolate the corrosive heating loop side of the system from the boiler and tank side. Trouble is, the guy piped large sections of the loop side of the system in black iron, which is now horribly corroded inside - that definitely made the repair MUCH more difficult than it needed to be. (Nice pot feeder, huh? Don't see many of those on house systems.)









Had to start at the pump and strip back up to the Spirovent. Of course there was massive corrosion inside lots of those black fittings and nipples. Put a wrench on it and things started to crumble. I put a new B&G vent on that was slightly shorter than the Spirovent - then the new nipples and fittings went together slightly different lengths than the old and I had lots of grief getting the pump to bolt back up. That 3/4" diff bypass line had to be repiped in copper - old one would not fit no way no how after I changed the bottom flange and nipple (bad corrosion).

These are the times when you start to wonder where to draw the line between repair and rip-it-all-out-and-start-again. :laughing: I stayed on the repair-it side of the line - barely. I figure they can get another five or ten years out of that black iron and then I'll tear the rotten junk all out and replace most of it with copper.


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## Optimus Primer (May 20, 2009)

i bet it was from all the copper screwed into black iron :jester:. it all looks confusing from here


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## Redwood (Sep 8, 2008)

house plumber said:


> i bet it was from all the copper screwed into black iron :jester:. it all looks confusing from here


No, On closed loop systems it normally doesn't matter because the water is oxygen deficient, but on this one the radiant loops are poly-b without an oxygen barrier so its just like an open system...

Somebody screwed the pooch on the initial installation.


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## futz (Sep 17, 2009)

house plumber said:


> it all looks confusing from here


Ya, I bet you don't see much of that kind of thing there in Florida. 



house plumber said:


> i bet it was from all the copper screwed into black iron :jester:.


The black iron corrosion and the original boiler corrosion was definitely caused by non oxy-barrier poly-b heating loop piping. That stuff is very oxygen permeable and with constant free oxygen coming in, "the fire keeps on burning" (rust). With an oxy-barrier it rusts briefly until all the free oxygen is used up and then stops corroding (the fire runs out of air and goes out).

We routinely screw copper and brass into black iron on heating systems. It holds up pretty well. I don't know exactly why, but I assume the lack of free oxygen probably helps a lot. I try to keep it to a minimum anyway - this installer didn't. :whistling2:


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## Master Mark (Aug 14, 2009)

*grey poly ??*

is that actually grey poly pipe going down into the concrete???

that scares me to even think of the troubles ahead


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## Protech (Sep 22, 2008)

Actually, due to the lack of chlorine and low pressure, that will prolly go another 20 years.



Master Mark said:


> is that actually grey poly pipe going down into the concrete???
> 
> that scares me to even think of the troubles ahead


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## futz (Sep 17, 2009)

Master Mark said:


> is that actually grey poly pipe going down into the concrete???
> 
> that scares me to even think of the troubles ahead





Protech said:


> Actually, due to the lack of chlorine and low pressure, that will prolly go another 20 years.


What troubles? Poly-B lasts forever, especially in heating loops.

So you guys have had poly-b failures due to chlorine? I've never seen the stuff fail - it was always absolutely reliable here. And we DO have chlorine in our water. When they discontinued it I couldn't understand why. Always liked the stuff. But now I like pex better, so... meh...

The only poly-b failures I ever saw were in the first year we used it (and it wasn't the pipe) with those crappy grey acetal plastic fittings. They would crack if they were under any stress, or sometimes for no reason at all. Switched to copper & brass fittings and all problems went away. That first year we also got some aluminum crimp rings - failures showed up fast with those though and we stopped using them immediately.


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## Protech (Sep 22, 2008)

I a closed system like that, the only chlorine is the first bit when you fill'er up. After that, there is no more.




futz said:


> What troubles? Poly-B lasts forever, especially in heating loops.
> 
> So you guys have had poly-b failures due to chlorine? I've never seen the stuff fail - it was always absolutely reliable here. And we DO have chlorine in our water. When they discontinued it I couldn't understand why. Always liked the stuff. But now I like pex better, so... meh...
> 
> The only poly-b failures I ever saw were in the first year we used it (and it wasn't the pipe) with those crappy grey acetal plastic fittings. They would crack if they were under any stress, or sometimes for no reason at all. Switched to copper & brass fittings and all problems went away. That first year we also got some aluminum crimp rings - failures showed up fast with those though and we stopped using them immediately.


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## futz (Sep 17, 2009)

Protech said:


> I a closed system like that, the only chlorine is the first bit when you fill'er up. After that, there is no more.


I know, in heating it's never an issue. But I was talking about poly-b for waterpipes. What was the actual problem that was causing failures in the pipe for you guys? As I said, I've never seen the pipe fail (except when frozen solid in a cold snap :laughing: ).


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## Protech (Sep 22, 2008)

In areas with extremely high chlorine content and/or high pressure, the pipe itself can split. It's rare, but it does happen. 

I have also seen the 1" bluemax brand stuff that was used on water services get pinhole leaks (a bit more common). I suspect the chlorine causes it but I don't really know.



futz said:


> I know, in heating it's never an issue. But I was talking about poly-b for waterpipes. What was the actual problem that was causing failures in the pipe for you guys? As I said, I've never seen the pipe fail (except when frozen solid in a cold snap :laughing: ).


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## Redwood (Sep 8, 2008)

It was actually a bunch of them...
Acetal fittings...
aluminum rings...
Tubing failures...
Then Lawyers....:laughing:


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## futz (Sep 17, 2009)

Redwood said:


> Then Lawyers....:laughing:


Ya, frickin shyster ambulance chasers. Varmints. That'll do it.


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## Protech (Sep 22, 2008)

I thought he was referring to the tubing itself.......

I see very few problems with the later PB systems that were done with brass fittings and copper crimp rings.



Redwood said:


> It was actually a bunch of them...
> Acetal fittings...
> aluminum rings...
> Tubing failures...
> Then Lawyers....:laughing:


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## beachplumber (Feb 7, 2010)

first call yesterday was a pipe failure. small crack in pipe right where it went through a floor joist. didn't appear stressed, and the hole was large enough. it did appear that it may have been kinked at some point, but had been that way a long time. I would venture to say that the original plumber probaly kinked it when pulling through at construction.
the blue stuff is great it randomly breaks all the time around here. 12" deep 10$ ft. easy money


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