Yikes-copper pipes becoming porous in radiant floor system

flanger

I thought I had a leak in a run of copper pipe that feeds one zone in my 19 yr. old Solaroll radiant floor heating system. As the repairman pulled back the black insulation, we saw that the length of pipe is forming drips of glycol at various points - no holes, just drops. The copper is acting porous whenever the zone is running.

Notes:

Since my new boiler went in 3 yrs. ago, the Solaroll side, which is clearly allowing oxygen in, is seperated from the ferrous boiler side side by a heat-exchanger. Copper piping is running all through my walls, ceilings, and floors to feed the Solaroll manifolds. I have had very slight pressure/fluid loss for several years but never found a leak - and this find explains why.

I have only found one stretch of copper pipe that is acting porous. After replacing it, should I invest in a sledge hammer, furnace, chemistry book, or just wait until I see puddles forming in my house? Has anyone ever seen anything like this before?

John_21

Pipe

Was the pipe very thin or blue/green in color? If so look at the ph of heating fluids. John

Unknown

glycol maintanance

Have you ever checked the PH level of your antifreeze? Anyone put in stabalizer?

There is annual, yes YEARLY, maintanance that should be done to the glycol in your system. Amount of degradation is caused by many factors.

wheels

Jim Eastman

low pH

The system noted above has a pH of less than 6.5. That is the lowest reading of my pH test kit. What is puzzling is that only the horizontal copper piping is showing the exterior pin hole leaks. None of the vertical piping is "sweating" and only half of the horizontal piping is showing the symptoms. Mark Eatherton has suggested that excess flux useage 19 years ago may have caused enough damage to prevent the patina from forming and now that we have acidic water situation, it is eating up the copper tubing on the bottom of the pipes. Could it be that two separate technicians installed the piping---one was professional and used appropriate amounts of flux while the other was a sloppy and greedy flux user? We plan to repipe the obviously damaged tubing with Kitek. We will know more about the "undamaged piping" as soon as we cut it out while repiping the leaky sections. We will be flushing the remaining glycol, repairing the leaky sections, and adding water treatment to achieve a pH of around 9.0. Thanks, in advance, for any help that you can provide!

Jim Eastman
Precision Plumbing
Boulder, CO

hot_rod

Dozens of reasons for copper failures

In your case I, too, would suspect the low ph. Take a sample to a water treatment company to have the ph accuratly tested.

I'd suggest a good hydronic cleaner be added, circulated and flushed before new glycol is added.

The CDA at www.copper.org has lots of good info on copper failures, causes and prevention.

Get a copy of the copper tube handbook A4015. Lots of good info for anyone that works with copper tube.

hot rod