Results and Thanks for the help!

Jim Eastman

I hollered for help a month ago about a "sweating copper pipe" situation. This is a solar roll radiant system that had developed numerous sweating leaks on horizontal piping that goes to the manifolds out in the system. I want to thank Mark Eatherton, Hot Rod Rohr, Phillip Gray of the Copper Development Assn and Scott Haldiman of Rhomar Water Management, Inc. for their generous and helpful advice. The pH of the system was below 6.5 and the piping had "barnacle" like cysts where the leakage was occuring. According to Scott Haldiman, these formations develop an extremely low ph (acid) fluid within the "cysts" and that is what causes the "sweat like" leaks. I cut out the affected copper piping (120 feet total)and replaced it with 3/4" Kitek. After replacing the piping, I flushed the entire system and cleaned the system with an alkaline cleaner. I wanted to avoid the acid type cleaners because I didn't want to create more leaks where they didn't currently exist. I used Rhomar Hydro-Solv 9100 alkaline cleaner. I will leave it in the system for approximately 20 hours while all five zones are running at temperature. I will flush the system tomorrow and clean, again, if necessary. (This system is on it's third boiler due to oxidation damage so there is a lot of crud in the system and the solar roll tubing doesn't flow too fast anyway!) After the system is as clean as I can get it, I will put in glycol and boost the corrosion inhibitor in the glycol with Rhomar 922 water treatment. This product has molybdate in it to stabilize the existing "barnacles" and hopefully stop the weeping and corrosion. I will continue to monitor the pH of this system and boost the corrosion inhibitors whenever the ph of the system drops below 7.5. I need to have the glycol because one of the manifolds is located in an unheated storage closet on an exterior wall.

I will post an update the Wall if I discover anything else worth passing on. Thanks, again, for the assistance by the professionals listed above for helping this Wethead learn from a challenging situation! What a great trade we have the blessing to be part of!

Jim Eastman
Precision Plumbing
Boulder, Colorado