Has anyone had trouble with ferrous parts rusting when using Onix radiant tubing? I am repiping our system that has staple up Onix and finding the pumps are rusting pretty severely after just 3 years and there is lots of rust slime coating all the pipes. I've had plumbers blame the Onix, saying it doesn't have an oxygen barrier. But Watts Radiant clearly is marketing a product with sophisticated oxygen barrier. The tubing is only a few years old, so not the old school rubber which definitely had problems.
on a number of Onix tubing systems. If there is a barrier I do not think it works very well. I have replaced corroded pumps, flow checks and seen expansion tanks and spirovents clog up w/ rust. Your system should be flushed and cleaned. Then a good O2 inhibitor added. Rhomar or Fernox come to mind.