Ed. Cleaners should really not be in the system more than 1 week...10 days Max. Power flushing is highly recommended. When the stuff is flushed out typically the sanitary sewer in fine. What did you figure on for a boiler? Need to look at the fine print especially if it is a Bosch/ Buderus. They can void warranty stuff when it comes to Non- barrier tubing. Where are you located?
Ed, I don't know of any studies that have been done only the jobs that I have been to. That is upwards on 20 that have Onix tubing installed. I have flushed out the systems, power flushed out 4-5 and saved some of the fluid. After it settles out (and it is a suspension) I have run a magnet through the material left. It sticks to the magnet. If the tubing was what was breaking down it would not stick to the magnet. This suggests that its all the ferrous parts of the system... Cast iron boiler, expansion tank, air scoop and circulators. In those cases the tubing appears intact. I have swapped out as much of the ferrous components and treated the system w/ an inhibitor. I have used Fernox and Rhomar. Both will help.... I actually think Rhomar is a bit better. Hope this helps. kevin