pex for hot water radiator heating

johnzenobia

Do I need to run special pex for hot water radiator lines?

Daniel Holzman

I use Wirsbo PEX tubing. Wirsbo makes Aquapex for potable water applications, and oxygen barrier PEX for radiant heat applications. I would guess that other manufacturers also have different tubing for radiant heat versus potable water applications. If you purchase your tubing from a plumbing supply store and explain the application, the clerk should be able to direct you to the appropriate tubing.

beenthere

You want Hpex/ oxygen barrier.

johnzenobia

I thought so, I am taking over the plumbing work in this job and I noticed that the plumber ( no longer working on this job) ran 3/4 " red pex on another radiator. What would be the harm in leaving his in the system?

beenthere

Cast iron+water=oxyugen makes rust. And lots of it. Can cause circulators to fail prematurely. Along with rusting out other ferrous parts of the system(like any steel pipes). Along with causing the system to either become air bound, or that radiator.

johnzenobia

Sorry, I don't understand.

Daniel Holzman

The tubing for radiators incorporates a special oxygen shield to keep the oxygen from the air out of the tubing, otherwise the oxygen reacts with iron in the water to form iron oxide (rust). Normal PEX tubing used for potable water does not have the oxygen barrier, so it is not suitable for radiator use. The color of the tubing does not tell you anything, you need to check the writing on the tubing to make sure it is oxygen barrier PEX. If it does not say explicitly that it is oxygen barrier PEX, the tubing may have a manufacturer identification mark on it that can be traced to the manufacturer's website, where hopefully it will state whether it is oxygen barrier PEX or not.

johnzenobia

OK I understand now, thanks. I will check the other lines that were run to see of they say o2 barrier on them.