Is pex safe

leaking

Is pex safe to use for piping to radiators on boilers that can reach 200f. What if the aquastat fails and temps go higher. Is it even logical to consider Pex for high temp boilers where pressure may be 20 to near 25lb. It sounds risky and unsafe.

kevin_58

pex

Pex is rated 100 lbs at 180 degrees for domestic hot water

Alan (California Radiant) Forbes

PEX Safety

To answer your question, no, PEX is not safe to use in any kind of heating system unless you install your own safety high limit.  Ever since I had a runaway boiler that melted the PEX tubing supplying radiators, I've installed a high-limit aquastat on the supply piping.



If you are uncomfortable even with the use of your own high limit, use copper.

Bob Bona_4

yes

it is safe.

Is there something more behind this question?

NRT_Rob

why the heck

would you allow your boiler to run to 200 deg F in this day and age???

Robert_25

Solid fuel boiler

Most of the barrier pex I have seen lists a rating of 80 psi at 200 degrees F.  Look up the specs on your tubing to be sure.



NRT_Rob, 200F is not uncommon with wood or coal fired boilers in the spring and fall.   e.g.  I have a dump zone set at 200F on my coal boiler.



-Rob

NRT_Rob

so add

a tempering valve...