Oxygen Barrier Pex??

[Mark Smith]

Hello all.  I recently had a local plumbing & heating company come inspect a boiler and water heaters while I have a house under contract.  The plumbing & heating company noted that the pex used on the boiler was not oxygen barrier pex, and needed to be swapped out.  The next day the seller contacted me, saying he checked out the pex and believes it IS oxygen barrier.  Can anyone tell me how I can tell the difference, if there is a way?

[Michael Knaus]

At my supplier the OB PEX is black. Is there any marking or print on the tubing? Colored OB PEX should have a gloss coating to it which is the barrier. Standard PEX is like a dull matte finish. Maybe take a piece down to the supplier. Sharkbite connections make it easy to remove/replace a piece. 

[Michael Gessner]

From my experience at least from my distributor here in NY, the oxygen barrier pex Ive purchased was grey and dull in color, the pex required by id say most buildings codes for heating will be the oxygen barrier tubing, which will have an additional barrier inside the tubing, I know the pex ive used had markings on the tubing every few feet. The blue and red real glossy stuff, again from my distributor is for only hot and cold applications not for heating and has no additional barriers. I know there is two types of oxygen barrier from pex, one has the aluminum barrier infused in an inner black layer and grey outer layer, the other does not, and has a different type of barrier but it is 2 separate walls. Id check the tubing real good and see if there is any markings, almost all the pex ive done has had markings

[Mark Smith]

Thank you @Michael Knaus and @Michael Gessner.  I trusted when the plumbing & heating company said it wasn't OB, so I didn't have a good feeling when the seller told me he believed it was OB.  I'll take a look at it and see what markings are on it.  The seller mentioned "ESR 1099" and "cross link" markings, but I think that would apply to just about any pex and certainly isn't definitive.

[Pat L.]

We have an old boiler with hydronic heating runs in several one of our multi-units. Over the last 5 years I have updated all the runs with the OB Orange Pex & have not had any issues. Love the stuff.

By updating the baseboard units etc heating costs have been reduced significantly.

I decided to eliminate the old 3ft baseboard units in the kitchens to make room for more base cabinets. So I installed hydronic 14inch kickspace heaters (with an electric blower) under one of the kitchen cabinets. The tenants are very impressed with the 2 speed blower & it really heats the room nicely. I have also been putting them under the vanities in the bathrooms as it heats the bathroom more effectively. The ladies love the warmth at their feet while they get ready at the sinks & no risk of fires with electric heaters.