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[Kingman719]

My wife and I purchased a home in northern Maine built in 1890 the home has an old custom made wood boiler to heat the home other than that it has a woodstove the boiler runs fine but it has several leaks in the old copper pipes running to and from the home one underneath the boiler the system has one expansion tank and a taco cartridge circulator that when I plug it in makes no noise not sure if its suppose to or not the water is fed from my well pump but back to the leaks this boiler is huge and I was wondering if I could run pex to and from the boiler and could I use shark bite connectors or am I stuck buying a lot of copper pipe this is a big job because the pipes to and from the house are in a steel pipe one end through the foundation the other into the concrete house built around the boiler what are my options? Thanks for any help this is my first wood boiler the po told me you could load it up and it would burn through the night into the next day and heat the entire house sorry about the typos I'm on a iPhone there's no Internet here

[Scott7m]

Yes you can use shark bite to go from pex to 1" copper

[Kingman719]

Okay thank you so much I was worried it would melt the pex or the seals in the shark bite I'm not sure if its 1" pipe though looks smaller is there a special type of pex I should use? So much cheaper to run 50ft of pex both ways to the boiler and house than copper not to mention not having to sweat pipe every ten feet

[Scott7m]

Pex will be fine, the shark bites will handle it, I use them daily. 

Pex is generally rated at 180 degrees at 100psi, if it says that on it your fine... 

[dwneast77]

PEX is fine.  Should be PEX with oxygen barrier, which is just an extra coating on the outside of the pipe.  I was told to use it for heating applications as it doesn't lose as much heat as regular PEX.  I've used several hundred feet of it.  Seems to work great for me.

[RSI]

PEX is fine.  Should be PEX with oxygen barrier, which is just an extra coating on the outside of the pipe.  I was told to use it for heating applications as it doesn't lose as much heat as regular PEX.  I've used several hundred feet of it.  Seems to work great for me.

You are correct that he should use oxygen barrier pex but not for that reason. (I would question everything that person said if I heard that, the OB has nothing to do with heatloss)

You want to use oxygen barrier pex because it is a pressurized system.

[Scott7m]

Good catch RSI, I overlooked the pressurized part completely..

Yea I don't see how it's any  better in open systems, I don't see how it has any benefits

[dwneast77]

I got that from 2 sources actually.  My CB dealer as well as my local true value guy who I trust with just about anything (if you knew him you'd understand why.  A wealth of knowledge.)  Both know my system is non-pressurized.  And both said that regular pex just allows the heat to disperse out, huge heat loss.  I don't know.  I just went with it.  What do I know.  This system of mine is the only boiler experience I've had.

[Scott7m]

I got that from 2 sources actually.  My CB dealer as well as my local true value guy who I trust with just about anything (if you knew him you'd understand why.  A wealth of knowledge.)  Both know my system is non-pressurized.  And both said that regular pex just allows the heat to disperse out, huge heat loss.  I don't know.  I just went with it.  What do I know.  This system of mine is the only boiler experience I've had.

Aluminum is not an insulator. There is no debating that. 

There is even insulated pipe on the market where the 2 - 1" lines are completely surrounded by PEX, the entire tile is filled with it.

If there was any difference in heat loss, we would have no reason to carry regular pex as the price difference isn't dramatic, but it's still the same priciniple, aluminum does not insulate

[RSI]

If you can find one test anywhere that shows the slightest difference between oxygen barrier pex and non-barrier pex I would be surprised. The oxygen barrier is just a super thin coating of another type of plastic. It is there for one reason, to keep oxygen from getting through the pex.

There are many myths out there about oxygen barrier pex. Most started from someone that had no idea what it is for and it gets passed on to people that hear it and don't never bothers to research it. The Ace Hardware guy probably heard it from a customer and since thermopex only is available with OB a lot of different stories get started by the dealers.

I have sold insulated pipe to hundreds of customers and have heard many different thing that they have been told it was for. (many by central boiler dealers)

[dwneast77]

Well I guess my question would be, What is the oxygen barrier actually for?  Keeping oxygen in or out??  Does it stop condensation?  I have never seen any condensation on my lines even when water was flowing cold.  My manifold was condensating like crazy, ruined a pair of gloves sitting on it but the lines were dry.  I wonder if regular pex would have been condensating under those  conditions.  And what would that suggest if it did??   Maybe there is something else to it.  I don't know.  I have seen regular pex in a home basement running cold water and covered in condensation.  Things to ponder.   

[willieG]

pex..pex ala pex oxygen barrier pex, copper or steel pipes will be covered with condenaste when the temps are right, condensate is caused when the temp inside the pipe is cold enough to cause warm "moist" air outside the pipe to give up it's moisture and it collects on the pipe now we do know copper is much beter at transferring heat than pex of any kind so it would stand to reason that copper would condensate before pex. that may be the reason you seen the manifold covered in water and not the pex. i can tell you this also, when i first start my OWB in the fall, for the first few minutes whent things are heating up i can hold my hand on the incoming pex lines but not the copper manifold

[dwneast77]

Yeah, it all makes sense willie.  I can hold my hand on my hot OB pex lines much longer that I can the manifolds.  I just wonder if regular pex would feel the same way or hotter.  Without having any installed to compare it's hard to say.

I'm just trying to figure out the real purpose of the oxygen barrier.

[willieG]

ox barrier is to keep air from entering the water in the pipes

[Scott7m]

Yea oxygen barrier is to keep u2 out, you can't have a closed pressurized system when o2 is free to move about. 

In terms of regular open boilers, I know of no benefits.