# Hot Water Baseboard return with Pex?



## JohnH1 (Jan 9, 2009)

I would say if local code permits it the pex is fine. I have used it several times for baseboard.


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## gnosti83 (Jan 6, 2010)

JohnH1 said:


> I would say if local code permits it the pex is fine. I have used it several times for baseboard.


I know the pex will work, i just didnt know if it was taboo to do since the fins could cut the pex.


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## JohnH1 (Jan 9, 2009)

Pex is very tough. I dont think there any way the fins could damage the pex.


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## gnosti83 (Jan 6, 2010)

thanks john, i was hoping that would be the case, looking forward to not having to solder more pipe in that cramped space


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## beenthere (Oct 11, 2008)

Run the pex under the element, and fasten it to the brackets, not the element.


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## gnosti83 (Jan 6, 2010)

beenthere said:


> Run the pex under the element, and fasten it to the brackets, not the element.


Ill take a look to see if this is possible, I would imagine this would be a better scenario as gravity would take the pex away from resting on the fins. However, it looked like there was very little room below to attach to.


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## beenthere (Oct 11, 2008)

And the more room between the pex and the element, the better the heat transfer from the element.

having it rest on top of the element, lowers the heat output of the element. As it restricts the air flow.


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## gnosti83 (Jan 6, 2010)

Yeah i heard the return line in the baseboard can cut heat output by more then 25%, but my options are limited with the slab


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## gnosti83 (Jan 6, 2010)

This is what i ended up coming up with, I ran the line on the underside of the baseboard, but i did not like the way it looked as some of the line was visible.


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## NHMaster (Dec 21, 2009)

Pex expands a lot and I have seen it push the cover off the baseboard. I would use copper till I hit the drop.


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## beenthere (Oct 11, 2008)

Hope it isn't pulled up tight against the bracket. Or it will rub through.


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## gnosti83 (Jan 6, 2010)

I think i pulled them pretty tight, i will have to loosen them all up.


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## asb313 (Feb 20, 2014)

*PEX inside slant fin 30*

Hi gnosti83, I know it's been over 3 years since this post but I'm hoping to get some info about your inside baseboard return using PEX. 

what did you use to make the bend from the fin/tube connection? two 90 elbows or a return bend? if return bend, was it 3/4" 2" center-center? I see return bends on the net but most are 2 1/2" center to center. I'm also curious if you used push fittings such as sharkbites. I too have to add some baseboard over a slab level. 
Thanks, 
-asb313


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## gnosti83 (Jan 6, 2010)

see if this opens for you. This is what i used with one of those pieces vented to release air.

https://plus.google.com/photos/1095...5432728796005483954&oid=109573609612780499057


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## asb313 (Feb 20, 2014)

it did and thanks! I already installed some baseboard and notice you sweated the brass pex fitting to a copper fittings on pics 4 and 8. I didn't have much success with those. the solder would not hold. is there a special solder for brass to copper?


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## gnosti83 (Jan 6, 2010)

should be fine with enough heat, propane will take a really long time to heat up the brass, mapp gas worked fine


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## gnosti83 (Jan 6, 2010)

also make sure u are using the more expensive O2 barrier PEX so you dont get rust in there


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## asb313 (Feb 20, 2014)

yes i am using the O2 barrier.
thanks again for your quick reply.


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