Pex for Webasto/Proheat

Ericbsc · November 23, 2009, 07:30:01 AM

Has anybody used pex for hydronic heat. I used it for everything else. Greatest thing since sliced bread!!! Not one leak with a thousand turns!! Advise? Good bad?

luvrbus · November 23, 2009, 07:37:35 AM

Eric, they use it in homes it is good up to 200 degrees go for it be sure and strap it down in you bus.FWIW use the brass crimp on fitting

good luck

Ericbsc · November 23, 2009, 08:12:03 AM

I used the brass for all. Would you put pipe insulation on it?

TomC · November 23, 2009, 08:34:52 AM

Pex makes special tubing just for heating. Check out their web site. Good Luck, TomC

prevost82 · November 23, 2009, 08:56:10 AM

That's what HydroHot sent me when I bought the self-install kit. High-temp PEX and brass fittings

Nick Badame Refrig/ACC · November 23, 2009, 09:46:55 AM

Hi Eric,

It's just called "Heat Pex" it has an oxygen barrier and is good for temps to 240geg. Not much more money either..

Try and stick with 3/4" or larger. Especially if you build a manifold because the pumps in Proheats and Webasto's are

not as powerful as conventional/home type circulator pumps. They are magneticly coupled together and tend to

give you slipage under a strain.

Good Luck
Nick-

Ray D · November 23, 2009, 02:39:25 PM

I am just getting started with the PEX, haven't seen brass crimps, I have the copper ones. Are these the same or am I missing something, haven't seen brass?

Ray D

luvrbus · November 23, 2009, 02:57:39 PM

Ray, the crimp rings are copper or stainless, aluminum was available for a while but they have been taken off the market because of to many failures.
I use the stainless crimp rings with Watts brass fittings myself

good luck

Don4107 · November 23, 2009, 10:05:31 PM

Saw an interesting version of what I think was Pex on "This Old House". It was three layers. Two plastic with thin aluminum in between. You could bend it and it would hold it's shape. Have not worked with Pex but it looked like it might be easy to work with.

sweeney153 · November 24, 2009, 04:37:39 PM

I used pex for the radiant heat in my house. 20 years so far no problem. Easy to work with.

Ericbsc · November 24, 2009, 07:50:03 PM

Thats what i'll use then. 5 zones including the dash heat. I am going to use the engine coolant system as the expansion tank. I have valves to take the proheat off line if I have a problem. Good bad idea?

Ray D · November 24, 2009, 08:34:35 PM

Do you guys use fittings for every 90 bend? Trying bend 90's with that stuff is like fighting a damned python and you need a boat anchor to hold it in place; well almost.......

Ray D

Kevin Warnock · November 24, 2009, 10:38:25 PM

I am not familiar with this kind of heating in a bus conversion. Do you put it on the floor directly, and then install a new floor over the top? What kind of floor can you put it on? What kind of flooring material can go over it?

How about in the lower wall below the windows? Would that work?

Thanks

scanzel · November 25, 2009, 03:37:08 AM

A friend of mine just did his whole house with the Pex, including all plumbing, radiant in floor heat and even in floor heat in the garage. I would suggest you visit some Pex internet sites and read into radiant floor heating before you install it in a bus. There are many different ways to secure it. NO you do not want to put fittings in the floor and then have it covered. If you should develop a leak all your plywood would become saturated with your antifreeze solution and it would never dry up. Could be a very expensive and labor intensive learning lesson if not done correctly.

belfert · November 25, 2009, 04:37:24 AM

Some kinds of PEX are more flexible than others. The brand I bought for my fresh water plumbing is quite flexible. I used Flex Pex.