Connecting Entran 3 to Pex-Al-Pex

Prevch

I have Entran 3 radiant heat tubes attached to a manifold in my basement right now. I am planning on replacing that manifold and rearranging some other piping for my heating system since I am installing in floor heat on my main level and second level. In order to do so, I need to extend the Entran 3 tubing. I would like to go from Entran 3 to pex-al-pex. Based on how the Entran 3 is currently connected to the manifold, my plan is to go from 1/2" pex barb to 1/2" female threads as seen here:

https://www.supplyhouse.com/Bluefin-PXF050-1-2-PEX-x-1-2-NPT-Brass-Female-Adapter-Lead-Free

to:

1/2" Male threads to 1/2" pex press as seen here:

https://www.supplyhouse.com/Viega-90521-Zero-Lead-Bronze-1-2-PEX-Press-x-1-2-M-NPT-Adapter-w-Attached-Sleeve

The Entran 3 was here when we moved in so I have never made a connection with it or ever used it. Am I thinking right? Will this approach work to connect the two hose?

kcopp

Working with that Entran 3 is a bit on the risky side. How does it feel to you? I have seen it be as brittle as a dry twig before.
Tread carefully....

SuperTech

I'd consider replacing all the Entran. Isn't all that stuff non O2 barrier tubing?

Prevch

@kcopp The tubing doesn't feel too bad. @SuperTech
Unfortunately, I cannot replace the Entran 3, because it is in the cement slab, the rest of the house will be pex-al-pex, but the basement runs are permanent. The reason I need to connect to the Entran 3 is because I am installing a new manifold and where I want to put it would require some longer tubing off the basement Entran 3 coming out of the floor.

kcopp

You are fortunate.
The in slab set up probably helps w/ the O2 ingress.
That and that slab set up require lower water temps.

hot_rod

What size Entran? Look like some suppliers still have the sweat to barb adapters, sweat into the Appropiate Pex al Pex fitting. Also you the Watts selftite clampshttps://www.supplyhouse.com/Onix-Fittings-12870000

Prevch

The Entran is 1/2". Thanks guys.

hot_rod

I would definitely use the Watts barb Onix adapters, not a universal hose barb connection. Not sure if they offer threaded adapters, you may end up sweating together adapters.

Here is an example with a couple pex barb choices. This is a 3/8 Onix barb to 1/2 Pex

Prevch

@hot_rod Thanks. I actually took an old Entran 3 coupling out of the hose and took it to the hardware store. It actually was a 3/8" barb. The barb is the same as a garden hose barb so I bought those, but now I am a little scared based on your comment. I purchased 3/8" barb to 1/2" female thread so I am going to try that and see how it goes.

hot_rod

Give it a try, at low pressure you may be fine

HomerJSmith

Entran lost a class action suit and a compensation settlement fund was provided. I don't know the status of that now.

I never used it because I replaced a lot of car radiator hoses and I was wise to what happens to rubber and hot water, nor did I ever use that Shell gray crap either. If I had saddled a customer with that stuff, I would feel bad it today.

Prevch

@HomerJSmith I did look into the Entran lawsuit. It was specifically related to Entran 2, so hopefully Entran 3 will hold up better. If I could redo it, I would, but unfortunately, with it being in the slab, just have to work with what I got. @hot_rod I do appear to have a clogged line though, any info on how to release the clog?

hot_rod

The bigger issue with rubber tube, then and still now, seems to be O2 ingress somehow that causes ferrous metal breakdown and sludge formation. Sometimes you can flush it by applying your building water pressure, maybe 60 psi or more.
Most pros have a flush cart, high pressure high gpm that they use to clean those systems. With 10 gpm or more you can flush multiple loops at a time to speed the process.
Flush into a white bucket or barrel to see when you have it flowing clear.

Once loops are all open, add and circulate a hydronic cleaner to free up and wash out all the remaining sludge.

Once you have it all flowing, put in good quality, low TDS water and add a conditioner like Fernox or Rhomar. Those hydronic conditioners have O2 scavengers. It will need an inhibitor boost from time to time. Keep temperatures as low as possible to slow O2 ingress.

Even the newest version of that rubber tube seems to be prone to sludge, this was sent to me recently, after a few years of service.

After you flush see if a magnet attracts the sludge, proof that it is metal breakdown, not the clay dissolving from the tube

Prevch

@hot_rod Thanks for that info. That is a scary picture! I will give that a shot and see if I can get it flowing.

psb75

I have used a 1 hp submersible well pump in a 55 gal drum of water to try and "free up" some radiant loops of this kind of tubing installed in slab in the 1980s. It was this same red-brown sludge. Two loops I couldn't get flow through and had to abandon them. I think I was the first to ever flush them.

Prevch

hot_rod said:

I would definitely use the Watts barb Onix adapters, not a universal hose barb connection. Not sure if they offer threaded adapters, you may end up sweating together adapters.

Here is an example with a couple pex barb choices. This is a 3/8 Onix barb to 1/2 Pex

Hi hot_rod,

I know this has been awhile, but I am working on it now. In the adapter photo you provided above of the barb one side and pex the other, where did you find that? I am looking for a 3/8" barb to 1/2" pex and I am struggling to find it.

hot_rod

I made my own, looks like SupplyHouse has the adapters.
Also use the spring type clamp, not a stainless screw type. The spring clamps keep a constant tension better.

Prevch

hot_rod said:

I made my own, looks like SupplyHouse has the adapters.
Also use the spring type clamp, not a stainless screw type. The spring clamps keep a constant tension better.

Awesome thank you. I actually tried a 3/8" pex to 1/2" pex adapter and use the screw clamps on the Entran side and the cinch rings on the pex side. It sort of worked. Some of the Entran tubes have ridiculously slow drips, so close, but no cigar, hence me asking about the adapter.

Just for the sake of experiment, I am going to try a cinch clamp on the Entran side just to see what happens. 1/2" rings were too small, but the 3/4" were too big, so I ordered some 5/8" from Supply House, we will see what happens.

Anyway, I appreciate the help.

hot_rod

It really needs to be the Onix adapter, it has a taper built in, unlike a hardware store adapter. Also the clamp needs to be able to "self tighten". At one point a rubber cement was used with the barb.

mattmia2

Mcmaster-carr might be a good lace to look for odball size hose barb and spring clamps.

Prevch

mattmia2 said:

Mcmaster-carr might be a good lace to look for odball size hose barb and spring clamps.

Thanks I will check it out!

Prevch

hot_rod said:

It really needs to be the Onix adapter, it has a taper built in, unlike a hardware store adapter. Also the clamp needs to be able to "self tighten". At one point a rubber cement was used with the barb.

Yeah, it seems like that is what will end up happening, but since I have everything torn apart anyways, I thought I might as well experiment

mattmia2

Is there a layer of aluminum in that tubing?

hot_rod

I'd be inclined to buy the correct clamps, designed and engineered to work with that tube and barb.

Both 1/2 & 3/8 are at SupplyHouse.
E3, then E3∆, orange colored, then the black colored Onix, which has the aluminum layer.

Prevch

mattmia2 said:

Is there a layer of aluminum in that tubing?

Yeah as @hot_rod said, mine does not have the aluminum in it.

mattmia2

Prevch said:

mattmia2 said:

Is there a layer of aluminum in that tubing?

Yeah as @hot_rod said, mine does not have the aluminum in it.

Oh. i asked the question, then i read the title and thought oh, wait it is right in the title. But then i thought if there is a layer of aluminum, how is oxygen getting in.

Prevch

So just to update everyone, I was able to get the project completed successfully. The sandy junk that was stuck in the Entran lines I was able to successfully flush with the house water pressure. To connect the Entran 3 to the 1/2" pex-al-pex, I used 3/8" pex to 1/2" pex adapters. On the pex side, I used 1/2" cinch rings, on the Entran side, used hose clamps. A few of the hoses did have a very slow leak, but adjusting the clamp seemed to fix that. It also helped when heat was run through it from the expansion. Seems pretty solid right now, don't know how long it will hold up, but I am going to keep my eye on it. Attached are some pics. Thanks so much for everyone's advice and help.

hot_rod

Not ideal, might work for awhile.
That type of hose clamps will eventually cut through the jacket and O2 barrier. And may need occasional tightening as that hose expands and contracts from hot to cold, that is why the constant tension clamps are used. The more you chinch that hose clamps the more they damage the tube
You should not need to distort the Onix tube like that to get a tight seal.
The Onix barb is a fairly specific fitting, took about 6 years to get it right. The correct combination of barb and clamp will not leak from day one, or sunset day. A pex barb is far from a hose barb as you can see just looking at them.
Other than that...:)

Prevch

hot_rod said:

Not ideal, might work for awhile.
That type of hose clamps will eventually cut through the jacket and O2 barrier. And may need occasional tightening as that hose expands and contracts from hot to cold, that is why the constant tension clamps are used. The more you chinch that hose clamps the more they damage the tube
You should not need to distort the Onix tube like that to get a tight seal.
The Onix barb is a fairly specific fitting, took about 6 years to get it right. The correct combination of barb and clamp will not leak from day one, or sunset day. A pex barb is far from a hose barb as you can see just looking at them.
Other than that...:)

I hear ya, I am sure I will have to change it again in the future, but I was being stubborn lol

I have spent so much money on this project, three cross manifolds, tons of pex, press tool and press fittings, etc., I REALLY didn't want to buy more fittings, but it will probably come back to bite me. Stay tuned!

hot_rod

Norma is a brand of gear clamps that are smooth on the inside, a better clamp for soft rubber.
Or this bolt and nut type common at auto part stores. This type was actually the very first Heatway clamp, until they discovered the need for constant tension type.

Prevch

hot_rod said:

Norma is a brand of gear clamps that are smooth on the inside, a better clamp for soft rubber.
Or this bolt and nut type common at auto part stores. This type was actually the very first Heatway clamp, until they discovered the need for constant tension type.

Thank you!