Watts radiant onix tubing...rip out?

hot_rod

To scrub heavy deposits once they start to plug tubes like that requires velocity. The purge pros tell me you need at least 5 fps, (feet per second) to move solids along a tube or pipe.

So IF you can get flow going, use a booster pump or 1/2hp purge pump to get some serious flow velocity.

If a 100 psi water pressure did not move flow however...

This quick chart shows the gpm required to get various flow velocity known as FPS. It starts at 3/4, find other tables online that go down to 1/2" tube if that is what you have.

hot_rod

Updated chart, starts at 1/2"

Mark Eatherton

System has obviously gone through the "Turn it UP" syndrome, which doesn't bode well for a host of reasons. Obviously the heat sources is probably shot. Ferric oxides have to be coming from some component(s). If you can get ANY flow, it might be a good idea to put a Cat Pump (positive displacement) on it with a 4 way reversing valve, and a magnetic trap/conditioner. Running water backwards through a system does wonders for knocking clinkers loose.... You'd want to be very aware of maximum allow pressure exposure to all components, will need a pressure relief/bypass.

Put a good strong hydronic cleaner in it and let it run for as long as you can, check filter for loading on a regular basis until it starts to run clean. Then maintain a good chemical control program on it.

So long as it hasn't gotten hard on you yet, it may be salvageable.

I see some partial wall occlusion going on in those photos, but have seen MUCH worse corrosion in steel and galvanized pipes.

ME

Jamie Hall

The Cat pump -- or some other positive displacement pump -- is a good idea. Hadn't thought of that. However, I will double emphasize what @Mark Eatherton said: You MUST put a pressure relief valve on it. It should be set to the rated pressure of the piping or the pump, whichever is lower -- and connect it only to the piping.

Bluechair55

Thank you! I'm going to check that out.

Btw, anyone happen to know where I can find warranty info on this tubing from 2006? I can only find 2010 forward.

Bluechair55

Never mind, found the warranty info.

archibald tuttle

i would recommend breaking down your purge attempts into smaller units. i don't know if the upper logical rating for the onix is the same as the copper baseboard but i think you might have better success at least cutting the baseboard and purging each baseboard loop separately with no onix.

then try to purge the onix down to the basement.

is the baseboard also 1/2"

if you got the baseboard purged, is it really that difficult to imagine running new leads to the basement?

brian

PS - i proviso is there might be some onix loops under doors and such in the baseboard loops, esp. on the 1st floor, but maybe if you a have a deck exit door on the second floor or some internal loop that leads to a bathroom. (and its time to put a warm floor in the bathroom anyway.). So you might want to break it into smaller sections. It is isn't fun to think about, but with the cooperation we've been getting in the weather, if go a room a time and pull the furniture away from the walls, you could cut the full lengths of baseboard out easily with an autocutter style tubing cutter and take them outside and blast them out then take them back in and solder or shark or propress.

I have done this on 3 story house that froze (and it was fricking freezing out and we did it the unfinished basement). Because all the baseboard slightly expands from the freezing even when it doesn't split and getting new fittings requires 'creativity' and making a mess and we did most of our soldering and repair on horses in the basement and then took the completed lengths back up and put them in. took us about a day a floor with two guys.

Bluechair55

So the supplier of that tubing recommended using a Fernox power flush machine. He's shipping one up here and talking an area HVAC expert through the process. Could cost up to $2,000 for labor. Worth the money if it fixes it. But if it doesn't....

He said he's never seen this machine NOT unclog a system. I say mine will end up being the first.

Bluechair55

GOOD NEWS! The machine worked. It unclogged the tubing. Put in a cleaner and inhibitor and I'm back to having heat! It took about seven hours for everything and cost $1400, but it's cheaper than ripping out my walls and replacing the tube....

kcopp

That's a tool I want on my wish list....

archibald tuttle

kcopp-there is a tool you don't have on your wish list?

bluechair - happy purge. what was your interim heat solution why you were waiting to get this back?

hot_rod

Keep a close eye on the fluid quality, or else the condition may return

Good quality gill water and an inhibitor will help prevent sludging

Larry Weingarten

Hello, A trick I've used to clear blocked tubing is to open up both ends of the tube and then apply water pressure to one end for a minute. Then reverse. Reverse again. Keep doing this and you might begin to see a bit of movement. Any movement is good! I've had to work on a line for half a day, but eventually I've had it clear.

Yours, Larry

Bluechair55

Archibald, I used electric space heaters. My electric bill was not fun, but they worked well.

Hot rod, thanks! An inhibitor was put in. I've been told it needs to be redone every four to five years. Had that been your experience?

Larry, that's essentially what the machine did, but with the addition of a very powerful magnet that grabbed the sludge.

Kcopp, it was very cool! I would highly recommend it.

kcopp

I would not wait around 4-5 years.... the only way to know for sure it to check it EVERY year. Your system is a baseboard system and it runs at a fairly high water temperature. The higher the temps the more likely you will have issues.
A magnetic filter will also grab that junk out of the system as it flows.

newagedawn

check the mixing valve, they get plugged with garbage from time to time and wont allow water past

hot_rod

I agree with Kevin in checking it yearly.

It you do start having problems with junk plugging valves, etc, then the inhibitor or water quality are still a problem. Usually it indicates O2 is still getting into the system beyond what the inhibitors can handle.

Systems that allow high levels of O2, typically the early rubber hose Entran or non barrier PB or pex need yearly inhibitor boosts, especially the high temperature system.

Once fluid quality gets away from you the sludge forms, ferrous components corrode and cause valves, pumps, heat exchangers to fail.

A healthy hydronic piping system should drain clear water, and a very thin, several micron layer of film provider will be seen if you cut into the piping. The film provider in the hydronic conditioners coats the cleaned or new metals to protect them from aggressive fluid conditions and lime scaling to a certain extent.

archibald tuttle

hot rod (et al),

i just had to open a PB system that i used to run off a cast iron heat exchanger side piped on a 'snowman' converted coal steam boiler.

there was a little iron oxide fetch in one of brass couplings to copper manifold that i disassembled, but all in all, after 30 years of service i was impressed (about 20 years in one of the connectors on the heat exchanger gave up the ghost and i replaced it with a passively circulated hot water storage type heater.)

so this had limited heat regulation. i had an early 3-way valve that i bought form the guy who published the new hydronic news back then - since it was before the internet, radiant dudes had to cluster around the mailbox - but it still ran pretty hot at times. didn't maintain heat for the floor, it was constant circ freewheeling off of whatever heat was created when the boiler was making steam. but i'd say might have seen 150 or so for some time at the high ends when steaming.

i'm pretty impressed with the lack of trouble i've had. but don't know how the PB relates to the onix for oxygen diffusion and or the additional temps and running right through the combustion arena vs. heat transfer, abeit cast iron in both cases.

anyway, it was my first warm floor and it still works like a champ although i have it a little better regulated these days.

hot_rod

It often takes a good high velocity power flush to see what is hiding in those old systems. A cleaner will also losses up settled out or adhered debris.

These pictures came to me last week from an installer that added a water treatment device that has an anode rod installed. The electric boiler system has consumed several anode rods over the past 3 years. So the question becomes if the anode is causing more problems that it is solving. Is it a combination of the filtered (demineralized) water and the anode being attacked by that lower ph?

All systems handle fluid quality differently. We have seen some sludge within the first 5 years, others run 10- 15 with now problems. I remember early non barrier rubber systems causing expansion tank pin holes within the first few years of operation, back in the early 90's. It wasn't a random ocurrance.

I've yet to find a common denominator, to fluid quality induced failures maybe never will.

Most systems will present warning signs of fluid induced corrosion or sludge formation, but it takes a yearly test and analysis of the conditions to catch and prevent expensive fluid related failures.

Chris_82

I have 640 feet of 3/8 running just fine from 2002, with no issues whatsoever. Till I started connecting a few large CI radiators. So the preventive measure is to now add a dirt mag. But for the last 10 years no strainer, no cleaner, and no water treatment, and no issues. Still works like a charm. My concern is and this goes for pex as well, is the early failures of the non o2 pex and having to rip everything out. I just think that as time goes on that's going to be the test. Fortunately except for the cost none of my onix jobs have had any issues whatsoever, most have been running for over 16 years! Can't say the same for those Campenelli jobs in MA from the 60s' and that was copper tube for those that remember that little fiasco.

hot_rod

Is your tube the black colored Onix. Most of the problems were with the early Entran and TwinTran, non barrier orange colored tube.

Assuming the tube is not slugged up inside, the one option is the separate any non barrier tube with all non ferrous components. The pump, expansion tank, plate HX. You eliminate the rust and magnetite concerns if it is not in the circuit.

There are still copper tube systems from the 1950's in my area. A wholesaler in the St Louis area still bends up copper grids for ceiling radiant. It really depends on what the copper tube is in contact with, and moisture issues if it was in ground.

Zman

Chris said:

I have 640 feet of 3/8 running just fine from 2002, with no issues whatsoever. Till I started connecting a few large CI radiators. So the preventive measure is to now add a dirt mag. But for the last 10 years no strainer, no cleaner, and no water treatment, and no issues. Still works like a charm. My concern is and this goes for pex as well, is the early failures of the non o2 pex and having to rip everything out. I just think that as time goes on that's going to be the test. Fortunately except for the cost none of my onix jobs have had any issues whatsoever, most have been running for over 16 years! Can't say the same for those Campenelli jobs in MA from the 60s' and that was copper tube for those that remember that little fiasco.

The non O2 barrier pex did not fail. It did what it was designed to do perfectly. The failure was in the installers putting in the wrong product.

archibald tuttle

zman - one could back up to where i started and say the PB didn't fail it was the fittings. once a pattern of problems emerges the principal material gets a bad name whether it was poor spec or ancillary system fittings that actually lead to failures. PB did not fail, we failed it. But for those observing but not participating in the industry, the failure will forever be PB.

hot rod - wow, is the annode on those heating elements somewhere or is that just the result. i gotta say the more i see of problems like this the more i believe in heat exchanger between boiler and system. every system i have runs that way because i have such a large base of non-barrier tubing , but i started with that design before the problems of non-barrier tubing were apparent but as temperature mediator because this was way before the age of condensing boilers.

that is all floor radiant systems, i haven't been separating for higher temps in baseborad. i never really thought about it as i didn't start running anything but copper until well into the barrier pex era. it never seemed to be a big efficiency issue with floor systems and i usually used an indirect tank meant for DHW and it provided a bit of a flywheel when i did get to lower mass boilers. of course barriers are not absolute, they just slow down the effect. I did my first extensive barrier pex feeds on a loop of baseboard couple 3 years back where the original feeds were in uninsulated outdoor wall and i had to sneak replacements in for this loop. fingers crossed.

hot rod, i know you like water tests, but i wonder about the show me approach. obviously you can run some water at various system taps but is any kind of windowed fitting worthwhile?

hot_rod

Actually PB and early pex did have some tube failures if used with highly chlorinated water, especially on the hot side. Remember some manufacturers limited the time period that you were allowed to run the recirc pumps to help alleviate the tube failure.

There still is a chlorine standard listed on pex tube, ASTM F2023. Better brands of pex have better chlorine resistence.

Pex 1306, 3206, 5006, for example. The first digit indicates the chlorine resistance.


0 being not tested or does not meet the test standard.
1 indicates 140F for 25% of the time a typical 6 hour a day period.
3 indicates 140F for 50%
5 indicates 140F for 100% or continous recirculation applications.

I think Rehau is an example of a 5 rated tube, some of the other brands have upped their tube quality to meet the continuous use rating 5.

Find a long string of listing numbers on good pex, the MDC (Material Designation Code) the PPI Plastic Pipe Institute has all the info decipher the numbers.

I would suggest with legionella issues dictating potentially higher DHW temperatures it would be wise to use a Pex 5006 tube.

archibald tuttle

interesting. how does that string of numbers relate to the basic A, B, C designations that also indicated (in the case of A i believe) suitability for expansion style fittings.

Interesting on the chlorine side. I had understood those failures to be related to early plastic fittings moreso than pipe. Guess i haven't been doing my homework as well as i thought. Now i'm going to read some pex for that number although virtually all my radiant installs are in non-chlorinated settings. On the other hand, plenty of water system use of pex on chlorinated water systems. I suppose that could be a case for a fancy whole house water filter that takes out the chlorine although that could spur issues in the local piping, esp. in much lesser used legs. How does this affect flowing vs. closed water systems. Because on the heat side (vs. DHW) you put water with a certain amount of chlorine (unless you use non-chlorinated source) into the system and then that's it, maybe it gets repated on purging, but on flowing water systems you are always getting a fresh dose.

Of course I would have thought, on the up side, that a closed system esp. with chlorinated water wouldn't have been a vector for legionella . . . not that i'm going to start losing sleep over small percentage s#$t at this point.

Speaking of which, the city of Providence is on a tear with whole house Backflow preventers - of course going after businesses and apartment houses first because "they can afford it". There's a sensible rubric, kind of like looking for something you lost under the light. I've never heard of any instance of the lack of such backflow preventers for 100 odd years on this system leaded to any human health impacts in the contemporary era.

I understand the theory and I understand why they are installed on closed hydronic applications where the water is essentially resident and not replaced every time the system is used, but the whole house stuff is turning into an expensive nightmare, first on the install and then demanded testing every year. geez if we didn't have these damn things for 100 years and 10% of em go bad is that that much of a worry? And they cut water pressure, one of the few upsides of city water. It isn't that one can't describe issues of dead end piping and conditions that can still lead to issues within the house house water piping, but the prevalance of these and contribution to any actual danger seems marginal . I digress but it is a favorite saw of late.

hot_rod

No doubt the acetyl fittings failed, most from over crimping or mis alignment when crimped. Also the original aluminum crimp rings were not quite up to the task.

Within those pex numbers is other test data

Second digit is UV resistance 0-3

Last two digits are HDS design factor

Plus a bunch of ASTM, NSF/ ANSI, CSA, maybe others.

I'd guess the bargain price pex has few if any listings. Listing costs can be crazy expensive.

archibald tuttle

Hot Rod - HDS = ?

is there a standard so the four numbers will be there and just be 0 if not tested or might untested pipe simply not have this four digit code. And then there is the difference between Pex-A and Pex-B and Pex-C. My main focus there had been I believe A is rated for the original pipe expansion tool for connection?

And I know I asked a million questions along with disquisition on backflow preventers there. Was wondering if the chlorine assault on the tube is cumulative such that closed systems with limited water change would be less subject to damage than flowing domestic potalbe systems (esp. because of heat sensitivity DHW).

There is probably a raft of technical literature on this maybe archived by the manufacturers who have the most highly tested pipe?

thanks,

brian

hot_rod

Generic info here from the Plastic Pipe Institute.

They have other papers dealing with chlorine, UV, pressure, temperature, etc in more detail at their site. And they explain that alphabet soup of numbers found stamped on tubing.

https://plasticpipe.org/pdf/pex_designguide_residential_water_supply.pdf

I'm not convinced that all the pex types should be cold expanded. The pex A folks have no doubt tested then other pex types and brands with cold expansion fittings I think Rehau pioneered pex A back in 1968, Wirsbo maybe around 1972? I think that is a good period of time to prove a product.

Pex, like most other manufactured products, you get what you pay for. The brands with higher ratings and more listings are going to be more $$. You and you customer get to decide what they are comfortable with.

With all the different chemicals being use today to protect public water, I'd want a tube that has been tested and third party certified from a known manufacturer. Some of the "no name" bargain price tube, buyer beware.

archibald tuttle

So this is a typical of the plumb pex brand tubing i have employed for water service in my rack. the flash might be a little much in the center but the ASTM specs are F876, F877, F1807 and F2908 (I believe those are system specs of a sort. I associate the 1807 for use with crimps/shields, but i'm sure the material physics have something to do with those ratings but don't think those are the 4 digit codes you referred to. But, I believe maybe that code you are referring to on this pipe is 5582 which can be seen clearly in the photo, but i thought the second digit could only go up to 3, so should i go back to the drawing board here? Or maybe its like the amps in Spinal Tap?

I also looked at a piece of zurn barrier tube which did not have any 4 digit code i could find . . . is it different with barrier tube?

hot_rod

SDR is the outside dimension to wall thickness, 9-1 on that tube. GEO pipe is typically thicker wall, different SDR standard dimensional ratio.

The ASTM numbers are fitting and connection listings, copper crimp, stainless cinch, expander, etc.

As you can see NSF, UPC, ICBO, on that piece. You might see HUD CAN/ULC, CABO, SBCCI Southern building code, on some tube also. They all have their hands out for adding their approvals.

It is a lot of time and $$ to keep up and maintain listings. Caleffi for examples sells product in 57 or more countries, all with a long list of standards that need to be on the product, it is a department in itself for listings.

I know some manufacturers list their non barrier and barrier to different standards, not sure if it is a listing cost, or if the tube is extruded differently. I suspect the recipe has change somewhat over the years, older tube may not carry all the listings that you see today.

And of course brass fittings need to be listed to low lead standards for potable water and now also California Prop 65.

Usually the tech info at the manufacturers website tells about all the listings they carry. Google each one of those numbers to find out what the represent as far as testing requirements.

Alankr

Bluechair55 - I'm having a similar problem. I'm wondering if this solved the problem or if the problem returned? Also, can you send me a copy of the warranty if it is from the tube manufacturer (Watt)? my email is alan@team-styles.com. thanks!!

I have a condensing boiler and radiant in the floor - temperature usually around 120 degrees, not real hot. I have black Onix tubing - installed in 2005 on the first and 2nd floor and some kind of orange tubing buried in the concrete cellar floor. I had a Munchkin boiler installed in 2005, replaced twice and I finally pulled it out in 2021 since parts were getting scarce. None of the heating guys ever said anything about the water being black or that being a problem. It was actually piped wrong twice and the 3rd guy was a munchkin expert did it right and we had no trouble after that until he got sick and the local guys didn't know how to deal with a Munchkin.

So we installed an IBC in 2021 and have had trouble with the internal pump ever since and they tell me it's due to black particles in the water. They say the onix is breaking down.

My heating contractor is suggesting the same solution, flush it, add additives and add a magelectric? filter. But I'm concerned in 2 years I'll be right back here and concerned that eventually the black onix will spring leaks. I'm wondering how the fix noted above worked out and if anyone has experience with long term black onix?

Also, someone noted in an earlier post that most of the problems were with the early Entran and TwinTran, non barrier orange colored tube. We have orange tubing in the concrete, but my heating guys think it's Pex? How would I be able to tell? I can't see any markings where is comes up to the manifold.

Thanks so much for your assistance. These posts are amazing!

hot_rod

The black sludge or water you see is probably due to magnetite. When ferrous metals break down they form "boiler ink." Let a glass of it settle overnight, if the particles stick to a magnetite, that is the metals breaking down from oxygen ingress.

The radiant hose is soft, like a rubber garden hose. Spring or screw clamps on connections.
If it is pex it will be hard, maybe shiny, and have crimp rings on the connections.

No harm in doing a power flush to see what comes out. Add good water and a conditioner like Rhomar or Fernox.

Alankr

Thanks! I have well water that has a filter and a softener. Hopefully it's good by the time it gets into the system.

I'm not sure where ferrous metal would be coming from? The pumps are cast iron, I don't think anything else is ferrous? I thought it was the rubber breaking down?

My big concern is the future - would the rubber tubes keep breaking down and eventually leak? We added Fernox 2 years ago when they installed the new boiler and years before that with the old boiler.

Do you know anything about the Watts warranty or how I can message Bluechair55 who is probably not active on this anymore? he said he had found the warranty from 2006. I'm also curious what his experience has been several years later. Thanks so much! This platform is amazing!

hot_rod

Alankr said:

Thanks! I have well water that has a filter and a softener. Hopefully it's good by the time it gets into the system.

I'm not sure where ferrous metal would be coming from? The pumps are cast iron, I don't think anything else is ferrous? I thought it was the rubber breaking down?

My big concern is the future - would the rubber tubes keep breaking down and eventually leak? We added Fernox 2 years ago when they installed the new boiler and years before that with the old boiler.

Do you know anything about the Watts warranty or how I can message Bluechair55 who is probably not active on this anymore? he said he had found the warranty from 2006. I'm also curious what his experience has been several years later. Thanks so much! This platform is amazing!

The lawsuit which I believe is closed covered the orange colored Heatway tube Entran 2 and TwinTran. Allegedly the plasticizer would come out of the early tube under certain conditions. Clay is used as a plasticizer in EPDM tube manufacturing. So the sludge could have been from that breakdown.

If you have the black colored Onix it has an aluminum oxygen barrier. The aluminum barrier started in 1995 as I recall, some of it was an orange colored tube. The newer version has or had a has a Durel inner hose. So the EPDM is gone, and it has an aluminum O2 barrier, not unlike PAP, pex aluminum pex.

The tube you have, as all of the tube from day one has a lifetime warranty. That is for tube failure not system corrosion issues.

It's not so easy determining where O2 enters a hydronic system, or proving that it is the tube itself. We see systems without any plastic or rubber tube have O2 ingress problems.

Cast iron is a ferrous metal, as is the steel expansion tank and any steel fittings or nipples. If you have a lot of O2 ingress it usually shows up as the pump volute corroding, breaking down. That black water or particles are the result of that breakdown.

So the two choices are flush, clean, add DI water and keep a conditioner with O2 scavengers in the system. Test the fluid yearly with the manufacturers test kit. It may need yearly doses of additional scavengers added.

OR use all non ferrous components to run the tube. Either the entire system, or a heat exchanger separates the hose from the boiler and ferrous. On the tube side you use stainless or composite pumps, brass and copper, and a stainless expansion tank or a tank that has an internal coating Amtrol Extrol Pro for example. Get the hose away from any ferrous metals, basically.

Alankr

When you say add DI water,  should I purchase special water to fill the system? Or is there a way to treat water to become DI?

The black water in my system has little bits of black in it which I don't think are rust. One of the local consultants I spoke with says that is the tubing breaking down,  not rust?

kcopp

Its prob just rust & scale. I really dont think its the tubing breaking down.
I have seen it in Poly butylene.
You can filter the water by using one of these.

https://axiomind.com/axiom_product/puropal-1/

Alankr

Thanks! You guys are great! My HVAC guy recommended a dirt/magnet separator which I saw recommended in earlier posts.  The DI filter looks a lot more affordable? Would it be enough? Should I do both? My water is not DI. 

Larry Weingarten

Hi, Backing up a bit, you mentioned that you're filling the system with softened water. That concerns me as salt softened water is not good for ferrous parts.

Yours, Larry

Alankr

But my water is very hard and that's not good for a heat exchanger?  

kcopp

Running it through the Axiom filter will reduce that.

Doing the power flush cart will get a lot of that junk out of your system.
That is a big part of this process.
Getting EVERY steel/ iron part out of the system is important.