Hi Rharns...

You definitely CANNOT use CPVC on a radiator.

I believe CPVC has an upper working temperature limit of 200F... way to close to the high limit of 190F that most forced water heat systems work at... ;)

In terms of domestic cold/hot water supply to the house, CPVC is a tested and proven product.

In terms of a residential forced water heat system you can use black iron, copper tubing and even an oxygen-barrier PEX tubing material to connect to a forced water radiator... but no way on CPVC or PVC.

Why do you ask?

Mark

NO! Iron pipe is generally used in steam and hot water heating systems. Regards, Tom

Rharns,

I'm shocked to see you getting such poor advice here and hope it's not too late.

You absolutely can use CPVC for hot water rads/radiant heating and there are CPVC pipes manufactured for the last 40 years specifically for this.

Harvel makes Flowguard Gold rated to well above the 100PSI/180F rating of ANY hot water boiler system. Coming from a cold climate I cringe to think of anyone who is running a 190F boiler water temp. especially with the efficiency of today's radiators. 150F is more than sufficient in a temperate/cold climate zone.

I am a landlord with multiple buildings and have had this pipe spec'd by various mechanical engineers for applications in restaurants and commercial complexes. The oldest installation I have is 18 years and still no problems.

The only fallacy is in the R value. Regardless of manufacturers specifications, I would recommend to avoid unnecessary heat loss the Flowguard Gold should still be insulated.

Hope this helps!

Simon.

Hi Simon...

I completely disagree with you on this... especially seeing how I have been installing steam and forced water systems for over 30 years throughout Mass. CT, VT, NH, and Maine, and I want you to know that there isn't a single contractor that would even consider using CPVC... never mind that with the newer PEX systems, it just wouldn't make any sense to even consider using CPVC nowadays. Simply put, CPVC is NOT rated for heat work.. PERIOD!

Now, running a hot water system at 150F like you suggest you would do (or are doing) may allow you to work and get the specifications to allow the use of CPVC, but again, got to tell you, there is nobody in New England that I know of that runs lower than 180F. Homes here are older and many homes have trouble maintaining temperatures as it is.

Finally, we try to remain open to all information that pops up at the Askmehelpdesk. I would ask you to please refrain from calling anyone's advice here, "POOR" until you have taken a few minutes to present your information and to discuss it with us as I have just done with you. In your case, using CPVC at 150F seems OK (I still wouldn't do it), but at 180F or hotter, CPVC is not something any plumbing or heating professional would even consider... ;)

Mark

We always run baseboard at 180-190. Common practice everywhere that I know of. Floor heat we run between 120 and 140 depending on floor type etc. Even many boiler install manuals will tell you 180-190 for basebaords, or radiators, and that's straight from the manufacturer. In my area, only copper, black iron, brass, and pex is allowed. Cpvc is a big no no and would never pass inspection here, and Im sure in many areas.

I am shocked that a person would walk in a room, in this case come onto a website, and make such a brash statement about the advise of a couple of professionals with a lifetime of experience, on a subject outside his own area of expertise.

I couldn't agree more Harold.

From the MFG web site.

"The Spears® CPVC system, including the joint, has a continuous
Rated working pressure of 100 psi at 180° F or 400 psi at 73° F.
CPVC systems have the capability to withstand shortterm
Temperature/pressure increases above 100 psi at 180° F,
As evidenced by their ability to consistently surpass the 48 hour,
150 psi Uniform Building Code test at 210° F. CPVC pipe should not
Be used where temperatures will consistently exceed 180° F.

It appears that you are safe up to 180 degrees.

Submanx1 said, "CPVC pipe should not be used where temperatures will consistently exceed 180° F. It appears you are safe up to 180 degrees"...

As I stated so many times in this thread, CPVC is NOT rated for use with steam or forced hot water systems as they CONSISTENTLY run above 180 degrees. In fact, these systems can get as hot as 212F or higher, so your advice here is very poor and shows a lack of knowledge of the product and the systems we are talking about!

No need to get into a shouting match. It is simple. If you keep the temps below 180n degrees the specs say that CPVC will be OK. If you operate above that temp CPVC is not. The boiler temp is adjustable and in many climates the systems operate well below 180 degrees. I have over 20 such systems (old systems with large cast iron radiators that operate at low enough temps that the cats sleep on them) so I do know what I am taking about. No need to reply for it is apparent that we disagree.

I'm from Florida where we don't have hot water heat but do hot water systems never exceed 180 F? Just curious. Tom

I'm from Florida where we don't have hot water heat but do hot water systems never exceed 180 F? Just curious. Tom

As you are likely aware potable hot water is never even near 180 degrees. 180 degrees presents a severe scalding hazard.

As for hot water (hydronic) heating systems I am not able to comment on all possibilities. I am in the mid Atlantic region where winters are mild. My case is dealing with old (75-100 years) houses where the system was originally designed to handle a house that has little to no insulation and has severe air infiltration. When I renovate I insulate heavily, install energy efficient windows and seal air leaks. This results in a much lower BTU load requirement. I do not replace the old radiators or piping ($$$) except to repipe when I move a radiator or install a new one. The old radiators have a BTU per hour capacity much higher than required if operated at a high temp so I run the systems at a lower temp thus supplying the required heating capacity. If I were to replace the radiators with smaller ones it is possible that the system would have to run at a higher temp.

I note here that many new hydronic systems are using a high quality residential hot water heater instead of a boiler. It is all a matter of getting the required BTU distributed to the right places. If you can do that with lower system temps there is no apparent reason not to. I have generally used Burnham boilers and they are virtually indestructible but the next one I have to replace I am going to use a forced draft condensing hot water instead of a boiler. They should run at about 98% efficiency at 140 or so degrees and, as I understand it, can be piped to supply both hot water and heat.

Before some of you go to battle I know that one cannot run potable water through the radiators.

Hi again Submanx

You have clarified your position and I understand that in your case, CPVC may be working well and it is important to share your view point for future readers to get a well-balanced perspective on the subject.

However, with that being said, people come in from all over the world and as plumbers that moderate the page we need to be sure that they also understand that in most cases, 140-160F is NOT what heating systems operate at (not even the newer ones as you suggested) in most areas of our country and CPVC is not going to be the recommended piping materials.

I have stated the correct materials for most applications above, but again, appreciate that you shared your experience from a warmer climate (with radiators that are "oversized")!

Thanks!

Mark

Hi again Submanx

You have clarified your position and I understand that in your case, CPVC may be working well and it is important to share your view point for future readers to get a well-balanced perspective on the subject.

However, with that being said, people come in from all over the world and as plumbers that moderate the page we need to be sure that they also understand that in most cases, 140-160F is NOT what heating systems operate at (not even the newer ones as you suggested) in most areas of our country and CPVC is not going to be the recommended piping materials.

I have stated the correct materials for most applications above, but again, appreciate that you shared your experience from a warmer climate (with radiators that are "oversized")!!

Thanks!

Mark

One final note on this. As I previously mentioned I generally use Burnham equipment. The boiler comes factory set to 180 degree high limit. The setting is adjustable from 140 degrees to 220 degrees. Some quick math and a little trial and error will be required but in milder climates you can adjust it down and still get satisfactory performance.

Sounds like the quality of the trade is going to pot in some areas. Bound to get worse before it gets better. Heck, before you know it professionals will be running rubber hose with band clamps for hot water baseboards. Is everybody getting to lazy to do good quality workmanship? I know it gets tiresome to use those pipe wrenches, and god forbid we actually have to lite a torch, but really, where do we draw the line between a professional tradesman that will only install quality products, and a handyman that will use any material as long as it minimally meets some local code? As you may have guessed, I would not stand for the use of cpvc for any hot water domestic space heating, period. Now, I will go so far as to say that you do make a good point, sub, I just don't agree with any of it (of course I am in a climate that is extremely cold in the winter, so that plays a big part in my ignorance here). I still believe there are pros out there that will stick to their guns when it comes to quality materials and not buckle just to make the job "easier" or to get the bid. So basically, quality of workmanship, and materials used says a lot about a tradesman.

You are correct, subman, no need to go to battle. I am right, you are wrong, I win, you lose.., or possibly visa versa?

PS. submanx1, all my nonsense aside, I thank you for your input. Very well spoken and very possibly helpful for other readers of this thread. Fact is, if you have been doing these type of systems with the materials mentioned and had no major problems with 20 different settups. that speaks volumes ( I would question how long the systems have been in place with the cpvc, one year, ten, etc?). Believe it or not, I am a strong supporter of "if it has worked this long with no problems, testing or not, it can't be all bad, right? Anyway, like I said, good info. Take care.
Lee.

Sounds like the quality of the trade is going to pot in some areas. Bound to get worse before it gets better. Heck, before you know it professionals will be running rubber hose with band clamps for hot water baseboards. Is everybody getting to lazy to do good quality workmanship? I know it gets tiresome to use those pipe wrenches, and god forbid we actually have to lite a torch, but really, where do we draw the line between a professional tradesman that will only install quality products, and a handyman that will use any material as long as it minimally meets some local code? As you may have guessed, I would not stand for the use of cpvc for any hot water domestic space heating, period. Now, I will go so far as to say that you do make a good point, sub, I just dont agree with any of it (of course I am in a climate that is extremely cold in the winter, so that plays a big part in my ignorance here). I still believe there are pros out there that will stick to their guns when it comes to quality materials and not buckle just to make the job "easier" or to get the bid. So basically, quality of workmanship, and materials used says alot about a tradesman.

You are correct, subman, no need to go to battle. I am right, you are wrong, I win, you lose..,, or possibly visa versa?

PS. submanx1, all my nonsense aside, I thank you for your input. Very well spoken and very possibly helpful for other readers of this thread. Fact is, if you have been doing these type of systems with the materials mentioned and had no major problems with 20 different settups., that speaks volumes ( I would question how long the systems have been in place with the cpvc, one year, ten, etc?). Believe it or not, I am a strong supporter of "if it has worked this long with no problems, testing or not, it can't be all bad, right? Anyway, like I said, good info. Take care.Lee.

Thanks for your capitulation. ---- you can come down off the ceiling I'm joking

But your comments about professionalism were a bit harsh. Times and procedures change.

A word of caution is in order here. I noted that the boilers were factory set to 180 degrees. If any of you are tempted to use CPVC be sure that you turn down the allowable max operating temp. While the specs say that CPVC will handle 180 degrees and there is usually a safety margin it is still close and there is no reason to push it. But do not go below 140 degrees or you run the risk of condensation rusting out your boiler. I usually find that 160 degrees works pretty well.

Also I would not put it near the boiler. I may have misled you somewhat. In fact I have never used it for the main supply and return lines. On the rare occasion when I run main supply lines I use copper and dielectric unions and wrap it with insulation. I use CPVC to add or move individual radiators. In these locations the temps have fallen substantially below those found in the boiler.

I would not recommend CPVC for baseboard applications without some additional study. I've not done one but I would guess that since baseboard units are somewhat smaller than the old cast iron radiators that I am dealing with they may run hotter so some caution is in order.

I have installed a radiant floor system with PEX and as I recall those systems run at about 140 degrees max indicating that if you have enough radiating surface you can go with lower boiler temperatures..

I haven't used PEX in a radiator system. It is soft and expands and contracts with the temperature (as does CPVC). CPVC fittings are glued and most PEX fittings are mechanical (clamped or sharkbite types). I'm concerned that the mechanical fittings will work and eventually leak.

You certainly make valid points. I am seeing your advice in a different light now. Again, thanks for sharing your experience on the matter.
Lee.

Further up date.

The 2009 IBC Mechanical code allows CPVC in hydronic heating systems as follows:

Chlorinated polyvinyl chloride
(CPVC) plastic pipe ASTM D 2846; ASTM F 441;
ASTM F 442

Any plastic pipe that does not have an oxygen diffusion barrier, should not be used in a heating system that uses ferrous components. Lowering a systems operating temperature does not reduce the potential for oxygen permeability.

Any plastic pipe that does not have an oxygen diffusion barrier, should not be used in a heating system that uses ferrous components. Lowering a systems operating temperature does not reduce the potential for oxygen permeability.

Don't know about the O2 barrier characteristics of the CPVC. Only know that CPVC with those ASTM ratings is specifically allowed in the code chapter 12 section 1202 table 1204.

Cpvc has no O2 diffusion barrier, and, if it is used in hyronic applications that contain iron components , there will be corrosion...

Here is the entire section

SECTION 1202 MATERIAL

1202.1 Piping. Piping material shall conform to the standards cited in this section.

Exception: Embedded piping regulated by Section 1209.

1202.2 Used materials. Reused pipe, fittings, valves or other materials shall be clean and free of foreign materials and shall be approved by the code official for reuse.

1202.3 Material rating. Materials shall be rated for the operating temperature and pressure of the hydronic system. Materials shall be suitable for the type of fluid in the hydronic system.

1202.4 Piping materials standards. Hydronic pipe shall conform to the standards listed in Table 1202.4. The exterior of the pipe shall be protected from corrosion and degradation.

TABLE 1202.4 HYDRONIC PIPE

MATERIAL

STANDARD (see Chapter 15)
Acrylonitrile butadiene styrene
(ABS) plastic pipe ASTM D 1527; ASTM D 2282
Brass pipe ASTM B 43
Brass tubing ASTM B 135
Copper or copper-alloy pipe ASTM B 42; ASTM B 302
Copper or copper-alloy tube
(Type K, L or M) ASTM B 75; ASTM B 88;
ASTM B 251
Chlorinated polyvinyl chloride
(CPVC) plastic pipe ASTM D 2846; ASTM F 441;
ASTM F 442
Cross-linked polyethylene/
Aluminum/cross-linked
Polyethylene (PEX-AL-PEX)
Pressure pipe ASTM F 1281;
CSA CAN/CSA-B-137.10


(continued)

TABLE 1202.4—continued—HYDRONIC PIPE

MATERIAL

STANDARD (see Chapter 15)
Cross-linked polyethylene
(PEX) tubing ASTM F 876; ASTM F 877
Ductile iron pipe AWWA C151/A21.51; AWWA C115/A21.15
Lead pipe FS WW-P-325B
Polybutylene (PB) plastic pipe
And tubing ASTM D 3309
Polyethylene/aluminum/polyethylene
(PE-AL-PE) pressure pipe ASTM F 1282; CSA B137.9
Polyethylene (PE) pipe, tubing
And fittings (for ground source
Heat pump loop systems) ASTM D 2513; ASTM D 3035;
ASTM D 2447; ASTM D 2683;
ASTM F 1055; ASTM D 2837;
ASTM D 3350; ASTM D 1693
Polypropylene (PP) plastic pipe ASTM F 2389
Polyvinyl chloride (PVC)
Plastic pipe ASTM D 1785; ASTM D 2241
Raised temperature polyethylene
(PE-RT) ASTM F 2623
Steel pipe ASTM A 53; ASTM A 106
Steel tubing ASTM A 254


1202.5 Pipe fittings. Hydronic pipe fittings shall be approved for installation with the piping materials to be installed, and shall conform to the respective pipe standards or to the standards listed in Table 1202.5.

TABLE 1202.5 HYDRONIC PIPE FITTINGS

MATERIAL

STANDARD (see Chapter 15)
Brass ASTM F 1974
Bronze ASME B16.24
Copper and copper alloys ASME B16.15; ASME B16.18;
ASME B16.22; ASME B16.23;
ASME B16.26; ASME B16.29
Ductile iron and gray iron ANSI/AWWA C110/A21.10
Ductile iron ANSI/AWWA C153/A21.53
Gray iron ASTM A 126
Malleable iron ASME B16.3
Plastic ASTM D 2466; ASTM D 2467;
ASTM D 2468; ASTM F 438;
ASTM F 439; ASTM F 877; ASTM F 2389
Steel ASME B16.5; ASME B16.9;
ASME B16.11; ASME B16.28;
ASTM A 420


1202.6 Valves. Valves shall be constructed of materials that are compatible with the type of piping material and fluids in the system. Valves shall be rated for the temperatures and pressures of the systems in which the valves are installed.

1202.7 Flexible connectors, expansion and vibration compensators. Flexible connectors, expansion and vibration control devices and fittings shall be of an approved type.

Approval does not guarantee compatibilty! Spend some time tomorrow with technical support from US Boiler corp. Taco, or any other manufacturer of hydronic components, tell them you've been using cpvc on your installs, and I guarantee an eye opening learning experience for you...

Approval does not guarantee compatibilty! Spend some time tomorrow with technical support from US Boiler corp., Taco, or any other manufacturer of hydronic components, tell them you've been using cpvc on your installs, and I guarantee an eye opening learning experience for you..........

I agree that mistakes can be made by anybody but... the code issuing organization is in my opinion is VERY to the point of overly conservative. Bottom line -- it is approved, I've been using it in this application for some time with no problems and intend to continue to do so. As for readers of this site they can evaluate the pros and cons for themselves. If they choose to use it and they get hassled by code officials they can point to the section of the code that allows it.

There is a website that I frequent, Heatinghelp.com, it is a community of the most knowledgeable heating professionals in the world, who are very willing to share their expertise. I doubt that you will continue to challenge the laws of physics after spending some time there...

There is a website that I frequent, Heatinghelp.com, it is a community of the most knowledgeable heating professionals in the world, who are very willing to share their expertise. I doubt that you will continue to challenge the laws of physics after spending some time there..........

I'll go there and thanks for the tip. Your comments have piquéd my interest in the potential O2 issue. BTW I have a BS in Physics and Math and 33 year career as a Physicist.

The information available at the heating help website will be of great interest to you, as will the discussions regarding 02 permeation and the ensuing DIN standards, that I believe were developed by a consortium of German physicists. By the way, I'm only a plumber, how much could I know...

The information available at the heating help website will be of great interest to you, as will the discussions regarding 02 permeation and the ensuing DIN standards, that I believe were developed by a consortium of German physicists. By the way, I'm only a plumber, how much could I know..............

Just responding to your physics comment. Did not intend to disregard your experience. Haven't gotten to Heating help yet but a review of the Charlotte Pipe web site indicates that CPVC can be used in Hydronic systems as long as the operating temps and pressures are not exceeded and providing that the pipe is properly installed. The O2 issue is not addressed in the tech lit that I reviewed.

Don't worry guys, I have more undergrad and graduate degrees than anyone here and I am still disagreeing with the idea of CPVC for heat (approved or not), especially when someone can use O2 barrier PEX nowadays... just doesn't make sense to me!

Thanks for updating the page, Submanx1... makes for a great link for people to make an informed decision!

Have a good one guys!

As I said before the O2 issue has put a different spin on the question.

I've been discussing this with Charlotte Pipe (Flow Gold) Here is a quote from them.

"CPVC CTS FlowGuard Gold does not typically require an oxygen barrier. In accordance with ASTM D 2846, CPVC CTS FlowGuard Gold is manufactured as a solid wall piping system and is not manufactured in a cross linked or co-extruded process like other materials that are prone to oxygen permeation. Unlike CPVC, some cross linked systems used in applications such as hydronic heating, require a layer of aluminum to be present to stop oxygen
diffusion through the polymer matrix."

I have been unable to get a CPVC O2 diffusion vs temp curve. Can any of you help? Flowgold provided some numbers for a specific temp but the units are in a form that is difficult to compare to the DIN standard.

Yes I know that you think I am obsessed but this question has so many loose ends that need to be tied so --

I think that the Germans have approved CPVC for hydronic applications under DIN EN ISO 15877-1. However I do not seem to be able to to get a look at it without paying $150 or so. Any Ideas for getting a free copy of DIN EN ISO 15877-1?

The community of professionals that frequent the " heatinghelp.com " website can help you answer your questions for free, and I think it will make for an interesting discussion.