[rharns1594]

[massplumber2008]

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

[speedball1]

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

[landlord_simon]

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.

[massplumber2008]

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

[mygirlsdad77]

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.

[hkstroud]

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.

[mygirlsdad77]

I couldn't agree more Harold.

[submanx1]

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.

[massplumber2008]

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!

[submanx1]

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.

[speedball1]

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

[submanx1]

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.

[massplumber2008]

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

[submanx1]

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.

[mygirlsdad77]

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.

[submanx1]

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.

[mygirlsdad77]

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.

[submanx1]

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

[Mike45plus]

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.