PVC Venting on boilers again!

Jack

The topic that

correctly, in my opinion, will not go away. Charlotte took a page from the tobacco industry. They have published their disclaimer. Nowhere in any of the ANSI Standards to which their pipe is tested is appliance venting listed. their "tobacco" warming that tells you that then goes on to say that "the appliance manuf are best able to determine the best venting methods on their appliances". Essentially saying they are disclaiming any liability by posting tobaccos warnings. I think some enterprising attorney will blow right through that defense.



I represented Selkirk back in the Plex-vent/Ultravent days when the product was recalled. Wow, what a scene. I think PVC is going to end up being the mother of all recalls...someday

Someday the Trail Lawyers Assoc is going to get wind of this "unapproved product" with big numbers attached to it and whether it works or not, it will blow the whole thing up. There will just be too much money attached to it. I wonder how the CPSC views this?



The thing is, when we began using PVC for a vent material there was really nothing else. Today there are better products and they are available.

kcopp

So if you...

anted to use AL29-4C stainless to vent the modcons they do not make an adapter to go from the PVC OD to the std 3" Stainless. Kind of makes it tough to do the best thing.

Paul48

Where

would you need to put this adapter?

TonyS

Can we all agree

to limit this conversation to once a decade or....when there is actually a fatality from the proper installation of PVC.

kcopp

on top...

of the boiler..... Same place where you start off w/ PVC.

Ironman

Like Button

We need a "Like" button on here similar to what FB has.



Bob Boan likes Tony's comment.

SWEI

You need an "Appliance Adapter"

for that first segment.

Rich_49

CentroTherm

has a list of adaptors for damn near every piece of equipment manufactured .

jonny88

like button

like,like

SWEI

Appliance Adapters

See pages 7-9 of http://www.centrotherm.us.com/files/7213/2526/1012/CT_2012Catalog_PROOF_FINAL.pdf (and they have others as well -- that's a 2012 catalog.)  Most boiler manufacturers now list the approved transition fittings for both Duravent and Centrotherm in their I&O manuals.

HDE_2

Talked about a lot but still missunderstood

I do find a link often between the nay-sayers and personal compensation like the post that started this conversation up again.



Those of you that know of Ron George and his PVC venting articles in an engineer mag, may not know he was also trying to patent a safety control required by appliances that would allow to safely use PVC as a venting material. PVC is bad but I have a sole patented solution? Deeper investigation should have exposed many manufacturers already have flue temp protection.



Making you think; OK ah yes yet?



The boiler manufacturer will determine the class of venting material specified for its boiler based on testing criteria laid out in ANSI Z21.13, CSA 4.9 Standard For Gas-Fired Low Pressure Steam And Hot Water Boilers, which defines a minimum specification.



Focus on the manufacturer, not the pipe. A sagging, fallen, failed galvanized vent that has killed a family has never garnered so much attention. Surely, we could have made them devise a way to have a locking band system to prevent such a poorly installed catastrophe?

Steamhead

Took me a while to look this up

but here is NFPA 54 (2006)'s basic definition of a gas vent (caps are mine):



"3.3.105.2 Gas Vent. A passageway composed of LISTED factory built components assembled in accordance with the manufacturer's installation instructions for conveying vent gases from appliances or their vent connectors to the outdoors."



This also appears in section 1.7 of the 1999 version. Here's more, pertaining to Categories II, III and IV appliances:



"12.5.3 Special Gas Vent. Special gas vent shall be LISTED and installed in accordance with the special gas vent manufacturer's installation instructions."



Obviously, if PVC/CPVC/ABS manufacturers have not listed their pipe for gas combustion venting, they won't provide installation instructions.



On that basis, wherever NFPA 54 has the force of law, PVC/CPVC/ABS pipe would not meet Code for gas combustion venting, since it is not listed for that purpose.



Oh, and I don't think Ms. Fey would write something that is not true simply because someone wanted to pay her to do so.

j a_2

And then

Some states, such as mine, fall under different versions…We don’t make the rules,we just follow them….My opinion,,,end this subject…and move on to something else...

HDE_2

1993 & 2006?

We all have a responsibility to share accurate, up to date and correct information to all. Also, and Im not calling anyone out here, publishing incorrect info, using scare tactics, and other misinformed comments, doesn't help our industry.



Sharing incorrect information adds to the perpetuation of false knowledge and condensing boiler installation information. Lets refer to the NFPA 2012 if we want to quote rules here.



NFPA 54:2.5.1 Type of Venting System to be Used

The type of venting system to be used shall be in accordance with Table below (NFPA 54:Table 12.5.1)



Excerpt from table labeled "Type of Venting System to Be Used"



Appliances: Category IV Appliance

Type of Venting System: As specified or furnished by manufacturers of listed appliance.



NFPA 54: 12.5.2 Plastic Piping

Plastic piping used for venting appliances listed for use with such venting materials shall be approved.



NFPA 54: 12.5.3 Plastic Vent Joints

Plastic pipe and fittings used to vent appliances shall be installed in accordance with the appliance manufacturer's installation instructions. Where primer is required, it shall be of contrasting color.



I will go on record again, and since NFPA was specifically brought up and supports my statement, I will say it again:



Its up to the manufacturer to determine, certify and gain approval of the specified vent materials  appropriate for their appliances specific to the applications.



I can understand a person that works in the industry may have difficulty understanding or coping with stiff competition, but lets not make something more than it is. After all to quote flue temps higher than PP is approved for should make everyone question the accuracy. Everyone's entitled to their opinions, that's why were here. But we should thrive to have a professional and factual editorial to be read by trade persons.   

Steamhead

Inaccurate?

There are some jurisdictions still using these Codes. In some locations, the state may adopt one such Code, there might be another one at the county level and a city or town may use still another. So it all depends on where you are, and what the politicians do.



I picked NFPA 54- 2006 since that appears to be the latest version available for free online. This lets anyone reading this thread look it up for themselves.



The 2006 version does say that plastic pipe is approved if a manufacturer says it can be used on a specific appliance, but that strikes me as plastic versus something like stainless steel.  At any rate, you can't get past the provision that gas vents have to be listed. Stainless steel is listed. Centrotherm is. PVC/CPVC/ABS is not.

Steve_210

Polly propylene

This is taken from the manual of the well-known condensing boiler manufacture

I also never use PVC but have use cPVC in situations where I had a long run

Poly propylene would not work

I am referring to the Rigid not the flexible



When determining equivalent combustion air and vent length for polypropylene fl ex piping: • 1 foot of Duravent 3 inch fl ex is equivalent to 1.5 feet of piping • 1 foot of Duravent 4 inch fl ex is equivalent to 3 feet of piping • 1 foot of Centrotherm 3 inch fl ex is equivalent to 2 feet of piping • 1 foot of Centrotherm 4 inch fl ex is equivalent to 2.75 feet of piping



When determining equivalent combustion air and vent length for polypropylene single-wall piping: • 1 foot of Duravent 4 inch single-wall pipe is equivalent to 1.6 feet of piping

kcopp

Ya know...

After the Plexco / Hart & Cooley ultra vent mess and now the PVC concerns why am I to think that Polypropylene is going to be any better..??. I am inclined to go back to AL29-4c... no issues there. Fool me once...fool me a 3rd time?

Steamhead

Well, for whatever it's worth

polypropylene is listed. I'm not necessarily suggesting its use, but having the listing is better than not having it. It's one less thing the lawyers can use against you.

HDE_2

Listed?

Listed by who?

Where does it say a listing is required?

Back to the manufacturer, if they list it, it's OK.

HDE_2

*

Nothing wrong with that.

No one forces anyone to use PVC under the right conditions and application, just nice to have a choice.



What I have a problem with is the misinformed that don't understand PVC capabilities and proper uses.



Plexco and plexvent wasn't a bad product, only it's bad installs and misuse.

Steamhead

UL 1738 listing

as mentioned earlier, obtained by whoever made the pipe.



As I understand it, an appliance manufacturer can only get its own products listed. Unless the appliance manufacturer makes the vent pipe, that appliance manufacturer cannot get it listed. And as I said before, PVC/CPVC/ABS pipe manufacturers have not gotten this listing and probably never will.



HDE, what is your stake in this? Are people turning you down for mod-con jobs because they've read about PVC failures?

jonny88

venting a boiler.

HDE obviously you have your homework done.This is the problem i am having.I switched to centrotherm after the whole PVC debacle.How do we sell these units to customers if we are having basic concerns about venting.I mean should this be an issue.What do they do in Europe.This is why myy old company stays with atmospheric boilers.He cant handle the b/s.Look you got some great minds here and there is no definite answer on a basic question.Thanks for bringing it up.

icesailor

Not Bad Products:

Not so with Plexco, Plex Vent and Ultra Vent.

You needed RTV Silicone to seal it. Silicone will stick to your clothes but not adequately to smooth plastic pipe. Plus, the grey stuff needed the steel clips to help hold it in place. If you had a clip on the bottom of the pipe, and condensed water got past the RTV and got on the clip, the clip would rust, expand and could break a piece of pipe or fitting off. That, and just the plain falling apart.

I never installed any when new. I just found the bad ones and replaced it with SS.

Then, because it was a PITA and expensive to replace, the owner would call the original installer and complain. To which the OI replied that some one was full of ships and there was nothing wrong with the many of installs they had done.

Now, your considered a crook and a liar.

Paul Pollets

Liability vs Performance

It's interesting that nobody mentions the effect of the chlorides leaching from the PVC and washing down the heat exchanger with a corrosive residue.



That a listed product is now widely available for venting and removes all liability for venting or premature boiler failure is not quickly adopted and used, despite its modest cost, is sad. It reflects on the trade's ability to understand the implications of using listed products or who gets stuck with the costs if there are problems.

hot_rod

exactly, Paul

I was thinking the same. Chlorides and aluminum or stainless are a concern.



Richard takes a sample of the fluid inside the boilers and also the condensate running across the HX. Send the sample to a lab and ask what it contains.



If in fact the flue temperature runs a few degrees from the supply temperature I suspect many mod cons run above 140F flue temperatures.

SWEI

Flue temps

should be lower than supply temps in a properly set up boiler.  Just a couple of degrees above the RWT from what I have seen.

hot_rod

that sounds better

good catch, Kurt

HDE_2

True Paul

No argument there, but it depends on the product design too. Many boilers route the condensate from the flue so that it never touches the heat exchangers.





And that's OK Rod, as the true PVC limit temp is actually 149, everyone makes the mistake thinking its 140. Yes only 9 degrees but that matters on low temp systems and with boilers that have 149 degree flue temp limits built in to meet CSA PVC venting requirements.



I keep hearing listed mentioned, listed by who? Manufacturers list PVC when approved by CSA. Other than that anyone can pay to have products listed, but why should they need to? Its listed as usable material by manufacturer. All codes refer back to manufacturer.......





And right on Kurt. If you control fire rate input to fire off of return water temps, you can maintain cooler than 149 degree flue temps on low temp applications.

HDE_2

I said products not techniques

I was only referring to the product not being bad, not the installation requirements. The installation was no worse than other field practices in the plumbing industry such as leading, sweating, pipe dopes, lubing, priming, solvent welding, sewer cleaning to name some.



If you work messy, you will get dirty.



Plexvent, plexco and others failures were due to installation, such as using non-UV fittings exposed, improper or lack of sealant, improper cutting of pipe causing splintering and the number one failure cause - Lack of support.

masterofnone

Homeowner concern watching this topic

Been watching this subject with interest since I am utilizing a Smart 40 indirect off of a Triangle Tube Solo 110 and venting with schedule 40 PVC exactly per the installation manual. I installed the sub-floor radiant system in 2010 following the TT manual and often researching "The Wall" for guidance. The 3" PVC is a short run out the side of our home with all piping very visible. Monitoring flue temperatures when making domestic water I've seen 150* and it seems, according to the manual, that the controller won't lock out the burner until a flue temp of 240*! Shouldn't that be concerning? For safety's sake, it seems lowering that value would be advisable. If I can adjust that value, I'd appreciate some feedback on that. Overall the entire system has worked almost flawlessly. Still, after following this topic, I am inclined to replace the vent pipe with CentroTherm, if I can obtain it. I'd rather be safe than sorry. Thanks for sharing your opinions. This has been a spirited topic.

ChrisJ

284F

I just found this on wiki.





http://en.wikipedia.org/wiki/Polyvinyl_chloride





PVC starts to decompose when the temperature reaches 140 °C with melting temperature starting around 160 °C.



140C is 284F.

If PVC starts to decompose @ 284F why is a PVC pipe's rating 140F? Is this @ a certain pressure?



I have a 4" PVC sewer pipe that has been laying on top of a steam pipe for 20 years which constantly sees 212+F and there are no signs of any damage or discoloration to the pipe.



Not to mention PVC drains all over the world seeing boiling water all of the time.

icesailor

Warnings:

I like the comparison someone made about "Cigarette Warnings". And all the drug warnings for the TV drugs advertised on Televisions.

If you don't understand that the manufacturers aren't passing the liability on to you, I suggest you suggest you speak with a Lawyer about deferred or transferred liability.

I just wonder how much water the Cigarette Warning would carry if the money was right. It hasn't made much difference with smoking lawsuits.

Paul48

You mean

the ones they settled with all the states? They didn't care because the Chinese market place was opening up, and they could, once again, sell to 8 yr olds.

Steamhead

HDE, we've already answered

your "listing by who": UL 1738, by the people that make the pipe. The appliance manufacturer cannot get a listing for something they do not manufacture.



Some quotes that you need to re-read:



"well known manufacturer stated to not use Sch 40 1094 pipe for exhaust venting but it was OK for air intake.  Sch. 80 CPVC was OK for condensing boilers that didn't have higher temperatures.  PP was approved in Canada at the time, and the boiler manufacturer sold a line of PP. But the compelling point was that no PVC pipe manufacturer listed their Sch 40 1094 PVC pipe for exhausting gas appliances, regardless what the manufacturer of the equipment said in the installation manual.



So I looked. No manufacturer stated that their pipe was approved by them for any product that was higher than 140 degrees."



"If the pipe fails, will Charlotte help you? Absolutely NOT. You used their product in a way that they didn't approve it to be used."



"Again, the people who make PVC/CPVC/ABS pipe have not listed it for venting combustion products. And, given the liability involved, they never will. They can sell a lot of pipe while others incur the liability if something goes wrong, so why change things?"



"Positive vent pressure venting should be listed. That means UL 1738 in the US. There are PP systems that are so listed but no PVC."



""Mr. Smith, were you aware that there were safer alternatives to using pvc for venting,asked the lawyer?" Please confine your answers to yes, or no. See how this works?"



"Nowhere in any of the ANSI Standards to which their (PVC/CPVC/ABS) pipe is tested is appliance venting listed."



Now how about answering my question from earlier: What is your stake in this? Why is it such an issue for you? Why do you continue to push for the use of an un-listed product?

icesailor

Right Again:

Right Again.

The market for nicotine delivery systems is vast overseas.

HDE_2

Your quotes are grabbing for straws, that's only one manufacturer.

IPex, a PVC manufacturer lists their sch 40 PVC pipe, fittings, primer and glue as ULC-S636 Class II A certified to 149 degrees Fahrenheit. The same pipe and fittings we are familiar with has a rating in Canada with labels on it and costs 5x more than what we pay for the same material. Paying more will make you feel more comfortable?



Just don't use it then, again my point is no one is making you, don't use it then but if the manufacturer lists and allows, what's the issue? If UL, CSA, NFG and NFPA says in thier codes to do what manufacturer says to use and follow thier certifications, then those that choose do may. Who cares what happens after that the boiler co accepts liability after listing PVC as a usable vent. Charlotte pipe is not in the equation so why keep sucking them into this as a excuse?



I will remind you once again , UL-1738 listing that is so important to you?

Per UL-1738 "These vents are intended to be installed in accordance with the installation instructions provided with the product." Product meaning the equipment if you didn't understand that meaning.



Those of you so vocal that don't want to why are you so determined to spew bad rhetoric on those that that use the allowable vent materials ? Just sayin



You ask, my issue is not about defending the PVC product as a vent but more about misinformed people speaking untruths about the proper use and application of PVC in the right conditions. The broad paint brush is unfair to the industry and 95% of the condensing boilers that can use PVC safely when done correctly.



I ask what's your stake in this? Your defense disregards most boiler manufacturer certifications and recommendations

Rich_49

OUR STAKE

Sir . Is that we are plumbers and heating technicians whose main objective is

"PROTECT THE HEALTH OF THE NATION "   JUST SAYIN .

Some codes also state that use of galvanized iron pipe is approved for the distribution of potable water , put that in your house . It's OK it conforms to the lead free act .

HDE_2

Return from vacation and read an article about Dan Foley's install of a Vitodens 100 with CPVC pipe vent. Nice install by the way.

http://mechanical-hub.com/foley-mechanical-performs-residential-radiant-makeover?utm_source=Jobsites+Email+5&utm_campaign=Jobsites5&utm_medium=email

Again just bringing up the misunderstandings of venting, materials and practices. Dan knows what he's doing and is well respected. Carol from Viessmann and the flue temps she quoted basically excludes all venting materials made except stainless steel.

Steamhead

Rich said:

OUR STAKE

Sir . Is that we are plumbers and heating technicians whose main objective is

"PROTECT THE HEALTH OF THE NATION "   JUST SAYIN .

Some codes also state that use of galvanized iron pipe is approved for the distribution of potable water , put that in your house . It's OK it conforms to the lead free act .

Well said. Another good quote is "Do no harm".

HDE, we have answered your question. You still have not answered ours. Why are you so fixated on using PVC when there are safer materials available? What's so special about PVC?

Bob Harper

As one who provides product liability support I will assure you it DOES matter that Charlotte Pipe and other mfrs. expressly state not to use their products for combustion venting. You are not only not heeding their warning but hiding that fact from your customers who are relying on the "skill of the seller". You therefore could be considered as putting them at unnecessary risk of harm while knowing of the hazards. This could incur criminal charges against you in the case of death. Yes, it does matter. Does a mfr. of terra cotta clay tile or garden hose have a duty to warn you not to use their products as combustion vents? No, because they are not tested or listed for that application. Just because some dopey mfr. of an appliance does some testing (no standard they can test to) and claims it's ok to use PVC does not make everything ok. There is also strict liability on the mfr. who fails to engineer a product that takes into acct. a reasonably foreseeable risk of hazard under the conditions of use. As more and more people become aware of these issues, more and more data will be compiled to paint a different picture of the "success" of PVC or its suitability. Meanwhile, the UL Standards Technical Panel has refused to entertain a listing similar to the Canadian S636 for a long list of concerns and problems. The polypro systems do Not use glued joints for one and are listed under 1738 for polymeric venting. You need to get off that 149F because the mfrs. referred to earlier in this thread clearly stated the exhaust temps can often exceed that temp. during normal firing cycles. What if a unit hits 159F for 30 seconds each time it cycles? Is that a problem? Who knows because it has not been studied but we know it does exceed the design specs. of the material and it is a material expressly forbidden to be used for the conveyance of gaseous media. Done.