Flue Venting Gone Wild

I saw the roof exhaust and new that I would have to pay special attention to the water heater and furnace. :o
Why do people do the things they do? LOL

I will add more pics below.

You will drive yourself crazy wondering why people do the things they do. I gave up on it years ago

Just look at things as if it is right or wrong and keep your sanity

keep ?

At least they are easy to document… although a HVAC contractor may need to take a bit better look at the HX…

What a mess. Pretty easy to comment on this. Fix this mess.

I wasn’t really asking why… just a figure of speach.

Most of the house is getting that type of comment: “Fix this mess” :wink:

Good Defect Pictures.:slight_smile:

Enter it for me or do I need to go to the other page and do that?


Just enter 2 of the Pictures that best describes the defect.

Here; http://www.nachi.org/forum/f11/accepting-nominations-best-defect-pictures-january-2013-a-77700/:)

I’m having some trouble understanding/seeing these pics. It looks like the installer indentified the old pipe as being a chase, which it looks like it is, pending the water heater vent termination/set-up. Where did the water heater exhaust to (rooftop)? Because it looks like in the attic pic, there’s only the HE furnace vent going through the chase, which would be fine, no? Did the water heater (3" ?) exit the roof via another location? What does the writing say at the T fitting on the chase? To me it looks like they ran the water heater vent beside the new PVC vent (in the water heater closet) and then in the attic the water heater vent “parted ways” with the HE vent (still using the chase) and exited at a different location.

Maybe its too early and I’m not seeing the obivious.

The furnace is in the crawlspace below the water heater. Both exhaust’s are using the same flue. The furnace pvc is inside the B vent at the water heater and exits at the roof. The writing is telling us to not use the duct as an exhaust vent, only as a chase.

There are many things wrong with the mechanical, electrical, plumbing, roof, windows etc… that I would be surprised if my client buys the home.

Just the fact that it is ABS piping and not correct on the roof should be a clue that whoever did it does not know what they are doing.
News > Features > 01/01/2009 http://www.plumbingandhvac.ca/images/documents/roy-collver.jpg
Venting with plastic - by Roy Collver
01/01/2009 For over 30 years, a number of boiler, furnace and water heater manufacturers have approved the use of various plastics to vent their appliances. I saw the first such venting system used by a pulse-combustion condensing boiler around 1974. I believe the plastic used was CPVC (chlorinated poly vinyl chloride). Shortly after that (around 1980), I saw the first ABS (acrylonitrile-butadine-styrene) venting system, which was used on a condensing forced-air furnace. I was surprised to see ABS as a venting system. However, because it was a condensing furnace with relatively low flue temperatures and because the appliance manufacturer had received certification with approval for the material, I thought it must be okay and never gave it a second thought. I wasnt alone. As time passed more and more appliances were approved with plastic venting. Most of them used ABS and PVC (poly vinyl chloride). Again, I never gave it a second thought until some power vented water heaters were approved with ABS. Just a minute, thought I, these appliances run much higher vent temperatures is ABS the right thing to use? I shrugged it off again, however, figuring that if the manufacturers were recommending it and their approvals went through, it must be okay. I wasnt alone. Fast forward to the mid eighties, where a plastic material known as HTPV (high temperature plastic vent) sold under the brand names Plexvent, Ultravent and Selvent. This stuff was approved for higher temperature, power vented appliances such as mid-efficiency boilers and gained wide acceptance for a number of years. Then things began to unravel. Widespread material failures (mostly cracking and mechanical joint failures) led to a partial and then complete ban of this material. The ban led to a recall and replacement program 1994 in Canada, 1998 in the U.S. Did these failures taint all plastic pipe used for venting? Not really. Most of us in the industry felt that plastic pipe used with low flue gas temperature condensing equipment would perform well over the long-term, which appears to be the case. So what seems to be the problem? The rules
According to the CSA B149 (natural gas and propane) codes, plastic venting systems are classified as BH Gas venting systems. The appliance must have a label describing: a) the classification of the special venting system, b) the rated flue gas temperature, and c) the rated vent pressure (positive or negative). In addition to the label on the appliance, the venting material must be certified under the ULC S636 Standard for Type BH Gas Venting Systems or be a venting system certified as a component of the appliance and provided by the manufacturer. There are some other requirements listed, but what is astonishing is that for approximately 30 years hundreds of thousands of gas-fired appliances have been installed in violation of the letter of the B149 as referring to type BH venting systems as far as I can interpret it. So what? Havent these systems been working okay anyways? Well, for the most part yes. I dont want to be alarmist here, because I have heard of very, very few incidents of failure with ABS, PVC or CPVC venting systems. They are inexpensive and easy to install and the materials are widely available through a broad range of distributors. BUT some failures have been noted. AND there is absolutely no consensus on the longevity of these systems from the very people you would expect would have the data readily available the plastic pipe and fitting manufacturers.
The failures
First, the failures: There will always be failures due to improper installation of a venting material. There are ways to limit these, the primary one is to ensure that installers are properly trained and licensed a practice already widespread in Canada. The failures that worry me more are due to material or mechanical fatigue or deterioration. These seem to be on the increase as some plastic venting systems age. Carey LaRose Alberta chief inspector, plumbing and gas reports that the Ontario Technical Standards and Safety Authority (TSSA) in Ontario noted and reported a growing number of ABS venting system failures on higher temperature applications, most notably, power vented water heaters (the plastic becomes brittle and can shatter). Concerns were tabled at an interprovincial gas council meeting, and they bounced it back to the CSA B149 venting committee, who in turn investigated and blew the whistle on the fact that these venting systems did NOT conform to the requirements of the B149. A supplement to the B149 will be issued shortly, although I dont see why it is needed, given the pretty specific current language already in the code. The supplement will reinforce that all special venting material be certified to the aforementioned ULC Standard S636. You can bet that the authorities having jurisdiction will be very strict in enforcement.
Now what?
So where does this leave plastic pipe? Can it pass the stringent tests outlined in the S636? Maybe yes, maybe no. One plastic pipe manufacturer tells me that they already have their PVC and CPVC pipe properly certified. **What about ABS pipe and fittings, I asked. The answer made the little hairs on the back of my neck stand up. Well, said the manufacturer: We dont think ABS pipe should be used for venting gas appliances and we have no intention of trying to certify it. The answer seems universal among plastic pipe manufacturers. **Not good not good at all. I dont think it is necessary to go running and screaming down the street yet, but this is what contractors should do. During regular service calls, carefully examine all existing plastic venting systems for damage and deterioration. Most responsible appliance manufacturers advise you to do this annually as part of the regular maintenance of the appliance. If you find a venting system that has deteriorated significantly, do the following: a) Repair it, keep the damaged part of the venting, noting the type of plastic material, the nature of the failure and the date of installation as well as the make, model and serial number of the appliance. b) Notify your local gas inspectors and give them the information and offer the damaged venting material for examination. Ask for their advice and inspection of the repair. c) Notify the appliance manufacturer. d) Drop me a line and give me the information also, I want to keep an eye on this one and gather more information. I dont think we will find a widespread problem but what bugs me is we just dont KNOW. Should you continue to install plastic pipe according to the appliance manufacturers instructions? I think caution is required at this point. I would look for a pipe manufacturer that has products certified under the ULC S636 standard, and install that product exactly as specified by the pipe and appliance manufacturers. (Editors note: At press time we knew of only one manufacturer that offers pipe certified to ULC S636.)
Roy Collver operates Mechanical Systems 2000 in Calgary. He can be reached at royc@ms-2000.com.

For some reason, I thought one of the crawlspace pics was in the attic :roll: