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taracol

Proper spacing of pvc piping from furnace

taracol
10 years ago

Hello. I live in MA. I know that there are certain codes that heating companies must follow and I was wondering if anyone knows the proper code for the amount of space between the intake and exhaust pvc piping that vents out the back of a home from a gas furnace? Thanks.

Comments (20)

  • mike_home
    10 years ago

    I believe the minimum distance is 12 inches between intake and exhaust. There are several other rules which must be followed some of which may be specific to the manufacturer.

  • taracol
    Original Author
    10 years ago

    I thought mine were too close. I just measured and there is only 3 inches in between the 2. I know there are other rules as far as the amount of space between this and windows as well. Does anyone have any knowledge of this? I left a message for the gas inspector in my town to get back to me but I dont want to stir up any trouble for the installer unless this was installed incorrectly. Thanks!

  • mike_home
    10 years ago

    The clearance to a window which can be opened is a minimum of 12 inches.

    Did the installer get a permit and was the installation ever inspected?

  • taracol
    Original Author
    10 years ago

    I am not sure if a permit was ever obtained. I was not charged for one. If the inspector ever came out I was not here at the time. Something tells me that neither happened.

  • taracol
    Original Author
    10 years ago

    Here is a photo. Please advise. My furnace book says 12 inches. I called the city inspector and found out that no permit was obtained. I was told that in my city it depends upon what each furnace book says for the spacing in between the pipes. Apparently this was never inspected either-otherwise the inspector would have red flagged this and made the installer correct it. I am not sure how the inspector would even know what my particular furnace book states so how would they know if it was incorrect even by looking at it? I called the installer and of course they are telling me that I "dont know how to read a book" which is crazy. The inspector is telling me if the installer refuses to move the pipes to get him involved. Now I am nervous because all of these people know each other and seem to have each other's backs. Any idea what I should do?

  • mike_home
    10 years ago

    I am not an expert on this topic, but I will post what I know. The installation of gas furnaces at a minimum must follow ANSI Z223.1/NFPA 54 which is the National Fuel Gas Code. You furnace book likely references this code.

    You have a second issue. The intake and exhaust openings are too low to the ground. They should be 12 inches higher than the highest anticipated snow fall. You don't want snow and ice blocking these openings. This should also be fixed.

    You should tell your installer you want this fixed ASAP. The inspector's job is to enforce the code. File for a permit and get him involved if necessary. I fear the installation has other problems.

  • bus_driver
    10 years ago

    Patching the holes may be problematic, so that introduces an additional potential complication.
    I have encountered my share of incompetent inspectors in addition to incompetent contractors. I do want my jobs to be done correctly. Twice I have had electrical jobs held up for 8 days each at considerable personal expense, embarrassment, and loss of customer confidence when the work was correct and ultimately found to be so when higher authorities were brought to the scene.

  • mike_home
    10 years ago

    No holes need to be patched. The two PVC pipes can be easily extended in order to meet code.

  • taracol
    Original Author
    10 years ago

    What are you referring to when you say that "patching holes may be problematic and that introduces an additional potential complication". What type of complication?

  • brickeyee
    10 years ago

    "What type of complication?"

    Finding matching siding.

    If you must move the holes try to use the same piece of siding, and the piece from the new location becomes the patch.

    The distances are to the open ends, not between the pipes themselves.

    While it may not look the best, keeping the same pipe spacing through the siding but extending the pipes outside the house may be a good option.

  • Tinmantu
    10 years ago

    Your installer should know that there are plenty of options without drilling new holes. Here is one below in the link.

    Here is a link that might be useful:

  • countryboymo
    10 years ago

    I think the best option at this point would be to 90 both pipes up and angle one or both away from each other and then build from there. If painted to match it might not be too noticeable. I would go 90 away from each other and up or whatever that will avoid a patch to cover the holes.

    I have seen more than one that 90 away from each other and then go up near the soffit and exit. I think this was because there was not enough room between floor joists to get the needed separation without drilling through a joist weakening it. A small hole might be needed in the bottom of the 90's at the house to drain any built up moisture. Straight lines will be much less noticeable than angles if possible.

    It isn't done right but there might possibly be some reason behind the distance apart.

  • mike_home
    10 years ago

    There is no need to drill holes at the bottom the the 90 degree elbows. The piping should be have a slight pitch back towards the furnace in order to allow for the water to drain. A big icicle would form if water dripped out of the pipe.

  • taracol
    Original Author
    10 years ago

    What about the gooseneck option? It seems like a great idea to avoid having to move a pipe and having another hole. Since we are talking about the exhaust pipe and its the one that sticks straight out from house would another even easier option be just to extend it 8" out by adding a piece of pipe to the coupling from where it
    ends now?

  • mike_home
    10 years ago

    You need to extend both pipes. The opening of the exhaust needs to be 12 inches above the highest snow fall. This is a judgement call since last year Boston was hit with 25 inches of snow. You can but a 90 degree elbow on the current connection and then have it terminate in a goose neck flat against the house. I would make the opening at least 30 inches above the ground.

    The exhaust should also get a 90 degree elbow and then terminate so that it is higher then opening of the intake and there is at least a distance of 12 inches. It should be terminated with another 90 degree elbow facing outward.

    This is about 10 minutes of work for someone who knows how to cut and glue PVC pipe.

    I can post a picture of my sidewall vents if you need to see an example.

  • taracol
    Original Author
    10 years ago

    Thanks Mike for all of your advice. I really appreciate it. If you could send a pic that would be incredibly helpful. I just dont trust this installer and I think he needs a pic and I would like one to make sure the job is done correctly. Thanks again.

  • taracol
    Original Author
    10 years ago

    Thanks Mike for all of your advice. I really appreciate it. If you could send a pic that would be incredibly helpful. I just dont trust this installer and I think he needs a pic and I would like one to make sure the job is done correctly. Thanks again.

  • felizabeth
    2 years ago

    mike, thank you for the picture. It was very helpful!

  • mike_home
    2 years ago

    You are welcome. It is hard to believe I posted this over 8 years ago.