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Fixing Outside Vent Question - Gas Furnace

27K views 15 replies 9 participants last post by  jsp267  
#1 ·
I have a gas furnace. I recently discovered that the manual says the intake and exhaust pipes should be 12" distance between each other but the installer only has 3" (picture attached). I want them to fix it so it is as it should be. I also would like to avoid another hole in the side of my house if possible. I came across this picture and was wondering if this would accomplish the same thing. Instead of putting the side by side distance 12" they added a gooseneck to the exhaust pipe so it is 12" vertical. Wouldn't that accomplish the same thing? Any help/advice would be appreciated.
 

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#2 ·
while I cannot say, since you did not list make/model of your unit, you might reread your instructions again.

This does NOT look incorrect, but could be for your unit.
 
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#4 ·
I did not make any changes. The gooseneck picture is one I found online (I know it looks just like my house siding color). My manual says 12" distance so that is why I am writing on this forum to see if anyone can answer if the gooseneck would work or would I need them to cut another hole in the house and move the pipe over 12 inches?
 
#6 ·
How would the installer check alternative venting options? I don't see anything in manual.

Also what would happen if the exhaust ever did recirculate...would carbon monoxide and other gases spread throughout the house or would it just get sent back out the exhaust but shorten the life of the unit? As you can see I have no idea about any of this stuff...but it sounds scary. The installer obviously did not read the book and I want to make sure its done correct. If I don't need to have another hole in my house if the gooseneck would accomplish same thing I would like to know from all of you experts on here...much appreciated!
 
#10 ·
Have your installer add the goose neck, creating the distance required for openings. As for the death smell you are experiencing, if it continues I would suggest a camera run in your duct systems. You never know and obviously we can't answer that one for you. Hope we helped.
 
#11 ·
Right now I have about 20 ft of pipe and 3 elbows. I am not good at this but that would give me around 35 ft at most. So if I had them add a 12" gooseneck to the end outside that would give add on around 11 more feet correct?

So that makes it less than 50 feet and book says I can have up to 90.
 
#13 ·
I am inclined to think that the existing set up will be alright but it could be improved.
One suggestion is to extend the exhaust by adding a piece of pipe to the coupling. Your measurement should be from the end of one pipe to the end of the other pipe rather than from side to side. Verify that the intake is the pipe with the 90*.

Your concern about gases entering the house is unfounded. Neither of those pipes connect to the duct system. However, problems can arise if the intake pipe is above the exhaust pipe which can draw the exhaust fumes back in to the combustion chamber. The decreased oxygen content will cause incomplete combustion and sooting.

Lennox originally specified 36" separation for the pipes for the Pulse furnace but even that distance was not adequate under all conditions. They then used the configuration shown in your photo. By extending the exhaust 10-12" from the wall the gases could disperse without being drawn in the other pipe.

If the pipes are close to the height of expected snow accumulation then they should both be raised with goose necks.

BTW, you may paint the outside of the pipes to match your siding.

Conclusion: As long as the vent gases don't recirculate, don't obsess over it.
 
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#14 ·
Kdean1 - I looked at the manual and there is actually a diagram specific to my unit which says min 8" from center to center of 2 pipes and max 36". If I measure center to center its now 5" so still off by 3". What would you do? A Gooseneck? It still isn't correct and if it was inspected would have failed even though its only 3".
 
#15 ·
Each manufacturer sets their own standards. I don't see how keeping the pipes 8" apart will matter at all. Only the point of termination matters. Ensuring proper dispersion of the exhaust and preventing recirculation are the issues. I concern myself with what works and what does not.
I would put a goose neck on the exhaust side, raising it 12" above the intake termination. Make sure both pipes are above your local expected snow accumulation levels.

To what inspection are you referring? A code inspector probably won't know about it. The manufacturer does not inspect it.
 
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#16 ·
I am referring to the city inspector when a permit is pulled. My main goal is as you say is to prevent recirculation and the installer did not follow the manufacturer manual for proper spacing. We are having other issues and I came across this when looking through manual - I always thought they looked too close but didnt think much about it initially. I want it fixed when they come back out in a few days. The exhaust has a coupling on the end of it it so didn't know if a quick fix would be just to add 8-12" pvc pipe extension onto it. That way it blows it out farther away from house and the intake pipe. By adding gooseneck it brings it up closer to windows even though they are obviously closed when heat is on and pipes aren't directly below them anyways :)

What is the proper spacing near windows or does it not really matter?
 
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