Stovepipe clearance of 18" vs. what the stove manufacturer certification plate states?

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Ludlow

Minister of Fire
Jun 4, 2018
1,437
PA
There seems to be quite a bit of confusion regarding this topic. Everyone says that single wall needs 18". My stove plate and instructions clearly state that single wall can be as little as 12". My particular install is 16.5" to the pipe so its not like I cut it to the bone. Even so....what gives with the conflicting info? I have poured over past threads but didnt see anyone post the actual stove chart. Here is mine: Note the "A" measurement in the single wall section below.
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The stove pipe clearance requirements trump the manual requirements. Single-wall is 18" unless shielded.
What stove is this manual for?
 
The stove pipe clearance requirements trump the manual requirements. Single-wall is 18" unless shielded.
What stove is this manual for?
I dissagree the stove manufacturer can lower that clearance requirement If they test it. That being said if it is under 18" i just use doublewall for peace of mind.
 
Stove is Heatilator WS18. Same as a Quadrafire 3100 without the bells and whistles from what I have read.
 
I dissagree the stove manufacturer can lower that clearance requirement If they test it. That being said if it is under 18" i just use doublewall for peace of mind.
I wouldn't trust that. Stove pipe radiates a lot of heat.

Ludlow, note that the Quad 3100's rear clearance is 15.25" which is proper. The flue collar is 3" inboard from the rear of the stove.
 
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They are not identical. The 3100 says 18.25 to the center of single wall. That means I would be golden at 16.5 to the side of the pipe if all else being the same.
 
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They are not identical. The 3100 says 18.25 to the center of single wall. That means I would be golden at 16.5 to the side of the pipe if all else being the same.
????
Stove is Heatilator WS18. Same as a Quadrafire 3100 without the bells and whistles from what I have read.
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The 3100 has 4 afterburner tubes. The ws18 has two. Not sure if that has anything to do with pipe output BTU. They also have different peak BTU ratings and different efficiency ratings. Very much similar but not identical. As well, the following is the install clearances that I got directly from the quad website. Not sure where the one you posted came from because it is indeed different.You may be looking at a different model. I dont believe the 3100 Millenium comes in a step top.
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Yes, not sure why you said it was the same as the Q 3100. Regardless, watch wall temps behind the pipe. Single wall stove pipe radiates a lot of heat. If wall temps are high, shield the wall, shield the pipe or switch to double wall stove pipe.
 
I guess I should have said similar. Although they look quite alike and have similar specs, they have different clearances. Even though I am past the minimums according to my stove, I am considering a heat shield on the back of the vertical stove pipe after our discussion. My point is the conflicting info between what the pipe minimums are and what the stove manual says. Then some stove specs say to the edge of the pipe and some say the center of the pipe. My head literally spins trying to make sense of it.
 
Single-wall stove pipe can get quite hot with some stoves. Highbeam was regularly reporting very high temps on his Heritage. When we had the Castine, the double-wall stove pipe was over twice the minimum clearance to the drywall behind it. And yet temps reached 165ºF there. The clearance guidelines are the minimums, but I always try to exceed them if possible.
 
Heck, I wanted to pull it out another 7 inches and go strait up with the connector instead of having an offset in the stovepipe but was overruled by others involved. Still, a person should be able to have faith in an install at the minimums stated on the cert. plate.
 
I wouldn't trust that. Stove pipe radiates a lot of heat.

Ludlow, note that the Quad 3100's rear clearance is 15.25" which is proper. The flue collar is 3" inboard from the rear of the stove.
But if it is tested by the stove manufacturer who are we to say they are wrong?
 
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Great! I am interested to hear. Thanks!
 
I don't assume the manual is always 100% correct. Humans make mistakes. Several errors in manuals have cropped up over the years. In this case we don't know if this is tested results or the result of poor editing. We do know single-wall pipe can radiate a lot of heat.
https://www.hearth.com/talk/threads/omg-this-is-why-you-follow-code.160606/page-3#post-2158788

I've contacted Heatilator to see what they say.
I just dont understand how you can be so rigid on this yet ignore a zero clearance fireplaces instructions concerning inserts.
 
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But if it is tested by the stove manufacturer who are we to say they are wrong?
I look at it like this, both of us manufacture single wall black pipe, we essentially make the same exact product, the only difference is that your company is called abc pipe co, mine is called xyz pipe co. Both of our products are ansi certified and both of our company's list a product clearance of 18"
Stove company 123 has tested there newest stove using xyz pipe, they just got certified and list the single wall clearances as 14"
A customer buys a stove company's 123 unit and installs if to the spec but uses single wall pipe from abc, there house burns down one day and the insurance lawyers call your company because your product was used. Your lawyer says "hey pal, we are not at fault here, yes the stove from company 123 was tested at 14" but that was using xyz pipe and we never tested or certified our pipe (abc) under 18" heres our paper work to prove it" Judge then tosses your part of the lawsuit out.
 
But my stove plate just says single or double wall. (see first post photo) There is no pipe BRAND distinction.
 
I just dont understand how you can be so rigid on this yet ignore a zero clearance fireplaces instructions concerning inserts.
Likewise. Not ignored however, one case is often a liability issue as explained by the CSIA spokesperson I contacted. The insert manufacturers do test and approve the installation and that is all I have recommended in the past couple years. This clearance on the other hand is a measurable safety issue. As noted, I've contact the manufacturer to see if they actually tested to a 33% clearance reduction for single wall pipe clearance.
 
I am thinking that the stove just isnt capable of high enough pipe temps. It is listed as over 80% efficient. By my calcs of the peak BTU and efficiency, it will at most put 9.5K btu up the pipe.
 
I am thinking that the stove just isnt capable of high enough pipe temps. It is listed as over 80% efficient. By my calcs of the peak BTU and efficiency, it will at most put 9.5K btu up the pipe.
Perhaps true if it is operated correctly and once the air is turned down in a timely manner. But pipe clearances need to cover incorrect operation and overfiring circumstances too.
 
You would think. Cant wait to hear what they say about it.

Random web image I thought would fuel discussion while we are waiting:
 

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You would think. Cant wait to hear what they say about it.

Random web image I thought would fuel discussion while we are waiting:
Lol, lots wrong, 1st the pipe is installed backwards, looks close to the wall, Idk whats up with the multiple elbows
 
Likewise. Not ignored however, one case is often a liability issue as explained by the CSIA spokesperson I contacted. The insert manufacturers do test and approve the installation and that is all I have recommended in the past couple years. This clearance on the other hand is a measurable safety issue. As noted, I've contact the manufacturer to see if they actually tested to a 33% clearance reduction for single wall pipe clearance.
Yes The insert manufacturer tests their unit in one or two fireplaces without any set standatd to test to. Yet you are ok with ignoring the fireplace manufacturer who says dont do it. But you question their stated clearances which have an established testing procedure to follow??? And would rather adhere to a generic clearance set by code which in all other cases are over ridden by manufacturers specs. What about if the pipe is used on a furnace which only requires 6" of clearance to single wall?
 
You would think. Cant wait to hear what they say about it.

Random web image I thought would fuel discussion while we are waiting:
Yeah i am having a hard time finding anything positive to say about it