Harman P68 install manual states exhaust is 3", it's not!

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Jan 29, 2021
147
VA, east central
The manual states exhaust for P68 is 3". It's actually 3 & 3/8" as I just found out after picking up my stove today. So the duravent pvp adapter cleanout tee I ordered for the stove has to go back. I was wanting to kill two birds with one stone using an adapter tee, but now I'll need two different expensive parts to go straight up right out of the back of the stove. What a racket... And why couldn't Harman just publish the actual exhaust diameter?
 

Pete Zahria

Minister of Fire
Jan 6, 2014
1,203
New Hampster
mcmanusfuels.com
. What a racket... And why couldn't Harman just publish the actual exhaust diameter?
What you are asking is for the industry to change it's ways..
A similar request would be to have the lumber industry advertise
a 2x4 as a 1-1/2 x 3-1/2 and a 1 x 8 as a 3/4 x 7-1/4..........

Dan
 
Jan 29, 2021
147
VA, east central
Should be a 3" INSIDE diameter. That's how all piping is measured.
You may need a stove adapter specific to Harman.
The inside is approximately 3&3/16". It might be close to 3" nearest the stove as the outlet seems slightly tapered. I knew piping is ID, but I expected a 3" adapter tee made to fit on "3 inch" stove outlets to probably fit, although I knew it was a bit of a coin toss for any given stove, especially since I saw that there was a Harman specific adapter. Obviously, the adapter tee fits on some stoves though as they wouldn't be making it otherwise.
My frustration is that Harman could/should provide more information in their manual about what is needed to connect to their stove. Simply stating "3 inch exhaust" in their install manual is practically useless as far as I'm concerned. Now I have to buy the adapter, PLUS a tee, vs just an adapter tee.
 
Jan 29, 2021
147
VA, east central
What you are asking is for the industry to change it's ways..
A similar request would be to have the lumber industry advertise
a 2x4 as a 1-1/2 x 3-1/2 and a 1 x 8 as a 3/4 x 7-1/4..........


Dan
I understand where you're coming from, but it's not quite the same in my view.
I'd be happy if the manufacturer would have specifically stated in their install manual that a Harman specific appliance adapter was required and other 3" stove adapters would likely not fit. Duravent, which I ended up going with, does make one. I don't know about Selkirk or any others. I've only had the Duravent one come up when I've searched for a harman adapter.
It wouldn't hurt for venting manufacturers to provide more information on the products either. It was next to impossible to figure out exactly what I needed to transition from 3" PVP to a masonry chimney. I'm still not sure that I have exactly what I need.
 

MalcolmH

Member
Jan 22, 2017
98
Ontario
I've had to use the appliance adaptor on both of my stoves, some stoves are made with different pipe wall thickness aswell, some are out of round from welding, if you are measuring the ID you should use a bore scope and mic it in a few locations and average it out not that it matters, so its kinda expected that one would need the adaptor since the vent pipe manufactures do not collaborate with Stove manufactures.
 
Jan 29, 2021
147
VA, east central
I've had to use the appliance adaptor on both of my stoves, some stoves are made with different pipe wall thickness aswell, some are out of round from welding, if you are measuring the ID you should use a bore scope and mic it in a few locations and average it out not that it matters, so its kinda expected that one would need the adaptor since the vent pipe manufactures do not collaborate with Stove manufactures.
What stoves do you have? I'm just ordering the duravent Harman adapter vs trying to fiddle with other stuff and maybe not end up with a sturdy connection.
 

MalcolmH

Member
Jan 22, 2017
98
Ontario
FP-45 & Windsor.
 
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