25-PDVC Fixing existing bad install...flue help.

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Brentd2183

New Member
Dec 2, 2020
5
Long Island
Just bought a house with an existing 25-PDVC manufactured in 10/2008. Did a simple ash cleaning of the burn pot and only ran about 3 bags of pellets through it before I realized it wasn't right. Black covers the window within 2 hours, luke warm heat, weak flame. Decide to do a complete maintenance cycle on the unit to start fresh. Ash filled everywhere, scrape everything down on the inside, disconnect unit from the flue and its 25-50% full of ash. End up taking the entire flue system off the house and brush and blow everything clean. Exhaust blower was full of soot and ash and convection blower was covered in dust. Fresh air intake screen was 75% clogged up too. My guess is the previous owner didn't do any of the larger cleanings.

But I think root of the problem is the flue venting. When stove was first installed a stud and outlet were in the way of where a simple 45 degree offset would have let the pipe leave the stove and go through the wall but because they moved over to the center of a stud bay they had no choice but to use a 45 degree and a 90 degree right off the bat leaving the stove. It also forced the stove to sit more forward and off center on the tile flooring.

Manual wants 3 feet of vertical rise outside assuming the unit just vents right out the wall with no elbows, he doesn't even have that, he only installed 2 feet of verticals before the 90 and cap. Manual wants an extra 3 feet for every elbow used, so my 90, 45 would mean an extra 6 feet of vertical on top of the 3' for a total of 9'. Well I have a soffit in the way, I can add 1 additional foot of height to get to 3' and still have the required 24'' of soffit clearance but I don't meet the required vertical.

With these stove with an exhaust blower does it help overcome poor flue venting vs natural draft only? I've read that you can get away with it but if power goes out the smoke will want to come back in the house if your flue design is poor and only worked because of the mechanical push.

I don't want to turn the unit as its in the corner. My options are so far this....

1. Open up the wall and move the outlet and cut and box out around the stud so I can use only a single 45 degree elbow to get from the unit to outside. Add the extra 1 foot piece or replace with a single 3' foot piece so I get my 3' of vertical even through with a 45 degree I should be at 6' vertical.

2. Go up and through the eave and the roof, getting the 9' required rise allowing existing elbows and holes through wall to stay.

3. Do step 1 and step 2 since more vertical is better as long as I stay less that 15' so I dont have to go up to 4'' pipe

4. When I do go through the roof I do not want to stop at the required 1 foot higher than the roof as I have solar panels right there and dont want any soot so I would go up higher to at least the peak of the roof which would be about 4 feet of pipe from roof line to get to the height of the peak of the roof so total vertical run in that case would be 9.5' which would give me the vertical required to keep the elbows.
behind stove.jpg

clogged flue.jpg

convection blower.jpg

outside1.jpg

outside2.jpg
 

Ssyko

Minister of Fire
Nov 6, 2017
4,256
Lorraine NY
That stove only requires a 3foot rise. I would come off the stove clean out T then another 45 straight up 3 feet 90 and out the wall to a legal termination done. Keep you residual heat from the pipe in the house
 
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Mt Bob

Minister of Fire
Oct 31, 2013
3,345
park county montana
Manual wants an extra 3 feet for every elbow used,
That is wrong,and not sure where you get this idea.
However,being an older unit,consider what England's says-
"3. Horizontal run not to exceed 4' "
SO you are on the right track.
A straight out would be better,An up and out,like Ssysco says,would be great,but,because it is winter,I bet even if you just take out the 90,turn the stove,even if you have to use another straight section,you would be fine.Unless stove also has other issues,lol!
 

Brentd2183

New Member
Dec 2, 2020
5
Long Island
That is wrong,and not sure where you get this idea.
However,being an older unit,consider what England's says-
"3. Horizontal run not to exceed 4' "
SO you are on the right track.
A straight out would be better,An up and out,like Ssysco says,would be great,but,because it is winter,I bet even if you just take out the 90,turn the stove,even if you have to use another straight section,you would be fine.Unless stove also has other issues,lol!
reference.jpg


This was in the beginning of my manual and where I got the 3' thing from.
 
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Brentd2183

New Member
Dec 2, 2020
5
Long Island
That stove only requires a 3foot rise. I would come off the stove clean out T then another 45 straight up 3 feet 90 and out the wall to a legal termination done. Keep you residual heat from the pipe in the house
inside.jpg


For reference this is the inside setup, I have that lower ceiling there, granted it certainly has room for the 3 feet of vertical there and then go outside.
 
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gfreek

Minister of Fire
Nov 5, 2010
1,421
Attica,,New York
Exhaust vent cap clearance from the window ?
 

Brentd2183

New Member
Dec 2, 2020
5
Long Island
Exhaust vent cap clearance from the window ?

Totally didn't notice that till looking back at pictures, its on the line but under 4' so that's a no no. And re drilling the hole to put the stove in the correct centered spot and eliminate the 90 at the back of the stove only makes it worse. I could make it a non opening window to be legal.
 

ericofmaine

Burning Hunk
Feb 8, 2012
211
Southern Maine
I would go with what Ssyko said and try to get your 3' of verticle inside the house. Its how I have my PDV (this stove's bigger brother) piped. Going that route, you may find that your able to shoot the gap in your wall studs and meet all of the manufacturer's requirements. Only thing that will suck is closing up the existing opening.

Eric
 
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tbear853

Feeling the Heat
Totally didn't notice that till looking back at pictures, its on the line but under 4' so that's a no no. And re drilling the hole to put the stove in the correct centered spot and eliminate the 90 at the back of the stove only makes it worse. I could make it a non opening window to be legal.
What was said above … and if you can move the stove a few inches straight out from the corner, you could eliminate the 90 degree out the back, just flip the 45 degree over. Might need to add 6" to the straight pipe that comes through the wall …. I googled such last night ... they do make DuraVent in even 6 inch lengths as well as 1, 2, 3, 5 foot lengths. They even have adjustable sections like this: Duravent 3PVL-12R Pellet Vent Pipe, Adjustable ~ 3" x 12" 662492011263 | eBay .
Then there is the option of using an adjustable elbow adjusted to near straight. Between all that, you can get the stove centered and eliminate the immediate 90 degree turn. I just bought Permatex Red hi temp RTV that is good for up to 700 degrees, good to wipe over joints, especially those in the home.

11-30-20 stove back 640w.jpg
 
Last edited:

SidecarFlip

Minister of Fire
Feb 7, 2010
5,273
S.E. Michigan
When you are done fiddling with the venting, I suggest you put a surge suppressor on the line cord between the outlet and the plug. as well. Nothing better than a fried board on the wallet.