Venting basement pellet stove issues

[McPellet]

Hey all,
I've been reading posts for some time and searched for my situation, so as to try not to waste anyone's time. But haven't quite seen it. I installed a ComfortBilt stove last year, connecting a Duravent PelletVent Pro 90 deg elbow to a tee to an existing chimney pipe, and all went well. This year, I'm adding a stove to my basement, and not so lucky.

I'm using another ComfortBilt stove, running out a Duravent PelletVent Pro 90 deg elbow to a tee, up 4' to another 90, out 2' to the Duravent cap (using their kit). I've had loads of smoke through the elbows, at the creases/bends that I didn't think needed sealing. I sealed and sealed, no real luck, having especially bad leak from the tee cap. I taped and all, not much better.

I finally took it all apart and realized I'd botched the elbow to tee connection, not fully seated. Great, hoped this was it, but guess what. That connection won't allow for a seated 90 deg to my stove (perpendicular from vert tee to horizontal to stove). I can be up about 30 deg, or down a lot.

So, key questions are -
Why can't I get the angle? (upstairs unit is same and worked fine, fully seated.
Can I "over crank" the Duravent pipe? As in, can I force it to turn farther and still maintain a good connection?
Am I partly experiencing a mistake in pipe width, and need to to go to 4" since the math I usually see has me at EVL of 19, a hair over permissible?
(I'd talked to DuraVent last year and they thought my original install was fine, but it quickly went to wider chimney after elbow and tee.)

Pics show my overall setup and the elbow angle problem. Other important details would be that I want this particular setup in order to place the stove on an existing mat, centered in front of fake brick backboard, and to avoid a condemned chimney and studs (thimble is solidly placed). I have a call in to Duravent but waiting to hear back about elbow issue (still confused how one worked last year and now can't make the angle). Any help would be very welcome.
Thanks!

 

[johneh]

Looks to me like the straight up-pipe is about 1 inch too long
replace the top one with an adjustable pipe
this should allow the 90 to go on straight and be level

 

[McPellet]

I think the photo angle is misleading. The tee opening and the stove exhaust port are level (same height). I'm just stuck with that elbow not connecting and locking at the proper right angle, either a bit up, or way down (using neighboring slots on tee pipe). Apparently, per Duravent, the connection parts are randomly stamped at the factory, so they don't consider these angles of alignment. I would have thought they'd be designed to be parallel or perpendicular once seated correctly.

 

[shtrdave]

Curious if you could come of the stove and instead of doing two 90° bends make something more 45ish and run the long up pipe at a slight angle instead of straight up the wall?

 

[rickwai]

The pipe pictured is the box store durabent not pellet vent pro. Pellet vent pro has a swivel built into the tee in question and it has a oring seal. The pipe pictured we used years ago. We filled the gap with silicone then twist locked. The rope gaskets are useless in that type of pipe,

 

[mtnbiker727]

Why not delete your bottom 90, slide the stove over and get a straight connector to run the T straight into the back of the stove (with an appliance adapter)? If you're tight on space, you could probably put the appliance adapter straight into the cleanout T.



Also, when I gooped my connections (the second time), I put the goop on the inside of the connection, then twisted it together, then wiped the excess goop off. That made a lot tighter seal than when I slathered it all over the outside like you did. Get some of that red RTV silicone from Lowe's or wherever.

Oh, and please take the books out of there before you light the stove. My T gets hot when the stove has run for a while.... I'd hate to have you come on here and say you burned your house down because the pipe didn't fit right.

 

[johneh]

Mine is set up somewhat like yours except clean out Tee set at 45
to a short run of pipe, 45, then straight up
Makes it look like the stove pipe comes out the center of the stove

 

[shtrdave]

The only brand I have ever messed with is Harman. On your stove I wonder why they brought the exhaust out the back of the stove on a downward angle?

 

[McPellet]

Thanks, all! Couple responses to you helpful folks.
My pic is misleading (bad angle), and the stove exhaust is straight, my pipe is angled up in that pic since the connection is bad on the tee.
I could move the stove to skip the elbow, but it would be way off to the right, far off center on pad and in relation to back wall.
Two 45s could do the trick, but I have updates.
Duravent makes PelletVent Pro, so maybe mine is the less Pro version, but it's the kit I could find.
That clear silicone is Rutland heat goop, all good, just not red.

I heard back again from the terse but somewhat helpful folks at Duravent. And I found that if I attached the 90 elbow to the tee in the next (imagine turning clockwise) position, so at first it angled down, then backed it up to true (yes, diabolical!), I could get a bit of a grab on the tee connection and get it fully seated (the real key is fully seated to close the internal seal. Arguably, the bigger tip, which is Not in their documentation, in line with what Mtnbiker said, is to put a nice bead of silicone on the Inside of the male connector, so it locks to the inner wall of the female when inserted. Perfectly logical, though not what I had done originally. I had done internal, but not there. That outer goop piling on in the pic was my desperate attempt to fix my original problem, and has been removed during the fix.

So, I did all that, and it's much better. I still have smoke at startup, but then it all clears. I'm still going to run some silicone around a few spots, but think I have it licked. Most of the issues were the smoke getting between pipe layers, and yes, the ropes are a joke, which is why people use tape or silicone on the outer edges. Minor breaks in the internal seal will let smoke in there, but sealing will keep it in there until the draft pulls it out.

And yes, the books were there to support the vertical pipe while the stove connector wasn't doing that job. Promptly removed before startup.

Thanks again, all!

 

[mtnbiker727]

So, I did all that, and it's much better. I still have smoke at startup, but then it all clears. I'm still going to run some silicone around a few spots, but think I have it licked. Most of the issues were the smoke getting between pipe layers, and yes, the ropes are a joke, which is why people use tape or silicone on the outer edges. Minor breaks in the internal seal will let smoke in there, but sealing will keep it in there until the draft pulls it out.

I'm glad you were able to get it mostly resolved!

Turn the lights out when you start it and use a flashlight back there. You can see the "shadow" of the smoke, then you can pinpoint where it's coming from. I ended up getting Sharkbite silicone tape to wrap around one pesky seam. That stuff will chemically bond to itself, but not your pipe, so you can easily cut it to get the pipe apart if needed, and then stretch it again and reattach it.

 

[shtrdave]

That is great news. Hope you post up some new pictures of the set up.