Total Creosote Blockage After 1-2 Fires

[rippinryno]

i was really just wanting to give the OP some insight on creosote buildup due to a cold flu.

That's fine - but by extrapolating your experience of a cold flu not making creosote, to rule out that is what is happening here, would then also extrapolate to mean it would not happen anywhere. I'm quite sure cold flues can make creosote, even though you're not seeing it.

Hope this thread plays all the way out to a resolution - there should be lots of learning potential for others if a cause & solution can be found.

I was not saying a cold flu does not make creosate, i was really just stating that after about 20 fires, mine does not build it that rapidly and certainly not that rapid after only 2 fires. just wanted to give him some input based on my experience, that would be a very fast creosote buildup if a cold flu is the reason.

I too would like to see what it learned in the end.

 

[maple1]

I was not saying a cold flu does not make creosate, i was really just stating that after about 20 fires, mine does not build it that rapidly and certainly not that rapid after only 2 fires. just wanted to give him some input based on my experience, that would be a very fast creosote buildup if a cold flu is the reason.

I too would like to see what it learned in the end.

What does yours have for a cleanout on the bottom?

 

[rippinryno]

a tee

 

[maple1]

Yes, but does it have a tight cap on it? That would be the difference, I suspect - if so, yours couldn't pull cold outside air into the bottom of the pipe. Which is what I think is happening here.

 

[rippinryno]

it's got a cap on it yeah, how tight, i dunno, but yeah it's got the typical cleanout cap on the bottom.

 

[Whiskey Fun]

i was really just wanting to give the OP some insight on creosote buildup due to a cold flu.

That's fine - but by extrapolating your experience of a cold flu not making creosote, to rule out that is what is happening here, would then also extrapolate to mean it would not happen anywhere. I'm quite sure cold flues can make creosote, even though you're not seeing it.

Hope this thread plays all the way out to a resolution - there should be lots of learning potential for others if a cause & solution can be found.

EDIT: And to add a bit more input on that, I am feeling quite sure that the chimney is pulling air with less resistance from the bottom of itself (the cold cleanout area), than it is from the narrowed stove pipe section. Suspect the smoke from the stove is lazily travelling into the chimney T, where it is immediately being hit by a cold upward blast from the cleanout. Stack effect could even giving that a boost - but don't know much about the area the cleanout is in.

Basically there's the T with no cap, about 5' of empty chimney, then the clean out in the basement, but did brick it up and install an cast iron door. The basement can get cold, 45-50 degrees. Which is why I bought a new T and a 4' piece of SS rigid and a cap. Unfortunately I had to destroy the liner to get it out.

 

[maple1]

How much room to spare do you have in the chimney?

Wonder if you could get an insulated 7" liner in it?

Sounds like you need a new liner now? If so that might be a blessing in disguise (although certainly also an unwanted expense) - you could maybe put a new one in that is smaller so matches your stove better.

I've never installed a liner before, so more experience should chime in. I wanted to say 6" insulated liner at first, but not sure if that would be going a tad too small if wanting to keep future options open as far as a stove swap or the like.

EDIT: Never mind most of that, I looked back & had my wires crossed about how big your pipe & stove outlet were. Sounds like you're on it looking at a 6" insulated liner already.

 

[begreen]

Basically there's the T with no cap, about 5' of empty chimney, then the clean out in the basement, but did brick it up and install an cast iron door. The basement can get cold, 45-50 degrees. Which is why I bought a new T and a 4' piece of SS rigid and a cap. Unfortunately I had to destroy the liner to get it out.

You want nothing cooling down the flue gasses. They will cool down enough just traveling up the liner to the cap.
Cold air was being sucked up into the flue. That instantly chilled the flue gases to the point of condensing into a tarry mess. To remedy you need to go for a complete liner and cap the bottom of the tee. To clean, remove the connector after sweeping and vacuum the tee with a shop vac. Or extend the bottom of the tee with more liner to just at the cleanout door height so that the bottom of the pipe can be tightly capped with a removable cap.

 

[Whiskey Fun]

You want nothing cooling down the flue gasses. They will cool down enough just traveling up the liner to the cap.
Cold air was being sucked up into the flue. That instantly chilled the flue gases to the point of condensing into a tarry mess. To remedy you need to go for a complete liner and cap the bottom of the tee. To clean, remove the connector after sweeping and vacuum the tee with a shop vac. Or extend the bottom of the tee with more liner to just at the cleanout door height so that the bottom of the pipe can be tightly capped with a removable cap.

If I put in an insulated liner, I'd have to go down to 5.5" as the terra cotta's inside diameter is 11"x7". Would the improved draft from the insulation negate the needed downsize? I should mention I plan to get a Jotul F500 Oslo in the near future. Would an insulated 5.5" liner work with that stove?

 

[begreen]

bholler will say no, but I have seen 5.5 work fine with a 6" stove as long as there's enough height. Or consider installing a preinsulated 6" liner like DuraLiner. It's 6 5/8" OD.

 

[bholler]

bholler will say no, but I have seen 5.5 work fine with a 6" stove as long as there's enough height. Or consider installing a preinsulated 6" liner like DuraLiner. It's 6 5/8" OD.

no it absolutly can work with enough height.

 

[begreen]

See, I knew you would say no. J/K

 

[bholler]

I do generally prefer to break out and go with 6" because it leaves more options open in the future but I know 5.5 can work many stove makers give you a height at which you can downsize.

 

[begreen]

If I put in an insulated liner, I'd have to go down to 5.5" as the terra cotta's inside diameter is 11"x7". Would the improved draft from the insulation negate the needed downsize? I should mention I plan to get a Jotul F500 Oslo in the near future. Would an insulated 5.5" liner work with that stove?

How tall is the chimney?

 

[Whiskey Fun]

How tall is the chimney?

30' straight run.

 

[bholler]

30'

You should be fine with 5.5 then.

 

[maple1]

30' is lots of chimney.

You might need a pipe damper once you get to that point. Point of insulated liner that is.

 

[Whiskey Fun]

30'

Str

You should be fine with 5.5 then.

Is the pre-insulated liner I linked above, the "crap" you were referring to?

 

[bholler]

Is the pre-insulated liner I linked above, the "crap" you were referring to?

no that is a totally different product. What i am referring to is light wall smooth interior liner. It is dont like a regular smooth wall with an inner layer of flat very thin metal.

 

[Whiskey Fun]

Thank you all for the input. I'll order the liner tomorrow. I'll try it with the Vilgilant and post the results. If I get the same results, then we know it wasn't cold air getting in the flu or all the 90 degree bends, and must be the 8" to 6" reduction, wet wood and poor burning technique. And vice versa if it does work.

 

[Whiskey Fun]

That looks like just single wall stove pipe, not flex. I had tagged bholler hoping he would give you advice on how to remove the existing pipe as he does this sort of thing for a living. Looks like you got it out though, so what are your plans now?

It looks like stove pipe but it's actually SS. It must've been compromised somewhere something fierce. Hard to tell by the time I got it out. New liner is suppose to arrive Friday. I'll install it and fire her up Saturday and post results. Suppose to be a cold weekend :-/

 

[English BoB]

I think you were screwed before you started, every thing was blocked so bad there is nothing you can do but replace, just because they said they did doesnt mean they did it correctly.

bob

 

[Whiskey Fun]

I think you were screwed before you started, every thing was blocked so bad there is nothing you can do but replace, just because they said they did doesnt mean they did it correctly.

bob

Bob I couldn't agree with you more!

 

[Whiskey Fun]

So the new liner is in! I stupidly went with 6" smooth wall flexible + 1/2" insulation. It kept getting hung up on clay mortar joints. So I ended up having to remove the insulation for the bottom half. There is an extension piece of rigid going down to the clean out with a cap on it. I added an 18" flu extender because I didn't like the furnace and stove flus being the same height. I may trim that down a bit if I see creosote build up there. Perhaps I should insulate that as well?

The first 2 pics show my ridiculous set up. I've found no other option for gradually reducing an 8" oval to a 6" round. So the added length makes it impossible to have the stove straight. I'll tell people the stove is straight, it's the house that was built crooked.

The 3rd pic is the the fire after 5 minutes. Very good draft.

The 4th pic is the fire after 10 minutes. The stove temp is 300 degrees. The draft is phenomenal. As I closed the door, the draft actually tried to pull the door closed. Mind you, we are having wind gusts of 20-30 mph coming from a ridge a 1/2 mile away.

After 30 minutes the temp is 550 degrees and the logs are all embers. Perhaps it ran a little too hot for too long. I'm about to reload, wait for it to catch and play with the built in damper. The Vigilant has just the 1 damper setting, open or closed. And the 2 adjustments on the rear and side (the last pic), I'll call the "flap" and the "hole". Does anyone have any advice on how to adjust the flap and hole for optimum burning?

Thank you

 

[claydogg84]

The rear flap is thermostatically controlled by the coil up top. The flap should be shut when you get stovetop temps up around 600. I only used the side hole for getting the stove up to temp, otherwise I always let the rear flap do all of the air control.