Pacific Energy Super 27 and excessive cresote

[Boedie]

Hi all, new to the forum, however not new to wood stoves. I recently purchased a used Super 27, built in 2001 and installed it into my home. We had a 25 year old Country before. With the older stove, it would not keep the house warm enough, but we rarely had to clean the stove pipe. We would clean it once a year for safety sake, but it did not display signs of over creosoting. With the new (used) stove, we have had to clean it after a few months and the 6" stove pipe was completely clogged. The stove pipe consists of 6' of uninsulated stove pipe to the ceiling, then it passes through the ceiling into the second "half" story. From there, it goes into insulated pipe for 4' and then passes through the ceiling/roof. On top of the roof are 2 4' sections of insulated stove pipe and into a chimney cap. The cap is above the roof line of the house. It is extremely hard to clean, because you have to take the roof top sections apart in order to get a brush down the pipe. (steep roof, tall pipe) We live in the PNW, so we burn primarily Doug Fir and larch. We really like the new heat output of the stove, but despise the excessive creosote issues.
Any ideas on what is going on? The new efficient stove probably keeps the stove pipe cooler, so in turn we get more build-up, however this current set-up is not working. Thanks for any input.

 

[rideau]

First suggestion:

Until you resolve the creosote problem, clean monthly.

Clean from below: detach the stove pipe just below the ceiling.
duct tape a heavy black plastic garbage bag to the ceiling box;
make a slit near the top of the bag, just below where it is taped on;
run your brushes through the slit up to the cap to clean;
take bag off (which will contain the creosote);
take detached stove pipe section outside and clean - put any creosote into bag used for cleaning chimney, close and discard.

Reattach stove pipe and you are ready to go for another month.

Re burning:

Can you give some info re burn technique and temps at which your are adjusting for long burn, temps you are typically burning at (both stovetop and flue)?

 

[webby3650]

The stove pipe consists of 6' of uninsulated stove pipe to the ceiling, then it passes through the ceiling into the second "half" story. From there, it goes into insulated pipe for 4' and then passes through the ceiling/roof.

So do you have stovepipe exposed upstairs? Does stovepipe go through the floor or does it change to chimney pipe at the first floor?

 

[Boedie]

So do you have stovepipe exposed upstairs? Does stovepipe go through the floor or does it change to chimney pipe at the first floor?

The insulated/double wall stove pipe starts indoors on the second floor.

 

[Boedie]

First suggestion:

Until you resolve the creosote problem, clean monthly.

Clean from below: detach the stove pipe just below the ceiling.
duct tape a heavy black plastic garbage bag to the ceiling box;
make a slit near the top of the bag, just below where it is taped on;
run your brushes through the slit up to the cap to clean;
take bag off (which will contain the creosote);
take detached stove pipe section outside and clean - put any creosote into bag used for cleaning chimney, close and discard.

Reattach stove pipe and you are ready to go for another month.

Re burning:

Can you give some info re burn technique and temps at which your are adjusting for long burn, temps you are typically burning at (both stovetop and flue)?

Rideau, that's how we ended up cleaning it. Kind of a mess. I do not have a flue thermometer, however I start the fire with dry kindling using as little paper as possible. We have been burning hotter fires to try to prevent as much creosote as possible and just end up starting a fire every morning. I keep an iron kettle on top of the stove to admit steam into the room. We live in a pretty dry region and often run a humidifier for our 5 month old son.

 

[rideau]

If I were you I'd get the supercedars. They are cleaner than newpaper, and also much hotter. Get the fire going quickly, up to temp quickly, which should alleviate some of the creosote problem.

Also, do you use a stove top thermometer for assistance in knowling when to close the stove air intake down?

If you put that thermometer on a single wall pipe, you can then take the reading and multiple by 2 to get a pretty accurate idea of the flue temp. Which you want to be at least 400,

More infor about your complete burning technique (how/when you close the air down, how much, what wood you are burning, size of wood, etc) will allow for more feedback about how to alleviate the creosote problem.

Re cleaning:

I get no mess cleaning that way. Make sure the bag is well sealed at the box. Make the slit just big enough for the brush to fit through, and right at the top of the bag. All the creosote should fall to the bottom of the bag. As you take the bag off, close the top so no ash comes out the top or through the slit, and take the bag outside right away. Clean the removed stovepipe outdoors.

 

[begreen]

Welcome Bodie. Just to clarify then, the original post is incorrect, right? The insulated pipe needs to start as soon as the 1st floor room envelope is penetrated. There should be no uninsulated pipe showing on the 2nd floor level. If that is correct then there is 6' single wall connected to 12' of insulated pipe for a total of 18'. That should work fine. BTW, good for you on keeping track of the build up in the pipe!

The odds are here that the wood is not fully seasoned. Fir has a high oil content and burns even when only partially seasoned. But it creates lower temps and heavy smoke. I think that could be part of the problem. Fir needs at least a season to dry out thoroughly. The other problem may be how the stove is being run. The new stove doesn't work like the old one. It needs to burn hot enough for good combustion of the unburnt wood gases. You may need to run the stove a bit hotter. Do you have a temp gauge on the flue or stove top? If so, what temps are you running it at? Creosote condenses below about 250F flue temps. If your flue gas is running at about 300-400F (interior gas measurement) off the stove, by the time it gets to the outdoors pipe it's cool enough to condense. For a surface thermometer that would be about 150-300F.

 

[Boedie]

Welcome Bodie. Just to clarify then, the original post is incorrect, right? The insulated pipe needs to start as soon as the 1st floor room envelope is penetrated. There should be no uninsulated pipe showing on the 2nd floor level. If that is correct then there is 6' single wall connected to 12' of insulated pipe for a total of 18'. That should work fine. BTW, good for you on keeping track of the build up in the pipe!

The odds are here that the wood is not fully seasoned. Fir has a high oil content and burns even when only partially seasoned. But it creates lower temps and heavy smoke. I think that could be part of the problem. Fir needs at least a season to dry out thoroughly. The other problem may be how the stove is being run. The new stove doesn't work like the old one. It needs to burn hot enough for good combustion of the unburnt wood gases. You may need to run the stove a bit hotter. Do you have a temp gauge on the flue or stove top? If so, what temps are you running it at? Creosote condenses below about 250F flue temps. If your flue gas is running at about 300-400F (interior gas measurement) off the stove, by the time it gets to the outdoors pipe it's cool enough to condense. For a surface thermometer that would be about 150-300F.

I probably should pick up a flue thermometer. The first post is correct, but I think reads a little funny. Yes the insulated stove pipe starts on the second floor. I never have had this much problem with creosote. We get most of our wood in the summer. This year, we just got another cord a few weeks ago. We still have snow on the ground, so I'm sure the new cord is not as dry as it could be. I have not been closing the flue very much lately and have been letting the fires burn out. It has been a mild winter. I'll try some of the fire starters on the market, and see if that helps. Thanks for the tips on the flu temp.

 

[begreen]

I probably should pick up a flue thermometer. The first post is correct, but I think reads a little funny. Yes the insulated stove pipe starts on the second floor. I never have had this much problem with creosote. We get most of our wood in the summer. This year, we just got another cord a few weeks ago. We still have snow on the ground, so I'm sure the new cord is not as dry as it could be. I have not been closing the flue very much lately and have been letting the fires burn out. It has been a mild winter. I'll try some of the fire starters on the market, and see if that helps. Thanks for the tips on the flu temp.

Sounds like you got some fresh cut wood last summer. That is probably the issue. Get your next season's wood now and get some extra. Stack it now so that the prevailing winds blow through the stacks. Any wood purchased in winter is not going to be dry or well seasoned. Modern stoves are fussier about dry wood. With fully dried wood you will see a nice improvement.

Do you use a key damper or by damper do you mean the air control on the stove under the ash lip? Describe how you normally run the fire.

 

[mikesin]

Hi, I am not burning the same wood as you and as suggested above, drier wood may be the issue. Fortunately we do not have a creosote issue .I am not sure I can tell you your exact problem however, I can share my reading for some what of a reference. This is how we burn our Super 27,
Using a Condar probe thermometer installed in the double wall pipe. (which I recommend a probe thermometer to help)
If I reload using 3 (dry/below 20% moisture reading on a fresh split) splits on an orange coal bed and the temp. probe reading between 200 - 300*. Open the the air to high, load the splits, shut the door. Within 10 mins or less the probe is reading 400*. Over the next few minutes (after reaching 400*) I slowly lower the air adjustment in small increments not allowing the probe temp to get over 700* preferably 600 - 650*. I look for the secondaries to be burning. often I have to get down and look up to see them burning close to the front going up the chimney. Most of the time once the secondaries are burning and the probe temp. is above 500* the air control is almost closed or closed. It stays this way for the remainder of the burn. Sometimes I close down the air to fast resulting in the secondaries to stop burning and or your probe temp lowers then you have to open the air just a bit. . This stove holds 600* until the flames start to die down a few hours later. I let the stove to cool down and burn up coals till the probe temp. reaches 200/300* and repeat.
Hope this helps.