First chimney sweep

[MCC]

I had a BK Princess 32 installed last fall. I've run it 24/7 since it got cold enough. I noticed in the last couple of weeks the smoke spillage had increased during reloads and then one day if was really bad. I climbed up on the roof and found my raincap half plugged with flaky bubbly creosote deposits, whick i cleaned out. I also recall hearing what sounded like ice pellets from up high in the chimney occasionally, maybe 10 times or so in the last 6 weeks. I bought a Sooteater and cleaned out my flue for the first time last night. I am curious what you guys see? The pipe didn't look too bad to my novice eyes and cleaned up easy enough, but the end of the pipe and cap has some buildup. Was that sleet sound crap burning off my cap maybe?

TIA,
Dan

 

[bholler]

I had a BK Princess 32 installed last fall. I've run it 24/7 since it got cold enough. I noticed in the last couple of weeks the smoke spillage had increased during reloads and then one day if was really bad. I climbed up on the roof and found my raincap half plugged with flaky bubbly creosote deposits, whick i cleaned out. I also recall hearing what sounded like ice pellets from up high in the chimney occasionally, maybe 10 times or so in the last 6 weeks. I bought a Sooteater and cleaned out my flue for the first time last night. I am curious what you guys see? The pipe didn't look too bad to my novice eyes and cleaned up easy enough, but the end of the pipe and cap has some buildup. Was that sleet sound crap burning off my cap maybe?

TIA,
Dan

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You had a chimney fire atleast once. That's burnt creosote

 

[EbS-P]

I would not want my chimney to look like that. Do you have a flue gas thermometer?

 

[MCC]

Was it most likely just a fire at the cap? How common is this and what should I be doing to prevent it? I am burning Ash and Elm, both of which test under 20% and I run the stove WOT for 20 to 30 minutes after each reload. I hadn't planned on sweeping my chimney until after the burn season based on a couple of friends experience, but they don't have combustor stoves. Are combustor stoves more prone to creosote build up because of cooler flue temps?

 

[MCC]

I would not want my chimney to look like that. Do you have a flue gas thermometer?

I do not have a flue gas thermometer. What will that information tell me and what changes could I make based on that information? I only have the throttle on the stove to adjust.

 

[GrumpyDad]

I would not want my chimney to look like that. Do you have a flue gas thermometer?

Is there an easy - ish way to get a thermometer into the upper parts of a flue? Seems it really doesnt matter what the temps are down low right?

 

[kborndale]

When you test your wood are you doing it on a room temperature piece that you just resplit right before testing it?

 

[EbS-P]

It will tell you how hot you were burning. And is may indeed be hot enough you will just have to sweep every 3-4 weeks. Or you will find out that your temps are too low. It’s another tool. Once you self calibrate your habits to the flue temp it could be used as a digital cat thermometer.

I highly doubt anyone with a BK Will adjust burning habits based on temps at the top of the flue.

The Auber AT 200 thermometer alarm is nice. Set the high limit and it will let you know that you left the bypass open too long. I have one for each stove.

 

[reaperman1]

I'm curious, as long as the cat is in the active range, shouldn't it be hot enough for a clean burn? From what I've read, isn't the biggest asset of a cat stove is its ability to burn low and slow? What flu temps should someone looking to maintain to avoid creosote buildup?

 

[kborndale]

I'm curious, as long as the cat is in the active range, shouldn't it be hot enough for a clean burn? From what I've read, isn't the biggest asset of a cat stove is its ability to burn low and slow? What flu temps should someone looking to maintain to avoid creosote buildup?

It's hot enough coming out the cat, but that doesn't mean it will be hot enough at the top of your chimney, especially if the chimney is an uninsulated exterior chimney.

 

[bholler]

Was it most likely just a fire at the cap? How common is this and what should I be doing to prevent it? I am burning Ash and Elm, both of which test under 20% and I run the stove WOT for 20 to 30 minutes after each reload. I hadn't planned on sweeping my chimney until after the burn season based on a couple of friends experience, but they don't have combustor stoves. Are combustor stoves more prone to creosote build up because of cooler flue temps?

You can't possibly have a fire just at the cap. The fire had to get there somehow

 

[GrumpyDad]

It will tell you how hot you were burning. And is may indeed be hot enough you will just have to sweep every 3-4 weeks. Or you will find out that your temps are too low. It’s another tool. Once you self calibrate your habits to the flue temp it could be used as a digital cat thermometer.

I highly doubt anyone with a BK Will adjust burning habits based on temps at the top of the flue.

The Auber AT 200 thermometer alarm is nice. Set the high limit and it will let you know that you left the bypass open too long. I have one for each stove.

That's the only thing I miss from not having an alarm, is it letting me know when I have air control up too high or the bypass open for too long.

 

[GrumpyDad]

I'm curious, as long as the cat is in the active range, shouldn't it be hot enough for a clean burn? From what I've read, isn't the biggest asset of a cat stove is its ability to burn low and slow? What flu temps should someone looking to maintain to avoid creosote buildup?

Well the little stop top magnetic thermometers you put on stop tops say anything less than 400 is creosote zone.
I tend to agree with that. I once burned at like 325-350 and my doors and interior was coated in about 1/8" of creosote. It looked like someone tarred my stove as a prank. I know most will say that flue temps are the most important, but taking that temperature 24" from the stove is going to read one thing, then when it's up in the chimney there's a whole other world happening there right? So, Im not sure why people take flue temps that low, other than to correlate build up with the temps down below.
For example, less than 500 burning for a week and the pipes are more dirty than say above 550...dunno..im speculating.

 

[reaperman1]

I once burned at like 325-350 and my doors and interior was coated in about 1/8" of creosote. It looked like someone tarred my stove as a prank.

My BK is like that pretty much all of the time. Overnight the stove temps fall as the wood is being burned. If I burn hotter the wood burns faster and wont keep the flu temps up til morning. If I burn slower it for sure burns cooler and gets gunked up, cant win. Either way the cat is always in the active stage. Today I checked my chimney for the first time since getting this stove (2.5 months). The chimney only showed a little dust from bottom to top, I was happy to see that.

 

[GrumpyDad]

My BK is like that pretty much all of the time. Overnight the stove temps fall as the wood is being burned. If I burn hotter the wood burns faster and wont keep the flu temps up til morning. If I burn slower it for sure burns cooler and gets gunked up, cant win. Either way the cat is always in the active stage. Today I checked my chimney for the first time since getting this stove (2.5 months). The chimney only showed a little dust from bottom to top, I was happy to see that.

Sounds like your cat is doing its job then, keeping the gunk from entering the flue

 

[kborndale]

My BK is like that pretty much all of the time. Overnight the stove temps fall as the wood is being burned. If I burn hotter the wood burns faster and wont keep the flu temps up til morning. If I burn slower it for sure burns cooler and gets gunked up, cant win. Either way the cat is always in the active stage. Today I checked my chimney for the first time since getting this stove (2.5 months). The chimney only showed a little dust from bottom to top, I was happy to see that.

When you burn hotter you don't have to worry about when the stove cools off causing creosote. The wood has already off gassed the moisture in it that was causing the creosote.

 

[Highbeam]

That’s a super gross chimney. I burn conifers all season in a warmer climate and have found that you can run too cool even with an active cat. I like 400 internal flue temperatures 18” above the stove.

That, or, your wood is wetter than you think.

 

[MCC]

When you test your wood are you doing it on a room temperature piece that you just resplit right before testing it?

I resplit the wood and tested it at about 50 degrees. Would this skew my results not being up to 70? The wood was Ash and Red Elm that was dead and standing that I just cut and split this year. I have checked the moisture several times and always have read 14 to 18 on any piece I have checked. I am guessing my wood is wetter than I think.

What is a good no thrills Flue Thermometer? Is there anything on the cheaper end that you guys recommend?

Thanks everyone for your help.

 

[Highbeam]

Yes, the wood needs to be up to 70 degrees before the split so leave some big ones in the house overnight. Colder wood creates an error towards drier than reality. Then check in a few spots, not just the ends. The newer BK manuals have some pretty good instructions for this as I recall.

The standard probe thermometer for double wall is the condar flue guard for around 30$. Mine has been in service and very dependable for over 15 years. Can't say the same for the OEM BK meter. It's really useful having a flue meter. You can read it from across the room and the color ranges are actually very useful.

The BK system does not make for a clean flue for most folks. Due to longer lower burns you can expect more accumulation and blacker accumulation than a noncat but certainly nothing like your photos.

 

[Jcapo29]

@MCC it seems you and I have had similar situations based on our posts I. The last couple months. I also found out the jokers that initially installed mine screwed up a few things that I finally got straightened out.

I am also running with no probe on my flue but was always confused as I had one on my old single wall system at my old house. After learning here i will also be ordering a thermometer as suggested above by @Highbeam. I would like to thank you all for the information you put up.

@MCC you are not alone brother. We will figure this out. Sorry to sidebar your thread, please carry on. I admit I was quite befuddled looking at my cap and responses as I thought I was doing everything right as well. The learning curve seems steep but I think we are almost there bud.

 

[trail guy Mike]

You had a chimney fire atleast once. That's burnt creosote

Which is burnt creosote? The shiny black stuff, or the gray powdery stuff?

It seems to me there is more creosote at the very top of the chimney after a spell of extra-cold weather. The exhaust doesn't always leave the chimney quickly enough, cold air mixes in, and it precipitates around the cap; mostly on the downwind side.

AND your wood may have excess moisture, as others have noted.
Is there any downside to having super low moisture in the firewood?

 

[kborndale]

Is there any downside to having super low moisture in the firewood?

Not really, if you have excessive draft really dry wood will make it easier for the stove to run away, but you fix that with key dampers, not subpar wood.

 

[bholler]

Which is burnt creosote? The shiny black stuff, or the gray powdery stuff?

It seems to me there is more creosote at the very top of the chimney after a spell of extra-cold weather. The exhaust doesn't always leave the chimney quickly enough, cold air mixes in, and it precipitates around the cap; mostly on the downwind side.

AND your wood may have excess moisture, as others have noted.
Is there any downside to having super low moisture in the firewood?

The kind of fluffy ring full of bubbles around the top that we see in the first picture

 

[Nealm66]

I haven’t had hardly any creosote buildup with mine. I don’t have the probe but I must be running a bit hotter/shorter than most and generally 2 reloads a day. I can’t remember my length of chimney but I have 2 90’s with a clean out T. From previous pre epa experience, I like to let my wood season in the weather before I dry. I’ve seen dry but green wood create creosote way more than seasoned wood at least with Doug fir

 

[bholler]

I haven’t had hardly any creosote buildup with mine. I don’t have the probe but I must be running a bit hotter/shorter than most and generally 2 reloads a day. I can’t remember my length of chimney but I have 2 90’s with a clean out T. From previous pre epa experience, I like to let my wood season in the weather before I dry. I’ve seen dry but green wood create creosote way more than seasoned wood at least with Doug fir

Dry wood is dry wood. Doesn't matter how long it takes to get there just get it under 20% on a frash split face and you will be good.