Need advice on creosote buildup/safety

[JessicaL]

Hi Everyone,

We had a new Avalon Olympic wood stove insert installed last March, following a terrifying chimney fire. We're still learning the art and science of this stove, and now we realize we've made some mistakes.

Primarily, the wood we've been burning wasn't dry enough, so the stove typically doesn't burn above 300-350 - although once or twice we were able to get it up to 400. Now we know we should be closer to 400-500 or more on a regular basis.

We've also been doing the slow overnight burn, which causes creosote to form on the glass in the morning. From now on, we plan on making sure it's burning hotter than that, and/or let it burn out.

We also just switched wood suppliers, and the new wood looks looks really good. And we have an appointment with the chimney sweep late next week.

But we don't know if it's safe to burn in the meantime, and that's where I could really use your help. After the last fire, I am just terrified about the possibility of another one!

So we looked up into the chimney this morning, and there's a fine grey dusty creosote coating the inside, just above the stove. (We can only see about 4' up, because the chimney goes into an angle after that.) Maybe there's a 1/4-1/2" of the stuff lining the pipe, maybe less... but it's hard to gauge the thickness exactly. I gather from research that this is Stage 1 creosote.

I found a picture of what the creosote itself looks like on the Internet (this is NOT our chimney):

Ours isn't anywhere near that thick from what we could tell.

We also don't know what the upper part of the chimney looks like after the bend.

So my question is, do you think it's safe for us to burn with this kind of buildup, until we get it cleaned?

And do you think we might be able to burn this out with several small hot fires, if we let them burn out and keep checking the chimney in between?

BTW, I found this forum last Spring when we were selecting which stove to get - and you guys/ladies were enormously helpful, even if I only lurked!

Thanks so much!

 

[WellSeasoned]

Looking up the chimney will show next to nothing compared to what the top portion of the chimney will look like, as it is cooler up there. Not seeing the actual chimney, one cannot tell you if it is safe or not. Based on your low temp fires, wet wood, I would say to at least inspect the upper part of the chimney, or wait for the sweep if you are concerned. When has the chimney been swept last, and how long have you been burning since the last sweep. With burning poor wood, the chimney should be swept monthly I'd say, minimum. Good luck

 

[Backwoods Savage]

Welcome to the forum Jessica.

Not knowing what your chimney is like it is difficult to tell if it is safe or not. If you don't feel safe, then don't burn until the sweep finishes.

Now is a great time to plan ahead. Knowing the problem with the wood and knowing you can't buy good dry wood, you need to get a stock ahead. Buy for next year. Get it stacked and stack it where it will get wind to help it dry. I've always recommended folks get 3 years ahead on their wood but at least being one year ahead will help. Then you also need to know what kind of wood you are buying. That is because some wood takes longer than a year to dry; for example, oak.

Also, when a seller says his wood is seasoned, it is meaningless. Ask when the wood was split and how long it has been stacked after splitting. This is what counts and we know that wood sellers just can't do this, so they just tell you it is "seasoned." So plan this year for next year.

 

[northwinds]

Great first post. If you are terrified of another chimney fire, then wait until the chimney has been professionally inspected.

A short, hot fire would probably be more likely to set off existing creosote than a low temperature fire. You've got the 'problem figured out. You might not have a chimney fire if you continue to burn, but why take the chance if you don't need to. Get that chimney swept clean, burn hotter after it's clean, and sleep soundly at night.

 

[BrotherBart]

Where are you measuring temperature on that insert? If you are reading on the front of it odds are that the top of the stove is a hundred to two hundred hotter. But I concur with the above that both what you see at the bottom of the pipe won't tell you anything about up top and that you should wait for somebody to get up there and take a look down.

 

[DanCorcoran]

Yes, you may or may not know that the higher you go, the cooler the flue/chimney. The cooler the flue/chimney, the more creosote will be deposited. Thus, the portion you are seeing is the "best" part.

 

[Heaterhunter]

My creosote builds up 3 feet below the top of the chimney. This equates to where the chimney exits the insulated house. My chimney runs up through the center of my house versus an outside wall. So if this is the case with yours that will typically be the problem area of the chimney. I wish I took a picture of what the top of my chimney looked like last march to show you. YIKES! The biggest clue that it was clogging up was my lack of draft when attempting to start fires. Kept getting smoke in the house when starting fires and loading the stove after it was going. Like everyone else has said don't burn unless you feel REAL confident the chimney is ok or even better look down from the top. Happy and safe burning.

 

[JessicaL]

Wow, you people are amazing! I knew I loved this forum. Thank you all so much for the advice, and for the warm (pun intended) welcome!

Now to answer some questions/clarify:

When has the chimney been swept last, and how long have you been burning since the last sweep.

The chimney had a brand new sleeve put in last March, after the chimney fire. It's a 6" flexible tube, and the chimney itself is I believe ceramic brick. So it's been 9 months since it's been sparkly clean.

The guy who installed the new insert and sleeve is the best in our county - highly recommended by everyone from the insurance adjuster, to other chimney sweeps. So we shouldn't have any issues with quality of installation.

We've been burning since beginning of last March, except of course for summer months (we're in NY, so we didn't burn May through September-ish). When we do burn, it's 24/7.

Now is a great time to plan ahead. Knowing the problem with the wood and knowing you can't buy good dry wood, you need to get a stock ahead.

Absolutely agree...but that just wasn't an option for us last year. (Rough patch.)

The new wood supplier came highly recommended by the guy who installed the stove, who also buys from him. He's not a fly-by-night trying to make extra income - this is a professional operation. And the wood looks and sounds well seasoned when we knock them together - plus the guy uses a moisture meter (on our list to get one!). So it should be ok, and it's all stacked in our garage.

Where are you measuring temperature on that insert?

We have a Rutland thermometer stuck on the top of the stove.

I wish I took a picture of what the top of my chimney looked like last march to show you. YIKES! The biggest clue that it was clogging up was my lack of draft when attempting to start fires.

I'm so glad that many of you mentioned how the top of the chimney is cooler and more likely to collect creosote than the bottom - great point. I hadn't thought of that!

We do have excellent draft/draw in the stove, so I'm pretty sure the top isn't too blocked. But we have about 3-4" of snow on the roof, and it's a relatively steep pitch...so hubby isn't too keen to climb up there right now.

I just have no idea what a "healthy" chimney looks like between cleanings, so it looked like it might be ok with just a little sooty looking creosote. Clearly not worth the risk!

Thanks again, everyone ... sounds like we'll have to crank up the oil furnace after all.

Happy New Year!

 

[JessicaL]

PS Just in case anyone wants to know, the chimney fire did NOT start from a fire in the fireplace (where the insert is now). We were using a beautiful old wood cookstove that fed into the same chimney, which sat around the corner from the fireplace. (I know, I know - big no-no!! But this is how it was when we bought the house.) That cookstove is now completely disable/disconnected, just pretty decoration now.

And the chimney is in the middle of the house, not on an exterior wall.