Hot Burns to Clean out Chimney - Fact or Fiction?

[jpl1nh]

I have often heard this as conventional wisdom, used to do that quite a bit myself. As I have thought about it, I question whether indeed this is the case. Short of cleaning your chimney with a brush, or perhaps using a stove applied chemical to alter the chemical structure of the creosote deposits, it would seem to me that the only other way to really reduce creosote deposits would be to burn them off. :snake: Nothing like a chimney fire to really reduce creosote! So my question is; does simply upping the flue temps another hundred or so degrees actually reduce creosote? I would think it would have to return it to gaseous form for that to happen and would fear that you would then be in danger of actually setting it on fire!

 

[JohnnyBravo]

seems to clear up the glass on the stove, but that takes quite a bit of heat.

 

[RedRanger]

Reminds me of a neighbor that used to live across the road from us. He had a huge chimney fire going, flames belching all over the place. So I did the smart thing and called the fire department. Next day, when he found out that it was me that called them, he reamed me out something awful. Totally pissed because he started the fire on purpose to clean out his chimney. Said he had always done that-couldn`t see anything wrong with it. Still, even to this day, that seems like a prettry loonie idea to me.

 

[Todd]

I think it depends on what kind of chimney. If it's thick solid masonary or stone I might consider it, but a pefab type with lots of 2x4 framing around, no way. If you burn dry wood you shouldn't have much creosote from an EPA stove, and it doesn't take much to run a brush down once or twice per season.

 

[JimWalshin845]

I do a hot burn before I clean my stove. I empty the stove while still warm (usually in the AM) and then use several stips of corregated cardboad which will create a very hot burn but for a short length of time. I will do this several times until I do not hear any crinkling inside the stove. There is very little residue to clean up except for the corners of the stove.

I imagine it helps burn some of the soot or creosote in the chimney flue too, ours is masonary. We clean the flue afterwards and then add TSP immediately on the next burn. Our chimney is pretty clean and we did a video inspection for any real build up. Don't know if I would do it on a metal flue?

 

[thechimneysweep]

The folk wisdom about hot fires and creosote wasn't about deliberately lighting off a chimney fire.

The airtights of the day typically had draft controls that closed down all the way, and no secondary burn whatsoever at that setting. In an effort to prolong the burn cycle for an "all night" burn, people would turn the draft control way down into smolder range, which resulted in huge volumes of relatively cool, unburned particulates and water traveling slowly up the flue. This led to fairly heavy liquid creosote condensation onto the inner walls of the chimney.

Two things cause liquid creosote to solidify: temperature, and time. If layer upon layer of wet creosote was allowed to build up, it would eventually solidify over time, but in the form we call heavy glaze, which is extremely difficult to remove.

Here's where the folk wisdom came in. If, after every all-night burn, you made sure to have a hot morning fire, the liquid creosote that had formed overnight would dry out quickly and solidify in granular form, not glaze. This actually worked, and although our smolder-pot customers who adhered to this custom tended to have heavy buildup, it would sweep right out without chemical treatments.

 

[jpl1nh]

The folk wisdom about hot fires and creosote wasn't about deliberately lighting off a chimney fire.

The airtights of the day typically had draft controls that closed down all the way, and no secondary burn whatsoever at that setting. In an effort to prolong the burn cycle for an "all night" burn, people would turn the draft control way down into smolder range, which resulted in huge volumes of relatively cool, unburned particulates and water traveling slowly up the flue. This led to fairly heavy liquid creosote condensation onto the inner walls of the chimney.

Two things cause liquid creosote to solidify: temperature, and time. If layer upon layer of wet creosote was allowed to build up, it would eventually solidify over time, but in the form we call heavy glaze, which is extremely difficult to remove.

Here's where the folk wisdom came in. If, after every all-night burn, you made sure to have a hot morning fire, the liquid creosote that had formed overnight would dry out quickly and solidify in granular form, not glaze. This actually worked, and although our smolder-pot customers who adhered to this custom tended to have heavy buildup, it would sweep right out without chemical treatments.

Thanks for the explanation Tom! As Todd says, with today's EPA stoves it should be a relatively moot point but I hear people refer to it here often so I was curious as to whether it was really fact or fiction!

 

[RonB]

Another reason to run wide open for a period of time that is pertinent to modern stoves is found in my Quadrafire manual, "NOTE: Stove should be run full open for 15 minutes a day to keep air passages clean."

 

[North of 60]

I think any stove cat or non cat, epa or non epa you have to let er rip after each reload to flash off that moisture content before you turn it down. This will then reduce your amount of creosote made at the end of the burn, making it safe to let er rip on the next load. Starting off with a clean chimney And properly seasoned wood makes this a safe rule not a myth. (in my opinion)
Monthly inspections and manual cleaning when required can never be substituted by a hot fire.

 

[babalu87]

Mythbusters say:
CONFIRMED

 

[rdrcr56]

Running a high burn rate at least once a day burns off accumulated creosote from within the stove and venting system. Now, in the morning after an extended low burn rate. is a good time to create your daily high burn rate; run it for about 20 minutes or so. Not only does this hot fire promote a clean stove and chimney, it also helps keep the glass clean for easy viewing of the fire within. From the Hearthstone homestead manual.

 

[TReuter]

Jim:

Tell me more about adding TSP. I have not heard of this. Are you referring to the cleaner?

Thomas

I do a hot burn before I clean my stove. I empty the stove while still warm (usually in the AM) and then use several stips of corregated cardboad which will create a very hot burn but for a short length of time. I will do this several times until I do not hear any crinkling inside the stove. There is very little residue to clean up except for the corners of the stove.

I imagine it helps burn some of the soot or creosote in the chimney flue too, ours is masonary. We clean the flue afterwards and then add TSP immediately on the next burn. Our chimney is pretty clean and we did a video inspection for any real build up. Don't know if I would do it on a metal flue?

 

[JimWalshin845]

Jim:

Tell me more about adding TSP. I have not heard of this. Are you referring to the cleaner?

Thomas

Yep, Trisodium Phosphate. or you can buy the stuff that Rutland sells.

 

[TReuter]

Jim:

Tell me more about adding TSP. I have not heard of this. Are you referring to the cleaner?

Thomas

Yep, Trisodium Phosphate. or you can buy the stuff that Rutland sells.

Jim:

How does TSP work on creosote build up?

Do you use this on a regular basis or just after the chimney cleaning?

Thomas

 

[JimWalshin845]

author="ErieMan" date="1198107032

Jim:

How does TSP work on creosote build up?

Do you use this on a regular basis or just after the chimney cleaning?

Thomas

We use it weekly, reacts with any creosote build up so it will cystallize.

Rutland makes this:
(broken link removed to http://www.rutland.com/FC&H;_/WI-21124_21212_21250.html)

And if you look at the data sheet the main ingrediant is TSP:
(broken link removed to http://www.rutland.com/FC&H;_/MSDS/MSDS%20WI-21124.pdf)

 

[DoubleClutch]

Jim,

I haven't read the links you posted yet (they seem to be dead links), but I, too, am curious about using TSP to crystallize creosote.

I currently use a product from Hercules called Flip-Stick, but it contains some kind of Cu compound (copper chloride?)

(broken link removed to http://www.herchem.com/specs/flipstick.pdf)

Does TSP work on the same principle? (Not that I know the principle Flip-Sticks work on...)

Thanks,

DC

 

[JimWalshin845]

Your right.. the links don't work.

But go to www.Rutland.com

then click Rutland Products > Fireplace, Chimney and Hearth > Creosote Removers

and you can get the info and spec sheet

 

[JimWalshin845]

Jim,

I haven't read the links you posted yet (they seem to be dead links), but I, too, am curious about using TSP to crystallize creosote.

I currently use a product from Hercules called Flip-Stick, but it contains some kind of Cu compound (copper chloride?)

(broken link removed to http://www.herchem.com/specs/flipstick.pdf)

Does TSP work on the same principle? (Not that I know the principle Flip-Sticks work on...)

Thanks,

DC

Yep.. Flip Stick has Copper Chloride and TSP. I don't burn a Cat stove but I know you are not suppose to burn metal in a Cat stove... I'd be careful of the Copper Chloride if you are.

I was just on the roof today, chimney cap has a hole in it and needed repair. I get some creosote on the top two flue tiles (10x10") but the same amount is usually there, about the thickness of a fingernail. Otherwise the flue is pretty clean, so it works for me.

 

[eernest4]

tsp-
tri sodium phospate works good.
A lot of people here on hearth.com use it sucessfully.
There are posts, for every year, going back to 2005 recommending it.