Temps ? stove top, base of flue and top of flue , Creasote ignition ?

[InspectorLance]

Hello, Im Kninda new around here. I have searched the site, but havent found an answer.
1. What is the high and low aceptable stove top temps ?
2. What is the minimum flue temp thats acceptable ? Measured where ?
3. What temp does Creosote ignite at ?
4. What temp does creosote begin to build up at ?

Thanks for your info.
I am running a 1983 Country free standing wood stove with about 6' of pipe in the home and 6 ' over the roof. She is nice and air tight, and seems to like runnig around 350-400 deg on the stove top. What I worry about is the top of the flue near the ceiling is only betweent 115-200 deg. Measured at the last sigle wall pipe. Guess Im kinda worried about creosote build up.

thanks

Lance

 

[Backwoods Savage]

Lance, welcome to the forum.

Part of what you are asking is dependent upon your stove and the manual should state what the temperature maximums should be.

To give an example, we have a soapstone stove and our manual says to not go over 700 degrees stove top. Yet, another soapstone manufacturer says 600 degrees for theirs.

I would not be afraid to say that any stove could run 500-600 degrees with no harm done and you get good heat from them at those temperatures.

The flue temperature will vary a lot. When first loading up the stove you need to leave the draft open full to get the fire burning nicely. We let our flue temperature rise to 500 degrees with a maximum of 600 (but our pipe runs horizontally too) before we cut the draft back. I've read of others who let their's go much higher. Once the fire is established, then our stove top goes to 500-650 (in these cold days. Cooler when the weather is warmer) but the flue temperature then decreases to around 300 degrees and sometimes down to around 250 degrees.

The trouble with running too low of a stove top temperature (and flue) is that creosote can and will form especially if your wood is not fully seasoned. And the wood is the main culprit when it comes to creosote! You can burn so much better with properly seasoned wood. Even if you buy wood, I would prefer to let that wood sit for a full year after you purchase it before attempting to burn it. Sellers really don't seem to know what seasoned wood is or they just say it is seasoned no matter what it is.

Right off the top of my head I can't come up with the temperature creosote will ignite at but someone will chime in here so I won't look that up. I've burned wood over 50 years and have never had that experience of a chimney fire.

Creosote has a tendency to form near the top of the chimney first. You should check that monthly until you are comfortable in knowing what is happening.

Please allow me to state that the number one thing you can do is have the right fuel and have it on hand long enough so that you know it is seasoned. Never take a seller's word for it. Also know that different wood needs different times to fully season.

To season our wood, we cut during winter months. In Spring we split and stack. Summer is good seasoning months and we leave our wood piles uncovered all summer and most of the fall months. We cover the top only in late fall or early winter and for sure we leave that wood pile sitting for a full year or more. At present we are working on the wood we will be burning in the year 2015.

Good luck.

 

[LLigetfa]

What I worry about is the top of the flue near the ceiling is only betweent 115-200 deg. Measured at the last sigle wall pipe. Guess Im kinda worried about creosote build up.

Since the boiling point of water is 212 and you're below that, I would be worried about condensation. It then comes down to how clean you burn and how dry the wood is.

If creosote builds up, flakes off, and falls back down the chimney, does it fall into the stove or are there any elbows or Tee it can collect in?

 

[mellow]

According to this article: http://www.inchem.org/documents/icsc/icsc/eics0572.htm

Autoignition point of Creosote is: 335°C or 635°F