I’m pretty new to using a Jotul F55 V2 and don’t really understand the way firewood burns yet, so I had a question. If my stove top thermometer shows it’s in the “best zone” (400–650°F), but there’s still smoke coming from the chimney, does that always mean creosote is being produced? For context, I’m burning kiln-dried oak.
Creosote is being produced or not? thanks!
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Yes you are producing creosote any time you are burning wood. If you are burning properly there will be very little deposited in the chimney but if you are seeing smoke that's not a good sign
Yes I agree there should only be smoke at the beginning. Then as the fire and chimney/stove pipe heat up the smoke should be burned in the stove and only the hot air and a bit of particulates going up hopefully a hot chimney.
What does your air control need to be set at to get 650F stove top temp? There is no way that stove should be sending white smoke up the chimney as it has secondary burn. There must be something not right. Did you check the temperature with a heat gun or another thermometer?
If this is a brand new stove, and does not seem to burn correctly it is possible there is something wrong with it. I know it can happen for sure, because a friend bought a brand new Jotul and had problems. This guy was Mr. Wood Burning very experienced. That is why he bought that brand. He had nothing but problems. Had the dealer back many times. Eventually they took the stove apart and something was wrong inside.
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It’s possible that you’re seeing steam out the top too. Any time you burn a byproduct is water vapor. It condenses as it cools and steam comes out the top of the chimney.
Check your chimney and cap. If you’re burning clean there aren’t any particles of unburnt wood that can condense onto the flue as creosote. Or at least there is a lot less.
Check your chimney and cap. If you’re burning clean there aren’t any particles of unburnt wood that can condense onto the flue as creosote. Or at least there is a lot less.
Does what looks like smoke drift away, or dissipate a few feet from chimney? You could be seeing water vapor condensing in cooler air, not smoke.
Wood contains about 6% hydrogen molecules. The molecular weight ratio of hydrogen to water is 9. So you get 9 times the amount of water from hydrogen weight when burned. 6% or .06 X 9 = .54 pounds water for each pound of oven dry wood consumed.
As exhaust gases cool below 250f before exiting out top, this water vapor condenses on pipe and flue walls. Smoke particles stick, forming pyroligneous acid. In liquid form this is harmless. When allowed to bake on flue walls, this forms the various stages of creosote.
Flue temperature is only important while smoke is present. During the coaling stage there are no particles, and newer stoves consume more smoke particles in the stove, allowing lower exhaust gas temperatures.
To maintain secondary combustion above fire burning smoke particles, about 1100f is necessary internally. Single wall stove top, or pipe reads a surface temperature of about half the internal temperature. This is why you monitor stove top temperature.
Older stoves monitor flue temperature on or inside pipe before entering chimney to maintain hot enough flue gases to prevent condensing of water vapor. Since all venting systems cool differently, the required flue gas temperature at bottom varies greatly for older stoves with more particulate available to form creosote.
Wood contains about 6% hydrogen molecules. The molecular weight ratio of hydrogen to water is 9. So you get 9 times the amount of water from hydrogen weight when burned. 6% or .06 X 9 = .54 pounds water for each pound of oven dry wood consumed.
As exhaust gases cool below 250f before exiting out top, this water vapor condenses on pipe and flue walls. Smoke particles stick, forming pyroligneous acid. In liquid form this is harmless. When allowed to bake on flue walls, this forms the various stages of creosote.
Flue temperature is only important while smoke is present. During the coaling stage there are no particles, and newer stoves consume more smoke particles in the stove, allowing lower exhaust gas temperatures.
To maintain secondary combustion above fire burning smoke particles, about 1100f is necessary internally. Single wall stove top, or pipe reads a surface temperature of about half the internal temperature. This is why you monitor stove top temperature.
Older stoves monitor flue temperature on or inside pipe before entering chimney to maintain hot enough flue gases to prevent condensing of water vapor. Since all venting systems cool differently, the required flue gas temperature at bottom varies greatly for older stoves with more particulate available to form creosote.
Just because your wood is kiln dried does not mean it is less than 20% moisture content. Some places only cook it enough to kill the bugs. Get a moisture meter, resplit a piece and check if it's dry enough.
As already noted, flue temperatures are more important than stove top temps.
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