How Hot Should You Burn an Airtight Wood Stove?

Stove Construction

• Old-fashioned Franklin, potbellied and box wood stoves allowed air into their fire boxes through loose-fitting doors and gaps. An airtight stove is equipped with a door gasket that creates a tight seal so air can only enter through an intake vent or damper located below the firebox. Many airtight stoves also feature baffles or metal plates affixed to the top of the stove above the firebox where secondary smoke travels and is reheated during a secondary burn. It's called a secondary burn because it happens after the wood has ignited and produces the much higher temperatures needed to efficiently heat the room. Airtight stoves that function in this way can withstand the high temperatures necessary to burn off these secondary gases.

Stove Operation

• As with any wood stove, starting a fire in an airtight stove involves heating the stovepipe and getting the initial kindling hot enough to burn larger pieces of wood. The air intake vent or damper should be wide open, during this process, as the initial flames need all the air they can get to stay burning long enough to ignite the nearby wood. Allow the fire to burn hot and fast for about 20 minutes before adjusting the damper and keep an eye on how the fire behaves once you start depriving it of air. Many airtight stoves are double-walled and can safely handle even the most extreme heat.

Advantages and Disadvantages

• Airtight stoves offer advantages that older wood stoves do not, including burning for longer periods of time, requiring less frequent reloading and controlling the amount of air moving into the firebox. While these are all convenient features in the short term, the significant buildup of creosote in the stovepipe and chimney may ultimately outweigh them. A strong hot fire burns significantly larger amounts of the gases and emissions that result in creosote. Airtight stoves effectively starve a fire of the oxygen it needs to completely burn the wood, and the potential dangers of excessive creosote buildup should be a primary concern. One solution is to stop thinking of an airtight stove as a low-maintenance source of heat and to treat it more as if it were an older model that lacks airtight components.

Considerations

• Use the damper in your airtight stove judiciously and don't allow the fire to smolder for hours. Burn only well seasoned wood that has been air-dried for at least six months, preferably a year. Keep your stovepipe and chimney clean as a hot fire can ignite built-up creosote, causing a chimney fire. Go outside often to check the color of the smoke coming from your chimney. The whiter it is, the more efficiently your stove is functioning. And as tempting as it might be to let the fire burn slowly overnight, it's best to allow it to go out and to start a new fire in the morning.