University of Missouri Extension

G1731, Reviewed October 1993

Wood Stove Maintenance and Operation

Heating with woodDavid E. Baker
Department of Agricultural Engineering

After selecting and installing a wood stove you will be anxious to get it going. Learn to operate and maintain the stove so it can provide warmth and comfort in a safe and efficient manner.

Operation

Once a good stove has been selected and installed correctly, the next important factor is proper operation. Many problems that arise with a correctly installed stove are the direct result of incomplete combustion.

Combustion

Combustion consists of a complex chemical reaction between the fuel (wood) and oxygen. The combustion of wood in a stove results in heat and water vapors, carbon dioxide and other products of combustion such as gases and ash. To ensure satisfactory combustion and safe operation, you must meet several conditions:

Ensure complete combustion by supplying air and maintaining a sufficient heat level. Incomplete combustion results from an insufficient air supply, misapplied air or insufficient heat.

Wood combustion

There are three basic stages to wood combustion:

Starting a fire

Since moisture must be evaporated and expelled before wood will burn, the wood should be cut and seasoned. Use well-seasoned wood with a low moisture content to reduce the likelihood of creosote buildup.

When building a fire, follow the manufacturer's recommendations. The following steps will also serve as a guide:

New stoves with cast-iron parts should be "seasoned" to avoid cracking. Do this by building only small fires for the first two or three times.

The entire system must be properly maintained to operate safely and efficiently. The chimney connectors, joints and flues must be clean and in proper working order.

Control creosote buildup

When wood is burning rather slowly, the smoke usually contains a substance called creosote that collects in the relatively cool chimney flue. The main causes of creosote buildup are:

The best way to control creosote is to prevent its buildup by maintaining a briskly burning fire with dry, well-seasoned wood. Maintain a flue temperature exceeding 250 degrees Farenheit to prevent creosote condensation.

Some new, more efficient stoves deliver more heat to the room than an open stove or fireplace. This reduces the amount of heat escaping up the chimney and lowers the flue temperature. Make sure creosote is not building up as a result of improper operation of these stoves. Additional inspections and clean-outs may be needed.

Chimney fires

With the increased accumulation of creosote in the flue comes the increased possibility of a chimney fire. The combustion of these creosote deposits is most likely to occur during a very hot fire in your stove. Burning creosote deposits cause a very intense fire, a roaring noise, and flames and sparks shooting from the top of the chimney.

Any chimney, metal or masonry, can be weakened or deformed by a chimney fire. The complete chimney should be inspected after a fire, and any repair should be made or parts replaced before re-starting the stove.

If a fire occurs, follow these steps to reduce your losses:

Chimney inspections and cleaning

Stovepipes and chimney flues should be inspected each year before you use your stove. Look for cracked flue liners, broken or missing bricks, heavy creosote deposits, bird nests and other foreign material. Thoroughly clean the flue and stovepipe of any soot and other residues. Repair the chimney or replace the stovepipe to avoid any problem later in the season.

The stovepipe and chimney should be inspected frequently during the heating season for creosote buildup. If you use an air-tight stove, check the stovepipe at least once a month.

Your chimney cleaning schedule will depend on how frequently your stove is used and how it is operated. Should your chimney have an excessive buildup, a stiff wire chimney cleaning brush like the ones used by professional chimney sweeps are available at a reasonable cost.

Some people recommend pulling a bag containing wire netting weighted with chains or rock up and down the chimney; others use tire chains or wire netting without a bag. The effectiveness of these techniques is questionable. Tire chains or a weighted bag may damage the flue liner.

Disposal of ashes

Store ashes in a non-combustible metal container with a tight lid. The closed container should be placed on a non-combustible floor or on the ground well away from all combustible materials pending final disposal.

Fire extinguishers and detectors

In addition to the extinguishers already in the home, a multipurpose fire extinguisher should be installed for each stove. The extinguisher should be located near the stove within easy reach. To offer your family additional protection in case of fire, equip your home with an early warning fire detection system.

Safety points

 

G1731 Wood Stove Maintenance and Operation | University of Missouri Extension

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