Consumers often turn to alternative heating systems like wood pellet stoves (a.k.a. wood burning stove or wood pellet furnace) during the winter to heat their homes. If you’re considering switching to a wood pellet stove, space heater, or fireplace this winter, consider the following safety information.
- Before using any heating device, install carbon monoxide detectors in several parts of the house.
- Except where specifically recommended by the manufacturer, only the fuel (e.g., pellets, corn, log wood, coal or gas) for which a stove is designed should be used.
- Never use a kerosene heater indoors.
Alternate heating stoves can vary in construction regarding self-contained insulation and thermal protection. A single layer iron-walled stove, for example, can generate enormous heat several feet in all directions. On the other hand, more sophisticated multiple walled insulated forced-air stoves can remain safe to the touch when in use.
Placement of the stove must take into consideration adequate space for installation, maintenance and replacement, flue or vent pipe routing, and most importantly, safe location relative to combustible materials. The National Fire Protection Association (NFPA) recognizes appropriate American National Standards Institute (ANSI) and Underwriters Laboratories (UL) standards and testing of the reduction of heat with distance from the unit as well as non-combustible shielding (defined in codes). Properly tested and rated stoves will have an attached safety label and an installation manual, which will detail the manufacturer’s recommended minimum separations. Some general guidelines are provided for different types of stoves in the following sections for cases when labels are missing.
In most cases, protection of the floor or combustible surface under a stove is required and specified including shielding beneath and extending on all sides in accordance with the code and label requirements. This includes adequate protection in front of the fire box and where ash removal is required.
Standards also exist for locating and routing flue and vent pipes in order to provide separation from combustibles adjacent to and through walls and to existing chimneys.
These modern devices operate through an automated fuel-delivery process. In some designs, a fan delivers air to the fire and blows exhaust by-products out of a vent pipe that is smaller and typically less expensive than a chimney. Often, a separate fan blows air through heat exchangers in the stove and out into the home.
- Always hire an installer who is licensed and certified.
- Stove placement must allow for access to proper venting and electrical sources and must meet minimum required clearances. Certified installers operate according to these guidelines.
- Outlets must be checked for proper voltage, grounding and polarity.
- According to model building codes, multiple walled insulated forced-air stoves within compartments or alcoves should have a minimum of 3 inches of working space clearance along the sides, back and top with a total width of the enclosing space being at least 12 inches wider than the stove.
- Stoves having a firebox open to the atmosphere should have at least a 6-inch working space along the front combustion chamber side.
- Keep the stove clear of all combustible materials.
- Use PL vent pipes tested to UL 641.
The following materials should never be used to vent pellet appliances:
- Dryer vent
- Gas appliance Type B vent
- PVC pipe
- Single-wall stove pipe, unless approved by local codes and the installation manual
- Inspect chimney before installation. Relining may be required.
- Altitudes higher than 2,500 feet may require special venting options.
- An outside air source may be required for houses with tight construction or strong kitchen, bath or other exhaust fans.
- Manufacturer’s instructions must be closely followed regarding sealing joints and seams, particularly of pressurized mechanical exhaust vents.
- Regular maintenance is critical to ensure safe operation.
- Frequency of cleaning will depend on the fuel type, grade and content.
- Components should be inspected daily.
- Professional cleaning is recommended for vent systems before each seasonal use.