ATTLEBORO - With the purchase of wood and pellet burning stoves on the rise, city Building Inspector Doug Semple and his crew are on the lookout for homes that appear to have new stoves because they may have been installed illegally.

He estimated that permits issued for wood and pellet burning stoves have jumped about 60 percent this year.

With a huge increase like that, there are sure to be people who installed stoves without permits or inspections, which can lead to dangerous situations, Semple said.

Safely installed and operated, wood- and coal-burning stoves and furnaces offer an opportunity to save on heating bills at the expense of a certain amount of convenience.

However, an improperly installed stove can be a disaster, possibly resulting in catastrophic fires or releasing deadly carbon monoxide gas within a building.

That's why detailed state laws and building codes exist to ensure that stoves, fireplaces and boilers are safely built and installed.

According to the Massachusetts Executive Office of Public safety, wood- and coal-burning appliances, including factory-built fireplaces, pellet stoves and wood-fired boilers must meet the following conditions:

Be listed as tested in accordance with National Safety Standards and labeled for the intended use. Wood-burning boilers must be constructed and stamped in accordance with the A.S.M.E. code.

Be placed a safe and established distance from combustible materials, such as wood, draperies, furniture, carpets and wood floors. Building code and manufacturer's specifications set out minimum clearances and flue connection requirements for stoves and other devices.

Be properly vented to the outside of the building.

Be installed, operated and maintained in accordance with building code requirements, as well as conditions placed on the unit by the manufacturer.

The state agency also recommends that smoke and carbon monoxide detectors be installed before using such appliances.

Installation requires a building permit through the local city or town building department.

Except in the case of a homeowner installing his or her own equipment in one-or two-family detached dwellings, the installation contractor must be licensed as a construction supervisor.

In addition, if the installation is intended for an existing residential building which has one to four units and is owner-occupied, the person with whom the homeowner is contracting must be registered with the state as a home improvement contractor.

Chimneys should be checked and cleaned regularly.

Anyone with questions about the requirements for installing such equipment should contact their local building inspector or building department.