Factory-built fireplaces are prefabricated metal units which are installed complete with chimney. They have been used widely in recent years in new home, apartment and condominium construction. Installation and operating instructions usually are included with these units but this information may not always reach the fireplace user. Over half of the units inspected by chimney professionals are improperly installed. Most factory built fireplaces are tested and listed by an independent testing laboratory as decorative heating appliances, and will not withstand the same level of use as a masonry fireplace. Severe over firing will often badly damage these units. Regular yearly maintenance and careful monitoring is needed to assure safe operation of the system.  Many prefab chimneys seem to be a preferred nesting site for birds.  Nesting material can easily catch fire or block critical airway passages allowing the chimney to overheat. Finally, prefab fireplace systems eventually just wear out. A factory-built unit will reach the end of its useful life when repair of the unit is no longer possible, particularly if the components that are necessary to maintain the listing are no longer available. The Charlotte Fire Department recommends that users of prefabricated fireplaces understand their limits, follow the manufacturer's operating instructions and strictly adhere to these safety guidelines at all times:

• Clear the area around the hearth of all combustible items and flammable materials.
• Never use any flammable liquid to start a fire.
• Build small fires that burn completely and produce less smoke and heat.
• Never leave a fire in the fireplace unattended.
• Extinguish the fire before going to bed or leaving the house.
• Soak hot ashes in water and place them in a metal container outside your home.
• Maintain and repair prefabricated fireplaces and chimneys as needed and recommended
• Never ignore smoke alarm or carbon monoxide alarm activations when using a fireplace