Factory built fireplaces have a general life expectancy of about 25 years. This can be less when considering additional factors such as heavy or improper use and leakage that can accelerate the deterioration to the unit. If your fireplace is rusted and deteriorated, it may not only be passed to for replacement, but it may present a significant fire hazard. Give us a call at 1-800-257-2066 and have your fireplace swept and inspected annually.