The lifespan of a heating furnace can vary depending on factors such as its type, usage, maintenance, and quality. On average, a well-maintained and properly installed furnace can last anywhere from 15 to 20 years. Gas furnaces tend to have a slightly shorter lifespan compared to electric furnaces. However, routine maintenance, such as cleaning, filter replacement, and regular inspections, can significantly extend the life of your furnace. Additionally, advancements in technology and improvements in manufacturing have led to more durable and efficient furnaces in recent years. It's essential to consult with an HVAC professional for regular maintenance and assessments to ensure your furnace operates efficiently and safely throughout its expected lifespan.