The answer to 'how long will furnace last' is that the average lifespan of a furnace is 15-20 years with proper maintenance. Furnaces are built to last a long time, but their actual lifespan can vary depending on factors like the quality of the equipment, how often it's used, and how well it's maintained.
Proper maintenance is key to extending the life of your furnace. This includes regularly changing the air filters, having the system professionally serviced and tuned-up once a year, and addressing any issues or repairs promptly. With good care, many furnaces can last 20 years or more. However, older furnaces become less efficient over time and may need to be replaced sooner to save on energy costs and ensure reliable heating.