How long does a furnace typically last?
Many furnaces last about 15 to 20 years with proper maintenance. Around the 15-year mark, it makes sense to compare repair costs and efficiency against a replacement.
Service Guide
Furnace Replacement
Furnace replacement is a major home investment. The right decision balances safety, comfort, efficiency, and long-term cost. This guide explains when replacement may make sense, what drives price, what to ask before you book, and how to compare HVAC companies.
Typical rangeUS: $3,800 - $12,000
Next stepCompare local hvac companies
Use this forCosts, questions, and project fit
What homeowners should know
Furnaces typically provide reliable heat for many years, but performance and efficiency can decline with age. Many pros point to around the 15-year mark as a time to evaluate replacement options, especially if repairs and energy costs are rising.
Replacement decisions should consider proper sizing and installation quality, not just brand. Ask whether your contractor will perform a load calculation and evaluate ducts, venting, and airflow. Efficiency (AFUE), fuel type, and installation complexity can all affect comfort and operating costs.
Prices can vary widely based on furnace size (BTUs), efficiency, fuel type, venting, duct condition, and local labor. Ask about rebates and ENERGY STAR options that can improve efficiency compared with older equipment.
When this service is needed
Your furnace is around 15 years old or more and having more frequent issues
You see uneven heating, cold rooms, or airflow problems that persist after basic service
Rising energy bills or frequent cycling suggest declining efficiency or capacity
Strange noises, repeated ignition problems, or safety shutoffs keep occurring
Repair vs replacement
A repair may be sensible for newer units with isolated issues. Many homeowners weigh age, the specific repair cost, and plans for the home. Some pros use a 50 percent guideline: if a major repair approaches roughly half the cost of a new system, replacement may be the better long-term value, especially for older furnaces.
Consider replacement when the unit is around 15 years old, has repeated failures, or is inefficient compared with current ENERGY STAR models. If you plan to stay in the home, the savings and comfort from a properly sized, efficient furnace can help offset upfront cost. If you expect to move soon, a targeted repair may be reasonable if it is safe and reliable.
Common problems to compare
Uneven heating or cold rooms that point to airflow, capacity, or duct issues
Frequent cycling or a blower that runs continuously
Strange banging, rattling, whistling, humming, or clicking noises
Rising energy costs without increased use
Burning smells or smoke; shut off the system and call a pro
Questions homeowners often ask
Do I need permits or inspections for a furnace replacement?
Local rules vary. Ask whether your contractor will handle any required permits and schedule inspections. Also ask for documentation of the load calculation, equipment sizing, and any code or venting updates included in the job.