Modern furnaces differ from older models primarily through higher energy efficiency, advanced two-stage or modulating heating, variable-speed blowers, and electronic ignition. While older units waste considerable fuel and rely on continuously burning pilot lights, new furnaces convert 90 % + of their fuel into heat, significantly lowering utility bills.
The $5,000 rule is a guideline to help homeowners decide whether to repair or replace their HVAC system. You multiply the age of your unit by the cost of the needed repair. If that number exceeds $5,000, replacing your HVAC system is often more cost-effective.
Newer furnaces are 50–60% more efficient than they were 30+ years ago, so you will immediately start to see lower energy bills after installation.
Average Cost to Replace a Furnace
However, the cost of furnaces can range widely depending on their size, type, and efficiency, and homeowners can generally expect a new furnace to cost anywhere between $3,800 and $10,000. If efficiency is important to you, high-efficiency models can reach up to $12,000.
Your energy consumption is rising for unexplained reasons. Furnaces lose efficiency as they age, making them run longer to provide the same amount of heat. The cost of repairs is 50% or more than the cost of a new high-efficiency unit.
Furnaces typically last 15 to 20 years, but well-maintained units can often operate longer. If your furnace is 25 years old, it likely means you've been maintaining it properly by scheduling annual maintenance and routine care. However, its age puts it at a higher risk for increased repairs and a complete breakdown.
Yes HVAC prices have steadily increased over the past few years, and 2026 is no exception. These increases are affecting everything from entry-level systems to high-efficiency units, making it more expensive than ever to install or replace HVAC systems.
The best time to buy a furnace is during the off-season, specifically late spring (April-May) or early autumn (September-October), when HVAC companies are less busy and offer lower prices, rebates, or promotions. Purchasing in these shoulder seasons ensures faster installation times and better negotiating power compared to winter peak season.
If you make qualified energy-efficient improvements to your home after Jan. 1, 2023, you may qualify for a tax credit up to $3,200. You can claim the credit for improvements made through December 31, 2025. For improvements installed in 2022 or earlier: Use previous versions of Form 5695.
Below are some of the best furnace brands for different homeowner priorities:
5 Warning Signs It's Time for Furnace Replacement
It is almost always cheaper to lower your thermostat when you are away or sleeping than to maintain a constant temperature, according to the Department of Energy.
The heat exchanger is often considered the most costly part of a furnace to repair or replace. It is a critical component that transfers heat from the combustion process to the air that circulates throughout your home. Over time, heat exchangers can crack due to the constant heating and cooling cycles they undergo.
How Do I Claim a New Furnace on My Taxes? As a homeowner, you can claim a credit on your energy-efficient furnace by filling out Form 1040 (or 1040NR for non-resident aliens). To determine your credit amount, complete the Residential Energy Credits Form 5695.
Most 2,000-square-foot homes need a furnace between 50,000 and 65,000 BTUs, depending on climate and insulation. Colder regions or older homes may need more heating power, while well-insulated houses in mild climates may need less.
A furnace generally needs to be replaced every 15 to 20 years. However, the exact timing depends on maintenance and usage. If your heating system is approaching this age, or if you are experiencing rising utility bills or frequent breakdowns, it is often more cost-effective to upgrade to a new unit.
For the 2025–2028 tax years, individuals age 65 or older by the end of the tax year can claim an additional $6,000 deduction ($12,000 for married couples) under the "One, Big, Beautiful Bill". This deduction requires a Modified Adjusted Gross Income (MAGI) below $75,000 for individuals ($150,000 joint) and is available regardless of whether you itemize or take the standard deduction.
The most overlooked tax break depends on your situation, but the Saver’s Credit (Retirement Savings Contributions Credit) and out-of-pocket charitable/medical expenses consistently top the list. These breaks reduce your tax bill dollar-for-dollar without requiring you to itemize.
Furnaces
Shop around. Getting competitive bids from several contractors will save you money. For large installation jobs, it's common for company-to-company price differences to exceed $1,500 for the same equipment and work. Even for smaller installation jobs, prices vary considerably.
You should probably Replace if: [ ] The repair costs more than 50% of a new unit. [ ] The furnace is over 15 years old. [ ] You have had to repair it more than once in the last 2 years.
Prices will only climb in 2026. If you have a major repair pending or your system barely made it through summer, getting a quote now will save you money. During the fall and winter, we offer up to 20% off new systems. A $12,000 system can look more like $10,500 with these savings.
While rare, a furnace can last up to 30 years with excellent maintenance, but most systems begin to lose efficiency and reliability after 15 to 20 years.
A new furnace can cost anywhere from $3,500 to $7,500 in 2026, depending on fuel type, efficiency, and installation requirements. If you're replacing both the furnace and air conditioner, most homeowners spend $5,000 to $15,000 for a complete system upgrade.
In short, the 20-degree rule of air conditioning states that you should always keep your AC unit at no more than 20 degrees lower than the outside temperature. It means that, if the outdoor conditions are at 95 degrees, you should set your thermostat at no less than 75 degrees.