Choosing the right furnace for your home requires assessing your fuel source, calculating the exact heating capacity (BTUs) required, and balancing energy efficiency with upfront costs. Always hire a licensed professional to perform a strict heating load calculation to prevent oversizing or undersizing the equipment.
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.
Choosing a new furnace involves selecting the right size (measured in BTUs), fuel type (gas, electric, oil, propane), and efficiency rating (AFUE) for your home, typically costing $4,000–$8,000 installed. Focus on high-efficiency models (90%+ AFUE) for long-term savings, ensure proper sizing via a professional load calculation, and choose between single-stage, two-stage, or variable-speed options for comfort.
The national average cost for replacing a gas furnace in the U.S. for a 1,600 to 2,000-square-foot home is about $7,000. 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.
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.
Federal tax credits for residential furnaces and HVAC systems expired at the end of 2025. If your furnace was installed and placed in service in 2026, it no longer qualifies for the Section 25C Energy Efficient Home Improvement Credit.
A standard residential furnace lasts 15 to 20 years. However, the exact lifespan varies based on the type of system and how well it is maintained.
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.
Yes, you should highly consider replacing a 30-year-old furnace. Most furnaces have a lifespan of 15 to 20 years. At 30 years old, your system has likely outlived its expected life. It is operating at a much lower efficiency than modern units and presents a significantly increased risk of catastrophic breakdown or dangerous carbon monoxide leaks.
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.
When choosing a furnace, the best brand depends on what you prioritize: reliability, high-end efficiency, or budget-friendly value. Based on industry consensus and consumer ratings, the top three furnace brands are Carrier, Trane, and Lennox.
12 Questions to Ask an HVAC Installer When Replacing Your Unit
5 Warning Signs It's Time for Furnace Replacement
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.
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.
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.
The reality is that furnace replacement costs in California can vary dramatically – we're talking anywhere from $3,500 to $12,000 or even more in some cases, with Bay Area pricing typically running 20-30% higher than national averages.
You know it is time to replace your furnace when it is over 15 to 20 years old, requires increasingly expensive repairs, or struggles to maintain consistent heating. Waiting for a total, freezing-weather breakdown leaves you with higher costs and limited options, so being proactive is crucial.
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.
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.
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.
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.
Type of Furnace
Some types of furnaces are more durable than others. For example, oil furnaces are built to last longer but may require more frequent maintenance. Gas and electric models, while easier to maintain, may have shorter lifespans.
Most furnace installations can be completed in a single day. On average, a professional job takes 4 to 10 hours, though the specific duration depends on several factors. If everything is straightforward—like replacing an old furnace with a new, compatible unit—you may be enjoying heat again in as little as half a day.
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.