A new Lennox furnace costs between $3,200 and $10,000 fully installed, depending on the specific model and the size of your home. The unit itself accounts for roughly $1,100 to $3,700 of that price, with installation labor making up the rest.
Below, we break down Lennox furnace costs based on furnace size, SEER rating, unit type, and labor fees. Homeowners can expect to pay between $3,200 and $8,000+, or $5,600 on average for a Lennox furnace, depending on the model.
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.
A Lennox furnace typically lasts 15 to 20 years. With premium, high-efficiency models and rigorous, routine maintenance, they can sometimes reach 20 to 25 years.
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.
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.
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.
Lennox's furnaces have AFUE ratings from 80% to 99%, offering homeowners hundreds of dollars in potential energy savings. As a leading brand in energy-efficient furnaces, Lennox has award-winning products such as the Lennox SL297NV, recipient of the 2023 Green Builder Sustainable Product of the Year.
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.
Credit Calculation
The furnace tax credit equals 30% of your total qualifying costs, including both equipment and installation expenses, up to a maximum of $600 per furnace. Homeowners can claim 30% of the costs for upgrading heat pumps, with a maximum cap of $2,000.
5 Warning Signs It's Time for Furnace Replacement
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.
Premium Quality and Materials. Lennox manufactures its air conditioners and other HVAC products using top-of-the-line materials chosen for their ability to contribute to reliable, efficient systems. Every unit sold consists of precision-engineered components that enhance system performance.
The "best" furnace depends on your climate, budget, and long-term priorities. Overall, Trane and Carrier are top-tier leaders, Lennox provides unmatched energy efficiency, and Goodman/Amana offer the best value and warranties.
Uneven Heating
Uneven heating is a common sign that your furnace is no longer distributing heat effectively. This issue can result from various problems, such as a failing blower motor or duct issues, and often indicates that furnace replacement is needed to maintain consistent temperatures throughout your home.
HVAC Energy Efficiency
Even when compared to other top-of-the-line options, like Carrier, Lennox comes out on top. This leads to energy savings which leads to budget savings. Though other HVAC systems may be cheaper, the long-term energy savings provided by Lennox help make up the difference.
The Rule of 5000 Rule is simple: Multiply the cost of the needed repair by the age of your air conditioner. If the result is greater than 5000, AC replacement is generally the smarter choice. If it's less than 5000, a repair might still be worth the investment. Here's a quick example.
Your experienced Lennox Dealer knows how to check the operation of your HVAC equipment under all kinds of conditions and during every season. For maximum system effectiveness, it's advised that you have at least two tune-ups per year — one for your heating system and one for your cooling.
You may be able to improve efficiency by replacing a part, but if your furnace is 15+ years old, a new furnace will be more efficient and more cost-effective. You'll save money on repair bills and future energy bills. Learn about American Standard's Best Furnaces.
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.
Most furnaces installed 20 years ago operate at around 60 to 80 percent efficiency. That means a large portion of the fuel you pay for is wasted instead of being converted into heat. Modern furnaces, by comparison, often operate at 90 percent efficiency or higher.
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.
A standard furnace needs to be replaced every 15 to 20 years. However, electric models can occasionally last up to 30 years, while lack of maintenance or severe climates can shorten this lifespan.
Yes, it is cheaper to replace your furnace and AC together. Bundling the two installations into a single job saves an estimated $2,000 to $5,000. It also improves long-term system performance and reduces utility bills.