Choosing between Lennox and Goodman depends on your budget and long-term goals. Neither is universally "better," as they serve different needs:
Comparing Goodman and Lennox furnaces comes down to your priorities: Lennox is a premium, high-efficiency brand known for advanced comfort and quiet operation, while Goodman offers superior upfront affordability, accessible repairs, and standout warranties.
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.
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.
A Lennox furnace typically lasts 15 to 20 years. However, achieving the upper end of that lifespan heavily depends on routine maintenance (such as annual cleanings and replacing filters) and local climate.
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.
The "two-foot rule" in HVAC is a duct design and installation guideline that requires a minimum of 24 inches of straight, uninterrupted space between branch take-offs (where air taps off the main trunk). It is also applied to spacing branches away from end caps, transitions, and the main plenum.
The top three air conditioning brands for reliability and premium performance in the US are Carrier, Trane, and Lennox.
For the best balance of price, reliability, and value in 2026, Rheem, Goodman, and Amana are top choices, frequently cited for offering durable, high-efficiency systems at a lower cost than premium brands. For DIY or budget-focused buyers, MRCOOL central heat pump systems (around $3,000−$3,600) offer high SEER2 ratings and modern features.
A 16 SEER air conditioner is generally better for long-term savings, comfort, and environmental impact, while 13 SEER (or the modern 14 SEER minimum) is better for lowest upfront cost. A 16 SEER unit typically provides 15–20% higher energy efficiency and superior humidity control, often paying for itself through lower energy bills over its lifespan.
Based on Consumer Reports reliability surveys, Trane and American Standard consistently rank as the top overall HVAC brands, offering excellent-to-very-good predicted reliability alongside top-tier customer satisfaction.
Common Problems Found in Goodman Furnace Systems
Lennox Central Air System Not Cooling
In 2012, Goodman was purchased by Daikin Industries, Ltd and became a member of Daikin Group. Daikin is a global Fortune 1000 company and is a worldwide leader for residential and commercial heating, ventilation and air conditioning.
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.
Choose a 2 ton AC if your home is 800 to 1,200 sq ft with average insulation and a moderate climate. Choose a 2.5 ton AC if your home is 1,200 to 1,500 sq ft, has high ceilings, poor insulation, or is in a hot and humid climate.
Simply put, it means you should never set your thermostat for a temperature more than 20 degrees cooler than the outside air. Why not? Most air conditioning systems can only handle a 20-degree difference between the outside and inside air temperatures.
Have HVAC Prices Gone Up in 2026? 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.
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.
For a 2,000 square foot home, the cost of a new gas furnace typically ranges from $3,800 to $10,000, including professional installation. Labor alone often starts around $1,600.
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.
5 Warning Signs It's Time for Furnace Replacement
Lower your thermostat to 68∘F68 raised to the composed with power cap F68∘𝐹 (and 10∘−15∘𝐹 lower while sleeping). Seal drafts around windows and doors with weather-stripping or caulk, and change your furnace filter monthly. These simple actions significantly reduce energy consumption and can quickly lower your overall heating bill.