Yes, an 80% efficient (AFUE) furnace is good enough if you live in a mild climate, have a tight budget, or are installing the unit in a cold attic where high-efficiency units are prone to freezing. However, if you live in a colder state or pay high gas rates, a 95%+ high-efficiency furnace is usually the better long-term investment.
No, an 80% AFUE (Annual Fuel Utilization Efficiency) furnace is not considered high efficiency; it is classified as a standard or mid-efficiency unit. While 80% is common and often meets minimum legal requirements, high-efficiency furnaces are defined as having an AFUE of 90% or greater.
The Basics of The New Gas Furnace Mandate
While the current standard AFUE (Annual Fuel Utilization Efficiency) for a residential furnace is 80%, this mandate will require all gas furnaces to maintain a fuel efficiency rating of 95%.
Here's a general breakdown: Older, standard-efficiency furnaces (80% AFUE): 15–25+ years. High-efficiency furnaces (90%+ AFUE): 12-15 years with proper care-
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.
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 $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.
5 Warning Signs It's Time for Furnace Replacement
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.
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, eligible R-410A equipment can still be legally installed.
Currently, only New York has a statewide natural gas restriction. In May 2023, New York became the first state in the U.S. to restrict natural gas and other fossil fuels in most new buildings.
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.
For a 2,000 sq. ft. home, you typically need a furnace between 60,000 and 80,000 BTUs. The exact size depends heavily on your local climate, ceiling heights, and home insulation.
Yes, R-32 is generally considered better than R-410A due to its higher energy efficiency, lower global warming impact, and use of a single compound. However, because it is mildly flammable (A2L classification), it requires dedicated HVAC systems rather than a direct replacement.
Average Furnace Installation Cost Range
A new furnace installation typically ranges between $4,000 and $8,000, depending on system type and efficiency. This total is an all-inclusive number, including the new furnace, labor, removal of the old unit, and minor ductwork adjustments.
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.
Short cycling
This is one of the most common furnace problems, and it can stress important furnace components such as the blower motor, limit switch, or flame sensor. There are several potential causes of short cycling, including some that are related to your furnace's built-in safety 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.
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.
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.
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.
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.