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AFUE: The Five Essential Questions Your Service Company Should Ask You Before You Buy In

Right here, we have all the answers to your questions on AFUE, including a quick video on Ron’s Story, the five essential questions you should be asked before your job is priced, and US Department of Energy guidelines that will help you along the way. AFUE can be confusing at first, but once you are armed with the knowledge you need to make an informed decision tailored to your specific situation, you will feel empowered. 

“The Five Essential Questions Your Service Company Should Ask You Before You Buy Into AFUE” includes –  

  1. A Brief Overview of AFUE 
  2. Ron’s Story/Quick Video Explanation 
  3. The Five Essential Questions 
    1. How? 
    2. When? 
    3. What? 
    4. Are? and… 
    5. Did? 
  4. US Department of Energy 
  5. Understanding ENERGY STAR  
  6. Your furnace or boiler (Do you need to buy the same equipment you have?) 
  7. Get a free quote instantly, without a tech visit to your home 


A Brief Overview of AFUE 

When you’re on a quest for information about AFUE you’re most likely in the fact-finding phase of HVAC replacement or repair. HVAC stands for Heating, Ventilation and Air Conditioning, which not many are aware of, and refers to the heating and cooling industry as a whole. So, let’s discover the meaning of AFUE together and start a discussion on why it’s important to have a clear comprehension of what it is. Additionally, what are the questions you need answers to before you make any decisions about your home heating system? In this blog post, we have the five essential questions your service company should ask you before you buy into AFUE. If they don’t ask you these questions or haven’t asked you them yet, you may want to consider a second opinion on your furnace or boiler diagnosis.  

afue photo

AFUE is a commonly used acronym within the HVAC industry. The Annual Fuel Utilization Efficiency is a percentage that expresses the amount of heat you will benefit from throughout your home versus the amount that will escape through the flue.  

Wait, what?!  

Yes, something has to keep the birds warm. (You can insert your smile here.) It is true, the heat escaping through the flue from lower efficiency equipment is a major ouchie for your heating bill. The good news, though, is the higher efficiency level your equipment is, the less fuel you will literally lose to the birds. That might mean you pay more money for a furnace up front, but over the lifespan of your system, you’re spending less on fuel. 

The heat produced by your furnace in correlation to the level of fuel used is the AFUE. Some older homes have furnaces with extremely low or even unmeasurable levels of AFUE, which means those homeowners are spending much more money on fuel than recommended by US government agencies like the Department of Energy. New Energy Star rated equipment is rated between 80-98% AFUE, as opposed to older homes with no AFUE rating on their equipment at all. Homeowners with much older systems waste a lot of fuel to these lucky (and warm) “birds we are referring to. 

Upgrading to a new system can save you a lot of money on fuel, which means you will be getting more bang for your buck, but how will you know whether its time to replace your furnace or simply repair it??  

Before you even get to this decision-making step, there are a few questions your service company should ask you as a homeowner in a time of need  

Here’s a quick tip to keep in the back of your mind throughout the process. As of the year 1992, the US Department of Energy set the standard that all furnaces sold in the US must be minimally 78 AFUE. Other specific types of furnaces have different standards, and as of 2015, even higher levels of AFUE are required between 80-83 AFUE. So, to comply with these standards, when purchasing new equipment should operate at this efficiency level.   

If you’re looking for a deeper dive into the meaning of AFUE, there is a plethora of information on the What is AFUE post. Click Here.


Ron’s Story

Learn more about AFUE and the Five Questions Your Service Company Should Ask You By Watching THIS VIDEO about Ron’s Story.

As some of you can relate, Ron’s story is not uncommon to those with older homes. But like Ron, you, too can take this crash course on heating terminology and get yourself up to speed to make an informed decision. With that in mind, we’ve curated a list from industry experts on the top 5 questions you have to listen for… Your service company should be asking you these 5 questions, and if not, perhaps it’s time to make sure they know your answers. 


The 5 Questions 

  1. How frequently do you operate your furnace? Is it running year-round, or is it running more seasonally, or occasionally? 
  2. When did you move into your home and how long do you plan to stay put? 
  3. What is your budget for a new heating system? 
  4. Are you aware the repairs on a higher AFUE heating system are more expensive than on a minimally required AFUE percentage? 
  5. Did you know you can cut out added costs by shopping online for your ideal AFUE system?  


These questions lead to your system diagnosis and a recommendation or repair or replace. Please bear in mind, however, that if your system is 10 years or older, most will advise you to replace.  

Many sales people will tell consumers that they’ll save a lot of money by installing a high-efficiency furnace. But if you’re replacing an older furnace that has an AFUE rating between 55-70%, then installing an 80% AFUE furnace will already be a substantial upgrade, and you will immediately see a huge savings on your utility bill.   

If you plan on living in your home less than five years, the payback time period may not be enough to justify the additional cost of a high efficiency furnace if you buy from a contractor.  

The distribution channel for furnaces consists of a manufacturer, distributor, and then a dealer (the installing company). Each channel adds a markup. The dealer usually adds a 100% markup. Costs vary, but compared to an 80% furnace expect to pay $1,100 dollars or more for a 90% AFUE furnace.  A 95-99% AFUE furnace will probably cost you between 150-200% more than an 80% AFUE furnace.     

When they ask about your budget, just be honest. What do you expect a new system to cost? What about a repair? The thing you must know here is that the repairs on a more efficient system, or – one with a higher AFUE, will cost more money than they will on a lower AFUE system.  

That brings us to the final of the five essential questions your service company should be asking you before you repair or replace. So, here’s a question or two for you to ask yourself. Are you a sharp, smart consumer? Do you pride yourself in seeking knowledge before you invest your money in a large purchase? If yes, then you will be rewarded by arming yourself with information and seeking pricing for HVAC replacement equipment online. This is a great way for you to see a real breakdown of what you should expect to pay for a replacement.  


Understanding ENERGY STAR 

When you are looking for information on energy efficient equipment to replace your existing system or occupy a new home, you will want to have a concise understanding of government standards. ENERGY STAR certified, guaranteed products are not only good for you and your home, they have beneficial-for-the-environment operational standards. They meet strict criteria in order to carry this label. For detailed information on products that carry the label, you can visit their website (Link to: ) 

Here are a few criteria furnaces must meet in order to carry an ENERGY STAR label:

Gas furnaces in the southern United States must be a minimum of 90% AFUE. In the northern parts of the US, gas furnaces need to operate at 95% AFUE (as a minimum efficiency level standard). Oil furnaces must have an 85% or higher AFUE rating. For a specific breakdown of the US states per region, please click here.


Your furnace 

As a general rule of thumb, if your equipment was or is heating your home comfortably, it is the proper size you’ll need for a replacement. You can search the model number written on the product tag online to see what type of system you have.  

Money conscious consumers who want to avoid paying a retail markup are encouraged to get a bid and compare online at At there is never a retail markup, or commissions paid to sales people that drive up the price – just complete transparency and the guaranteed lowest prices on central heating. Search for replacement equipment in the comfort of your own home or office, or from the library, or from Starbucks, or the car! You can access the information you need on your phone or tablet, on-the-go or on your couch. Call or chat if you have questions. 

Now that you know the essential questions your service company should be asking you – what are you going to do to resolve your home or office heating woes?

What is AFUE – Your Personal Efficiency Guide for Heat

The Acronym AFUE stands for Annual Fuel Utilization Efficiency and is an indication of how efficient a furnace is at converting fuel to heat. AFUE is measured as a percentage, and the higher the rating, the greater the fuel efficiency. Please read below for further demystifications on AFUE, so you can decide which level of efficiency is best for your needs and budget.

Here’s what we will cover below:

Your Personal Efficiency Guide to AFUE includes –

  1. Definition
  2. Word Breakdown
  3. John and Rita’s Story/Quick Video Explanation
  4. AFUE Mathematics
  5. FTC and US Department of Energy
  6. What does AFUE have to do with MPG?
  7. 4 Questions for Clarity
  8. Benefits and Regulation
  9. Types of Fuel


The Introduction to AFUE

If you live in Florida, where the Pricefixer corporate offices are located, you most likely lean toward traditional condensing units to cool your home as your primary temperature control method. However, you never know when a cold front is going to come through, so it’s essential to be prepared to weather the fallout from the storms. If you’re in other parts of the United States such as the chillier climate near the Great Lakes or throughout the mid-west, you are certainly going to be interested in educating yourself about furnaces and AFUE, especially if you own a home or are considering becoming a homeowner. So, what exactly is AFUE, and why does it matter to you? Read below for a clear definition and your complete personal efficiency guide to AFUE, and to review supporting visuals like photos and a video explainer depicting John and Rita’s story, if you prefer to watch instead.


afue photo



The acronym AFUE stands for Annual Fuel Utilization Efficiency. It’s important to understand what AFUE means while contemplating the purchase of a furnace for your home, because a misunderstanding could lead to a lot of lost money, time and effort. The overall definition of AFUE, in neophyte terms, is a measurement of the efficiency level of the furnace to utilize the fuel within. To examine this concept a bit deeper, the amount of heat a furnace produces in direct relationship to the amount of fuel used is called, AFUE.


An AFUE furnace that is 92% efficient means that for every $100 of gas consumed, it will generate $92 worth of useable heat. To find out where that $8 goes, watch the video below.

But, if you’re still unsure, no worries because there’s an even more in-depth definition, and beyond that, we will give you another example.


Word Breakdown

Let’s break it down here into individual word segments. Annual refers to the efficiency on a yearly basis, and how well your system performs over a 12-month time span. Fuel is a material that is burned to produce power, or to produce heat, in this instance. A few examples of fuel in this application could be heating oil, natural gas or propane. The word Utilization refers to the action of making use of something in a practical way. Efficiency is the part of the acronym that is defined by the productivity level of a system or machine (or furnace, in this instance) to achieve the highest levels of output. These words make up the larger concept of Annual Fuel Utilization Efficiency, and when you can break it down into smaller meaningful parts, sometimes the explanation becomes more digestible. Please note, AFUE does not refer to the electricity usage of your furnace or boiler, it directly refers to the fuel efficiency of the equipment in regard to gas, propane or oil.


For a Quick Video Explanation, Click Here!


AFUE Mathematics

Now, let’s get into AFUE by the numbers, and what they mean. Newly manufactured furnaces vary in levels of AFUE from efficiency levels of 80% up to the level of 98%. (Lower efficiency models exist in some homes built before energy efficiency standards were put into place by governing agencies. So, it is possible your home has a much lower level of AFUE. More on that later.) For now, back to the example: this means a furnace with 90 AFUE will convert 90% of the equipment’s fuel consumption to consumable heat. Sounds great, right?

So, when you look at an 80 AFUE furnace, it will convert 80% of the fuel consumption to heat. So, how much heat does a 98 AFUE furnace convert? Well, now you are armed with all the powerful information! Now you know a 98 AFUE furnace will convert 98% of fuel to consumable heat, and so on. Your knowledge in heating will make it much easier for you to determine the best system for your needs when the time comes. If you take 100% and you subtract the amount of AFUE, you will know the amount of heat loss your equipment will be responsible for. For example, in an 80 AFUE furnace, 20% of the heat produced escapes through the chimney or other places.


FTC and US Department of Energy

The FTC or Federal Trade Commission has guidelines in place that make it a requirement for manufacturers of furnaces and boilers to display the AFUE on equipment so consumers like you can determine the energy efficiency of your system. There are also a plethora of rules and notices put forth by the U.S. Department of Energy that delve deeper into the standards of operations for consumer furnaces and more, available here.


What does AFUE have to do with MPG?

Another way to think about AFUE is to draw a parallel to a similar topic that you may have dealt with in your lifetime. For every dollar of fuel consumed, AFUE measures the amount of heat produced. Here’s an example for you that will put you on a clear path to strong knowledge around this topic. You can compare the way AFUE applies to: heat a furnace produces, similarly to the miles per gallon on a car, SUV or truck you are considering purchasing. If you’re not currently in the market, perhaps at some time you were, or know of someone who has been. For this purpose, let’s use you for the example.

Your fuel costs will increase the lower your AFUE, and similarly, the money you spend on fuel for a higher AFUE heating system will be less than what you spend on a low efficiency system. The higher the efficiency, the less money the equipment will cost you to operate, specifically regarding fuel. (See graph below.) When your vehicle gets 30 MPG or miles per gallon, it has better fuel efficiency than, say, a larger gas-guzzler that might only get 12 to 15 MPG.

Operating Costs


When you go to the dealership, do you purchase the vehicle based solely on the miles per gallon it gets? Or do you make your decision based on multiple factors that ultimately weigh into examining and determining your best option?


Questions for Clarity

Some other factors you should consider are:

  1. Usage
    Ask yourself this: Do you run your furnace or boiler year-round?

  2. Homeownership plan.
    Ask yourself this: How long will you live in your home?

  3. Cost
    Ask yourself this: Am I prepared to invest in a higher-efficiency furnace that will cost more money up-front to purchase?
  1. Repair or replace?
    Ask yourself this: Does it make more sense to repair or retrofit my current furnace or boiler, or to replace it altogether?


AFUE Savings


Benefits and Regulation

If you are most interested in a high efficiency, or 80+ AFUE heating system, consider keeping your eyes open for an ENERGY STAR® label, which can be found on the most efficient models. The government standard on new heating equipment is a minimum of 80 AFUE, so no matter what, when you purchase a new furnace or boiler, make sure it operates to this level of efficiency and that the equipment is clearly labeled.


Types of Fuel

Types of fuel utilized within your heating system bear a significant weight on the costs of operating the equipment, additionally. Different types of fuel include natural gas, propane, heating oil, firewood and more. For details on fuel types and associated AFUE, check out our post here. (insert link to fuel article.)

If you prefer an electricity-operated system instead of a fuel-reliant method such as a boiler or furnace, you can learn more about heat pumps here. (insert link to heat pump blog.)

Here is a recap of what was covered in this article:

  1. Definition
  2. Word Breakdown
  3. John and Rita’s Story/Quick Video Explanation
  4. AFUE Mathematics
  5. FTC and US Department of Energy
  6. What does AFUE have to do with MPG?
  7. 4 Questions for Clarity
  8. Benefits and Regulation
  9. Types of Fuel

To learn more about replacing your heating unit, click here.

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