Low cost, high efficiency – but choose your installer carefully

The Goodman gas furnace line goes from the minimum 80% AFUE (Annual Fuel Utilization Efficiency) required by law, to an impressive maximum of 98% AFUE on their top models. And Goodman furnaces are generally lower priced than brands like Lennox or Carrier. You may find a lot of negative Goodman gas furnace reviews on the web but bear in mind that most people who are happy about their furnace tend not to think about writing an online review, while homeowners who take the trouble to write a Goodman furnace review usually do so because they’re upset about how the furnace is working, or about a problem with support or maintenance.

Any fool can criticize, condemn, and complain – and most fools do.

Let’s start by looking at the different models of Goodman gas furnace, and then cover warranty and quality of installation issues.

What’s in a model: Efficiency, blower motors, and everything else

The Goodman gas furnace line currently has eighteen models, but the units fall into two main groups: ten ultra high efficiency models (96% to 98% AFUE), and six 80% efficient models

My personal recommendation for anyone considering buying a furnace is: don’t! Buy a high efficiency heat pump instead. Heat pumps have improved considerably over the last decade. 98% efficient sounds pretty good for a furnace, but how about 450%? That’s the kind of efficiency you’ll see with a high efficiency heat pump – they produce up to 4.5 units of heat energy for every unit of electrical energy they use. And, more importantly, they don’t emit any greenhouse gases, so they don’t contribute to the climate crisis. We all need to do everything we can to cut our CO2 emissions, and replacing your old furnace with a heat pump is an easy way to have a big impact on that front. As for the argument that heat pumps can’t handle really cold weather, that was true 20 years ago but is no longer – see the article linked above for full details.

Note that HVAC installers who don’t tend to sell heat pumps will give you all kinds of arguments why you should go with a gas furnace instead – but if they don’t sell heat pumps, how do they know anything about heat pumps?

OK enough abotu heat pumps, let’s get back to furnaces.

My personal recommendation for anyone stuck on buying a gas furnace is to go for a high efficiency model (96% or higher) if you live in a zone where the furnace is running more than three months a year, because that extra 15% to 18% efficiency will probably pay back the extra cost of the higher efficiency unit over the life of the furnace, especially for a Goodman gas furnace which is typically less costly than other brands.

The high efficiency models achieve their peak efficiency in part by using a sealed combustion chamber with both intake air and exhaust gases vented to the outside through PVC pipes. By drawing in outdoor air for combustion these furnaces avoid sending already warmed indoor air outside. The heat exchangers in all models are a patented tubular design made of aluminized steel, and ensure that most of the heat produced from combustion goes into warming your indoor air instead of warming the outdoors via the exhaust. You know your furnace is efficient when it can send its exhaust out in a PVC pipe!

An 80% efficient gas furnace is really not much of an improvement over the most basic furnaces sold 20 years ago. 80% has been the minimum required efficiency in the US and Canada for many years, so if you go for an 80% efficient model you are getting the least efficient furnace available.

One often forgotten aspect of energy efficient furnaces is the impact on overall operating cost that the blower fan can have. You don’t see the electricity consumption of your furnace in your fossil gas bill, but in a forced air gas furnace, the blower motor can consume 500 watts of electrical power at full operation. The high efficiency Goodman gas furnace models have an ECM motor (Electronically Commutated Motor) which is a brushless DC motor. These ECM motors offer a number of advantages. First, DC motors tend to be more efficient than their AC counterparts. Second, a brushless ECM motor doesn’t have any brushes to wear out, so its durability is better. Finally, the DC motors on the high efficiency Goodman gas furnace support a continually variable speed, so that the blower motor can adjust precisely to the level of air circulation needed for your home’s moment-to-moment heating needs.

Choosing a Goodman furnace installer

It’s easy to find consumer complaints against Goodman gas furnaces on user-contributed review websites, but as I explained earlier this is a biased sample, since satisfied customers don’t tend to write reviews of their furnaces. You’ll find more complaints against Goodman than against competitors such as York, Trane, Bryant or Carrier (Bryant and Carrier are made by the same company). On the other hand Goodman also gets more favorable reviews than those brands, and has a higher ratio of favorable to unfavorable than any brand but Trane.

I really don’t think a few disgruntled customers are enough to base your decision on, and I generally discourage people from reading owner-submitted furnace reviews, because whatever brand you start with, you’re likely to decide not to go with that brand based on the built-in negative bias of online furnace reviews.

Most furnaces are made of the same basic components, and in many cases those components are sourced by multiple furnace manufacturers from the same parts manufacturer. For example, most of the controller systems for modern furnaces are made by Emerson, a leading manufacturer of electrical components, while the gas control valve for Goodman and other furnaces is made by Honeywell. As for the engineering and quality of the Goodman units, many of the pros believe Goodman gas furnaces are as well designed and as solidly built as other common brands that sell for substantially more.

Instead, I think what is behind the reported problems with Goodman gas furnace quality is the result of a small percentage of installers lacking the skills or ethics to do a good job of sizing the customer’s system properly, installing it correctly, and providing the right annual maintenance.

Goodman is a relatively new company for the HVAC industry. It’s a privately held company founded in the mid 1970’s. Compared to some of its more established competitors like Lennox (founded 1895), or Carrier/Bryant (with histories stretching back to the early 1900’s), it is kind of the new kid on the block. As a younger, privately held company they may have taken a few short cuts in recent years on one aspect of quality control: the approval process for becoming a qualified Goodman installer. If you don’t carefully screen the companies that are authorized installers of your product, you’ve essentially lost the quality battle, because that small percentage of unscrupulous installers that wouldn’t have passed a more rigorous screening program will create a vocal minority of unhappy customers.

Here’s how I believe this plays out. Goodman is known for lower than average prices on its gas furnaces. Installers know that, for some homeowners (or landlords or developers), low sticker price is the key decision factor. So they will start by suggesting an inexpensive furnace like a Goodman gas furnace, and then cut corners during the installation.

The first corner they are likely to cut is doing a proper heat loss calculation for your home to determine what BTU capacity of furnace you need. In most cases, installers who just want to cut a quick deal will skip over the heat loss calculation entirely (and may not even know how to do one), and will just eyeball it and tell you what BTU capacity you need based on gut feel for your house (or for your pocket book).

Then when it comes time to install, they’ll use lower quality components, may damage parts during installation, may hook things up incorrectly, and so on. It’s possible, for example, to get the air intake and combustion exhaust pipes mixed up, so that the air intake is above the exhaust pipe on the outside wall, instead of below it (I’ve seen this done). If an installer does this, your furnace is drawing in air that contains less oxygen (since some of it has been burnt previously), as well as combustion byproducts that are corrosive to metals, and your heat exchanger is likely to last five or ten years instead of twenty. (And your warranty is void.)

Remember: High quality costs more, once. Low quality costs less, again and again.

Quality starts with the team you choose…

On the other hand, if you hire a company that has a solid five star reputation, you are off to a good start. First of all, make sure that as part of the quotation process you get a proper ‘manual J’ calculation of your home’s heating requirements, so that you get a system correctly sized to your home. Interview at least three different companies – you can start on the phone, and then only bring to your home those who sound dependable enough to proceed to the next step and who are willing to do the heat loss calculation. Find out (still on the phone) what brands each contractor sells, and why. Find out what brands they dislike and why. In my experience, an HVAC contractor that puts a lot of effort into attacking brands they don’t sell, is not the best choice for the job. I’d put my money with the contractor who provides compelling reasons for why the companies whose furnaces they install make a quality product.

Also be sure to ask your prospective contractors what level of energy efficiency you should get. In general, a salesperson has three paths to take: the downsell, the upsell, and the honest sell. A downsell means he will try to sell you the lowest efficiency (i.e. 80% AFUE) furnace he has, since it will be cheaper and so his price will seem competitive. An upsell means he will try to sell you the most efficient furnace along with all the extra goodies, without helping you understand whether the added long term savings justify the added up front cost. The honest sell is the one who doesn’t push one or the other, but asks you to think about your own goals in terms of up front costs, total lifetime operating costs, and energy efficiency.

Check your contractor’s references by phoning at least three past customers and asking them about their experience having their furnace installed, and the performance of their furnace since then.

And quality lasts only as long as good service

Most furnace failures in the first few years after installation can be traced back to errors or shoddy workmanship by the installer. That’s why it’s important to select the right HVAC company – in fact, I would argue that choosing a highly regarded contractor is much more important than what brand of furnace you choose.

If you buy a Goodman gas furnace from a competent and professional HVAC company, and buy a long-term parts-and-labor service contract from them, with annual furnace tuning included as part of the contract, you will be off to a good start. An installer who knows that all future service is on his nickle, and who has the assurance of a small future income stream from the service contract, is motivated to do a good job at the installation, because it’s always cheaper to do it right the first time.

In the case of Goodman furnaces, they come with one of the best warranties in the industry – in many cases, a lifetime warranty (to the original homeowner) on the heat exchanger, and a ten-year warranty on parts. (Just make sure you register your warranty within 60 days of purchase.)

The heat exchanger warranty on all Goodman gas furnace models is unequivocal: if the heat exchanger ever fails, Goodman will replace the entire furnace with a new model of equivalent efficiency and output, provided it is the same homeowner and the furnace is in its original installation instruction. Considering repeated heat exchanger issues reported for some other furnace brands – such as the cracked Carrier heat exchanger that resulted in a class action lawsuit settlement – a complete replacement warranty on the heat exchanger is a strong statement by Goodman that they will stand behind their products for the long term.

A full service contract is still a good idea because that will cover you for the labor costs associated with any repairs. I’ve also heard that annual service fees for Goodman gas furnaces are among the lowest in the industry. A low service fee usually means the HVAC company doesn’t have to do a lot of service calls on the units, so they can charge a lower fee to cover their costs.

3 replies
  1. Steve Pozgaj
    Steve Pozgaj says:

    Excellent post. What a thoughtful and well-written piece. Certainly gave me the peace of mind I need to move forward with my new furnace purchase. I thank you very much for this!

  2. Bob
    Bob says:

    Great post. Been looking for a good post on furnaces, deciding between BRYANT, YORK AND GOODMAN. GOODMAN I was on the fence about, but the post made me realize that the parts for these furnaces are pretty much the same, and complaints are people who like to complain, there is a lot of good feed back on GOODMAN. IT’S all in the contractor you get to install the furnace.
    [ DOING A GOOD JOB ].. Can a person with Handyman -gas and wiring skills install one with the installation instructions that comes with a furnace.?

    • Robin
      Robin says:

      There are at least four reasons you should engage a professional for something as significant as installing a new furnace:

      1) Insurance – you may void your home insurance if the furnace is in any way involved in a damage claim and they find out you installed it yourself

      2) Warranty – you may void the warranty if you install it yourself and don’t have all the required credentials and manufacturer-required training

      3) Sizing – a professional HVAC consultant should size the system for you to make sure you’re getting the best size in terms of BTU/hr for your system (granted, that one is not all that hard to figure out)

      4) Peace of mind – I underpinned my own basement with no prior knowledge of how to do so – just reading books in the library and talking to an engineer and a contractor – and it worked out fine, but I have to say that every night for the next 3 months, whenever the house made a cracking noise as it shifted, I would worry about the house collapsing. I expect I would worry about my furnace blowing up or the house catching fire if I installed the furnace myself.

      To give you an idea of how easy it is to mess this up: When I dug out my basement, I had contractors do the refinishing. They rerouted the air intake and exhaust pipes to the furnace to go straight out the wall instead of to the back of the house – so there would be less ceiling space taken up by the pipes. Five years later during a routine servicing, the technician noticed a bit of rust on the burners, which he said was very unusual. It turns out that when the contractors did the repiping, they lost track of which pipe was which on the outside, and got the ends reversed – with the exhaust pipe pointing down, and the intake pipe above it pointing straight out. As a result, the exhaust was coming out the lower pipe, and the damp hot air was going up and being sucked into the air intake pipe. A little error like that could wreck the burner AND void the warranty / service contract. Luckily we had the pipe switchup corrected before major damage was done.


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