Lennox G26 Furnaces | FurnaceCompare®

Lennox G26 Furnace Overview

The Lennox G26 (discontinued) is a high-efficiency gas furnace offering 92% AFUE. This model was offered in in 4 different models with downflow and horizontal options.

The G26 was equipped with Lennox’s SureLight ignition system, which featured easy on board diagnostics with LED lights and was made of durable, silicon-nitride for long-lasting home heating.

Fully insulated cabinets and heating capacities of 50,000 to 125,000 BTUH are additional components of this unit.

Furnace Filters for the Lennox G26

Air Flow ConfigurationCabinet WidthFilter Size(s)
All16 1/4″14x25x1

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Consumer Reviews of Lennox G26


  • Very Satisfied
  • Somewhat Satisfied
  • Neutral
  • Somewhat Unsatisfied
  • Very Unsatisfied
  • #9 of 29 Lennox Furnace
  • 40% of customers recommended

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Lennox G26 Furnace Reviews

Showing 6-10 of 15 reviews

"Save yourself the headache, avoid Lennox"

1.0 rating
Very Unsatisfied

We have 2 Lennox g26q3 furnaces at in our local Historical Society Museum, plus three more Lennox furnaces in an other building. To put it short – they are junk; poorly designed and built with cheap components. The two g26q3 furnaces both fail 2-3 times a year, typically on a holiday. (I’ve become really good at repairing them). The two newer Lennox furnaces, (different models) at the other facility typically fail once a year. The only one that rarely has an issue is the 25 year-old “inefficient” furnace. The whole “high efficiency” design is a joke, because you will spend more on parts and service than you will save on your gas bill!

Newark, OH


1.0 rating
Very Unsatisfied

I have had to fix it every year since I had it. Turns out the dealer was very unreputable and went out of business soon after installation. I have done all repairs myself and every year I repair something new on it. I would never buy another lennox product ever!



1.0 rating
Very Unsatisfied

Not sure what exact one, but I am for sure it is a g26. 7 years ago my parents had carbon monoxide all through their house due to a heat exchanger cracking and now 7 years later it cracked again and was leaking carbon monoxide again all through the house. So now they have to sit in the cold with no heat until this part comes in, which they haven’t even ordered yet (been 2 days)! Not only do my parents live there but so does my 88 year old grandma and 2 year old niece. Called Lennox corporate and complained because the part is still under warranty but what about the over $500 repair fee that it costs?! Their answer to this was…. That’s your problem not ours..


"Lennox G26"

5.0 rating
Very Satisfied

I live in Charlotte NC and I’ve had a Lennox g26 for 11 years without a single hiccup. Perfectly quiet. It’s mounted in a basement, so it’s at a pretty constant temperature and reasonable humidity. I could see where a unit mounted in an attic could have service life issues here.

Charlotte, NC

"Home owner"

5.0 rating
Very Satisfied

I had a lennox g26 installed in my home 12 years ago and I have been very satisfied with it. I have never had a repair of any kind, I simply replace the filters regularly. This 40,000 btu unit replaced a 120,000 btu unit and though it has longer cycle times, it has never failed to keep us warm.

Other G26 Reviews

Although many HVAC contractors support Lennox products online, some consumer posts reflect disappointment and frustration with the G26. A consumer on diychatroom.com finds the LED diagnostic lights not very useful when trying to diagnose a system error. Simple fixes, consumers say, are made more complicated because the lack of activity on the board.

A conversation thread on ytmag.com highlights repairs, failing components, and hard-to-deal with repairmen. Hvac-talk.com also has many repair questions about the G26. From faulty ignitions to blowing cold air, consumers are unsure how to fix the unit without calling a professional.

Question and Answer


What is the efficiency of the lennox G23Q3/4-100-2


80% AFUE

Lennox G26 Model Numbers

The G26 is available in different models which vary in efficiency and capacity.

Model Number AFUE BTUs per Hour
G26Q2-50* 92.3 50,000
G26Q3-4-100* 92.3 100,000
G26Q3-4-125* 92.3 125,000
G26Q3-50* 92.4 50,000
G26Q3-75* 92.3 75,000
G26Q4-5-100* 92.3 100,000
G26Q4-5-125* 92.3 125,000
G26Q4-5-75* 92.3 75,000

G26 Warranty

The G26 was equipped with Lennox’s basic warranty. The product did not require registration and is automatically eligible for receive a lifetime limited heat exchanger warranty and 5-year limited covered components warranty.

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