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

Questions about this model?

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 1-5 of 15 reviews


5.0 rating
Very Satisfied

19 years old trouble free, I just replaced flame sensor and igniter by myself, mainly because I felt the flame sensor was kicking it off sometimes, it has 2 led lights and trouble code info on manual.


"CO Event and cracked heat exchanger"

1.0 rating
Very Unsatisfied

Thank heaven we added a co detector in our home and I encourage everyone to do the same! Had a co event that required a fire department response to evacuate the home and ventilate to remove dangerous co levels. Gas company said they never saw such high readings from a furnace. Furnace maintained annually by gas company and they were surprised at high levels of co output and internal cracks that leaked. When Lennox contacted they assume no responsibility and claim that any warranty had expired less than 60 days ago. This is a good news story where no one was injured. Who knows what would have happened without a detector. Resulted in a solemn promise by my family never to own a Lennox product again. I would urge you not to buy as well.

New England

"G26 has proven to be reliable"

5.0 rating
Very Satisfied

Had the furnace installed in 2002. The furnace that came with the house was a piece of junk can’t remember the brand but it wasn’t a high efficiency. Only had one issue in 2014 and that was water getting into the blower. I am on a maintenance plan which I think is a good idea for any furnace. We have a 1200 sq. Ft house and the furnace does a good job keeping it warm. I dislike that I can’t operate the blower motor in the summer to help circulate the colder air from the basement. (May be an installation oversight I don’t know). I would buy another Lennox.

Arthur Canada

"No problems"

5.0 rating
Very Satisfied

I got my G26 Lennox furnace installed in 1999 (17 years ago) under the “Pulse Program”, for the tidy sum of $640.00, and have never had a problem with it! Just replaced it due to its age, to insure trouble free service throughout the winter. If this new “Merit Series 14ACX” works as good as the last one, I will be very happy!


"Do you like pain"

1.0 rating
Very Unsatisfied

Run like hell from this Lennox furnace. I’ve got a new born baby in the house and this junk of a furnace is always down. Heat exchanger, pressure switch, induction fan, water leaks and more, except heat. Run like hell from this brand. Again, look at the other reviews and buy another brand unless you like pain, thanks.


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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