Lennox XC21 Central Air Conditioners | FurnaceCompare®

Lennox XC21 Air Conditioner Overview

The Lennox XC21 air conditioner is part of the Dave Lennox Signature Collection. It is Energy Star qualified and bears the Good Housekeeping seal of approval. It is rated for up to 20.5 SEER, which the Lennox company says can save up to $1500 in utility bills in five years when compared to a 10.0 SEER air conditioning unit. Buyers of the XC21 may qualify for a federal tax credit. The unit is equipped with a low-sound fan and a two-stage scroll compressor, which Lennox says is on a low setting the majority of the time, reducing power usage.

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Consumer Reviews of Lennox XC21


  • Very Satisfied
  • Somewhat Satisfied
  • Neutral
  • Somewhat Unsatisfied
  • Very Unsatisfied
  • #3 of 22 Lennox Air Conditioner
  • 57.14% of customers recommended

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Lennox XC21 Air Conditioner Reviews

Showing 16-18 of 18 reviews


1.0 rating
Very Unsatisfied

It hasn't ever worked. If we don't keep the a/c set on 70', it gets so humid in the house you sweat. You can't leave the house with the air above 72' because its like a sauna when you return. The air registers are growing mold. The a/c company that robbed us blind keeps saying the system works fine. I paid $10,000 for this lemon. My old unit would run great between 76' and 78'. My electricity bills have increased instead of decreasing with a "more efficient unit." I would not recommend this unit or any Lennox product to anyone.

M. Faller

Houston, TX

"My lennox air conditioner"

5.0 rating
Very Satisfied

When i was looking for a air conditioner which is highly efficient in cutting down the fuel costs i found this brand – lennox x21.I purchased this air conditioner 3 years back and it is working great since then.What i like the most is that it makes very less noise. My power bill has significantly reduced after i switched to this product. this air conditioner is highly efficient and also has earned energy Star label .While maintaining a cool, low-humidity home environment ,It runs on low level upto 80 % of its time which helps in less power consumption It has 2 levels of settings , one for hot days and the other for milder days.It also Comes with a 10 year warranty on its parts. This Air conditioner also has a self monitor which monitors the performance and helps to report if there are any issues. this Air conditioners can also combined as intergrated systems though I haven't tried yet to do it. I would highly recommend this airconditioner especially for warm areas due to the hot weather for most of the year.

Greensboro , NC

"Lennox two stage xc21 a/c system"

5.0 rating
Very Satisfied

I had a lennox xc21036 a/c system with a variable speed air handler installed 2 years ago. This system provides the best cooling that I have ever had you don't even know it is on most of the time. I replaced a carrier builder model that was only 5 years old that I was having lots of trouble with. and changed contractors (I found a contractor that knows what they are doing) the new construction contractors don't do a very good job of duct sizing and installation this was most of my problems.

tom m

south west florida

Other XC21 Reviews

Online posters have mostly positive things to say about the XC21, especially its high SEER. However, one poster in this online forum thread says the unit was not as efficient as he had hoped. Other posters attribute this to the model being a large one.

One poster in this thread says the XC21 appears to be a good value for its high SEER rating.

Lennox XC21 Model Numbers

The XC21 is available in different models which vary in efficiency and capacity.

Model Number SEER BTUs per Hour
XC21-024 21 24,000
XC21-036 21 36,000
XC21-048 18.2 48,000
XC21-060 16.5 60,000

XC21 Warranty

Lennox covers the XC21 with a 10-year limited warranty on the compressor and all other parts.

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