Lennox pulse furnace logo for identificationLennox Pulse 21 & Lennox G14 Heating Furnace Safety Notice - Heat Exchanger Inspection & Warranty Program

  • Lennox SAFETY WARNING - CONTENTS: Lennox furnace safety notice, heat exchanger leak warning, free heat exchanger inspections. Lennox furnace heat exchanger warranty program applies to furnaces sold in the U.S. & Canada. Furnace recalls, heating system safety notices. Lennox Pulse Furnace Warranty & Press Release. Links to Lennox Pulse Furnace Manuals
  • POST a QUESTION or READ FAQs about the Lennox Pulse furnace warranty & inspection program.

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Lennox pulse furnace safety notices:

This document describes carbon monoxide gas (CO) leak safety hazards on certain models of Lennox hot air heating furnaces and announces a Lennox pulse furnace safety inspection and recall/repair program for these systems.

Lennox Industries Inc., the maker of Lennox Pulse furnaces, announced it has set up a free program to inspect Lennox furnaces installed from 1982 to 1989 to check for carbon monoxide leaks or as the company stated: "because of "increased instances of corrosion in some Pulse furnace heat exchangers in units installed before 1990."

Page top photograph courtesy Arlene Puentes.

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Lennox Furnace Inspection Program and Heat Exchanger Warranty Program

Lennox furnace data tag - safety recall safety inspection noticeAccording to Bob Schjerven, president and chief operating officer for Lennox, dealers reported increased instances of corrosion in some Pulse furnace heat exchangers in units installed before 1990.

[Click to enlarge any image]

As part of the inspection program, Lennox will provide a free AIM Safety carbon monoxide detector.

The Lennox company urges owners of Lennox Pulse furnaces installed between 1982 and 1989 to schedule a furnace and safety check with an independent Lennox dealer.

We agree with other writers who've complimented Lennox for making an effort to honor the warranty on these items when other product manufacturers have disappeared or even been misleading about the hazards involved

For an example see Federal Pacific Electric FPE Panel Hazards

However the Lennox pulse combustion furnace safety inspection program does not appear to be in current operation (as of 2010-2012).

How To contact Lennox about a Pulse Furnace Warranty Question

We've seen a string of non-working contact numbers for Lennox, such as 800-537-4341 900-622-8000. Forget these numbers.

To find a Lennox Dealer near you go to and enter your zip code in the box at the web page upper right corner, OR
use the links to Lennox at the left side of this web page (supplied by Google). Contact information details for Lennox Corporation and links to some Lennox heating equipment manuals are provided

The Lennox Pulse furnace safety inspection is (or was) free, but if the furnace has to be cleaned in order to be inspected, the customer could be charged for the cleaning.

How to Identify a Lennox Pulse Furnace that May Need a Safety Inspection

Pulse 21 Name on the Furnace Access Door: To identify a Pulse furnace, look for its name on the door. If the unit is a Pulse 21 furnace, it was manufactured after 1990 and is not part of the inspection program.

For those with Lennox furnaces without the Pulse 21 name, the next step is to remove the front door and look for the name tag. These tags are usually placed on the inside cabinet wall on the left side of the furnace.

Locate the model number on the furnace data tag (either G14 or GSR14 followed by a series of numbers and letters) and the serial number on a tag below the name tag. The photo above [courtesy Arlene Puentes] shows a model number starting G14....

Homeowners who call the 800 number with the information will be told if their furnace is eligible for this inspection program.

The original Lennox furnace safety inspection program ran through July 1, 1999. If the warranted heat exchanger needed replacing, Lennox indicated that the company would provide a new heat exchanger at no cost to the owner. Labor costs for replacement parts are not part of the Pulse furnace warranty.

Owners of Lennox furnaces in this series who discover this fact after July 1, 1999 should still have the furnace heat exchanger inspected for safety, regardless of whether a new heat exchanger will be provided under warranty. A "rusty" heat exchanger, or one which has a rust hole or crack may be unsafe and risks leaks of dangerous, even potentially fatal carbon monoxide (CO) flue gas.

See HEAT EXCHANGER LEAKS for more information about heat exchanger leaks and furnace safety and

see CARBON MONOXIDE GAS TOXICITYfor information about carbon monoxide.

Re inspect Lennox Pulse Furnaces Every Four Years

Some Lennox installers (and possibly the company too) recommend any Lennox Pulse furnace still in use be pressure tested every 4 years.  This almost never happens and in our opinion a visual inspection or other simpler tests of heat exchanger safety are much less reliable. Therefore, unless you are provided with pressure test information at the time of a home inspection where a Lennox Pulse Furnace has been installed, you should ALWAYS recommend a pressure test by a Lennox trained technician, and a consultation with the Lennox dealer to determine the status of the warranty of the furnace. [Thanks to Roger Hankey for this tip.]

More details:

Lennox published this Service and Application Notes Feb. 1,2001, re-issued Nov. 3, 2003.

With the supply of replacement heat exchangers exhausted, a new G51MP furnace will be furnished to satisfy the remaining portion of the warranty. Just as the warranty does not cover labor and shipping of the G51MP is not covered.

If the homeowner wishes to upgrade to another Lennox furnace, the homeowner will be responsible for the cost difference between the two furnaces. The dealer is to order the upgrade furnace and will receive credit on the G51MP furnace only. In order to process a warranty claim of this type, the Lennox dealer must complete the attached form and have it signed by the homeowner.

According to Lennox procedure (#503594M, dated 11/97) a Lennox Pulse Furnace heat exchanger pressure test requires the heat exchanger assembly to be first plugged and then pressurized to determine if it can hold 4 psi pressure for 10 minutes. If not the heat exchanger is considered leaky and could be unsafe.

The Original Lennox Pulse Furnace Press Release is given Below

Original appearance at: Pulse Inspection Program Hotline 1-800-537-4341 [OBSOLETE NUMBER}

Lennox Heats Up Call For Consumers To Schedule Furnace Inspections - Sep 10, 1997

(DALLAS) -- Lennox Industries officials said that with cooler temperatures approaching, it is urgent that owners of Lennox Pulse furnaces installed before 1990 have those furnaces inspected.

Lennox, one of North America's leading residential and commercial heating and air conditioning equipment companies, will continue its Pulse furnace inspection program which began in April, 1997 and has already garnered over 25,000 consumer calls. The inspection program is a response to dealer reports of increased instances of corrosion in some Pulse furnace heat exchangers in units installed before 1990.

With all high-efficiency condensing furnaces, a combination of factors -- such as impurities in fuel or combustion air -- can cause corrosion of key components which could lead to potentially dangerous leaks. Furnaces which are inadequately inspected or improperly maintained can develop problems, including the possibility of carbon monoxide leaks that could be fatal.

According to Bob Schjerven, president and chief operating officer for Lennox Industries Inc., "Consumer response to the Pulse furnace inspection program has been terrific, but we need to reach everyone. We're urging all Pulse furnace owners, before they turn their thermostats from cool to heat, to call our 800 number and schedule a furnace inspection and a safety check with an independent Lennox dealer."

With each inspection, trained service technicians will perform the recommended 17-point Pulse furnace service check, conduct a visual inspection, and complete a pressure test of the unit's lifetime warranted heat exchanger. While Lennox is subsidizing participation in the inspection program, there may still be some cost to Pulse owners. Factors such as the location of the furnace, the condition of the furnace, and service unrelated to the inspection will determine the actual cost of the inspection.

If the warranted heat exchanger needs replacing, Lennox will provide a new heat exchanger at no cost to the owner. While labor costs for replacements are generally not part of the Pulse furnace warranty, Lennox will pay a reasonable allowance to the dealer for installation costs as part of this inspection program. There may be some costs to the owner, depending on the area of the country, type of installation, work required by local code requirements, and any other service required not related to the heat exchanger.

For those owners whose pre-1990 Pulse furnace has a heat exchanger which requires replacement, Lennox will provide, through the local independent Lennox dealer and at the owner's option, a $400 rebate on a new Lennox Pulse furnace. The Pulse furnace inspection program runs through July 1, 1999.

Lennox will also provide a free AIM Safety carbon monoxide detector, one of the highest quality detectors available, as part of the inspection program.

"Lennox has long been involved in a consumer carbon monoxide awareness program unrelated to this Pulse furnace inspection," explains Schjerven. "Since currently there is no device on the market that effectively shuts a furnace down if there is a carbon monoxide leak, it is important to install a carbon monoxide detector as a safeguard, in addition to annual maintenance and inspections."

Scheduling inspections: Homeowners can schedule a furnace inspection and safety check with an independent Lennox dealer by calling 1-800-537-4341. For convenience, the 800 number is staffed 24 hours a day, seven days a week. A Pulse furnace can be identified by its name on the door.

To determine whether your Pulse furnace should be inspected under this program:

1. Check for the Pulse name on the door. If the unit is a Pulse 21 furnace, it was manufactured after 1990 and is not part of this inspection program. However, as with all furnaces, annual inspections are still required.

2. Otherwise, remove the front door and look for the product identification stickers. These stickers are usually placed on the inside cabinet wall on the left side of the furnace.

3. Write down the model number that appears on the sticker (either G14 or GSR14, followed by a series of numbers and letters).

4. Write down the serial number on the product identification sticker (four numbers, followed by a letter, then five more numbers).

5. Call 1-800-537-4341 and have the model number and serial number ready.

All Furnaces Need Yearly Inspection

To maintain safety, efficiency, and reliability, Lennox recommends owners have their heating systems inspected at least once a year. The owner can extend the life of the furnace and help stop inefficient combustion and leaks, which could result in serious injuries, by:

1. Inspecting the filter monthly. Dirty filters can cause inefficient operation and could result in premature heat exchanger failure.

2. Watching for leaks and signs of deterioration. If found, call a certified service technician.

3. Insisting on a combustion efficiency test as part of the annual inspection.

Founded in 1895, Lennox Industries Inc. is an international manufacturer of air conditioning and heating equipment for residential and commercial applications. The company markets its products through a network of over 5,000 independent dealers.

Lennox Contact Information, Manuals, Safety Checklist

Contact Information for the Lennox Corporation is listed here

To assure that you have the latest and most accurate service manual or user's manual for your heating equipment we recommend checking with the manufacturer. Contact information for Lennox industries, in Dallas Texas:

Lennox Corporation
2100 Lake Park Blvd.
Richardson, TX 75080
P.O. Box 799900
Dallas, TX 75379-9900

1-800-9-LENNOX (1-800-953-6669)

To find a Lennox Dealer near you go to and enter your zip code in the box at the web page upper right corner, OR use the links to Lennox at the left side of this web page (supplied by Google).

To request Lennox product literature, you can also write to Lennox Consumer Affairs, P.O. Box 799900, Dallas, TX 75379 - but primarily the company sends product brochures, not technical manuals, from this contact point.

Free, downloadable Lennox Pulse Furnace User's Manuals and Service Manuals are listed

Lennox Pulse Furnace Inspection Checklist - 17 Furnace Inspection Safety Inspection Points

Here are seventeen inspection points suggested for Lennox Pulse Furnaces. If a simple visual inspection of your Lennox pulse furnace (or any other heating appliance) shows evidence of leaks, corrosion, or if the system is making strange noises or odors, call your heating service technician promptly as the equipment could be unsafe. Be sure that the building has working carbon monoxide detectors properly located and installed, especially where gas-fired heating equipment is in use.

1. Inspect the Lennox pulse furnace combustion air intake and exhaust PVC for condensate leaks and/or joint separations. Repair as necessary.

2. Inspect Lennox pulse furnace air diaphragm flapper material for dirt or deterioration and replace, if necessary. Air flapper material must be replaced every four years regardless of appearance.

3. Inspect Lennox pulse furnace purge blower for dirt build-up every year and clean, as necessary.

4. Inspect Lennox pulse furnace gas flapper material for dirt or deterioration. Replace entire assembly if flapper material is found to be worn.

5.Check the furnace combustion supply air blower wheel and clean, as necessary.

6. Inspect secondary heat exchanger for dirt build-up and clean, as necessary. Blower must be removed to do this check

7. Inspect Lennox pulse furnace heat exchanger assembly for any signs of corrosion or leakage. An air pressure test has been performed on the heat exchanger and exhaust venting system

8. Check all wiring for loose connections on the Lennox pulse furnace. Check for correct voltage.

9. Inspect stainless steel flexible gas connector for corrosion. Remember - Some soaps used for leak testing are corrosive to stainless steel. Failure to thoroughly rinse gas connector after leak check can lead to corrosion.

10. Inspect intake and exhaust pipe terminations to make sure they are free from obstruction.

11. Check the Lennox pulse furnace supply and manifold gas pressure. Adjust pressure, as necessary.

12. Check furnace firing rate by clocking gas meter.

13. Test oxygen/carbon dioxide level of flue gas to determine if proper combustion is taking place. For operating ranges, consult charts provided with testing instrument or unit information manual.

14. Test the Lennox pulse furnace exhaust carbon monoxide levels in flue gas. Level should never exceed 50PPM.

15. Check Lennox pulse furnace operating temperature rise and make sure proper speed is selected to match nameplate rating.

16. Check Lennox pulse furnace fan and limit controls for proper operation and setting.
(Refer to installation instructions)

17. Inspect Lennox pulse furnace condensate lines for free flow of condensate during operation.


Continue reading at HEAT EXCHANGER LEAK TEST or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.

Or see SAFETY RECALLS Chimneys, Vents, Heaters




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