Furnace not heating

Lennox furnace not heating? Read the code for your model

Stop first: these are not a code to look up

If you smell gas

Leave the building now. Do not touch light switches or use a phone inside. From outside, call your gas supplier, or the fire department if you cannot reach them.

Lennox's own words:

"WHAT TO DO IF YOU SMELL GAS:"
"Do not try to light any appliance."
"Do not touch any electrical switch; do not use any phone in your building."
"Leave the building immediatly"
"Immediately call your gas supplier from a neighbor’s phone. Follow the gas supplier’s instructions."
"If you cannot reach your gas supplier, call the fire department."

Lennox, User's Information Manual, EL296DFV, 506771-01 (07/2018), page 1

If a carbon monoxide (CO) alarm is sounding, or someone feels sick

Get everyone outside into fresh air now, then call 911 or the fire department from outside.

The U.S. Consumer Product Safety Commission's words (none of the furnace makers' documents held here prints what to do when a CO alarm sounds):

"Never ignore an alarming CO alarm! It is warning you of a potentially deadly hazard."
"If the alarm signal sounds do not try to find the source of the CO:"
"Immediately move outside to fresh air."
"Call your emergency services, fire department, or 911."
"After calling 911, do a head count to check that all persons are accounted for. DO NOT reenter the premises until the emergency services responders have given you permission. You could lose consciousness and die if you go in the home."
"If the source of the CO is determined to be a malfunctioning appliance, DO NOT operate that appliance until it has been properly serviced by trained personnel."

U.S. Consumer Product Safety Commission, Carbon Monoxide Fact Sheet, "What should you do when the CO alarm sounds?" (fetched 2026-09-24), page 1

If you see flame while the thermostat is not calling for heat

This is a stop condition. Do not reset or restart the furnace. Call a technician or your gas supplier now.

Lennox's own words:

"If overheating occurs or if gas supply fails to shut off, shut off the manual gas valve to the appliance before shutting off electrical supply.."

Lennox, ML180UHE installation instructions, 507103-04, page 28

If a reset button on the furnace tripped again after it was pushed

Do not push it again. Call a technician.

Answer the safety questions first. Then pick the brand, say what you see on the furnace without opening it, and give the model. The code is read from the table Lennox prints for that model's board, and quoted with its page. Nothing here asks you to open the furnace.

Field brief

Stop first a gas smell, a carbon monoxide alarm, flame while the thermostat is not calling for heat, or a reset button that trips again after it was pushed: each is answered at the top of this page, before any code. before any code

The code, by model read only from the table Lennox prints for your model's board, quoted with its edition and page. The documents held here for Lennox: 24. 24 documents

No reset step this page gives no reset or repair step, and nothing here asks you to open the furnace. A maker's reset words are shown only as the manual's words for a technician. manual's words only

01Source
receipt

Where these stop lines and code meanings come from

This page does not guess why a furnace is not heating. It asks the stop questions first. Then it reads a blinking light or a code only from the table the maker printed for that model's board, quoted with its edition and page from a copy held here and listed below with the md5 of that copy. The same count of blinks can mean different things on two boards from one maker, so the key is always the document and the series it is printed for, never the code number alone.

The stop questions, and whose words they are: The stop conditions are printed at the top of the page itself, above the check, and the check asks its 4 stop questions before anything else: "Do you smell gas, at the furnace or anywhere in the home?" "Is a carbon monoxide (CO) alarm sounding, or does anyone in the home feel sick in a way that could be carbon monoxide?" "Can you see flame in the furnace while the thermostat is not calling for heat?" "Did a reset button on the furnace trip again after someone pushed it?" The action line under each is this page's own. Beside it, the family's own maker is quoted where a document held here prints the words: a "what to do if you smell gas" box for 9 of the 10 families (none is held for Armstrong Air, AirEase, Ducane and Concord), and the order to shut the gas off before the power, as each of York, Goodman, Lennox, Rheem, Trane and Nordyne prints it. None of the furnace makers' documents held here prints what to do when a carbon monoxide alarm sounds, so that line quotes the U.S. Consumer Product Safety Commission: its Carbon Monoxide Fact Sheet, "What should you do when the CO alarm sounds?" (fetched 2026-09-24).
The makers' code tables, by furnace family: 153 documents from 12 makers, across the 10 furnace families this page reads. Each is named by the series it is printed for, with the edition it prints and the md5 of the copy held here. The list carries no links: what is held is a copy, and its address is recorded rather than republished.
York, Luxaire, Coleman and Champion14 documents
Not held for this family, so the page says so rather than guessing: York's newest lines (Z8, Z9, Y8, Y9, RL18, RG19): only their owner's manual's few light states are held, not the board's code table; 80% modulating models; Guardian and Fraser-Johnston furnaces.
York
Printed for 33 in. multi-position furnaces (TM, TL, TG, RGF, P9C, PLC)1010352-UUM-N-0121 (Copyright 2021 by Johnson Controls; Supersedes: 1010352-UUM-M-0120) · md5 f72f3e8f
An owner's manual's light states, read only where no board table held here admits the model. Which brands it speaks for is inferred rather than printed, so the page says a code is printed for this series and does not name a brand.
Printed for 33 in. multi-position furnaces (Y8/Z8, Y9/Z9, RL18, RG19)6100761-UUM-C-1124, Supersedes: 6100761-UUM-B-0423, dated 2024-11-04, Copyright 2024 by Johnson Controls · md5 84429a67
An owner's manual's light states, read only where no board table held here admits the model. Which brands it speaks for is inferred rather than printed, so the page says a code is printed for this series and does not name a brand.
Printed for DGAA/DGAH5165697-BUM-C-0818 (Supersedes: 5165697-BUM-B-1216) · md5 6cc137ba
Which brands it speaks for is inferred rather than printed, so the page says a code is printed for this series and does not name a brand.
Printed for TL8E/RUF186767341-UIM-A-0426, dated 2026-04-01, Supersedes: Nothing · md5 9657dfc3
Printed for TL9E5894307-UIM-B-0920 (Supersedes: 5894307-UIM-A-0320) · md5 7ecea3d7
Printed for TM8E5594752-UIM-B-0419 (Supersedes: 5594752-UIM-A-0119) · md5 bed94d2f
Printed for TM8V1034867-UIM-D-0616 (Supersedes: 1034867-UIM-C-0615) · md5 914a8d93
Printed for TM8Y5052632-UIM-D-0217 (Supersedes: 5052632-UIM-C-0616) · md5 f38f2c82
Printed for TM9E6019630-UIM-F-0423 (Copyright 2023 by Johnson Controls; Supersedes: 6019630-UIM-E-1122) · md5 4baedf18
Printed for TM9V5402851-UIM-A-0917 (Supersedes: 1083294-UIM-I-0817) · md5 38ce16ea
Printed for TM9V5750149-UIM-D-1219 (Supersedes: 5750149-UIM-C-1019) · md5 f4c9c1dd
It prints the same code table as another document held for this family, and that table is read for it, less any code this one does not print.
Printed for TM9Y5052617-UIM-G-0817 · md5 493a9725
It prints the same code table as another document held for this family, and that table is read for it, less any code this one does not print.
Printed for TM9Y5750144-UIM-D-1219 (Supersedes: 5750144-UIM-C-1019) · md5 f588a550
Printed for YP9C/CP9C/LP9C/TP9C1083292-UIM-F-1116 (Supersedes: 1083292-UIM-E-1016) · md5 2d3b3d57
Tempstar, Heil, Comfortmaker, Day & Night, KeepRite and Arcoaire15 documents
Not held for this family, so the page says so rather than guessing: the older Series A F/G96, F/G97 and F/G95 furnaces (most units in the field): their code tables are not held, and the Series B tables are not used for them.
ICP
Printed for F/G80VTL (Series B)FG80VTL2-01SI, Edition Date 06/23 (replaces FG80VTL-01SI) · md5 25eb2bb1
Printed for F/G95CSU (Series B)FG95CSU2-04SI, Edition Date 7/26 (replaces FG95CSU2-03SI) · md5 d9e453c6
Printed for F/G96CTN (Series B)FG96CTN2-03SI, Edition Date 7/26 (replaces FG96CTN2-02SI) · md5 7ee579cd
Printed for F/G96VTN (Series B)FG96VTN2-03SI, Edition Date 7/26 (replaces FG96VTN2-02SI) · md5 a18ad394
Printed for F/G97CMN (Series B)FG97CMN2-04SI, Edition Date 7/26 (replaces FG97CMN2-03SI) · md5 9687e81f
Printed for F/G9MXE440 04 4311 12, 10/15/2018 · md5 54d3d71d
An earlier line. It prints the same code table as another document held for this family, and that table is read for it, less any code this one does not print. Which brands it speaks for is inferred rather than printed, so the page says a code is printed for this series and does not name a brand.
Printed for N80MSN/N80MSLN80MSNL2-01SI, Edition Date 06/23 (replaces N80MSNL2-01SI REV A) · md5 b8a7181f
Printed for N80VSL (B series)N80VSL2-01SI, Edition Date 03/23 (replaces NEW) · md5 a6954e0b
Printed for N92MSNN92MSN2-03SI · md5 108d3578
It prints the same code table as another document held for this family, and that table is read for it, less any code this one does not print.
Printed for N95MSUN95MSU-03SI, Edition Date 7/26 (replaces N95MSU-02SI) · md5 9bb0454c
Printed for N96MSNN96MSN-03SI, Edition Date 7/26 (replaces N96MSN-02SI REV E) · md5 b37fcf85
Printed for N96VSN (amber light board)440 01 5200 00 REV D, Edition Date 06/23 (replaces REV C) · md5 9261004a
An earlier line.
Printed for N96VSN (Series B)N96VSN2-03SI, Edition Date 7/26 (replaces N96VSN2-02SI) · md5 dd366363
It prints the same code table as another document held for this family, and that table is read for it, less any code this one does not print.
Printed for N9MSE440 04 4402 07, 10/15/2018 · md5 028f5dc1
An earlier line. Which brands it speaks for is inferred rather than printed, so the page says a code is printed for this series and does not name a brand.
Printed for R96MSNR96MSN-03SI · md5 97237996
It prints the same code table as another document held for this family, and that table is read for it, less any code this one does not print.
Carrier, Bryant and Payne28 documents
Not held for this family, so the page says so rather than guessing: Carrier 59TN7, 58TN and the low-NOx models without their own manual; Bryant 987T, 927T, 810S, 830, 880 and 935; Payne PG97VTA, PG95MSU and PG80VTL; codes shown on an Infinity or Evolution wall control.
Bryant
Printed for 800SBEdition Date: 06/23, Catalog No: II800SB-01 REV B, Replaces: II800SB-01 REV A · md5 30c14a4d
It prints the same code table as another document held for this family, and that table is read for it, less any code this one does not print.
Printed for 820SAEdition Date: 08/21, Catalog No: II820SA-02 REV A, Replaces: II820SA-02 · md5 00abf8a6
It prints the same code table as another document held for this family, and that table is read for it, less any code this one does not print.
Printed for 820TAEdition Date: 08/21, Catalog No: II820TA-03 REV A, Replaces: II820TA-03 · md5 a3d5ffe8
It prints the same code table as another document held for this family, and that table is read for it, less any code this one does not print.
Printed for 912SEEdition Date: 07/26, Catalog No: II912SE-03, Replaces: II912SE-02 · md5 bb71df19
It prints the same code table as another document held for this family, and that table is read for it, less any code this one does not print.
Printed for 915SBEdition Date: 12/25, Catalog No: II915SB-05, Replaces: II916SA-04 REV D (sic, as printed on p74) · md5 3275d6dc
An earlier line.
Printed for 916SAEdition Date: 7/26, Catalog No: II916SA-03, Replaces: II916SA-02 REV E · md5 153010ef
It prints the same code table as another document held for this family, and that table is read for it, less any code this one does not print.
Printed for 926SAEdition Date: 06/23, Catalog No: II926SA-01 REV D, Replaces: II926SA-01 REV C · md5 cba26e57
It prints the same code table as another document held for this family, and that table is read for it, less any code this one does not print.
Printed for 926TCEdition Date: 7/26, Catalog No: II926TC-03, Replaces: II926TC-02 · md5 95051110
It prints the same code table as another document held for this family, and that table is read for it, less any code this one does not print.
Printed for 986TCEdition Date: 06/23, Catalog No: II986TC-01 REV D, Replaces: II986TC-01 REV C · md5 2bb70e9a
Printed for 987MCEdition Date: 7/26, Catalog No: II987MC-04, Replaces: II987MC-03 · md5 889a06c7
It prints the same code table as another document held for this family, and that table is read for it, less any code this one does not print.
Carrier
Printed for 58SB0AEdition Date: 08/21, Catalog No: 58SB0A-05SI REV B · md5 fb56ead5
An earlier line. It prints the same code table as another document held for this family, and that table is read for it, less any code this one does not print.
Printed for 58SB0BEdition Date: 06/23, Catalog No: 58SB0B-01SI REV B, Replaces: 58SB0B-01SI REV A · md5 d6c50626
Printed for 58SC0AEdition Date: 09/21, Catalog No: 58SC0A-05SI REV B, Replaces: 58SC0A-05SI REV A · md5 9da2e9e2
Printed for 58SP0AEdition Date: 08/21, Catalog No: 58SP0A-02SI REV A, Replaces: 58SP0A-02SI · md5 fe7c4644
Printed for 58TP0AEdition Date: 08/21, Catalog No: 58TP0A-03SI REV A, Replaces: 58TP0A-03SI · md5 b8d54a84
Printed for 59MN7CEdition Date: 7/26, Catalog No: 59MN7C-04SI, Replaces: 59MN7C-03SI · md5 c979df0f
Printed for 59SC2EEdition Date: 07/26, Catalog No: 59SC2E-03SI, Replaces: 59SC2E-02SI · md5 2b7f2f23
It prints the same code table as another document held for this family, and that table is read for it, less any code this one does not print.
Printed for 59SC5BEdition Date: 06/23, Catalog No: 59SC5B-04SI REV E, Replaces: 59SC5B-04SI REV D (p68) · md5 6adfb5c7
An earlier line.
Printed for 59SC6AEdition Date: 06/23, Catalog No: 59SC6A-01SI REV D · md5 43e4db42
An earlier line. It prints the same code table as another document held for this family, and that table is read for it, less any code this one does not print.
Printed for 59SC6AEdition Date: 7/26, Catalog No: 59SC6A-03SI, Replaces: 59SC6A-02SI REV E · md5 14d88e69
Printed for 59SP6AEdition Date: 06/23, Catalog No: 59SP6A-01SI REV D, Replaces: 59SP6A-01SI REV C · md5 0aee4476
Printed for 59TN6CEdition Date: 7/26, Catalog No: 59TN6C-04SI, Replaces: 59TN6C-03SI · md5 a8ae6e1b
Printed for 59TP6CEdition Date: 7/26, Catalog No: 59TP6C-03SI, Replaces: 59TP6C-02SI · md5 40b21bff
Printed for 59TP7AEdition Date: 7/26, Catalog No: 59TP7A-03SI, Replaces: 59TP7A-02SI · md5 54e14eb7
It prints the same code table as another document held for this family, and that table is read for it, less any code this one does not print.
Printed for PG80MSAEdition Date: 06/26, Catalog No: IM-PG80MSAA-02, Replaces: IM-PG80MSAA-01 REV B · md5 d180ccb4
It prints the same code table as another document held for this family, and that table is read for it, less any code this one does not print. Which brands it speaks for is inferred rather than printed, so the page says a code is printed for this series and does not name a brand.
Printed for PG92MSAEdition Date: 08/26, Catalog No: IM-PG92MSAA-04, Replaces: IM-PG92MSAA-02 · md5 9f5a2d52
It prints the same code table as another document held for this family, and that table is read for it, less any code this one does not print. Which brands it speaks for is inferred rather than printed, so the page says a code is printed for this series and does not name a brand.
Printed for PG96MSAEdition Date: 08/26, Catalog No: IM-PG96MSAA-03, Replaces: IM-PG96MSAA-02 REV E · md5 62778474
It prints the same code table as another document held for this family, and that table is read for it, less any code this one does not print. Which brands it speaks for is inferred rather than printed, so the page says a code is printed for this series and does not name a brand.
Printed for PG96VTABEdition Date: 7/26, Catalog No: IM-PG96VTAB-03, Replaces: IM-PG96VTAB-02 · md5 88436bc4
Which brands it speaks for is inferred rather than printed, so the page says a code is printed for this series and does not name a brand.
Goodman, Amana and Daikin29 documents
Not held for this family, so the page says so rather than guessing: *R9T96, *RVM97, *R9S96-U and Daikin DR97MC: no maker-hosted manual is held; older GMSS96, GMH8, GME8, GMH95, GMVC95 and GM9C80 furnaces.
Daikin
Printed for DM80VCIOD-2012H 06/2023 · md5 5110843c
An earlier line.
Printed for DM96HSRSD6612011r5 October 2017 · md5 38d02064
An earlier line.
Printed for DM96SNIOD-2029A 02/2022 · md5 998a5d2b
An earlier line. Which brands it speaks for is inferred rather than printed, so the page says a code is printed for this series and does not name a brand. 2 codes it prints are refused here, each with its reason when it is typed.
Printed for DM96VCIOD-2008N 02/2022 · md5 967bd65e
An earlier line.
Printed for DM97MCIOD-2007Q 08/2024 · md5 392c2fbc
An earlier line.
Printed for DR80TCIOD-2043 03/2024 · md5 c1eddb4f
3 codes it prints are refused here, each with its reason when it is typed.
Printed for DR96TCIOD-2044 04/2024 · md5 2fb754a8
3 codes it prints are refused here, each with its reason when it is typed.
Printed for DR96TNIOD-2038A 09/2023 · md5 63258f44
2 codes it prints are refused here, each with its reason when it is typed.
Printed for DR96TNRSD6612304 May 2024 · md5 6d896f8c
2 codes it prints are refused here, each with its reason when it is typed.
Goodman
Printed for *M9S80*UIOG-2031 09/2021 · md5 b588920e
An earlier line. 2 codes it prints are refused here, each with its reason when it is typed.
Printed for *M9S96IOG-2029A 02/2022 · md5 5ffad3cb
An earlier line. 2 codes it prints are refused here, each with its reason when it is typed.
Printed for *M9S96*UIOG-2032 09/2021 · md5 dbc91a00
An earlier line. 2 codes it prints are refused here, each with its reason when it is typed.
Printed for *R9S80IOG-2035C 07/2025 · md5 ac968651
2 codes it prints are refused here, each with its reason when it is typed.
Printed for *R9S80*UIOG-2039B 01/2024 · md5 721b3e8c
2 codes it prints are refused here, each with its reason when it is typed.
Printed for *R9S96IOG-2037A 09/2023 · md5 ebacff9a
2 codes it prints are refused here, each with its reason when it is typed.
Printed for *R9T80IOG-2036B 12/2024 · md5 eb80f524
2 codes it prints are refused here, each with its reason when it is typed.
Printed for *RVS80IOG-2041 04/2024 · md5 6d3d62a1
2 codes it prints are refused here, each with its reason when it is typed.
Printed for *RVS80*URS6621303r1 October 2025 · md5 91412adc
2 codes it prints are refused here, each with its reason when it is typed.
Printed for *RVS96IOG-2042 04/2024 · md5 d3d2e60f
2 codes it prints are refused here, each with its reason when it is typed.
Printed for *RVT80IOG-2043 03/2024 · md5 a2b03b83
3 codes it prints are refused here, each with its reason when it is typed.
Printed for *RVT96IOG-2044 03/2024 · md5 fe99f4b0
3 codes it prints are refused here, each with its reason when it is typed.
Printed for GM9C96RS6612020r1 March 2023 · md5 00b80215
An earlier line. 2 codes it prints are refused here, each with its reason when it is typed.
Printed for GM9S80RS6621008 July 2021 · md5 3a7ca2ff
An earlier line. 2 codes it prints are refused here, each with its reason when it is typed.
Printed for GMEC96RS6612013r10 June 2020 · md5 a7e13fcb
An earlier line. One code it prints is refused here, each with its reason when it is typed.
Printed for GMES80*U*RS6621006r2 June 2020 · md5 fe8e876b
An earlier line.
Printed for GMS8RS6612006r7 November 2017 · md5 83b439cc
An earlier line.
Printed for GMVC80RS6621004r3 October 2020 · md5 071570c2
An earlier line. 2 codes it prints are refused here, each with its reason when it is typed.
Printed for GMVC96RS6612010r6 November 2017 · md5 3a550580
An earlier line.
Printed for GMVM97RS6612015r3 April 2019 · md5 13221125
An earlier line. 2 codes it prints are refused here, each with its reason when it is typed.
Lennox24 documents
Not held for this family, so the page says so rather than guessing: the ML297V; Lennox furnaces from before about 2017; codes shown only on a Lennox communicating thermostat.
Lennox
Printed for EL180UHNE508545-01, 12/2025 · md5 dba2dd93
Printed for EL195UHNE507758-05, 04/2024, supersedes 01/2023 · md5 011bbce7
Printed for EL196UHE507764-06, 04/2024, supersedes 03/2024 · md5 42ec0093
Printed for EL280UHECorp 1901-L1, 04/2024 · md5 18118979
Printed for EL280UHEK100168 (no date on p1) · md5 b7951d1f
One code it prints is refused here, each with its reason when it is typed.
Printed for EL296UHECorp 1246-L10, Revised 08/2023 · md5 1b8ba51c
Printed for EL297UHEK100170 (no date on p1) · md5 6e22a35a
One code it prints is refused here, each with its reason when it is typed.
Printed for EL297UHV100088, 04/2024 · md5 5d49dffa
One code it prints is refused here, each with its reason when it is typed.
Printed for ML180UH507323-01, 07/2018, supersedes 11/2017 · md5 343a83c9
An earlier line. One code it prints is refused here, each with its reason when it is typed.
Printed for ML180UHE507103-04, 04/2024, Supersedes 02/2023, (c) 2024 Lennox Industries Inc. · md5 dacc4399
Printed for ML180UHV507945-02, 04/2024, supersedes 08/2023 · md5 f23083fd
Printed for ML180UHVK100166 (no date on p1) · md5 48a64cd7
One code it prints is refused here, each with its reason when it is typed.
Printed for ML193UHE507863-02, 04/2024, supersedes 03/2024 · md5 4151ee56
Printed for ML193UHECorp 1905-L1, 04/2024 · md5 83c818b5
Printed for ML196UHE507966-04, 04/2024, supersedes 03/2024 · md5 1b225751
Printed for ML296UHV507869-04, 04/2024, supersedes 10/2023 · md5 c68b68a5
Printed for ML296UHVK508520-01, 06/2026 · md5 a0814c24
One code it prints is refused here, each with its reason when it is typed.
Printed for SL280UHNV507649-01, 10/2017 · md5 1d6bb313
One code it prints is refused here, each with its reason when it is typed.
Printed for SL280UHNVK508561-01, 04/2026 · md5 1930909b
One code it prints is refused here, each with its reason when it is typed.
Printed for SL280UHV508245-01, 04/2024, supersedes 09/2022 · md5 06c951fe
One code it prints is refused here, each with its reason when it is typed.
Printed for SL297UHNV507760-02, 02/2018, supersedes 507760-01 · md5 18ac8775
One code it prints is refused here, each with its reason when it is typed.
Printed for SLP99UHV100001, 07/2024 · md5 ec326864
6 codes it prints are refused here, each with its reason when it is typed.
Printed for SLP99UHV507999-02, 04/2024, supersedes 03/2024 · md5 0968a2df
6 codes it prints are refused here, each with its reason when it is typed.
Printed for SLP99UHVK508587-02, 10/2025 · md5 4419d185
2 codes it prints are refused here, each with its reason when it is typed.
Armstrong Air, AirEase, Ducane and Concord17 documents
Not held for this family, so the page says so rather than guessing: the A98MVK and A962E, and the Ducane 97G2VK; Armstrong, AirEase and Ducane lines from before about 2019; no Allied owner's manual is held, so no Allied owner wording is quoted.
Allied Air
Printed for 96G2UHV507961-02, Issue 2302 · md5 23cbe2e8
An earlier line.
Printed for A80UH507324-01, Issue 1907 · md5 d14ae184
An earlier line.
Printed for A80UH1E507330-03, Issue 2128 · md5 4153fea4
An earlier line.
Printed for A80UH1EK508607-01, Issue 2503 · md5 fab624e0
Printed for A80UH2EK508610-01, Issue 2548 · md5 78f92a47
Printed for A80US2V508249-01, Issue 2205 · md5 f9668545
An earlier line.
Printed for A80US2VK508612-01, Issue 2545 · md5 004c417e
One code it prints is refused here, each with its reason when it is typed.
Printed for A93UH1E507867-02, Issue 2304 · md5 f909b3ea
An earlier line.
Printed for A93UH1EK508616-01, Issue 2629 · md5 66692fd9
One code it prints is refused here, each with its reason when it is typed.
Printed for A95UH1E507276-06, Issue 2304 · md5 761f9f8f
An earlier line.
Printed for A96UH1E508297-01, Issue 2304 · md5 da713975
An earlier line.
Printed for A96UH1EK508618-01, Issue 2629 · md5 5726a3ba
One code it prints is refused here, each with its reason when it is typed.
Printed for A96US2V508250-01, Issue 2234 · md5 60b82676
An earlier line.
Printed for A97UH2EK508621-01, Issue 2629 · md5 de3eeab6
Printed for A97US2V508362-01, Issue 2336 · md5 ace14dcf
An earlier line.
Printed for A97US2VK508623-01, Issue 2629 · md5 8a4f05af
One code it prints is refused here, each with its reason when it is typed.
Printed for A97USMV507028-05, Issue 2241 · md5 97016839
An earlier line.
Rheem6 documents
Not held for this family, so the page says so rather than guessing: Ruud: no document held names a Ruud furnace, so no Ruud code is decoded; Rheem's current Endeavor models (R951T, R951V, R921T, R962V, R972V, R97MV, R98MV, R802V): Rheem's own document library stops in December 2017; Rheem 80% furnaces other than the R801T.
Rheem
Printed for R801T92-24161-144-12, SUPERSEDES 92-24161-144-11 · md5 21a46393
An earlier line. One code it prints is refused here, each with its reason when it is typed.
Printed for R92T92-24161-154-03, SUPERSEDES 92-24161-154-02 · md5 e391a5fe
An earlier line.
Printed for R95T92-24161-120-16, SUPERSEDES 92-24161-120-15 · md5 b77ea171
An earlier line.
Printed for R96T92-24161-157-04, SUPERSEDES 92-24161-157-03 · md5 2c1a2805
Printed for R96V92-24161-124-12, SUPERSEDES 92-24161-124-11 · md5 9192ee4d
An earlier line.
Printed for R97V92-24161-126-04 · md5 2e56c72d
An earlier line.
Bosch4 documents
Not held for this family, so the page says so rather than guessing: Bosch BGS96 and 80% furnaces.
Bosch
Printed for BGH96 (flash board)3124627, 04.2020 (before Rev B) · md5 031fce26
An earlier line.
Printed for BGH96 Rev BBTC 770503101 L / 01.2025 (Rev B) · md5 8b599dec
Printed for BGH96 RevCBTC 772003301 C / 06.2025 (RevC, R454B) · md5 21426d58
Printed for BGH97BTC 772103301 A / 08.2025 (BGH97 RevA, R454B) · md5 54e2f162
Trane and American Standard4 documents
Not held for this family, so the page says so rather than guessing: the S9V2's alarm codes (its guide prints only its display and menu codes); the XC95m, XV95, XR95, XR80 and older American Standard furnaces.
Trane
Printed for S8B1, S8X1, S8X2 (PSAB)18-CE14D1-1A-EN, March 2020 · md5 db9ef0e3
Which brands it speaks for is inferred rather than printed, so the page says a code is printed for this series and does not name a brand.
Printed for S8B1, S8X1, S8X2 (PSC)18-CE16D1-1C-EN, April 2021 · md5 796ca223
Which brands it speaks for is inferred rather than printed, so the page says a code is printed for this series and does not name a brand.
Printed for S9V218-CE19D1-1B-EN, February 2022 · md5 9a4f8e57
Which brands it speaks for is inferred rather than printed, so the page says a code is printed for this series and does not name a brand. 18 codes it prints are refused here, each with its reason when it is typed.
Printed for S9X1, S9X2, S9B118-CE12D1-1D-EN, September 2020 · md5 429bc0da
Which brands it speaks for is inferred rather than printed, so the page says a code is printed for this series and does not name a brand.
Frigidaire, Gibson, Maytag and Intertherm12 documents
Not held for this family, so the page says so rather than guessing: Miller, Westinghouse, Tappan, Broan and other names no document held prints; Nordyne owner's manuals, and the older G6 and M7 furnaces.
Nordyne
Printed for (F,V)G8SD / L9X1 / MGC3SD(02/25) footer; portal title (F,V)G8SD L9X1 MGC3SD Ultra-Low NOx ii.pdf v3 · md5 d3d19ef8
Which brands it speaks for is inferred rather than printed, so the page says a code is printed for this series and does not name a brand. One code it prints is refused here, each with its reason when it is typed.
Printed for *G6 / L1 / G7 single stage (Channel board 1046399)10492440 (NEW), (10/24) footer; LED legend on wiring diagram 10492400 · md5 4d2a804c
One code it prints is refused here, each with its reason when it is typed.
Printed for *G7S(A,K,C,D) / MGC2 / MG3P / MG2R / CMF95 (Channel board 1046397)(08/25) footer; portal title Rpl Board Kit-Channel Board ii; LED legend on wiring diagram 10499330 (Figure 3) · md5 fba8c066
One code it prints is refused here, each with its reason when it is typed.
Printed for *G7S(A,K) / MGC2S(A,K)(02/25) footer; portal title G7S(A,K) MGC2S(A,K) ii.pdf · md5 fd94ecb7
Printed for *G7S(C,D) / MGC2S(C,D)(02/25) footer; portal title G7S(C,D) MGC2S(C,D) Gas Furnace ii · md5 972c4e59
Printed for *G7T(E,N)(02/25) footer; portal title G7T(E,N) Two-Stage Furnace ii · md5 84fd3436
Printed for *G7TA / PGC2TA(02/25) footer; portal title G7TA PGC2TA Two-Stage Gas Furnace ii · md5 793238f5
Printed for *G7TC / PGC2TC(02/25) footer; portal title G7TC PGC2TC ii · md5 fb286ee9
Printed for MG110502240, (03/25) footer · md5 cd5aca40
Printed for MG1E(02/25) footer; portal title MG1E A2L ii · md5 c72b15d9
Printed for MG2R1050022A, (04/25) footer · md5 47a7aeac
Which brands it speaks for is inferred rather than printed, so the page says a code is printed for this series and does not name a brand.
Printed for MG2S(05/25) footer; portal title MG2S A2L Gas Furnace ii · md5 f43bb640
Which brands it speaks for is inferred rather than printed, so the page says a code is printed for this series and does not name a brand.
How a code is answered, and when it is refused: A code is read only inside the documents whose printed series admits the model typed or the series picked, and only on a board that shows what the reader sees; with no model and no series there is no meaning, only the question of which unit it is. Where two documents held for that series print the code with the same meaning (a misspelling, or a unit written two ways), it is answered once and both are cited. Where their meanings differ, it is refused, because which one applies depends on the board fitted, and the page points to the code label or booklet the maker leaves with the furnace instead of guessing. A code the table does not print is refused, and so is one a document prints two contradictory ways. Where a row the refusal withholds is a stop condition on any board the unit may carry, the refusal says that first.
U.S. CPSC recall notices: 21 recall notices of the U.S. Consumer Product Safety Commission are served here, each as CPSC's own page printed it when it was read on 2026-09-22. Every one that names the furnace's brand is checked against the model given, and a notice the model meets is printed above any code. The serial is never asked for, because a furnace's serial plate can sit behind a panel, so a notice that also prints a serial condition is shown as one to check against the notice itself.
What this page does not do: It gives no reset step. Where a maker's code table prints reset words, they are shown as that table's words, labelled as written for a technician, and the one sentence quoted about a reset button that tripped again is the maker's own instruction to call for service, or in Rheem's installation instructions not to jumper or reset the switch. It never asks anyone to open a door or a panel. A yes to any stop question ends the check there: no recall, no code and no reset follows it. It does not rank causes, name a part or name a price.

Every maker quote, code meaning and recall notice on this page is LOOKED UP: the words are the maker's or CPSC's, reproduced with the document, edition and page. Nothing is computed except which held documents and recall notices your answers admit. A code meaning is what the board reports, not a diagnosis of the furnace, and the documents held do not cover every furnace each family has built: the lines that are not held are named under each family above. The code label or booklet the maker leaves with the furnace, and a technician at the unit, have the final say.

What this page reads for Lennox

Each code is read from the table printed in Lennox's own document for your furnace's series, and quoted with its edition and page. The documents held here:

EL180UHNE: Lennox 508545-01, 12/2025
EL195UHNE: Lennox 507758-05, 04/2024, supersedes 01/2023
EL196UHE: Lennox 507764-06, 04/2024, supersedes 03/2024
EL280UHE: Lennox Corp 1901-L1, 04/2024
EL280UHEK: Lennox 100168 (no date on p1)
EL296UHE: Lennox Corp 1246-L10, Revised 08/2023
EL297UHEK: Lennox 100170 (no date on p1)
EL297UHV: Lennox 100088, 04/2024
ML180UH: Lennox 507323-01, 07/2018, supersedes 11/2017 (an earlier line)
ML180UHE: Lennox 507103-04, 04/2024, Supersedes 02/2023, (c) 2024 Lennox Industries Inc.
ML180UHV: Lennox 507945-02, 04/2024, supersedes 08/2023
ML180UHVK: Lennox 100166 (no date on p1)
ML193UHE: Lennox 507863-02, 04/2024, supersedes 03/2024
ML193UHE: Lennox Corp 1905-L1, 04/2024
ML196UHE: Lennox 507966-04, 04/2024, supersedes 03/2024
ML296UHV: Lennox 507869-04, 04/2024, supersedes 10/2023
ML296UHVK: Lennox 508520-01, 06/2026
SL280UHNV: Lennox 507649-01, 10/2017
SL280UHNVK: Lennox 508561-01, 04/2026
SL280UHV: Lennox 508245-01, 04/2024, supersedes 09/2022
SL297UHNV: Lennox 507760-02, 02/2018, supersedes 507760-01
SLP99UHV: Lennox 507999-02, 04/2024, supersedes 03/2024
SLP99UHV: Lennox 100001, 07/2024
SLP99UHVK: Lennox 508587-02, 10/2025

What it cannot answer yet

For these, the page says so instead of guessing:

the ML297V
Lennox furnaces from before about 2017
codes shown only on a Lennox communicating thermostat

Questions

What should I do if my Lennox furnace smells like gas?

Leave the building now. Do not touch light switches or use a phone inside. From outside, call your gas supplier, or the fire department if you cannot reach them. Do not look up a code first. Lennox's own "what to do if you smell gas" words are quoted at the top of this page, with the document they are printed in.

Why does this page ask for the model before it reads a code?

Because the same number of blinks can mean different things on different boards from one maker. The documents held here show it in several families, among them York, Goodman, Lennox, Allied and Nordyne: a count that is a stop condition on one board means something else on another. So a code is read only from the table printed for your model's series, and where two held documents for that series print one code with the same meaning (a misspelling or a unit written two ways) it is answered once and both are cited, while where their meanings differ it asks which unit you have and never guesses.

Can I reset the furnace myself?

This page gives no reset step. Where a maker's table prints reset words for a code, they are shown as the manual's words for a technician. Rheem's installation instructions print "DO NOT jumper or reset this switch" for its rollout switches. If a reset button on the furnace trips again, stop and call a technician. Nothing here asks anyone to open a door.

All 10 furnace maker families

The same check for another maker's furnace.

Look up the unit's age and recalls by serial

The furnace's age, recalls and warranty, from its serial number.