Goodman and Amana furnace codes (LED flashes and display codes)

All Goodman codes

Meanings are quoted from Goodman service manuals and installation instructions. The "Who" column is our reading of theremedy in those documents: whether an owner can do the first checks, or the fix belongs to a licensed technician.

How to read a Goodman code

These pages cover Goodman and Amana gas furnaces. Goodman’s service manuals and installation instructions cover both brands, with titles such as “Goodman Brand GR9T96/GD9T96 & Amana Brand AR9T96/AD9T96” RS6612304, p. 1. Amana’s own literature library lists only product specifications, brochures and warranty certificates for gas furnaces (amana-hac.com, checked October 19, 2026).

How the code is shown depends on the control board. Goodman’s code tables are tied to the series named on each document’s cover; they do not say which board a given model number has.

• A single LED that flashes a count. The owner’s manual has you look through the blower compartment sight glass and record the number of flashes seen in sequence HIG-2002A, p. 8. The GMSS9 service manual says to count the flashes between pauses through the observation window in the blower access door RS6612012, p. 31. On these boards a steady light is normal operation. No light means no 115 volt power to the furnace, no 24 volt power to the control, or a fault in the control; continuous flashing means the polarity of the 115 or 24 volt power is reversed RS6612012R8, pp. 44–45. The table has this kind of board for the GMSS9, GMES9, GMES80, GKS9, GMS8, GMH8, GMH95, GME95 and GME8 series and their Amana versions.
• A three-color LED. On GMEC96 and GMEC80 boards the code is a color plus a number of repeating flashes. Green patterns and one or two amber flashes are normal operating states: solid green means the furnace is not receiving a call, and one amber flash is normal operation with a low stage call for heat. All red patterns are faults GMEC96: IOG-2011U, pp. 54–55; GMEC80: RS6621005R1, pp. 28–29. The 2019 service manuals for the Ultra-Low NOx MES96U and GMES80*U also use red, amber and green, with other meanings RS6612017, pp. 20–21; RS6621006, pp. 16–17. Their March 2023 revisions describe the same series with three-character codes RS6612017R4, p. 30; RS6621006R4, p. 33.
• A three-character display. Newer boards show codes such as EE0, EE3 or EAF. IdL means idle, which is normal IOG-2037D, p. 43. On the Ultra-Low NOx GR9S96U and GR9S80U, 888 with all segments lit means the control is powering up RS6612302, p. 11; RS6621302, p. 10. When the display gives no signal, the tables point to power: the GR9S96 service manual’s symptom “LED display provides no signal” goes with no 115 volt power to the furnace or no 24 volt power to the control RS6612301, p. 37, and the current instructions word that row “nonE” IOG-2037D, p. 43.
• Two characters on older ComfortNet boards. The tables for the GMVC9, GMVC8 and GMVC96 generations use codes such as E0, E3, d0 and b1, most of them with a matching message on a ComfortNet thermostat, for example E0 and LOCKOUT RS6612010R6, p. 47. These boards show OP or On while they wait for a call from the thermostat RS6612002, p. 48. The table on this page does not include the two-character codes. One edition of the owner’s manual adds that on a ComfortNet system a serious furnace fault makes the thermostat show “CALL FOR SERVICE” and scroll “CHECK FURNACE” HIG-2002, p. 8.

Read the code before you open anything or turn off the power. The GMES9 table notes that the LED flash code will cease if power to the control is interrupted through the disconnect or the door switch IOG-2020J, p. 40. The owner’s manual says an interlock switch keeps the furnace from operating when the blower door is not in place HIG-2002A, p. 6, and the current tables list an open door switch among the causes of the nonE row IOG-2037D, p. 43.

Why a flash count needs the series

The same count means different things on different boards. Four examples from Goodman’s tables; the single-LED column is the GMSS9 service manual, December 2017 revision (RS6612012R8, pp. 44–45; GMEC96: IOG-2011U, pp. 54–55; GMEC80: RS6621005R1, pp. 28–29; MES96U: RS6612017, pp. 20–21):

Flashes	Single LED, GMSS9	Red LED, GMEC96 and GMEC80	Red LED, MES96U (2019 manual)
1	Lockout after 3 ignition retries	“Flame sensed when no flame should be present”	Lockout after 3 ignition attempts
3	“Pressure switch circuit not closed.”	“Low fire pressure switch stuck open”	“Inducer not making pressure setting.”
6	“Rollout limit circuit is open/Control board fuse open.”	“Pressure switch cycling lockout, pressure switch has opened 5 times in the same heating cycle”	“Burner temperature limit switch open.”
7	“Flame sense microamp signal is low.”	“Lockout - excessive retries from flame not being proven during trial for ignition”	“Gas valve circuit shorted.”

Revisions of the same manual differ too. The April 2019 GMES9 service manual lists 1 to 7 flashes RS6612016, pp. 43–44; the 2022 installation instructions for the same series go to 12, adding for example 8 flashes, “Igniter Relay Fault”, and 9 flashes, “Twinning Fault” IOG-2020J, pp. 41–42. The GMES80 changed the same way RS6621003, pp. 36–37; IOG-2021H, pp. 29–31, and the 2017 revision of the GMS8 manual adds 8 flashes RS6612006R7, p. 47. The Ultra-Low NOx furnaces have more than one colored-flash table: the 02/2022 installation instructions for the MES96U carry their own table, worded differently from the 2019 service manual IOG-2013F, pp. 33–34, and the 02/2022 instructions for the GMES80U also word some counts differently IOG-2019G, pp. 26–27. The “2019 manuals” rows on these pages come from the service manuals only. Three-character codes have variants as well: E11 is “Open rollout switch.” in the GR9S96 installation instructions and “Open burner box limit switch circuit.” in those for the Ultra-Low NOx GR9S96U IOG-2037D, p. 44; IOG-2040D, p. 39.

Finding the rows for your furnace

1. Match the start of your model number to a series in the table. The series names come from the covers of Goodman’s service manuals and installation instructions.
2. Use that series’ document. Goodman’s owner’s manual has no code list and says: “Refer to Installation Instructions for code identification.” HIG-2002A, p. 8
3. Check the date. Tables change between revisions: the MES96U went from colored flashes to three-character codes (see above), and the 10/2026 installation instructions for the GR9S96 rewrote several corrective actions of the 09/2023 edition IOG-2037A, p. 43; IOG-2037D, pp. 44–45. Each row of the table names its document and page, and the document list on this page gives each revision.
4. If your series is not in the table, these pages cannot tell you what your code means.

What the owner’s manual tells you to do

Goodman’s owner’s manuals list neither models nor codes, so these pages follow the Gas-Fired Warm Air Furnace User’s Information Manual HIG-2002A (09/19). Its section “Troubleshooting / Before you request a service call” asks for these checks, in this order HIG-2002A, p. 8:

1. Look at the LED through the blower compartment sight glass. If it is flashing, record the number of flashes, shut the furnace down (next section) and contact a qualified servicer. If it is not flashing, go on.
2. Check that the thermostat is set to HEAT and its temperature setting is above room temperature.
3. Check the electrical panel for tripped circuit breakers or failed fuses, and reset the breakers or replace the fuses.
4. Check for dirty filters at least once a month, and replace or clean them. The manual calls dirty filters the most common cause of improper furnace operation. Disconnect electrical power before removing filters HIG-2002A, p. 7.
5. Check that return air and supply air grilles are not blocked by furniture, drapery, clothes or carpeting, and clear them.
6. On high efficiency furnaces, check that the intake and vent terminations are not blocked.

Checks 2 to 6 are for a furnace whose LED is not flashing. The manual draws the line there: do not troubleshoot beyond these points and “Do not attempt repairs yourself” HIG-2002A, p. 8. It also says “do not remove any internal compartment covers”, because electrical components are in both compartments HIG-2002A, p. 6. Maintenance is for a qualified service technician, and the owner’s part is limited to frequent air filter changes HIG-2002A, p. 6. The warning in the manual’s filter section says to disconnect electrical power before removing filters or performing any other maintenance, and never to operate the furnace without a filter installed HIG-2002A, p. 7.

Other editions of the owner’s manual differ. HI-115C (02/12) and HIG-2002 (07/19) also ask you to check that the manual gas shut-off valve outside the furnace is ON, and if it is OFF, to turn the gas on by the start-up steps HI-115C, p. 8; HIG-2002, p. 8. HIG-2002 adds the ComfortNet thermostat check HIG-2002, p. 8. HIG-2001B (09/2019) has no sight-glass step HIG-2001B, p. 8. HIG-2005 (01/2020) has no troubleshooting section and says to contact a qualified service agency should the furnace ever fail to operate HIG-2005, p. 2.

Shutting the furnace down

The troubleshooting section sends you to the start-up section to shut the furnace down. The shut-down steps on the same page are HIG-2002A, p. 6:

1. Set the thermostat to the lowest setting. The control closes the gas valve; the induced draft blower stops after 15 seconds and the circulator blower after a delay of 90, 120, 150 or 180 seconds.
2. Remove the burner compartment door.
3. Move the gas valve’s ON/OFF switch to OFF.
4. Close the external manual gas shut-off valve.
5. Replace the burner compartment door.

The safety label printed on page 9 of the manual calls this part the gas control lever. Use only your hand to push or turn it, never tools; if it will not move by hand, do not try to repair it, and call a qualified service technician HIG-2002A, p. 9. The shut-down list above does not turn off the electrical power. The label’s own shut-off steps do, before the gas control goes to OFF, if service is to be performed HIG-2002A, p. 9, and so do the start-up steps the troubleshooting section names HIG-2002A, p. 6. The manual’s maintenance warning is to disconnect electrical power before performing any service or maintenance HIG-2002A, p. 7.

Clearing a code

The owner’s manual gives one reset, for a lockout. It describes lockout as a non-functioning furnace, with the circulator blower possibly running continuously, “providing a diagnostic LED code” HIG-2002A, p. 6. On boards with a display, the GRVT96 instructions describe lockout as a non-functioning furnace with “an EE0 code displayed on the 7-segment display” IOG-2044B, p. 45. In Goodman’s tables, codes worded as a lockout include EE0, 1 flash on single-LED boards, and red 6, 7 and 8 flashes on GMEC96 and GMEC80 boards. The manual allows any of three methods HIG-2002A, p. 6:

• Wait. The control resets itself and tries to resume normal operation after a one-hour lockout period.
• Interrupt the 115 volt power to the furnace for more than 20 seconds.
• Interrupt the thermostat signal to the furnace for between 0 and 20 seconds.

If the condition that caused the lockout is still there, the control locks out again. The manual says a furnace that locks out often has a problem that must be corrected, and to contact a qualified servicer HIG-2002A, p. 6.

Service and installation manuals give other times: 1 to 20 seconds for both the power and the thermostat methods in the GR9T96 instructions IOG-2038E, p. 46; more than 5 and less than 20 seconds at the thermostat, or at least 5 seconds at the disconnect, in the GMSS9 service manual RS6612012, p. 31. The GMVC96*BA service manual describes the thermostat method as lowering the thermostat until there is no call for heat for 1 to 20 seconds, then setting it back RS6612014, p. 72. These pages give the owner’s manual times.

Boards with a three-character display also keep a list of past faults, “Last 10 Faults” in the board’s menu RS6612301, p. 34. Viewing and erasing it is done with the buttons on the control board and is described in the installation instructions IOG-2037D, p. 45; these pages do not repeat it.

When to stop and call a professional

The owner’s manual says installation and service must be performed by a qualified installer, service agency or the gas supplier HIG-2002A, p. 1. Goodman’s service manual adds that in jurisdictions that require licenses, only licensed personnel should service the equipment RS6612301, p. 1. Stop and call when:

• You smell gas. The steps from the cover of the owner’s manual are at the top of every code page HIG-2002A, p. 1. Some Goodman documents print a different block: HIG-2005 adds “Leave the building immediately.” HIG-2005, p. 1, and the English blocks in IOG-2032C and IOG-2013F are written for a vehicle IOG-2032C, p. 3; IOG-2013F, p. 3. In HIG-2002A itself, the French version of the block includes leaving the building and the English version does not HIG-2002A, p. 1. For propane, the manual asks for a gas detecting warning device, because the odorant can fade HIG-2002A, p. 5.
• The furnace overheats or the gas supply does not shut off. Turn off the manual gas shutoff valve outside the furnace before you turn off the electrical supply HIG-2002A, p. 2.
• Any part of the furnace has been under water. Do not use it; the label says to have a qualified service technician inspect it and replace any part of the control system and any gas control that was under water HIG-2002A, p. 9.
• The LED is flashing a code, or a lockout keeps coming back HIG-2002A, pp. 6, 8.
• The work goes past the filter HIG-2002A, p. 6.

Carbon monoxide: the manual’s warning is at the top of every code page HIG-2002A, p. 4. The manual also lists air starvation signals that indicate conditions that may produce carbon monoxide, or that carbon monoxide may be present: headaches, nausea, dizziness or flu-like symptoms; excessive humidity, heavily frosted windows or a moist, clammy feeling in the home; smoke from a fireplace that will not draw up the chimney; flue gases that will not draw up the vent pipe HIG-2002A, p. 4. It gives no separate step for these signs. Its general warning is to contact a qualified servicer at once if an abnormal condition is noticed HIG-2002A, p. 6.

See also

• Heat pump vs gas calculator
• HVAC and furnace tax credits in 2025 and 2026: 25C, 25D, 30C

Other gas furnaces: Carrier, Lennox, Rheem and Ruud

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