HeatingCodesGoodman furnace blinking light codes: what each flash count means
Which Goodman furnaces use flash codes
Goodman and Amana furnaces use two different ways to report faults. Two-stage and modulating models such as the GMVC96, GMVM97 and the newer GRVM97 have a three-character display that shows codes like EE2 or EE3 (see the Goodman code table). Single-stage models covered by service manual RS6612012r8 (December 2017), including the Goodman GMSS96 and GCSS96, the Amana AMSS96 and ACSS96, and the VMSS and VCSS versions, have a single diagnostic LED instead. You read it by counting flashes through the observation window in the blower door.
Goodman single-stage flash code table
| LED | Meaning (RS6612012r8) | Probable causes Goodman lists |
|---|---|---|
| Steady on | Normal operation | |
| Off | Control failure | No 115 V or 24 V power to the control, blown fuse or breaker, or an internal control fault |
| 1 flash | System lockout (retries exceeded) | Flame not sensed after three tries; failure to establish or loss of flame |
| 2 flashes | Pressure switch stuck closed | Faulty pressure switch or wiring |
| 3 flashes | Pressure switch stuck open | Disconnected hose, faulty switch or wiring, restricted intake or flue piping |
| 4 flashes | Open high limit (primary or auxiliary) | Low airflow from a dirty filter or duct restriction, faulty limit, faulty blower or blower speed set too low |
| 5 flashes | Flame sensed without gas valve | Short to ground in flame sense circuit, miswiring, lingering burner flame or slow-closing gas valve |
| 6 flashes | Open rollout limit or open control fuse | Restricted flue piping or improper combustion air |
| 7 flashes | Low flame signal | Coated or oxidized flame sensor, sensor out of position, or lazy flame from gas pressure or combustion air |
| 8 flashes | Check igniter or improper grounding | Improperly connected or bad igniter, or poor ground |
| Continuous rapid flash | Reversed 115 VAC polarity | Line and neutral reversed |
What happens during each fault
1 flash (lockout). Goodman says the control cycles the gas valve three times; if it cannot sense flame it locks out. It can be reset by turning the thermostat off for more than 5 and less than 20 seconds and back on, or by switching off power to the furnace for at least 5 seconds. The board also resets itself one hour after lockout. Goodman adds that if a furnace frequently has to be reset, a problem exists that should be corrected.
3 flashes (pressure switch stuck open). If the pressure switch does not close within 5 minutes of the inducer starting, the control goes into a 1-hour lockout and then restarts the ignition sequence by itself. This is the most common Goodman code in cold weather, because snow, ice or frost on the outside vent and intake pipes restricts airflow. Our furnace pressure switch error guide compares this code across brands.
4 flashes (open limit). When the limit opens, the circulator blower runs until the limit closes. A clogged filter is the first thing to check. 6 flashes means either the rollout limit or the fuse on the control board is open, and with a rollout trip the circulator blower runs all the time. 7 flashes means the furnace is running but the flame signal is weak, usually a coated flame sensor, which is a routine technician cleaning job.
If your Goodman has a display instead
If you see letters and numbers like EE0, EE3 or Eb9 rather than a blinking light, you have one of the display furnaces. The matching codes for this page's faults are EE0 (lockout, like 1 flash), EE2 (low-stage pressure switch open, like 3 flashes) and EE3 (open limit, like 4 flashes).
Safe checks for a blinking Goodman furnace light
- Count the flashesLook through the blower door window without removing the door. Count the flashes between pauses and watch twice to be sure.
- Check power and thermostatIf the LED is off, check the furnace switch, breaker and that the thermostat is calling for heat.
- Replace a dirty filterFor 4 flashes (open limit), replace a dirty filter and make sure vents and returns are open.
- Clear outside pipesFor 3 flashes, clear snow, ice or debris from the vent and intake terminations if you can reach them safely from the ground.
- Reset onceTurn the thermostat off for about 10 seconds (more than 5, less than 20) and back on. If the same flash code returns, call a technician.
Frequently asked questions
What does 3 flashes mean on a Goodman furnace?
On GMSS96-family single-stage furnaces, 3 flashes means the pressure switch is stuck open: it did not close within 5 minutes of the inducer starting. Goodman lists a disconnected hose, faulty switch or wiring, or restricted intake or flue piping.
What does a steady light mean on a Goodman furnace?
A steady-on LED is normal operation in RS6612012r8. An LED that is off means the control has no power or has failed.
How do I reset a Goodman furnace lockout?
Goodman says to turn the thermostat off for more than 5 and less than 20 seconds and then back on, or switch off power for at least 5 seconds. It also resets itself one hour after lockout.
Does my Goodman furnace use these codes?
These codes are from the GMSS9/GCSS9/AMSS9/ACSS9/VMSS9/VCSS9 single-stage service manual. Other Goodman lines, such as the GM9S80 or two-stage GMEC96, use different boards. Check the label inside the blower door.
Sources
- RS6612012r8 (December 2017) Service Instructions: GMSS9/GCSS9/AMSS9/ACSS9/VMSS9/VCSS9 Single Stage Gas Furnaces, Heating - Abnormal Operation and LED code chart (Goodman Manufacturing) Covers: Goodman GMSS96 / GCSS96, Amana AMSS96 / ACSS96 and VMSS / VCSS single-stage 96% furnaces with a single diagnostic LED.
- RS6612023 Service and Troubleshooting: 34.5" Chassis ACVC96/AMVC96/GCVC96/GMVC96 Gas Furnaces (Goodman Manufacturing (Daikin)) Covers: Goodman and Amana 96% two-stage condensing furnaces in the 34.5" chassis.
Safety note: this page is general information drawn from the sources above. Gas, combustion and line-voltage repairs belong to a licensed professional. Your own equipment's label and manual take priority over anything here. Read the full disclaimer.