Updated 2026-06-25

Goodman Furnace Error Codes & What They Mean

Compiled & reviewed by Nikolai Tsyrenov · Updated 2026-06-25

How do I read Goodman furnace error codes?

Goodman furnaces use a single blinking LED that flashes a simple count — count the blinks, note the pause, then it repeats (for example, 4 flashes means an open high-limit switch).

How to read Goodman furnace codes

Goodman furnaces use a single blinking LED that flashes a simple count — count the blinks, note the pause, then it repeats (for example, 4 flashes means an open high-limit switch). A steady LED means normal operation, no LED means no power, and a rapid continuous flutter means reversed line-voltage polarity or a grounding error. The flash-code legend is printed on a label inside the furnace's access panel.

Goodman furnace code list

CodeWhat it means (tap for fixes)
LED off (no light)No power to the control, or the control is not functional.
LED on steadyNormal operation — the control is powered and has no stored fault.
Rapid / continuous flashingLine-voltage (115V) polarity reversed, or a grounding error.
1 flashLockout due to too many ignition retries (3) — failure to establish or maintain flame.
2 flashesPressure-switch circuit is stuck closed at the start of the cycle when it should be open / draft inducer fault.
3 flashesPressure-switch circuit is open (did not close) when it should be closed.
4 flashesPrimary limit circuit (high-limit switch) is open — usually from restricted airflow.
5 flashesFlame sensed with no call for heat — the control sees flame when there shouldn't be any.
6 flashesFlame-rollout switch is open — a safety shutdown that can indicate blocked venting or a heat-exchanger problem.
7 flashesLow flame signal — the flame-sense micro-amp signal is minimal/weak.
8 flashesProblem with the igniter circuit.
⚠️ Safety first. Gas furnaces burn fuel and produce combustion gases. If you ever smell gas (a rotten-egg or sulfur odor), hear hissing, or your carbon-monoxide alarm sounds, do not touch light switches, thermostats, or the furnace — leave the home immediately and call your gas utility's emergency line or 911 from outside. Homeowners should limit themselves to simple, safe steps: setting the thermostat, checking and replacing the air filter, confirming the furnace switch and breaker are on, keeping supply registers and return grilles open, and clearing snow, ice, or debris from outdoor vent and intake terminations. Never bypass, jumper, or reset safety switches (limit, flame-rollout, or pressure switches), never open the gas valve or burner compartment, and never attempt combustion, electrical, or control-board repairs yourself. Error codes point toward a problem but are not a substitute for proper diagnosis — when in doubt, turn the system off and call a licensed HVAC technician. Keep working carbon-monoxide detectors on every level of your home.

Goodman furnace code FAQ

How do I read the error code on a Goodman furnace?
Goodman furnaces use a single blinking LED that flashes a simple count — count the blinks, note the pause, then it repeats (for example, 4 flashes means an open high-limit switch).
Where is the diagnostic light on a Goodman furnace?
It's on the control board, usually visible through a small sight glass on the lower blower-compartment door. You may need to remove the door panel to read it clearly.
What is the most common Goodman furnace code?
LED off (no light) — No power to the control, or the control is not functional.

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Sources: hvacdirect.com. General information for homeowners — confirm against your furnace's installation manual.