Heil furnace error codes
This chart covers the amber diagnostic LED on Heil G80CTL Series A gas furnaces, as printed on the Series A service label and diagnostic chart. Single numbers are counts of short flashes. Codes written with a plus sign start with short flashes and end with long flashes, so 6+1 is six short and one long, not seven. A code tells you what the control observed. It does not confirm which part failed, and several codes point to safety circuits that a technician should investigate before the furnace runs again.
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How to read the amber LED
Read the LED only through the original viewing window with the panel closed. Do not remove a panel while the furnace has power. Write down the full model number, the Series letter and the pattern. A heartbeat, which alternates bright and dim rather than counting out flashes, means the control has low-voltage power; it does not prove the burner is lit. On this control a steady-on LED is a temporary lockout, not a normal state, and a dark LED points to the power or fuse supply. Count several full cycles and keep short and long groups separate.
What this chart covers
This is the complete Series A chart: 13 fault codes, one timing status (1+2, blower running after power returns) and three LED states. It applies only to Heil G80CTL Series A. G80CTL Series B uses a different manual and is not covered, even though the product name is the same. Other Heil furnaces and replacement controls with a different label are also excluded. Because the model name alone does not show the Series, check the furnace label before using this chart.
- Heil G80CTL Series A amber LED control: Heil G80CTL Series A
Heil G80CTL Series A amber LED codes
| Code or flash pattern | Meaning | Model family | Details |
|---|---|---|---|
| Amber LED off (no light) | Control power or fuse A dark amber LED means the control is not showing that it has power, so the power supply or the fuse needs checking. A dark light alone cannot show which one. | Heil G80CTL Series A | View details |
| Amber LED heartbeat (alternating bright and dim) | Normal powered status A heartbeat, where the amber LED alternates between bright and dim, means the control has low-voltage power. It is a status display, not a counted fault code. | Heil G80CTL Series A | View details |
| Amber LED on solid (not flashing) | Temporary control lockout On this control, an amber LED that stays on without flashing means a temporary control lockout. The control has its own one-hour automatic recovery; that is built-in behavior, not a step for you to repeat. | Heil G80CTL Series A | View details |
| 2 short amber flashes, repeating | Pressure stays closed Two amber flashes mean the pressure switch feedback is still closed at a point where the control expects it to be open. The control will not continue the heating sequence on that signal. | Heil G80CTL Series A | View details |
| 3 short amber flashes, repeating | Low-stage draft not proved Three amber flashes mean the low-stage pressure switch or its relay did not close, or closed and then reopened. If it stays open more than five minutes, the control stops the inducer for 15 minutes before trying again automatically. | Heil G80CTL Series A | View details |
| 4 short amber flashes, repeating | Limit or vent protection alert Four amber flashes report an open temperature or vent safety circuit, or high-heat-only operation after two successive low-heat limit trips. The circuit can include the main limit, draft safeguard, rollout or blocked-vent switch. When a switch is open, the blower runs four minutes or until it closes, whichever is longer. | Heil G80CTL Series A | View details |
| 5 short amber flashes, repeating | Flame sensed, no gas call Five amber flashes mean the control senses flame when it is not calling for gas. The inducer keeps running until the condition clears. | Heil G80CTL Series A | View details |
| 6 short amber flashes, repeating | No flame proved on trial Six amber flashes mean an ignition trial ended without the control proving flame. The control can make up to three more attempts on its own, and if flame signal is lost the blower may run its off-delay. | Heil G80CTL Series A | View details |
| 7 short amber flashes, repeating | Protection circuit lockout Seven amber flashes mean a protection circuit has locked out heating. It follows a circuit open for more than three minutes or ten consecutive high-heat limit trips. The control recovers automatically after three hours. | Heil G80CTL Series A | View details |
| 8 short amber flashes, repeating | Gas control hard lockout Eight amber flashes mean the gas control circuit is in a lockout that does not clear on its own. Unlike the timed lockouts on this control, there is no automatic recovery. | Heil G80CTL Series A | View details |
| 9 short amber flashes, repeating | High-stage pressure fault Nine amber flashes mean the high-stage pressure switch or its relay did not close, or closed and then reopened. | Heil G80CTL Series A | View details |
| 10 short amber flashes, repeating | Reversed power polarity Ten short amber flashes mean the incoming line-voltage polarity is incorrect. Where two furnaces are twinned, 24-volt phasing is also involved. The code is ten short flashes, not a 1 followed by 0. | Heil G80CTL Series A | View details |
| 1 short, 2 long amber flashes | Power-restore blower run This status means power (115 V or 24 V) returned during a heat call, or the heat call ended during the blower-on delay. The blower runs for 90 seconds. | Heil G80CTL Series A | View details |
| 1 short, 5 long amber flashes | Blower response lockout For two heating cycles in a row, the blower did not reach 250 RPM or did not communicate within 30 seconds of being energized, so heating is locked out. It recovers automatically after three hours. | Heil G80CTL Series A | View details |
| 2 short, 5 long amber flashes | Model data or setup error If this shows four times at power-up and stops, the model plug is missing but the control is using stored model data. If it keeps repeating, the model data, plug, switch settings or twinning setup are invalid. | Heil G80CTL Series A | View details |
| 4 short, 1 long amber flash | Blower not responding The blower did not reach 250 RPM, or did not communicate, within 30 seconds of being energized or within 10 seconds during steady operation. It differs from 1+5, the lockout after repeated failures. | Heil G80CTL Series A | View details |
| 6 short, 1 long amber flash | Ignition retry lockout After four ignition trials without lighting and proving flame, the control has locked out heating. It recovers automatically after three hours. Read it as six short and one long, not seven. | Heil G80CTL Series A | View details |
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