Concord Furnace Error Codes

On the page here you can find the recommendations on troubleshooting with Concord furnace. If you notice something unusual in your furnace work, or there are some serious issues which make you think there is a problem, address these lists.

In the tables below you can find Concord Furnace error codes and their explanations. With the description you can also get some advice on what to do in case of the breakdown. For example, Concord furnace 3 flashes mean problems with pressure, and Concord furnace 6 flashes mean ignition problems. There are detailed recommendations on what to check for and what to fix if you experience these flashes or signals.

Concord 96G1E Furnace Error Codes

Status LED	DESCRIPTION
Heartbeat	Control has 24 VAC power
2 Flashes	Pressure switch did not open, check for obstructed pressure tubing
3 Flashes	Pressure switch did not close, or re-opened- Check for: excessive wind, proper vent size, defective inducer motor, low inducer voltaqe, defective pressure switch, inadequate combustion air supply, disconnected or obstructed pressure tubing, low inlet gas pressure, restricted vent, condensate cloqqed
4 Flashes	Limit circuit fault-a limit or flame rollout is open. Check for: restricted vent, proper vent sizing, loose blower wheel, excessive wind, dirty filter, defective blower motor, defective switch or connections, inadequate combustion air supply
5 Flashes	Abnormal flame proving signal-Flame is proved while gas valve is de-energized. Check for: leaky gas valve, stuck open qas valve
6 Flashes	Failure to ignite or flame sense lost while running. Check for: Flame sensor must not be grounded, low inlet gas pressure, oxide buildup on flame sensor,
	Manual valve shut off, proper flame sense microamps, gas valve defective or gas valve turned off, defective hot surface iqniter, control qround continuity,
	Inadequate flame carryover or rough ignition, green/yellow wire MUST be connected to furnace sheet metal.
7 Flashes	Limit circuit lockout- Lockout occurs if the limit or flame rollout is open longer than 3 minutes. Control will auto reset after 3 hours. Refer to #4
8 Flashes	Gas heating lockout-Control will NOT auto reset. Check for: mis-wired gas valve, defective control valve
10 Flashes	Polarity-Line voltage, polarity reversed. If twinned, refer to twinning kit instructions.
1 + 2	Blower on after power up- Blower runs for 90 seconds, if unit is powered up during a call for heat (R-W closed) or (R-W) opens durinq blower on delay.
6 + 1	Ignition lockout- Control will auto-reset after 3 hours. Refer to #6.
LED Off	Secondary voltage fuse is open- Check for: door switch not closed, 115VAC at LI and neutral, 24VAC RED and COM BLUE, 24V Fuse 3A, short circuit in secondary voltage (24VAC wiring)
LED On	Control circuitry lockout- Auto-reset after one hour
LED SOLID	Gas valve relay stuck open- Flame sense circuit failure, software check error, reset power to clear lockout, replace control if status code repeats.

Concord 80G1 Furnace Error Codes

RED LED Flash Code	Diagnostic Codes t Status of Furnace
Off	No power to control or board fault detected
Heartbeat 1	Control powered – displayed during all modes of operation if no errors are detected
1 Flash	Reverse Line Voltage Polarity
2 Flashes	Improper Earth Ground
3 Flashes	Burner failed to light, or tost flame during heat demand
4 Flashes	Low Flame Signal – check flame sensor
5 Flashes	Watchguard – burner failed to light, exceeded maximum number of retries or recycles.
6 Flashes	Not Used
7 Flashes	Primary or Secondary Limit Open or Watchguard Mode – Limit Switch Open Longer than 3 minutes
8 Flashes	Rollout Switch Open
9 Flashes	Pressure Switch failed to close or opened during heat demand
10 Flashes	Watchguard – Pressure Switch opened 5 times dunng one heat demand
11 Flashes	Pressure switch stuck closed prior to activation of combustion air inducer
12 Flashes	Flame Sensed without gas valve energized
13 Flashes	Low Line Voltage

Concord 92G1 Furnace Error Codes

LED Status	Fault Description
LED Off	No power to control or control hardware fault detected
LED On	Normal operation
1 Flash	Flame Present with gas valve off
2 Flashes	Pressure switch closed with inducer off
3 Flashes	Pressure switch open with inducer on
4 Flashes	High limit switch open
5 Flashes	Rollout switch open
6 Flashes	Pressure switch cycle lockout
7 Flashes	Lockout due to no ignition
8 Flashes	Lockout due to too many flame dropouts
9 Flashes	Incorrect line voltage phasing