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

HeartbeatControl has 24 VAC power
2 FlashesPressure switch did not open, check for obstructed pressure tubing
3 FlashesPressure 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 FlashesLimit 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 FlashesAbnormal flame proving signal-Flame is proved while gas valve is de-energized. Check for: leaky gas valve, stuck open qas valve
6 FlashesFailure 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 FlashesLimit 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 FlashesGas heating lockout-Control will NOT auto reset. Check for: mis-wired gas valve, defective control valve
10 FlashesPolarity-Line voltage, polarity reversed. If twinned, refer to twinning kit instructions.
1 + 2Blower 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 + 1Ignition lockout- Control will auto-reset after 3 hours. Refer to #6.
LED OffSecondary 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 OnControl circuitry lockout- Auto-reset after one hour
LED SOLIDGas 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 CodeDiagnostic Codes t Status of Furnace
OffNo power to control or board fault detected
Heartbeat 1Control powered - displayed during all modes of operation if no errors are detected
1 FlashReverse Line Voltage Polarity
2 FlashesImproper Earth Ground
3 FlashesBurner failed to light, or tost flame during heat demand
4 FlashesLow Flame Signal - check flame sensor
5 FlashesWatchguard - burner failed to light, exceeded maximum number of retries or recycles.
6 FlashesNot Used
7 FlashesPrimary or Secondary Limit Open or Watchguard Mode - Limit Switch Open Longer than 3 minutes
8 FlashesRollout Switch Open
9 FlashesPressure Switch failed to close or opened during heat demand
10 FlashesWatchguard - Pressure Switch opened 5 times dunng one heat demand
11 FlashesPressure switch stuck closed prior to activation of combustion air inducer
12 FlashesFlame Sensed without gas valve energized
13 FlashesLow Line Voltage

Concord 92G1 Furnace Error Codes

LED StatusFault Description
LED OffNo power to control or control hardware fault detected
LED OnNormal operation
1 FlashFlame Present with gas valve off
2 FlashesPressure switch closed with inducer off
3 FlashesPressure switch open with inducer on
4 FlashesHigh limit switch open
5 FlashesRollout switch open
6 FlashesPressure switch cycle lockout
7 FlashesLockout due to no ignition
8 FlashesLockout due to too many flame dropouts
9 FlashesIncorrect line voltage phasing