GPG13 - Flashing Code 1

​Goodman Package Unit: GPG13

Re: Flashing Code 1 / Won't Ignite

Code 1 = 3 Failed Ignition Attempts

► A Manual-Reset Auxiliary Limit and Roll-Out Limit are wired in series with the gas valve and will cause a Fault Code 1.

CHECKOUT:

1. Check Ignition Sequence

• If necessary, reset the furnace lockout by cycling high voltage or low voltage power.
• Initiate a call for heat from the thermostat and monitor the ignition sequence.
  • The inducer motor should start with no difficulty.
  • The pressure switch should close within a couple seconds of the inducer starting.
  • The Sparker should begin sparking and the Gas Valve should open.
    • No Spark → Step 2. Check Control Board Output
    • Sparks but Does Not Ignite → Step 2. Check Control Board Output
    • Ignites but Shuts Off → Step 6. Check Flame Sensor

2. Check Control Board Output

• Re-start the furnace with a call for heat from the thermostat.
• At the point of ignition, check for 24VAC between Terminal 3 (Purple) of the molex plug on the control board and "Common". 
  • No Power = Bad Control Board
  • Power Present + Spark + No Ignition → Step 3. Check Gas Valve
  • Power Present + No Spark → Step 5. Check the Sparker / Electrode

3. Check Gas Valve 

• Re-start the furnace with a call for heat from the thermostat.
• At the point of ignition, check for 24VAC between (PUR) and (BL) at the gas valve.
  • Power at Gas Valve + No Ignition → Step 4. Check Gas Pressure
  • Power at Molex Plug + No Power at Gas Valve ⇒ Check for Tripped Auxiliary Limit or Tripped Roll-Out Limit
    • Tripped Auxiliary Limit = Protection against blower failure
    • Tripped Roll-Out Limit = Protection against a bad heat exchanger

4. Check Gas Pressure 

• Inlet Gas Pressure
• Turn off power to the furnace and check the inlet gas pressure.
  • Minimum Pressure = 5" w.c. for Nat. Gas, and 11" w.c. for Propane.
    • No or Low Pressure = Bad Meter or Regulator
    • Normal Pressure ⇒ Continue
• Re-apply power to the furnace and activate a call for heat.
• Make sure the inlet gas pressure stays above minimum when the gas valve energizes.
  • Pressure Drops Below Minimum = Bad Meter/Regulator or Restricted Gas Line
  • Normal Pressure ⇒ Check Manifold Gas Pressure
• Manifold Gas Pressure
• Activate a call for heat and monitor the manifold gas pressure during an ignition attempt.
  • Normal Pressure = 2.5 - 3.5" w.c. for Nat. Gas, 9 - 11" w.c. for LP
    • No Gas Pressure = Bad Gas Valve
    • Low Gas Pressure ⇒ Increase Manifold Gas Pressure
    • Normal Gas Pressure + No or Delayed Ignition = Clogged Burners ⇒ Remove burners and clean spreaders

5. Check the Sparker / Electrode 

• With No Call for Heat, check the spark electrode wire from the control board to the electrode.
  • Make sure the wire makes good contact at the control board.
  • Look for any rubbed spots that may cause a short.
• Inspect the spark electrode.
  • Check for damage.
  • Look for any rust particles or other potential shorts.
• Check the Spark Generator:
  • Remove the spark cable from the control board and attach a good jumper wire to the spark terminal.
  • Turn the gas valve to the "Off" position.
  • Activate a call for heat.
  • Hold the open end of the jumper wire near a grounded piece of metal (be careful to not get shocked).
    • Sparks ⇒ Suspect a Bad Spark Electrode or Spark Wire
    • No Spark = Bad Control Board

6. Check Flame Sensor

• DO NOT clean the flame sensor before testing!
• On the multi-meter:
  • Switch the test leads to "COM" and "mA".
  • Set the meter on DC 200ù.
  • Check the reading when the burners ignite.
    • Minimum acceptable reading = 1 MicroAmp
      • Low Reading ⇒ Clean Flame Sensor & Re-check
      • Normal Reading (2 to 6 mA) + Shuts Off ⇒ Suspect a Bad Control Board
  • MOVE SENSOR LEADS BACK TO "COM" and "V" BEFORE PROCEEDING!

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