GPG14 - Flashing Code 1

Goodman Package Unit: GPG14

Re: Flashing Code 1 / Won't Ignite

Code 1 = 3 Failed Ignition Attempts

Qty	Possible Causes:
	Dirty Flame Sensor
1	Bad Control Board
	Low / No Gas
	Bad Gas Valve
2	Bad Spark Electrode or Spark Wire

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 9 (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
If the burners are running, wiggle the Purple wire at the molex plug to see if the gas valve drops-out (we've had several issues of a bad connection).

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: Low Fire = 1.5 - 2.5" w.c. High Fire = 2.5 - 3.5" w.c. for Nat. Gas
  - 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:
- OPTION 1
- 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
- OPTION 2
- Remove the spark electrode from the burners.
- Connect one end of the jumper wire to the electrode and the other to the grounded metal cabinet.
- Hold the electrode with an insulated set of pliers.
- Turn the gas valve to the "Off" position.
- Activate a call for heat.
- Watch for a good spark at the ignition electrode.
  - No Spark = Bad Control Board

6. Check Flame Sensor