Trane Package Unit: YCH
Re: Heating - Code 2
Code 2 = Failed to Sense or Sustain Flame (3 tries)
Qty |
Possible Causes: |
2 |
Bad Glow Plug |
|
Bad Ignition Control Board (ICB) |
|
Bad Gas Valve |
|
No Gas |
|
Busted Burner |
CHECKOUT:
1. Prepare for Testing
- Open the gas section access panel.
- Place an amp probe on one wire going to the glow plug.
2. Check Inducer Motor
- Reset the Ignition Control Board by momentarily unplugging the molex plug from the ICB.
- The light on the ICB should flash continuous if a call for heat is present.
- Light On (not flashing) = No call for heat ⇒ Energize a call for heat from the thermostat.
- Ensure that the inducer motor starts normally.
- No Inducer Operation ⇒ Check for 230V
3. Check the Glow Plug
- Monitor the glow plug amperage as the unit goes through an ignition sequence.
- Should draw approx. 3 Amps.
- Low Amperage = Bad Glow Plug
- No Amperage ⇒ Remove the plug feeding power to the glow plug and check for 120VAC between the two wires from the ICB during an ignition attempt.
- No Voltage = Bad Ignition Control Board
- Voltage + No Amperage = Bad Glow Plug
4. Check Gas Pressure/Gas Valve
- Manifold (Outlet) Pressure
- A pressure gauge that reads negative pressure is required.
- Proper manifold gas pressure = (-0.20" w.c.).
- Monitor the gas pressure as the unit goes through an ignition sequence.
- Pressure should start-off high negative and drop to -0.20" when the gas valve opens.
- Pressure Drops to -0.20" but Does Not Ignite = Bad Burner
- Pressure Doesn't Drop = Bad Gas Valve or No Inlet Gas ⇒ Check the inlet gas pressure.