ICB - Flashing Code 2

Trane Package Unit: YCH

Re: Heating - Code 2

Code 2 = Failed to Sense or Sustain Flame (3 tries)

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.