York package Unit: PCG4

Re: Flashing Code 1

Code 1 = Flame sensed with no call for heat.

In a Code 1 situation, the furnace control board thinks that the gas valve is stuck on and the flame is still burning without a call for heat. Therefore, when a control board goes into a code 1, it will lock the inducer motor and blower motor on.

CHECKOUT:

1. Check Wiring

• Ensure that the flame sensor wiring is correct.
  • On an LP gas furnace, a low gas pressure switch wires in series with the flame sensor.

2. Check Flame Sensor

• Visually check the flame sensor for rust flakes or other items that may cause a false reading.
• Look for foil-backed cabinet insulation too close to the flame sensor (shorting to the foil).
  • Cut-out the insulation near the flame sensor if necessary.
• Look for signs of water (rust) around the flame sensor.
  • ​​​​​​​► York Service Letter YSR001-23 addresses the issue:
    • Changes the exhaust outlet cover to a sloped cover identical to the inlet cover.
    • Adds a metal shield between the inducer and burner cover
    • Changes the flame sensor
    • Changes the inducer gasketing
• Check flame sensor Microamps when the burners shut-off.
  • No Microamp signal but controller locks-out = Bad Control Board

3. Check Gas Valve

• Start the furnace with a call for heat
• After the burners have been lit for at least 30 seconds, remove the "W" wire.
  • The burners should extinguish immediately (do this test multiple times).
    • Delayed shut-off = Sticking Gas Valve