P3DH - Flashing Code 5

York Gas Furnace: P3DH

Re: Flashing Code 5

Flashing Code 5 = Rollout Switch Open

Other symptoms associated with a Code 5:

• Blower and Inducer Running Continuous
• No Heat

CHECKOUT:

1. Check Rollout Switches

• Reset the furnace by cycling power.
• Start a call for heat by energizing "W".
• Monitor the LED on the furnace board for lockout indication.
  • If board immediately goes into a Code 5, press the reset button on each Rollout limit and retry.
    • Code 5 Goes Away ⇒ Check for Bad Heat Exchanger
    • Still Code 5 → Step 2. Check Control Board

2. Check Control Board

• At the control board 12-pin plug:
  • Check for 24VAC between Pin# 11 (BRN) and "C".
  • Check for 24VAC between Pin# 5 (BLK) and "C".
    • Power on One Side Only = Open Limit Circuit ⇒ Check resistance across each roll-out switch.
    • Power on Both Sides + Code 5 = Bad Control Board