York Package Unit: PCG4

Re: Flashing Code 3

If, after the induced draft blower is energized, the pressure switch does not close, the control will keep the blower on and wait for the switch to close. The diagnostic code for this problem is 3 short flashes followed by a pause.

► The diagnostic code will go away once the pressure switch closes.

► Multiple switch openings will cause a Code 6 lockout.

CHECKOUT:

1. Check Control Board

• Start the furnace with a call for heat.
  • The inducer motor should start within 15 seconds.
    • Inducer motor starts & runs normally → Step 3. Check Pressure Switch
    • Inducer motor does not run + Code 3 ⇒ Check for 230V power to inducer.
      • Code 3 + No Power = Bad Control Board
      • Power + Inducer Doesn't Run → Step 2.  Check Inducer Motor

2. Check Inducer Motor

• Start the furnace with a call for heat.
• Observe and listen to the inducer motor operation.
  • Inducer Runs Normally + Code 3 → Step 3.  Check Pressure Switch
  • Inducer Motor Hums but Doesn't Start ⇒ Test for a Bad Inducer Motor Capacitor
    • Capacitor OK + Motor Hums but Doesn't Start ⇒ Check for Item in Inducer (Remove the inducer assembly & check)
      • Inducer Fan Clear + Capacitor OK + Motor Hums but Doesn't Start = Bad Inducer Motor

3. Check Pressure Switch

• Remove the pressure hose from the inducer.
  • Look in the pressure port to make sure there is no Item Stuck in Pressure Port
• Use a pressure gauge to check the pressure at the inducer.
• Compare actual pressure to pressure rating on the switch.
  • Pressure Near or Below the Switch Rating → Step 4. Check Factory Restrictor Plate
  • Pressure Above Switch Rating + Open Switch = Bad Pressure Switch

4. Check Factory Restrictor Plate

• Use a pressure gauge to check the pressure at the inducer.
• Remove one wire from the roll-out switch (this will cause the inducer motor to run continuous for testing purposes).
• Adjust the angle of the factory restrictor plate (mounted in the outlet of the inducer) to achieve between .4" and .8" w.c. 
• Reconnect the roll-out switch wire.
• Reconnect the pressure switch tubing.
• Check heat operation.