York Gas Furnace

Re: Flashing Code 6

Code 6 = Pressure switch opened 4 times during a run cycle.

► This is a "Soft Lockout" which will automatically reset after 1 hour.

CHECKOUT:

1. Check Inducer Motor Operation

• Start the furnace with a call for heat from the thermostat.
• Observe and listen to the inducer motor operation.
  • Inducer motor hums but does not start:
    • Bad Inducer Motor or Capacitor
    • Item in Inducer (Remove inducer & check)
  • Sound of water "slurshing" = Water in Inducer --> Remove Inducer, pour out water, re-install inducer --> Step 3. Check Condensate Drainage
• Ensure that the pressure switch closes.
  • Pressure switch fails to close --> Step 2. Check Pressure Switch
• Listen for sounds of water in vent piping.
  • If water is gurgling in vent, look for low spots that will hold water.
    • Pipe must have constant slope back toward furnace.

2. Check Pressure Switch

• Use a pressure meter to check the pressure at the switch.
  • Watch for water in the pressure switch hoses.
  • On a two-hose switch, be sure to check both sides at the same time (differential pressure)
• Compare actual pressure to pressure rating on the switch.
  • Pressure near or below rating = Blocked or Restricted Vent / Intake
    • On a furnace with a sealed burner box, try removing the burner box cover & re-checking.
      • Drastic improvement = Restricted Intake
      • Little or no improvement = Restricted Vent
  • Pressure well above rating, switch should be closed.
    • Switch does not close = Bad Switch or Water in Switch
      • Water in Switch is usually caused by a mis-run pressure switch hose.

3. Check Condensate Drainage

• Check the drain coupling on the inducer outlet.
  • On horizontal runs, make sure the drains outlets are pointed slightly down-hill.
  • Remove drain hoses.
    • Water running out of coupling = Clogged Drainage
• Check drain hoses from inducer and collector box.
  • Make sure all drain hoses are clear and have a downward slope.
• ! Make sure there is an "Air-Gap" in the PVC drain immediately upon exiting the furnace !
  • Any trap after the collector box before the air gap will cause drainage issues.