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York Gas Furnace - Code 6

Article ID: 140
Last updated: 9 Nov, 2017

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.


Qty Possible Causes (From Most to Least Likely):
Bad Inducer Motor
Water in Vent
Water in Inducer
Improper Condensate Drainage
Bad Pressure Switch
Water in Pressure Switch / Tubing


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.
  • 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.

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Article ID: 140
Last updated: 9 Nov, 2017
Revision: 16
Access: Public
Views: 1636
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