YP9C - Flashing Code 5

Article ID: 219
Last updated: 8 Feb, 2019

York 97% Modulating Gas Furnace: YP9C

Re: Flashing Code 5

Flashing Code 5 = Rollout Switch or Condensate Pressure Switch

The rollout switches and the condensate pressure switch are wired in series, so either switch opening during a call for heat will cause a Code 5.

Qty Possible Causes (From Most to Least Likely):
2 Improper Drainage
Bad Switch
Bad Transducer
Rollout Switch Tripped


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.

2. Monitor Condensate Switch Pressure

  • Connect a pressure gauge to the low pressure switch hose.
  • Monitor the pressure as the system operates.

3. Check Condensate Drainage

  • Check drain hoses from vent coupling.
    • If installed horizontally, make sure drains are sloped downward.
    • Make sure vent coupling is installed with arrow pointing away from furnace.
  • 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 !
    • The collector box is internally-trapped.
    • Any trap in the drain after the collector box before an air gap will cause drainage issues.
  • In extreme cold conditions be cautious of Frozen Drains.

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Article ID: 219
Last updated: 8 Feb, 2019
Revision: 12
Access: Public
Views: 139
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