YP9C - Flashing Code 11

Article ID: 552
Last updated: 6 Dec, 2021

York Gas Furnace: YP9C

Re: Flashing Code 11

This indicates that a primary limit switch has opened and has remained open for more than five minutes. This condition is usually associated with an air circulation failure. 

 Code 11 is a Hard-Lockout which requires cycling 24VAC power to the furnace board to reset (or cycling 115V power).

Qty Possible Causes:
2 Bad V/S Blower Motor
Broken Blower Wheel
Bad Control Board
Bad Limit


1. Check Blower Motor/Wheel

  • Turn off power to the furnace.
  • Open the blower access door and check the condition of the blower wheel.
  • Check to see if the motor and wheel turn freely.

2. Check Motor Operation

  • Turn on power to the furnace.
  • Energize a call for "Fan" by jumping "R" to "G".

3. Check Control Board/Motor

  • At the blower motor power plug, check for 120VAC between "Blk" and "Wht".
    • No Power = Broken/Loose Wiring or Bad Power Factor Choke
    • Power Present + No Blower = Bad Motor or Bad Control Board (Most Likely the Motor)

4. Check Limits

  • Check for 24VAC between sides of the primary limit and "C".
    • Power on Both Sides = Limit Closed
    • Power on One Side Only = Limit Open 
      • Limit Open + Cool Chamber = Bad Limit
  • Alternatively, check for 24VAC between the Red/Grn wire on Pin#3 and the Red/Grn wire on Pin#6 of the 6-pin plug.
    • No Power = Limit Closed
    • Power Present = Limit Open
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Article ID: 552
Last updated: 6 Dec, 2021
Revision: 4
Access: Public
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