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TG8S - Flashing Code 3

Article ID: 201
Last updated: 30 Oct, 2017

York Gas Furnace: TG8S

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.


Qty Possible Causes (From Most to Least Likely):
Bad Pressure Switch
Bad Inducer Motor
Restricted Vent
Item Stuck in Inducer Motor
Bad Ignition Control


CHECKOUT:

1. Check Control Board

  • Start the furnace with a call for heat.
    • Inducer motor should start within 15 seconds.

2. Check Inducer Motor

  • Start the furnace with a call for heat.
  • Observe and listen to inducer motor operation.
    • Inducer motor hums but does not start:
      • Bad Inducer Motor or Capacitor
      • Item in Inducer (Remove inducer & check)
  • Ensure that the pressure switch closes.

3. Check Pressure Switch

  • Use a pressure gauge to check the pressure at the switch.
  • Compare actual pressure to pressure rating on the switch.
    • Pressure near or below rating = Blocked or Restricted Vent
  • Pressure well above rating, switch should be closed.
    • Switch does not close = Bad Switch

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Article ID: 201
Last updated: 30 Oct, 2017
Revision: 7
Access: Public
Views: 85
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