York Affinity YP9C seven red flashes: ignition lockout

What Does Error 7 red flashes Mean?

On the documented York Affinity YP9C, seven red flashes indicate lockout because ignition did not succeed after three attempts. The control waits one hour before another automatic attempt. The pattern reports the outcome, not whether the cause is gas supply, ignition, burner, flame sensing, grounding, venting, or control. Applies to: Affinity YP9C modulating gas furnaces This flash count is scoped to the YP9C manual cited here. York LX, Latitude, rooftop, heat-pump, and newer communicating controls can use other code systems, so the model and LED colour must match. Owner-safe checks: With panels closed, save the seven-red-flash pattern and observe one startup only through the factory viewing area without forcing another attempt. Qualified technician: Venting, pressure safeguards, ignition, gas, burners, flame current, grounding, combustion, and control testing require licensed York service.

Other Common York furnace — Affinity YP9C modulating gas furnaces Error Codes