York Furnace 2 Green Flashes (YP9C Modulating)
StatusShown as: Two green flashes after pressing the LAST ERROR button
Indicator for 'No error codes in memory'. Not a fault.
Manual wording: “Two Green Flashes - Indicator for "No error codes in memory".”
Documented for: YP9C, YPLC modulating furnaces
Likely causes, most common first
- No stored faults in the control's five-code memory
When to call a technician
Not a fault. Johnson Controls states only a qualified service technician should use the fault-history feature.
A York furnace throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.
Source
- Installation Manual - Modulating ECM Residential Gas Furnace with ECM Motor, Models YP9C*C / TP9C*C / CP9C*C / LP9C*C (Up to 98% Modulating Multi-position), 1083292-UIM-A-0114 (Johnson Controls Unitary Products (York), YP9C*C (York Affinity modulating), and the identical TP9C / CP9C / LP9C chassis) · checked 2026-08-25