York Furnace 2 Green Flashes
StatusShown as: Two green flashes after pressing the LAST ERROR button
There are no error codes stored in the control board's memory. This is what the board answers when the LAST ERROR button is pressed and the fault history is empty.
Manual wording: “If there are no error codes in memory, the LED will flash two green flashes.”
Documented for: All UPG boards with a LAST ERROR button
Likely causes, most common first
- No stored faults in the control's five-code memory
When to call a technician
Not a fault. If the furnace is still misbehaving with no stored codes, a technician will need to watch it through a full cycle.
A York furnace throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.
Sources
- Installation Manual - Single Stage PSC Residential Gas Furnaces, TG9S and GG9S Series (95.5% AFUE Multi-position), 1083287-UIM-A-0114 (Johnson Controls Unitary Products (York), TG9S*MP, GG9S*MP single-stage PSC 95.5% AFUE gas furnaces) · checked 2026-08-25
- Installation Manual - Two Stage Variable Speed ECM Residential Gas Furnaces, TM9V Series (96% AFUE Multi-position), 1083294-UIM-A-0114 (Johnson Controls Unitary Products (York), TM9V*MP two-stage variable-speed ECM 96% AFUE gas furnaces) · checked 2026-08-25