Goodman Furnace Continuous Rapid Flash
Soft lockoutShown as: continuous rapid flash
Reversed polarity. The 115 volt line and neutral wires feeding the furnace (or the control board) are swapped, or the furnace is not properly grounded, so the control will not run the furnace.
Manual wording: “Polarity of 115 or 24 volt power is reversed”
Documented for: Goodman GMES80, GCES80 (PCBBF145 control board)
Likely causes, most common first
- Polarity of 115 volt AC power to the furnace or integrated control module is reversed
- Orange and gray wires to the transformer are reversed
- Poor unit ground
What you can safely check yourself
- If the furnace was just installed or an electrical outlet or breaker was recently worked on, mention that to whoever wired it - this code almost always follows a wiring change
When to call a technician
Correcting line polarity and grounding is electrical work inside the furnace and the panel. Call the installer or an electrician.
A Goodman furnace throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.
Source
- Installation Instructions - *MES80 / *CES80 Gas Furnace, Category I - IOG-2021H (Daikin Comfort Technologies (Goodman brand), Goodman GMES80, GCES80 80% AFUE gas furnaces (PCBBF145 control board)) · checked 2026-08-25