Goodman GMVM970803BN 80,000 BTU 97% AFUE Modulating Gas Furnace with Variable-Speed ECM Blower 13-FLASH Error Fix: Outdoor Ambient Sensor Fault

Error code 13-FLASH on the Goodman GMVM970803BN 80,000 BTU 97% AFUE Modulating Gas Furnace with Variable-Speed ECM Blower means: Outdoor Ambient Sensor Fault. The outdoor temperature sensor (used on communicating systems for optimal staging and modulation) has reported an open circuit, short circuit, or out-of-range reading — this sensor is mounted outside and connected to the furnace control board; only applies to systems with the optional outdoor temperature sensor installed

The most successful fix is "Test and Replace Outdoor Ambient Temperature Sensor" (medium difficulty, ~40 minutes). Estimated DIY cost: $15-$25. HomeMD has 2 community-ranked fixes for this error.

This error is rated medium severity. It should be addressed soon, but your appliance may still function in a limited capacity.

Yes — the top-ranked community fix ("Test and Replace Outdoor Ambient Temperature Sensor") is rated medium difficulty and takes about 40 minutes. Tools needed: Phillips screwdriver, Multimeter.

DIY cost: $15-$25. Professional repair typically costs $110-$160. Many homeowners save money by trying the top-ranked community fix first.

The Goodman GMVM970803BN 80,000 BTU 97% AFUE Modulating Gas Furnace with Variable-Speed ECM Blower has 8 other known error codes, including: 10-FLASH (Incorrect Blower Speed / DIP Switch Configuration), 11-FLASH (Communication Error — ComfortNet Bus), 12-FLASH (Blower Motor Fault (ECM)), 1-FLASH (System Lockout — Retry Limit Exceeded), 2-FLASH (Pressure Switch Stuck Closed), and 3 more.