Goodman GMVM970803BN 80,000 BTU 97% AFUE Modulating Gas Furnace with Variable-Speed ECM Blower 5-FLASH Error Fix: Flame Sensed Without Gas Valve Call

Error code 5-FLASH on the Goodman GMVM970803BN 80,000 BTU 97% AFUE Modulating Gas Furnace with Variable-Speed ECM Blower means: Flame Sensed Without Gas Valve Call. Flame is being detected by the flame sensor when the gas valve has not been commanded to open — this is a dangerous condition indicating a possible gas valve leak, stuck-open gas valve, or a false flame signal from a faulty flame sensor or contaminated flame rod; the system will lock out for safety

The most successful fix is "Test and Replace the Flame Sensor or Gas Valve" (hard difficulty, ~60 minutes). Estimated DIY cost: $10-$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 the Flame Sensor or Gas Valve") is rated hard difficulty and takes about 60 minutes. Tools needed: T20 Torx screwdriver, Multimeter, Gas leak detector.

DIY cost: $10-$25. Professional repair typically costs $150-$250. 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)), 13-FLASH (Outdoor Ambient Sensor Fault), 1-FLASH (System Lockout — Retry Limit Exceeded), and 3 more.

Error code 5-FLASH also appears on 2 other Goodman models: GMSS920804CN 80,000 BTU 92% AFUE Single-Stage Gas Furnace, GMVC960804CN 96% AFUE 80,000 BTU Two-Stage Gas Furnace. The fix may vary by model, so check each model's specific page for tailored repair steps.