SLOW-FLASH
Goodman · GMVM970803BN 80,000 BTU 97% AFUE Modulating Gas Furnace with Variable-Speed ECM Blower
The LED is flashing slowly (~1 Hz continuous) — the system is in a timed lockout or startup delay period; wait for the delay to expire; if it persists, look for a counted flash pattern indicating a specific fault code
Error SLOW-FLASH on the Goodman GMVM970803BN 80,000 BTU 97% AFUE Modulating Gas Furnace with Variable-Speed ECM Blower means: System in Delay / Timed Lockout. The top-ranked community fix is “Diagnose and Clear Underlying Fault Causing Lockout” (hard difficulty, ~90 min, DIY cost: $0-$20). 2 community-ranked fixes available below.
Published February 2026 · 2 fixes · furnace
Content is based on manufacturer service documentation, community repair experience, and OEM technical bulletins. Always verify with your owner's manual.Learn about our editorial standards.
While many furnace repairs can be done safely at home, consider hiring a qualified technician if:
Average professional repair cost for this issue: $150-$300.
Incorrect Blower Speed / DIP Switch Configuration
Communication Error — ComfortNet Bus
Blower Motor Fault (ECM)
Outdoor Ambient Sensor Fault
System Lockout — Retry Limit Exceeded
Pressure Switch Stuck Closed
Pressure Switch Did Not Close
High Limit Switch Open
The Goodman GMVM970803BN 80,000 BTU 97% AFUE Modulating Gas Furnace with Variable-Speed ECM Blower has 8 other known error codes:
Error code SLOW-FLASH also appears on 2 other Goodman models:
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