LED heartbeat Control OK - idle or running, no faults

What the display is showing

The green status LED on the furnace control pulses (bright-dim heartbeat) when the control is powered and has no active fault. Right after a power interruption during a heat call the LED flashes code 1+2 during the blower run period, then returns to the heartbeat.

Applies to: (F/G)9MXE and (F/G)9MXT furnaces

Settings for these units

• Filter size by casing width · KeepRite (F/G)96VTN Two-Stage Variable-Speed Furnace

Models that show this code

16 models in KeepRite (F/G)9MXE Single-Stage Furnace, KeepRite (F/G)9MXT Two-Stage Furnace

Other codes on the same units

• 7 Limit circuit lockout
• 8 Gas heating lockout - manual reset needed
• 9 High-heat pressure switch or relay did not close or reopened
• 10 Line voltage polarity reversed
• Component self-test Run all furnace components for a short test
• LED off Status LED dark - no power to the control or blown 3 A fuse
• LED steady ON Status LED on solid - control lockout (resets after 1 hour)
• Stored fault recall Read the last stored fault code from the control