LED off Status LED dark - no power to the control or blown 3 A fuse

What the control is telling you

The green status light shows nothing at all, so the board is not getting 115 V or 24 V.

Applies to: KeepRite (F/G)9MXE single-stage and (F/G)9MXT two-stage 95% furnaces

Likely causes

• Breaker off or open wiring from the panel
• Blower door switch open or failed
• Transformer not putting out 24 V
• 3 A board fuse blown by a short in the 24 V wiring
• Failed furnace control

Test and repair steps

1. Confirm 115 V between L1 and neutral at the control; if missing, check the door switch and the breaker/wiring back to the panel.
2. With 115 V present, measure 24 V between the 24VAC and COM terminals.
3. If 24 V is missing and the fuse is fine, the transformer is bad - replace it.
4. If the 3 A fuse is open, look for a shorted low-voltage wire (thermostat cable included) before fitting a new 3 A fuse only.
5. If power and fuse are both good and the light is still dark, change the control board.

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

• 5 Flame sensed with gas valve off
• 6 Flame not proved during ignition trial
• 6+1 Ignition lockout after 4 failed tries
• 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
• LED steady ON Status LED on solid - control lockout (resets after 1 hour)