8 Gas heating lockout - manual reset needed

What the control is telling you

The control has locked out gas heat and will NOT reset itself. Turn power off for 5 minutes, then retry.

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

Likely causes

• Gas valve relay on the board stuck closed
• Gas valve wire miswired or shorted

Test and repair steps

1. Warning: this lockout points to a valve circuit fault - check carefully before restoring gas.
2. Turn power off, wait 5 minutes, power back on.
3. Inspect the gas valve wiring for miswiring or a short.
4. If the code returns with good wiring, replace the furnace control.

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
• 9 High-heat pressure switch or relay did not close or reopened
• 10 Line voltage polarity reversed
• 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)