Yellow 8 flashes Low or high line voltage (older ComfortNet board)

What the control is telling you

Yellow LED 8 flashes. Green OFF = low line voltage; green ON = high line voltage. Unit may look like it runs normally. Same meaning as L8 / H8 on newer boards (thresholds there: below 185 VAC / above 255 VAC).

Applies to: Earlier ComfortNet condensers/heat pumps with the PCBHR101-103 or PBBGR101-102 outdoor control (green, yellow and red status LEDs) - ASXC/DSXC/ASZC/DSZC revisions before the PCBHR104 change

Likely causes

• Supply voltage too low or too high
• Loose or undersized supply wiring

Test and repair steps

1. Warning: Kill power to the outdoor unit before touching wiring, the compressor terminals or the control.
2. Measure line voltage at the unit during start and run.
3. Check breakers, fuses and connections; confirm the supply matches the rating plate.
4. Contact the utility if the supply is out of range.

Models that show this code

24 models in Goodman/Amana ComfortNet ASZC/GSZC/DSZC

Other codes on the same units

• Yellow 2 flashes High side fault / high pressure trip / high pressure lockout (older ComfortNet board)
• Yellow 3 flashes Short cycling (older ComfortNet board)
• Yellow 4 flashes Locked rotor (older ComfortNet board)
• Yellow 5 flashes Open circuit (older ComfortNet board)
• Yellow 6 flashes Open start circuit / lockout (older ComfortNet board)
• Yellow 7 flashes Open run circuit / lockout (older ComfortNet board)
• Yellow 9 flashes Low 24 V control voltage (older ComfortNet board)
• Yellow ON + Red ON Compressor protector open (older ComfortNet board)