9 flashes Incorrect line voltage phasing

What the control is telling you

The control sees line and neutral reversed on the 120 V supply. The manual states the control is polarity sensitive and needs proper wiring and ground. Code listed only in the manual; no causes or steps given.

Applies to: A95UH, A93UH, 95G1UH, 92G1UH (sizes 045-08 to 135-20)

Likely causes

• Line and neutral swapped at the furnace
• Poor or missing ground

Test and repair steps

1. Turn off power at the disconnect before touching wiring or components.
2. Check line and neutral at the furnace feed and swap them if reversed.
3. Check the furnace ground.

Models that show this code

15 models in A95/A93/95G1/92G1UH, A95/95G1UH, A93/92G1UH

Other codes on the same units

• 3 flashes Pressure switch open with inducer on
• 4 flashes High limit switch open
• 5 flashes Rollout switch open
• 6 flashes Pressure switch cycle lockout
• 7 flashes Lockout - no ignition
• 8 flashes Lockout - too many flame dropouts
• LED off No power to control or control hardware fault
• LED on Normal operation