Status LED flashes nine times repeatedly, furnace will not operate

Safety: Electrical work can be hazardous. If you are not experienced with 120V wiring, contact a licensed electrician or HVAC technician.

Steps to check:

• Inspect power connections: Turn off power at the breaker. Remove the electrical access cover on the Trane furnace. Verify that the hot (usually black) and neutral (white) wires are connected to the correct terminals as indicated on the wiring diagram.
• Check ground: Confirm the green or bare copper ground wire is securely attached to the furnace chassis ground screw.
• Panel check (advanced): At the main electrical panel, verify circuits are wired correctly and neutrals/grounds are properly landed.
• Reset power: After correcting any wiring issues, restore power and check if the error clears.

When to call a professional: If you are unsure about wiring, or if the code persists despite correct polarity and grounding, have a professional evaluate the furnace control board and home wiring.