Furnace starts inducer but does not ignite; status LED shows 3 flashes repeating; unit may cycle the inducer several times.

Safety: Turn off power and gas before working on venting or internal components. Do not operate the furnace with venting disconnected.

Steps to check:

• Inspect vent and intake: For direct-vent Luxaire furnaces, go outside and check PVC intake and exhaust terminations. Remove any leaves, snow, nests, or debris. Ensure the pipes are not iced over or blocked.
• Check pressure tubing: Remove the tubing from the pressure switch and inducer port. Inspect for splits, soft spots, or blockages. Replace if brittle or cracked. Ensure the inducer port is clear by gently probing with a small wire.
• Verify inducer operation: With panels in place and power restored, call for heat. Confirm the inducer starts promptly and runs at full speed. Listen for grinding or squealing that may indicate bearing failure.
• Condensate system (condensing models): Make sure the condensate trap is properly filled and not air-locked. Clean the trap and hoses. A blocked trap can prevent proper pressure from reaching the switch.

When to call a pro: If the pressure switch does not close even with clear venting and a running inducer, a technician should measure the draft pressure and replace the pressure switch or inducer assembly as required.