Status LED flashes code 31 (three short, one long). Inducer may run but burners do not light; furnace may shut down after a few attempts.

Safety first: Turn off power and gas before removing vent or inducer components. Exhaust contains carbon monoxide; ensure area is ventilated.

• Inspect venting: Check the PVC or metal vent pipe outside for obstructions (leaves, nests, ice). Clear any blockage. Ensure termination is not buried in snow.
• Check condensate drain (if 90%+ AFUE): Locate the condensate trap and hoses. Remove and flush the trap with warm water to clear slime or debris. Ensure hoses are not kinked.
• Inspect pressure switch tubing: With power off, remove the rubber tubing from the pressure switch and inducer port. Check for water, cracks, or blockages. Clean or replace tubing as needed.
• Test inducer operation: Call for heat and verify the inducer starts promptly and runs smoothly. If it hums, is noisy, or fails to start, the inducer motor assembly may be failing.
• Check pressure switch contacts: With a multimeter, verify the pressure switch closes (shows continuity) when the inducer is running. If it does not close even with clear venting and good inducer, replace the pressure switch with a Payne-approved part.