Error code 03 and inducer runs continuously but burners will not light

Safety: Turn off power and gas before working on venting or internal components.

Error 03 usually means the pressure switch did not close when the inducer started.

• Check vent and intake pipes:
  • Inspect outside terminations for leaves, snow, bird nests, or insect screens clogged with debris.
  • Clear any obstructions and ensure both intake and exhaust are open.
• Inspect the inducer motor:
  • Confirm the inducer starts promptly and runs smoothly without loud grinding.
  • If it is slow to start, noisy, or very hot to the touch, the inducer assembly may need replacement.
• Verify pressure switch tubing and ports:
  • Remove the tubing and check for cracks, splits, or moisture.
  • Clear the inducer port and replace brittle tubing with OEM-rated tubing.
• Test the pressure switch:
  • With a manometer, verify the inducer is producing the required negative pressure (inches W.C.) listed on the switch label.
  • If proper draft is present but the switch does not close, replace the pressure switch.
• If venting or combustion air issues are suspected (long runs, many elbows), have a licensed HVAC technician verify installation against American Standard specifications.