Status LED flashes code 33 (three short, three long). Furnace starts but shuts down on limit; blower may continue to run.

Safety first: Limit and rollout trips indicate overheating. Turn off gas and power before inspection. Do not bypass safety switches.

• Replace or clean filter: Install a new filter of the correct size and MERV rating. Avoid overly restrictive filters on older Payne furnaces.
• Check airflow: Ensure all registers and returns are open. Remove any obstructions from grilles.
• Inspect blower speed tap: On the control board, verify the correct blower speed tap is used for heating (refer to the furnace data plate). Too low a speed can cause overheating.
• Reset rollout switches (if manual reset): Locate rollout switches near the burners. If they have a red or white reset button, press gently. If they trip again, stop using the furnace and call a professional to inspect for heat exchanger or venting issues.
• Test limit switch: With power off, check continuity across the primary limit. If open and not resetting, replace the limit switch.