York TM9V080B12MP11 Error Code Limit Circuit Open - Blower Failure: Limit Circuit Open - Blower Failure

What Does Code Limit Circuit Open - Blower Failure Mean?

The 11-red-flash code on the York S1-33103010000 board is a hard lockout triggered when a limit switch has been continuously open for more than 5 minutes. This is more severe than the 4-red-flash code (which is a standard limit trip). The extended open time suggests the furnace cannot cool itself at all, pointing to a serious airflow problem.

The most likely scenario is that the blower motor has failed or is running too slowly to move meaningful airflow. Without the blower circulating air, the heat exchanger retains all the residual heat and the limit switch stays open indefinitely. A severely clogged filter that has essentially become a solid wall of dust can produce the same result.

Unlike the soft lockout codes (which auto-reset after 1 hour), this hard lockout requires a manual reset — you need to cycle 24V power to the control board after fixing the underlying problem. Simply replacing the filter may resolve it if the filter was the cause, but if the blower motor is not running, professional service is needed.

How to Fix It: Check the Air Filter and Verify the Blower is Running

What You'll Need

• New air filter (same size as current — check dimensions on frame)
• Flashlight

Steps

1. Turn off power AND shut off gas supply Turn the furnace power switch OFF. Turn the gas shutoff valve to OFF (perpendicular to the pipe). Wait 5 minutes. If you smell gas at any point, leave the area immediately and call your gas company.
2. Check and replace the air filter Remove the air filter from your York furnace. If it is severely clogged (completely opaque, matted with dust, or partially collapsed from suction), replace it immediately. Install a new filter with the airflow arrow pointing toward the blower.
3. Check all vents and registers Walk through every room and make sure all supply registers and return grilles are open and unobstructed.
4. Reset the control board Because this is a hard lockout, you must cycle power to reset. With the furnace power switch already OFF, wait at least 30 seconds, then turn it back ON. Turn the gas back ON (parallel to pipe).
5. Call for heat and listen for the blower Set the thermostat to call for heat. During the heating sequence, after the burners ignite, the blower motor should start within 30-60 seconds. Listen for the blower — you should hear air moving through the ductwork. If the blower does not start or sounds abnormal, that is likely the root cause and requires a technician.

When to Call a Professional

Contact a licensed HVAC technician if:

• The blower motor does not start at all during the heating cycle
• The blower motor hums but does not spin
• You hear grinding, scraping, or loud squealing from the blower
• The 11-red-flash code returns after filter replacement and reset
• The blower wheel is visibly clogged with dust (do not attempt to clean while running)