A limit switch open on a furnace typically indicates that the furnace’s temperature has exceeded a safe threshold, causing the switch to trip and interrupt the operation of the furnace. This is a safety feature designed to prevent overheating and potential damage or danger.
When the limit switch opens, it cuts off power to the furnace burner and prevents further heating until the system cools down to a safe level. This could be due to various factors such as restricted airflow, a malfunctioning blower motor, dirty air filters, or other issues that cause the furnace to overheat.
It’s important to address the underlying cause of the limit switch opening to ensure safe and efficient operation of the furnace. This may involve troubleshooting the system or contacting a professional HVAC technician for assistance.
