Furnaces are designed to prevent fire or other hazards. To be able to do this, they have sensors that detect anomalies, triggering an automatic shutdown.The ignition lockout is the furnace controller. When the furnace detects an unsafe condition, the furnace will shut off power and fuel to stop any potential hazard. There are several sensors found in your furnace that can initiate ignition lockout. \
In most cases, the furnace will go into the ignition lockout mode if a flame is detected. Issues with flame sensors, igniters, and limit switches are also likely to trigger ignition lockout. Below are the main issues you should look at in case your furnace starts ignition lockout. \