Most furnaces are locked out of ignition because of problems with defective igniters, flame sensors, and dirty air filters. These are the most frequently-cited lockout triggers that are discussed.
The malfunctioning of the flame sensor is among the most frequent reasons for lockouts. When your furnace is about to fire, the sensor can detect the presence of flame; if your sensor is defective or dirty, the sensor will not be able to detect a flame, and the control will stop the fire-starting sequence. Most modern furnaces allow you to turn on the furnace twice before entering a lockout.
Fix: Make sure you check the burners on your furnace. If they don’t go out after a couple of seconds, it could indicate that the sensor isn’t functioning properly. Visual observation should be used as the second check. The warning indications are soot-covered flame sensors or cracks in porcelain casing.
The igniter is yet another commonly identified lockout cause. If the igniter in your furnace is not working, the sensor will not be able to detect the flame, and the controller will prevent the furnace from starting. After the third time, the furnace will likely enter a lockout state. If your furnace is equipped with an ignition light, the lockout could also result from failing to turn on your main burner.
Fix: The igniter is likely the issue if it displays continuity in the electrical circuit. If it does show no continuity, it may have to be replaced. If you need help, please call a heating service technician in San Bernardino.
If the first two parts above are in good working order, you’ll need to shift to the vents and air filters. This will concentrate more on the component known as the limit switch. It is responsible for monitoring the fuel pressure as well as the internal temperatures of the heater.
Fix: It is recommended to replace 1-inch filters every 3 to 6 months. For air filters 3-4 inches in diameter, you’ll have to replace them every 6 to 9 months. Ensure you inspect the vents to be sure nothing is blocking the air flow.
If none of these solutions works for you, the best option is to call experienced HVAC technicians to examine your furnace. Contact Daniels Heating And Air Conditioning at 888-523-2643 for heating repair in San Bernardino.