Does your furnace keep tripping the reset switch? Rather than warming up your home to the temperature set on the thermostat, it will turn off prematurely. When it trips the reset switch, your furnace will shut off – even if it hasn’t reached the thermostat temperature. By understanding why your furnace keeps tripping the reset switch, you can make the necessary changes to fix it.

The Reset Switch Explained

Most furnaces have a reset switch. Located around the blower, it allows homeowners and technicians to turn off the furnace if there’s a problem. You can activate the reset switch manually by pressing this button around the blower.

Your furnace, however, may trip the reset switch automatically if it detects a problem. The reset switch is a safety feature. If there’s a problem with your furnace, you can activate the reset switch manually, or your furnace may activate it automatically. Your furnace will shut off once the reset switch has been activated.

Overheating

Overheating may cause your furnace to trip the reset switch. Furnaces are designed to operate at a specific temperature. If your furnace exceeds this operating temperature, it may trip the reset switch. A lack of airflow, for instance, may cause your furnace to overheat and, thus, trip the reset switch.

Faulty Flame Sensor

If there’s a problem with your furnace’s flame sensor, it may trip the reset switch. The flame sensor is designed to detect the presence of a flame. It ensures that the gas valve is only open when a flame is present. If your furnace has a faulty flame sensor, it may trip the reset switch.

Gas Disruption

A disruption of your furnace’s gas supply may cause it to trip the reset switch. Assuming your furnace is powered by gas, it will need a readily available source of gas to operate. If the gas flowing to your furnace is blocked or otherwise disrupted, your furnace may trip the reset switch. A clogged gas valve, for example, will disrupt the flow of gas, in which case your furnace may trip the reset switch.

In Conclusion

Furnaces can trip the reset switch if they detect a problem. Maybe your furnace is overheating, or perhaps it has a faulty flame sensor. Problems such as these may trip the reset switch so that your furnace shuts down. If you notice your furnace tripping the reset switch, don’t hesitate to contact a heating, ventilation and cooling (HVAC) professional for assistance.