Basic Troubleshooting for a Malfunctioning Furnace Sensor

Furnaces have built-in safety measures to ensure that noxious gases and fumes donโ€™t leak into your house. A key component of the furnaceโ€™s safety circuit is the flame sensor, a small metal rod with a porcelain base that monitors the flame in the furnace through an electrical current. When the flame goes out, the furnace sensor immediately shuts off the gas supply to prevent it from leaking into your home and causing carbon monoxide poisoning. As such, itโ€™s important to make sure the furnace sensor is working properly.

How can you tell if the furnace sensor is malfunctioning? By keeping an eye out for certain warning signs. Stone Heating and Air, a trusted heating andย air conditioning company, lists them below:

Troubleshooting for a Malfunctioning Furnace Sensor

  • Furnace shutting down a few seconds after starting

  • Cracks in the sensorโ€™s porcelain base

  • Soot or rust on the tip of furnace sensor

The Usual Culprit Behind a Malfunctioning Furnace Sensorย 

While corrosion or wear and tear are possible causes, the usual culprit behind a sensor malfunction is carbon buildup. Thatโ€™s why itโ€™s important to routinely clean your furnaceโ€™s sensor.

How to Clean the Furnace Sensorย 

  • Shut off the furnaceโ€™s electrical supplyย – Simply turning it off isnโ€™t enoughโ€”you need to shut off the electricity supply. Remember: safety should always come first.

  • Remove the heat sensorย – The sensor is a rod-shaped device in the path of the burner. Loosen theย screws and remove it from its bracket.

  • Carefully remove residue on the sensor using emery paper or light-grit sandpaperย – After cleaning the sensor, wipe off the remaining dust using a lint-free cloth.

  • Reattach the furnace sensorย – Make sure to tighten all screws fully after putting them back in.

If youโ€™re still encountering furnace issues after cleaning the sensor or aren’t comfortable with handling sensitive furnace components, you should schedule an appointment with one of your localย home heating companies. As a rule, your furnace should be inspected by a technician at least once a year.

Are you looking for HVAC technicians near you?ย 

Stone Heating and Air is one of the most trustedย HVAC companiesย in the state. To schedule an appointment, call us at (541) 855-5521 or fill out thisย form.

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