{"id":1243,"date":"2024-02-26T11:00:00","date_gmt":"2024-02-26T16:00:00","guid":{"rendered":"https:\/\/www.accomfort.us\/blog\/?p=1243"},"modified":"2024-03-11T16:55:33","modified_gmt":"2024-03-11T20:55:33","slug":"the-flame-sensor-a-key-safety-device-in-your-furnace","status":"publish","type":"post","link":"https:\/\/www.accomfort.us\/blog\/heating-service\/the-flame-sensor-a-key-safety-device-in-your-furnace\/","title":{"rendered":"The Flame Sensor\u2014A Key Safety Device in Your Furnace"},"content":{"rendered":"
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Gas furnaces. They\u2019re everywhere. Even with the influx of technology like heat pumps and ductless mini splits, gas furnaces still hold the title of the most common type of home heating system in the US. Gas furnaces wouldn\u2019t be so popular if they created safety hazards, and all gas furnaces have several devices that help keep them running safely.<\/p>\n\n\n\n

Today, we\u2019re going to look at one of these key devices, the flame sensor. The flame sensor isn\u2019t just a safety mechanism: it helps regular normal furnace operation and keeps the system working efficiently and evenly.<\/p>\n\n\n\n\n\n\n\n

The Job of the Flame Sensor<\/strong><\/h2>\n\n\n\n

The flame sensor plays a critical role in how your gas furnace operates. The sensor detects the presence of flames from the burners, which is to ensure that the burner lights properly. If the flame sensor doesn\u2019t detect flames, it will shut off the gas valve and stop gas flow to the burner. This occurs to prevent unburned gas from flooding the combustion chamber of the furnace, where it presents a large combustion hazard that might escape into the areas around the furnace.<\/p>\n\n\n\n

Older furnaces used a device called a thermocouple to detect flames. Most modern furnaces use the more accurate and reliable electronic flame sensor. If you have a furnace that still uses a thermocouple, the heating system is probably old enough that you should consider replacing it. <\/p>\n\n\n\n

Signs of a Failing Flame Sensor<\/strong><\/h2>\n\n\n\n

If the flame sensor is starting to fail because of dust or dirt, or it has failed because of an electric malfunction, you may notice several warning signs:<\/p>\n\n\n\n