Your flame sensor is a safety device in your furnace. It ensures the gas that fuels your furnace is being burned and not escaping into the vent system. In this episode, we’re going over the basics of your flame sensor. We’ll talk about catching a bad one and what you can do in a pinch if it fails.
The flame sensor detects when a flame is burning inside the burner assembly of your furnace. It does that by checking for a tiny change in electricity that fire creates. If it doesn’t sense that change, the sensor assumes gas is building up in your furnace and shuts it down.
To do its job, the flame sensor needs to sit in the flame. Over time the sensor will form a coating of black buildup from the fire. That will stop it from sensing those tiny electrical changes. When that happens, it thinks there isn’t any flame. It’ll restart your furnace a few times, then lock it down.
We talk about the signs of a dirty flame sensor in the video. The good news is that if your flame sensor is dirty, you can try to clean it until you can get a tech over. We go over the steps in detail in the video as well, and some flame sensors are a bit more difficult to access. If you do have easy access to yours, it should be on the opposite side of the burner assembly from the igniter. A lot of times they’re held in by a single screw.
If you think your flame sensor is giving you trouble, Any Hour Services would be happy to help. One of our certified HVAC technicians can come to take a look and let you know what to try next. You can give us a call or schedule an appointment online.
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