There are a multitude of different components inside of a gas furnace, all of which have to be kept working to ensure that your house stays heated. When things do go wrong, it pays to be able to understand the various roles of the components in your furnace. This will make it easier to diagnose potential problems, thus saving your repair person the trouble of starting from scratch. In this article, you will learn about what the flame sensor is used for–and what can cause it to stop working.
The Flame Sensor
Flame sensors are found in gas furnaces that utilize hot surface igniters rather than pilot lights. A hot surface igniter utilizes electrical energy as a way of sparking the combustion at the heart of your furnace. The flame sensor’s job is to test for the increased heat that should accompany this combustion. If it does, gas is allowed to continue flowing into the combustion chamber. If it does not, it will shut down the gas flow, thus preventing the risk of explosions and gas poisoning.
As you can see, the flame sensor is a vital piece of your furnace’s safety system. Yet it can lead to unwanted problems if it loses its ability to correctly assess the temperature inside the furnace. This will cause the sensor to cut off the gas flow even when combustion is taking place–thus keeping your furnace from warming up your home.
By far the most common cause of a malfunctioning flame sensor is that it has become excessively dirty. As layers of soot and other combustion by products build up, they make it harder and harder for the sensor to detect heat. Fortunately, this problem can be kept at bay by having your flame sensor cleaned on a yearly basis.