A furnace relies on the flame sensor to detect a flame and ensure it is burning as required. As such, the flame sensor is a vital safety element that prevents an explosion if it reads unsafe levels of microamps. However, if the sensor malfunctions, it may cause the unit to go into a safety ignition lockout. This leads to indoor discomfort as your unit will not heat your space as needed. Therefore, you should engage a heating expert to diagnose and repair your system for peak performance. Below are signs your flame sensor is going bad.

Short Cycling 

If you notice your heating system powering down and starting at irregular intervals, you could be dealing with a faulty flame sensor. This happens because a defective sensor will not detect the heat when your turn on the unit. Subsequently, the system will close the valves, ceasing the system from operating. Over time, the burners will turn on but go off after a few seconds, causing short cycling. If you fail to address this issue, the furnace will deteriorate quickly, making it prone to breakdowns. Therefore, fixing your flame sensor as soon as it starts malfunctioning is crucial to prevent irregular heating cycles.

Broken Flame Sensor

A flame sensor may wear over time, reducing its operational efficiency. In addition, heat may accelerate the rate of deterioration, causing the sensor to crack. You should know that a crack in the outer porcelain part results in a broken sensor that cannot detect the presence of a flame, hence stopping the furnace operation. When this happens, you may want to check and see if you can remedy the damage. That said, even though the sensor is on the burner assembly, it isn't easy to locate due to the access cover. Thus, you must contact an HVAC contractor to replace it and restore its functionality.

Corrosion or Dirt Visible on the Flame Sensor

The combustion process produces small amounts of water that can infiltrate the flame sensor. As a result, the metallic sensor may corrode and rust over time. On the other hand, soot and other debris may cover the end of the sensor, reducing its performance. You must note that a dirty flame sensor produces a weak and easily extinguished flame. Furthermore, your unit may short cycle from the weak flame, causing it to wear down faster. Therefore, you should employ the services of a heating technician to clean the flame sensor as required. 

You should know that a faulty flame sensor will eventually cause an entire system breakdown. Thus, you should engage a furnace repair expert to service your system regularly for accurate flame detection.

To find out more, contact a furnace repair service.