Get a Sense of Your Furnace’s Flame Sensor

Modern oil-fired furnaces, boilers and water heaters use a Cadmium (or CAD) Cell sensor, usually located inside the oil burner tube, to detect the presence of a flame to assure that the oil burner assembly stops pumping oil into the combustion chamber if flame ignition is unsuccessful. If you find that your oil burner shuts down often, the CAD Cell could be the cause – although you should call a professional technician immediately for a more accurate diagnosis of the problem, and to make any necessary repairs.


How Does it Work?


The CAD Cell sensor works like a photocell – it detects light (in the case of your heating equipment, flame) and sends information to the equipment’s controls. If there’s a flame present, your furnace or boiler will work properly. If there’s no detection of a flame, the system will shut down until a flame is established or the system is reset.


What if it Stops Working?


If the red reset button on your heating equipment is popped up, this suggests that the CAD Cell shut down the system due to a supposed lack of flame. You can try resetting the system only once, but if the equipment doesn’t start up or stay running after the reset, you should immediately call a professional to take a look and assess the problem. The cause of a malfunction could be anything from dirt, dust or soot blocking the CAD Cell’s sensor, damaged electrical components or a faulty CAD Cell.


Overall, no matter what you suspect the problem is, if your heating equipment isn’t working the way it should, call or contact a service company that you trust – such as our heating and cooling service partner, Fuel Services. Their experienced staff can help get your equipment up and running like new.

Professional Crew, Prompt, and Service Focused!

- Julia S. - Westfield, MA