Flame Sensors, Detectors & CAD Cell Eyes

Browse quality options in CAD cells at F.W. Webb. Our collection includes CAD cell eyes, assemblies, and flame detectors and sensors for your oil-fired heating system. A CAD cell is a device that detects the oil burner flame and adjusts the electrical resistance when necessary. Explore CAD cells from trusted makers, including Honeywell, PurePro, Westwood, and R.W. Beckett, to find the right fit for a new or existing boiler, furnace, or water heater.

Frequently Asked Questions

Where is the CAD cell located?

The CAD cell is located on the relay switch, a gray box with a red reset button close to the oil burner assembly.

How do you test a CAD cell?

Follow these steps to test a CAD cell:

  • Turn the furnace off. Start the burner and observe for safety procedures.
  • Place a jumper on the terminal controller where the CAD cell is wired.
  • Connect an ohmmeter across the lead wires on the CAD cell to measure resistance.
  • Turn off the burner and remove the jumper.
  • Place meter leads over the lead wires to monitor the resistance of the dark CAD cell.
  • Reconnect the controller to the lead wires. Inspect the burner sequencing relay control; follow manufacturer instructions to ensure correct operation.
  • Remove the CAD cell and inspect it. Resistance should measure 100K {Ω}. Replace it if the resistance is off.
  • Remount the CAD cell correctly and remove all tape, jumpers, and test leads.
  • Inspect the furnace control circuit. Return the combustion system back to regular operations.

Is the CAD cell the same as the flame sensor?

Yes, a CAD cell is a type of flame sensor used specifically with oil-fired burners.