How to Clean the Oil Furnace Motor Sensor for Maintenance

hands repairing an oil furnace heating system
  • 1-3 hours
  • Intermediate
  • 0-50
What You'll Need
Bottle Brush
Dish Soap
Warm Water
Soft Cloth
Work Gloves
Refractory Cement

Cleaning the sensor on your oil furnace motor is something you need to do on a monthly basis to ensure your furnace continues to heat your home all winter. The sensor is designed to shut down your furnace motor if the burner does not ignite or your stack has become too dirty. Before taking your sensor assembly apart check to see that your fuel tank does not need to be refilled. Remember to press the reset button on the stack sensor control after cleaning.

Step 1 – Remove Stack Control

Turn off power to the oil furnace motor. Place newspaper under where you are working to collect soot. Use a screwdriver or wrench to remove the bolts that attach the stack control to the venting chimney. Remove the sensor and its housing from the vent.

Step 2 – Clean Sensor

With warm soapy water, use a bottle brush (or another soft-bristled brush) to scrub the soot from the sensor. Make sure you clean all of the soot from the sensor. Use a soft cloth to dry the control sensor.

Step 3 – Clean Stack

Wearing work gloves, remove the venting stack in sections. Holding the stack over newspaper, bang it firmly on the floor. Do this a couple of times for each section to remove as much soot as possible. Reassemble the venting stack.

Step 4 – Reinstall Stack Control

Replace the sensor and its housing in the vent stack. Reattach the bolts securing the stack control to the vent. Use refractory cement to reseal the joint between the stack control and the chimney.