How to change the gauge on an oil tank

Updated February 21, 2017

An accurate gauge is essential to monitoring your home fuel-oil consumption and preventing overfilling by the oil company. If your existing gauge is stuck or showing inaccurate readings, replacement gauges are inexpensive and readily available. Replacing the gauge in a fuel-oil tank requires only basic tools and can be accomplished in a matter of minutes.

Clean any dirt or debris away from the gauge in the top of the fuel-oil tank.

Use a wire brush to remove any paint or sealant away from the base of the fuel gauge. Spray penetrating oil on the base of the fuel gauge and allow it to soak into the threads for several minutes.

Tighten a Stillson wrench securely on the hex-shaped base of the fuel gauge and turn the gauge counterclockwise to remove it from the oil tank. Pull the gauge straight up out of the tank until the pivot point that attaches the float arm is visible in the gauge opening. Turn the gauge tube until the float arm is pointing straight down into the tank then pull the float arm and float straight up out of the tank through the gauge opening.

Hold the float arm on the new gauge up so it is parallel to the gauge tube and slide both into the gauge opening in the top of the tank. Make sure that the float arm unfolds once it clears the edge of the gauge opening.

Coat the threads of the new gauge with a thin layer of thread sealant and screw the gauge into the gauge opening, turning it clockwise until it is finger tight. Use a Stillson wrench to tighten the gauge an additional 1/2 turn.


Make sure that the reading window in the gauge will be easily visible after installation. Inspect your tank, gauge and lines regularly to ensure proper operation.


Fuel oil is extremely flammable. Do not attempt any repairs or service to your fuel-oil heating system near open flames or while smoking.

Things You'll Need

  • Wire brush
  • Penetrating oil
  • Stillson wrench
  • Thread sealing compound
Cite this Article A tool to create a citation to reference this article Cite this Article

About the Author

David Young has written for the website for the Save Darfur Coalition and is currently writing articles for various other websites. Young holds a Bachelor of Arts in philosophy from Western Carolina University.