How to bleed my heating/fuel oil burner after oil delivery

How to bleed my oil burner?

Running out of oil can cause a number of problems for your heating system.

First, you may have to bleed your oil burner so that it can get running again.


When you run out of fuel oil, air gets into your lines from the tank. This is not good and will cause your heating system to not run properly or at all. 

Don't fret! Our delivery drivers are trained to provide this service for a small fee after they fill your tank.

It is always good to know how your equipment works and how to perform small repairs like this one. It's easy and can save you from that small fee! We have provided you with step by step instructions with pictures and videos below!

Keep in mind...

Bleeding the oil burner is one of several problems that can be caused by running low or out of fuel. You can learn about all of the things running out can cause here

Stop worrying about running out of heating oil!

Checking the gauge, or even worse, sticking the tank IS ANNOYING!

We offer our valued customers a solution so they never have to worry about the negative effects of running low or out of oil again! Sign up for our Automatic Heating Oil Delivery service for the stress-free option of oil heat!


Part 1 - Prepare to Bleed your Heating Oil Furnace

1. Turn the reset cycle on.

You will need to flip a switch on or near your furnace to turn on the reset cycle. The furnace must be on and fuel is only pressurized when reset cycle is activated. The location of the reset cycle switch depends on the model of your oil furnace. 

How to bleed an oil furnace step 1 turn on reset cycle

2. Locate the bleed screw on the fuel pump near where the fuel line comes in.

The screw is usually a small nipple-like screw.

How to bleed an oil furnace step 2 locate the bleed screw

3. Place a small bucket or pan under the bleed screw. 

The bucket will catch any fuel that sputters out as you bleed an oil furnace.

  • If the screw is in an area that is impossible to put a bucket or small tray under, use a flexible tubing just big enough to fit over the bleed screw. Place the tube over the bleed screw and direct it to an area where you can fit the tray or bucket.

How to bleed an oil furnace step 3 Place a small bucket under bleed screw

Part 2 - Bleed the Furnace

1. Use a small crescent wrench or pliers to slightly loosen the bleed screw. 

Make sure the screw remains on the pump and is only a little loose, so it doesn’t fall completely off when you bleed the oil furnace.

How to bleed an oil furnace step 4 loosen bleed screw

2. Push the reset button on the furnace to turn it back on.

As the furnace starts to suck fuel in, air and fuel will spit out of the bleed screw.
  • Keep your pliers or wrench on the screw ready to tighten it. This will also ensure the screw remains in place, if you did loosen it too much.
  • If the furnace cycle ends before the air and fuel mixture stops sputtering, you’ll need to push the reset button again to continue the bleed process until the furnace pushes out all the air from the line.
  • Some furnaces may have a lockout system that won’t allow you to reset more than one or two times. If this happens, you can override the lockout by holding the reset button in until the furnace kicks in again.

How to bleed an oil furnace step push reset button

3. Tighten the screw as soon as the air stops sputtering out and a steady stream of fuel pours out.

Be careful not to tighten it too much. Replacing a stripped bleed screw can be a very costly project.

How to bleed an oil furnace step 6 Tighten the bleed screw

4. Let the furnace continue to run.

 It should run normally without problems now. If it doesn’t restart the next time, check the line for air again by repeating the bleed process. You may not have gotten all the air out the first time, or you may have a debris blockage in your fuel line.
How to bleed an oil furnace step 7 let the heating oil furnace run
Back to blog