How to Bleed an Oil Furnace: Step-By-Step Guide

Cleveland’s mostly mild summers and crisp autumns are a delight, but when winter rolls in, you need an oil heater you can count on to keep the chill at bay. The last thing you want is to be caught off guard on a freezing winter day with a furnace that’s run out of heating oil.

Fortunately, you can quickly restore warmth to your home by bleeding and restarting your furnace yourself. Before diving in, be sure you’ve got a fresh heating oil delivery on the way. Then, follow our step-by-step guide to get your furnace back up and running smoothly.

What Is Furnace Bleeding?

Over time, air can get trapped in a furnace’s fuel line, causing the furnace to sputter or even shut down completely. Furnace bleeding removes air from the fuel line, ensuring a smooth oil flow to the burner.

Regular furnace bleeding keeps your heating system running efficiently and helps prevent unexpected breakdowns during Cuyahoga County’s cold winter months. A relatively quick and straightforward DIY task, it can save you time, money, and the stress of dealing with a chilly home.

Steps to Bleed Your Furnace

Are you ready to tackle this critical heating maintenance task? Let’s get started!

Step 1: Turn the Furnace Off

This prevents accidental starts while working on the furnace, ensuring the equipment’s safety. Locate the main power switch or shut off the furnace using your thermostat. Let the system cool down before proceeding.

Step 2: Locate the Bleed Screw

The bleed screw is typically located where the fuel line connects to the burner; it might be a small, hexagonal or slotted screw. This is when the trapped air is released, so it’s crucial to correctly identify it before moving on.

Step 3: Place a Small Oil Pan Under the Screw

The oil pan catches any fuel that might spill as you bleed the line. Have some rags handy to clean up any drips, ensuring the area around your furnace remains clean and oil-free.

Step 4: Lightly Loosen the Bleed Screw

Use a wrench or screwdriver to gently loosen the bleed screw. Don’t remove it altogether — just loosen it enough so air can escape. You’ll hear a hissing sound, indicating air is being released from the fuel line. Take particular care during this step; if you open the screw too much, oil will flow out once the air is purged.

Step 5: Push the Reset Button

With the bleed screw still slightly open, press the furnace’s reset button. This triggers the pump to start, pushing oil through the line and forcing any remaining air out. Monitor the oil pan and listen for the sound of oil instead of air escaping, indicating the process is nearly complete.

Step 6: Tighten the Screw

Once you see a steady stream of oil that’s free of air bubbles, retighten the bleed screw by carefully turning it clockwise until it’s snug. Don’t overtighten the screw. This seals the system, ensures air doesn’t enter the fuel line, and allows the furnace to operate efficiently.

Step 7: Run the Furnace

Turn the furnace back on and let it run for a few minutes to ensure everything’s functioning correctly. The burner should run smoothly, without any sputtering or hesitation.

If everything seems in order, you’ve successfully bled your furnace and can enjoy the peace of mind that your heating system is ready to keep you warm! Remember, if you don’t want to tackle the task yourself, a quick call to our team of heating experts is all it takes to ensure your home stays comfortable all winter.

Choose P.K. Wadsworth Heating & Cooling for Furnace Services

If you don’t usually handle home maintenance projects, we don’t recommend you take furnace bleeding on as your first project. While the task isn’t inherently dangerous, you’re dealing with equipment that gets extremely hot and is connected to electricity. Why not let P.K. Wadsworth Heating & Cooling handle the job for you?

For over 85 years, Cuyahoga County residents have trusted us for all their furnace needs. We offer affordable, high-quality heating services that will keep your home comfortable and safe throughout winter.

Contact us now to learn more or schedule services with the P.K. Wadsworth Heating & Cooling team today.