Changing Your Furnace Filter: Step-By-Step Guide For Homeowners

Changing the fuel oil filter in your furnace is a simple task that can be done in a few minutes and will save you money and improve the efficiency of your heating system.

The first step is to turn off the electricity and oil supply to your furnace. Then, remove the filter base and clean the filter canister base. Next, add the new furnace oil filter and bleed air from the filter before turning the oil supply back on. Finally, clean the pump strainer if your unit has one.

Turn off the electricity and oil supply

Before changing the oil filter, it is important to turn off the electricity and oil supply to your furnace. This is a crucial safety precaution when performing any maintenance on your heating or cooling equipment.

To start, locate the shutoff valve on the oil supply line above the filter. Turning off the valve will cut the oil supply to the filter. Even after shutting off the valve, there may still be oil left in the line and filter, so be sure to place a catch pan or bucket below the filter to avoid any spills.

Next, turn off the electricity to your HVAC unit. This will ensure that you can work on the furnace safely, without the risk of electric shock.

Now that the electricity and oil supply are off, you can proceed to the next steps of changing the oil filter: removing the filter base, cleaning the filter canister base, and adding the new furnace oil filter.

Remove the filter base

To remove the filter base, you must first turn off the electricity and oil supply to your furnace. This is a necessary safety precaution. There should be a shutoff valve located on the oil supply line above the filter. Even after you turn off the oil, there may be some leftover in the line and the filter, so place a catch pan or bucket below the filter to prevent oil contamination in your home.

Your furnace oil filter is covered by a base that detaches from the unit. Depending on your model, you can either loosen the bolt that holds the base in place or simply unscrew the base from the supply line. Once you have done this, you should be able to remove the old filter and either throw it away or take it out for cleaning.

Clean the filter canister base

To clean the filter canister base, you will need to remove any oil sludge, dirt, debris, and oil from the bottom of the oil filter canister base. Check for water contamination in the oil tank when changing the oil filter cartridge. Water contamination in oil tanks can be detected by examining the bottom of the oil filter canister. If you see actual water, or more likely rusty red sludge, this may be evidence that water from the oil storage tank has been trapped in and rested in the bottom of the oil filter canister.

To clean the canister base, use a soft toothbrush or a cloth. If it is very dirty, you can soak the pieces in kerosene for a minute or two and then scrub them with a soft brush. Follow the same cleaning process if you have a unit with a permanent filter.

Add the new furnace oil filter

Now that you've removed the old filter, it's time to install the new one. The filter will usually be made up of a cartridge that fits into place in the canister base. Put it into the base, and screw the base directly into the top piece, or use the bolt to tighten it back into place.

Make sure that the O-ring that seals the connection between the top and base is fit securely in place when you do so. If your cartridge package came with new filters and gaskets, swap these in for the existing ones. If there was no O-ring included, check the quality of this part before your screw it back in. If the older seal looks cracked, brittle, or otherwise damaged, make sure to purchase a new one and install it before screwing the filter back on.

Bleed air from the filter and turn the oil supply back on

Bleeding air from the filter and turning the oil supply back on are crucial steps in ensuring your furnace functions optimally and safely. Here's a detailed guide on how to perform these steps effectively:

Bleed Air from the Filter

• Locate the Bleeder Valve: Find the bleeder valve, which is typically a small hexagonal or square nut, often located near the fuel line or oil pump. You may need to consult your furnace's manual for its exact position.
• Place a Container: Position a small container or bucket under the bleeder valve to catch any oil drips and avoid creating a mess.
• Open the Bleeder Valve: Using a suitable tool like a screwdriver or wrench, slowly turn the bleeder valve counterclockwise. You may hear a hiss of air, followed by a release of oil.
• Close the Bleeder Valve: Once you see a steady stream of pure oil without air bubbles, carefully close the valve by turning it clockwise. Be gentle to avoid overtightening, which can damage the valve.

Turn the Oil Supply Back On

• Refill the Oil Tank: Now, it's time to refill your oil tank. Use a can of heating oil or contact your oil supplier for a delivery. Ensure you don't overfill the tank and maintain the proper level as indicated by the tank's gauge.
• Restart the Furnace: Turn the power back on at the furnace or circuit breaker. Set your thermostat to a higher temperature to initiate heating. Your furnace should ignite and start distributing warm air throughout your home.

Remember, safety should be your top priority when performing any maintenance or repairs on your furnace. If you feel unsure or uncomfortable at any point, don't hesitate to contact a heating service professional for assistance.

Frequently asked questions