The heating oil tank filter removes particles from your home heating oil before they are able to enter your furnace. Removing these particles helps prevent premature failure of the furnace's components. Home heating oil contains numerous detergents which need to be eliminated. To that end, using a clean and efficient filter is an effective way to clean the oil as it leaves your tank. As a general rule, you should clean your filter before each winter season.
Locate the oil filter housing between the oil tank and your furnace. The housing is connected to the outlet of the oil tank. You will see a shut-off valve between the tank and the filter. Turn the shut-off valve to the "Off" position.
Place a pan under the filter housing to catch the oil that drains out.
Remove the retaining bolt from the top of the filter housing with a crescent wrench. As you loosen the bolt, hold the lower half of the housing in place. If you do not, the housing will fall to the floor as you remove the bolt.
Remove the lower half of the housing, pull the filter out of the housing and drain the oil into the pan. Discard the gasket from the lower part of the housing as well.
Place the new filter into the lower part of the housing. Rub a small amount of fuel oil on each side of the rubber gasket and then place the gasket onto the filter housing.
Place the lower part of the housing against the top part of the housing, thread the nut in place and then tighten it with the crescent wrench.
Open the bleeder bolt on the top of the housing with your crescent wrench. Open the shut-off valve approximately 1/4 of the way, or until oil starts to seep into the filter housing. Allow the filter housing to fill up and then close the bleeder valve with the wrench.