The General 1A-25A Fuel Oil Filter is probably the most common filter in use today in residential homes that have oil burning heating and water heating appliances. Replacing it is a relatively easy task that you can do. Replacing it can keep sludge, debris and small amounts of water from being pumped to your oil burner nozzle where it may clog the nozzle. The filter elements are cheap costing only $3-5 and can save down time and a service call.
To change a General 1A-25A Fuel Oil Filter Element you will need a good quality adjustable wrench or a wrench set, something to catch spilling oil with such as old metal baking pan, some rags, and a flashlight in most cases because the filter always is hidden away in a dark spot. You will also need to buy a new replacement element and the General part number you want is a # 1A-30, which is a 10 micron wool felt element.
I am assuming that you have already checked and made sure that your filter is a General 1A-25A. You will then need to locate oil burner service switch, which you need to turn off, and the valve that will stop the oil from flowing to the filter to allow you to change the element without excessive spillage. The valves used are unique because the valve is a fused valve, which in the event of a fire are designed to melt and close on its own. You will find that the knob unscrews then the stem of the valve snaps closed. Once the valve is closed, isolating the filter, go to the filter and place the catch pan under it to catch any spillage. I like to use the vent screw above the outlet to verify the oil is off, opening that first to check. The next step is to loosen the center bolt on the top of the filter. This bolt is the one that secures the filter canister in place. After the center bolt is loosened and it is raised about a 1/8” above the filter housing bang the center bolt sharply one time with the wrench and the canister will come loose. Invert the canister and the old element into the catch pan, and dump out the oil and old element. Make sure the gasket is removed from the canister and has come completely off the top housing. Remove the center screw and vent screw and take the washers off them. Open the box with the new filter parts and put the new washers from that box on the center bolt and vent screw. Place the new filter element and place it in the canister then take the rubber gasket for the canister and moisten it with a thin film of oil then push it into place on the canister. Lift the canister and new element into place, hand tighten the center screw, and make sure the gasket is seated properly then tighten the center screw tightening the canister into place. Leave the vent screw loose and turn on the oil valve returning to watch the vent screw and wait for oil to come out tightening the screw once oil reaches it. Wipe the filter off with a rag and check for any signs of leakage.
Once the filter element has been replaced get ready to bleed the air out before turning on the service switch. See “How to Bleed an Oil Burner After Running Out of Fuel” to read about bleeding the oil burner and restarting it. After bleeding the burner returning it to service its cleanup time.