Like engines, oil-fuelled heating systems depend on clean oil. Without oil filters boilers develop blockages in the pump, burners or pipework. Blocked filters also force your system to work harder, reducing its energy efficiency and shortening its life. Inline boil filters for domestic boilers are housed in a steel or aluminium pot between your fuel supply and boiler. Their filter elements are usually paper-based, but reusable steel elements also exist. The same assemblies work with diesel, paraffin or bio-fuels. Common brand-names include Altecnic, Crosland, and EOGB. Changing boiler fuel oil filters Although your boiler should be professionally serviced regularly, changing the heating oil filter is a straightforward DIY job. With a little preparation, you can avoid any mess. Protect your floor and have a bowl ready to catch spillage. Switch off the boiler at your breaker box and again at the switch on or near the boiler itself. Close the oil supply valve and wait for everything to cool if necessary. You release the pot that holds the filter by extracting the centre bolt from the assembly. The old filter lifts out, but it’s wise to tip out the oil to look for sludge or debris left inside. Wipe if necessary, push in the new filter and reassemble, remembering to check the bolt gasket is sound. Re-open the valve and watch for leaks. Depending on your model, there may be a bleed screw to let out air left inside, and this also has a gasket. Boiler oil filters for domestic boilers vary mainly according to pipe width. If in any doubt call us for advice.