Gas Heating (Force Hot Water) Filter?

Hi everyone, I'm a total newbie at this since I just bought my first house so please bear with me: I have gas heating with force hot water, do I need to replace the filters (the oil filters) periodically? Do filters for my system even exist? I've taken some pictures, hopefully someone can help me identify... Attachment 39100 (http://www.doityourself.com/forum/attachments/gas-oil-home-heating-furnaces/39100-gas-heating-force-hot-water-filter-img_1322-2-.jpg) Here's a wider picture of the entire system: