I don't know much about boilers but I moved into our new house assuming boiler was working fine etc. We felt it was using too much oil and had someone out to check the boiler. When he came he told me the boiler had never been commissioned on installation and that because of that it was using twice as much oil as it should ( because apparently there are things inside that are knocked about during delivery and must be put right once installed)- also all the settings done by the plumber were completely wrong. So yeah, I'd say its worth getting a proper guy out to service it and to check it. Anyway it has to be done once a year...