The best way to ensure that your waste oil burner will last a long time is to not only clean it quarterly and annually but to filter all the used motor oil going into it.
Keep in mind that this type of boiler is made to burn waste oil for fuel but you want the best quality motor oil going into it as you possibly can. This seems to be the major obstacle of most quick lubes purchasing these machines. Their employees never seem to care about filtering the oil, at all, and seem to have no qualm about adding oil with coolant and water (an absolute "no no") to this really expensive boiler.
The best way to ensure that the purest oil is going into your waste oil burner is to put the used motor oil through a centrifuge. You can suck the oil from a tank, put it through several different filters which take forever, than put it into the final holding tank to be used but this method takes an incredible amount of time. If something gets plugged, the filter or the hose, it can create a huge mess. I have done this many times!
A centrifuge is a round device that uses the sedimentation principal, where the centripetal acceleration causes the heavier particles in any fluid or substance to move out along the radial direction (to the bottom) and allows the lighter particles to move to the top or center. Basically a waste oil centrifuge will spin all the crap out leaving you will almost pure motor oil without any garage in it. This is the absolute best way to clean any waste oil you receive. It will guarantee that you are putting the very best fuel in your several thousand dollar piece of machinery.
