I have a oil boiler with a power vent. I usually cannot get through a heating season without a service call or two even though the system is cleaned/tuned up every fall. The technician says my trouble is the power vent and I should install a chimney. I do not intend on putting up a chimney and cannot understand that the natural draft chimney is better than a power vent. I assume that the power vent provides the same draft all of the time and that a consistent draft would be a good thing. The same tech says that the direct vent is better than a power vent but the chimney is the best. I'm disgusted with my situation and I have been considering installing a propane mod/con system. Thanks