The economizer installed on a recovery boiler is the component responsible for the greatest number of tube leaks that result in lost production for the pulp and paper industry. This technical information paper is based on a comprehensive study initiated by the AF&PA Recovery Boiler Committee (1). A condensation of the report was presented at a TAPPI Conference in 2006 (2). The study determined primary causes of economizer tube damage are stress or fatigue cracks, poor quality welds, internal and external corrosion and thinning, and mechanical design. The knowledge of failure mechanisms was applied to relate operating and maintenance practices that could contribute to failures and then apply these in a review of economizer failure incidents to seek confirmation of practices detrimental to economizer integrity. These guidelines are a summary of those analyses.