This report documents a study performed on a set of ICDE events related to heat exchangers. The events studied here had been collected in the ICDE database. Organisations from Canada, Germany, Japan, Spain, Sweden and the United States contributed to the exchange. The ICDE Project is the only international effort where large amounts of data from different countries are collected and analysed to draw conclusions about common cause failures. Forty-six (46) ICDE events, exhibiting at least some degree of dependency, and spanning a period from 1987 through 2007, were examined in the study. The database contains general statistical information about event attributes like impairment of the components in the observed populations, root cause, coupling factor, detection methods and corrective actions taken. The events contained in the ICDE database were analysed with respect to failure modes, degree of impairment, failure symptoms, failure causes, and technical fault aspects.