Feedwater heater (FWH) failures have had a significant adverse impact on availability and thermal efficiency in large fossil-fired power plants. The purpose of this study is to document the major causes of FWH failures and to make appropriate recommendations for improvement. Data were gathered through a literature search; a questionnaire distributed to utilities with fossil units over 500 MWe; and visits to selected utilities, architect/engineers, and FWH vendors. Responses to the questionnaire revealed that problems had been experienced in approximately one-third of all the FWHs at 44 utilities. Major problem areas were tube vibration, flashing in the drains subcooler zone due to inadequate level control, tube inlet erosion, corrosion, steam impingement, and difficulty in plugging failed tubes. The main conclusion from the study is that industry standards do not adequately address most of the major FWH problems that were reported. As a result, utilities do not have sufficient guidance to prepare purchase specifications so that these problems can be avoided. It is recommended that straightforward guidelines be developed to address each of these FWH problem areas.