Water treatment programs for boilers and heat-recovery steam generator (HRSG) units appropriately focus on chemistry controls during normal operation. However, rates of corrosion product transport and deposition can be much greater in boilers and HRSG units during start-up than during routine operation. For that reason, in addition to standard-programs for monitoring and control of corrosion product transport, deposition, and underdeposit corrosion, consider adding contingency plans for boiler water chemistry holds in the start-up process.