Diethylhydroxylamine (DEHA) and di-isopropylhydroxylamine can be used to remove iron deposits from the surfaces of closed loop systems. A closed loop system can be cleaned of iron deposits by first contacting the surface of the closed loop system having iron deposits with an aqueous solution of an oxygen scavenger; and then introducing diethylhydroxylamine, di-isopropylhydroxylamine, or mixtures thereof; into the closed loop system at a concentration sufficient to cause the iron deposits to release from the surface of the closed loop system. It can be desirable to use a filter or strainer to trap and remove the particulate iron deposits once they have been released from the surface of the closed loop system. In the alternative, a dispersant can be used to prevent released particulate iron deposits from reforming as scale.