A heat recovery steam generator (10) includes a gas inlet (12) for receiving a flow of exhaust gas (14) from a gas turbine (18), a gas outlet (34) opposite the gas inlet (12), at least one heat exchanger (30) intermediate the gas inlet (12) and the gas outlet (34), the heat exchanger (30) having a plurality of heat transfer surfaces configured to transfer heat from the exhaust gas (14) to a fluid within the heat exchanger (30), and a valve (60) associated with the heat exchanger (30) and configured to regulate a flow of the fluid through the heat exchanger (30). The valve (60) is controllable from an open position to a closed position to decrease the flow of the fluid through the heat exchanger (30) in order to effect an increase in a temperature of the heat transfer surfaces of the heat exchanger (30) to clean the heat transfer surfaces.