Economizer is a product which provides fuel saving and boiler efficiency in boilers, steam boilers, hot water boilers and hot oil boilers by using the heat of the flue gases in order to increase the temperature of the feed water (and fluids) in the system. The payback amortization of economizers varies depending on such factors as the capacity of the system, efficiency of the boiler, and its application areas. The pay-back period of an efficient economizer varies between 3 – 18 months.