Thermally Efficient Water Pre-Heaters work as deaerator and eliminate oxygen pitting inside the boiler pressure parts. Water Pre-Heaters are used to recover the heat from the boiler flue gas, which increases the thermal efficiency of the boiler by reducing the useful heat lost in the flue gas. Water Pre-Heaters combine features like easy installation, safe operation and less maintenance. Thermally Efficient Water Pre-Heaters can be retrofitted on all types of existing systems.