The Challenger Combination Boiler features a unique Two in One heat exchanger that provides both space heating and domestic hot water. The Challenger Combination Boiler is designed to fit the needs of today’s energy efficient homes with a BTU input of 30,000 to 110,000. The Challenger is not only energy efficient with an AFUE of 95%, but space efficient as well. As a combination boiler, the Challenger eliminates the need for a separate domestic hot water tank. The unique heat exchanger in the Challenger heats domestic hot water directly, allowing the boiler to condense in the DHW mode and eliminating a separate heat exchanger and three-way valve.