Abstract: A water heater includes an outer casing defining a longitudinal axis, an axial direction being defined as extending along the longitudinal axis. The water heater further includes a combustor for production of hot flue gases, a primary heat exchanger including a tube positioned within the outer casing, and a secondary heat exchanger including a plurality of plates coupled together by brazing to form a brazed plate heat exchanger. The secondary heat exchanger includes a first set of passages defined between the plates, and a second set of passages defined between the plates and alternating with the first set of passages in the axial direction. The primary and secondary heat exchangers are in fluid communication such that the flue gases flow through the second set of passages before being exhausted, and water to be heated flows through the first set of passages to a delivery point for use upon demand.

Abstract: A water heater includes an outer casing defining a longitudinal axis, an axial direction being defined as extending along the longitudinal axis. The water heater further includes a combustor for production of hot flue gases, a primary heat exchanger including a tube positioned within the outer casing, and a secondary heat exchanger including a plurality of plates coupled together by brazing to form a brazed plate heat exchanger. The secondary heat exchanger includes a first set of passages defined between the plates, and a second set of passages defined between the plates and alternating with the first set of passages in the axial direction. The primary and secondary heat exchangers are in fluid communication such that the flue gases flow through the second set of passages before being exhausted, and water to be heated flows through the first set of passages to a delivery point for use upon demand.

Abstract: A water heater system includes a tank for storing water; a flue assembly positioned within the tank, the flue assembly adapted to transfer heat from flue gases within the flue assembly to water in the tank; a burner in fluid communication with an inlet end of the flue assembly and operable in at least a high input mode and a low input mode to deliver the flue gases to the flue assembly, the exhaust assembly having a threshold temperature above which the exhaust assembly is not suitable; and an exhaust assembly including a fan, wherein at least in the low input mode, the flue gases condense in the flue assembly, and wherein operation of the fan reduces a temperature of the flue gases in the exhaust assembly to below the threshold temperature at least in the high input mode.

Abstract: A water heater system includes a tank for storing water; a flue assembly positioned within the tank, the flue assembly adapted to transfer heat from flue gases within the flue assembly to water in the tank; a burner in fluid communication with an inlet end of the flue assembly and operable in at least a high input mode and a low input mode to deliver the flue gases to the flue assembly, the exhaust assembly having a threshold temperature above which the exhaust assembly is not suitable; and an exhaust assembly including a fan, wherein at least in the low input mode, the flue gases condense in the flue assembly, and wherein operation of the fan reduces a temperature of the flue gases in the exhaust assembly to below the threshold temperature at least in the high input mode.