Abstract: A water heater system includes a primary heat exchanger including a tank and at least one flue, and a secondary heat exchanger including a core and a flue gas flow path. The water heater is operable in a heating mode in which a combustor produces hot flue gas and a water pump flows water through the core of the secondary heat exchanger and into the tank, and in a non-heating mode in which the combustor and the water pump are inoperative. The flue gas flows from the combustor through the at least one flue to heat the water in the tank and then through the flue gas flow path to heat water in the core before being exhausted.

Abstract: A storage-type water heater including a tank for supporting water to be heated, a first heating element, a first relay connected to the first heating element, a second heating element, a second relay connected to the second heating element, and a controller for selectively operating the first relay and the second relay. The controller includes instructions for selecting a mode from at least, a no-sequencing mode, wherein the first relay and the second relay are operated concurrently, and a sequencing mode, wherein the first relay and the second relay are operated sequentially. The controller also operates the first relay to supply power to the first heating element, and operates the second relay to supply power to the second heating element, based on the selected mode.

Abstract: A water heater system includes a primary heat exchanger including a tank and at least one flue, and a secondary heat exchanger including a core and a flue gas flow path. The water heater is operable in a heating mode in which a combustor produces hot flue gas and a water pump flows water through the core of the secondary heat exchanger and into the tank, and in a non-heating mode in which the combustor and the water pump are inoperative. The flue gas flows from the combustor through the at least one flue to heat the water in the tank and then through the flue gas flow path to heat water in the core before being exhausted.

Abstract: A storage-type water heater including a tank for supporting water to be heated, a first heating element, a first relay connected to the first heating element, a second heating element, a second relay connected to the second heating element, and a controller for selectively operating the first relay and the second relay. The controller includes instructions for selecting a mode from at least, a no-sequencing mode, wherein the first relay and the second relay are operated concurrently, and a sequencing mode, wherein the first relay and the second relay are operated sequentially. The controller also operates the first relay to supply power to the first heating element, and operates the second relay to supply power to the second heating element, based on the selected mode.

Abstract: A storage-type water heater includes a tank for supporting water to be heated, a first heating bank including a first heating surface disposed within the tank, a first contactor connected to the first heating bank, a second heating bank including a second heating surface disposed within the tank, a second contactor connected to the second heating bank, and a controller for selectively operating the first contactor and the second contactor.

Abstract: A storage-type water heater includes a tank for supporting water to be heated, a first heating bank including a first heating surface disposed within the tank, a first contactor connected to the first heating bank, a second heating bank including a second heating surface disposed within the tank, a second contactor connected to the second heating bank, and a controller for selectively operating the first contactor and the second contactor.