Abstract: A tank-type water heater includes a storage tank and a heating circuit outside of the tank. The heating circuit includes at least one heat engine and at least one pump for circulating water from the bottom of the tank through the heat engine and back to the top of the tank. A stratifier introduces the heated water from the heating circuit into the top of the tank in a diffuse manner to promote stratification of hot water in the tank.

Abstract: A water heater including a storage tank including a water inlet and a water outlet, a pump, an upper temperature sensor, a lower temperature sensor, and an electronic processor. The electronic processor is configured to receive an upper temperature signal and a lower temperature signal, compare the upper temperature signal to a sum of a setpoint temperature threshold minus a temperature differential, and compare the lower temperature signal to a high limit temperature threshold. The electronic processor is further configured to activate the pump in response to the first upper temperature signal being less than the sum of the setpoint temperature threshold minus the temperature differential and the first lower temperature signal being less than the predetermined high limit temperature threshold.

Abstract: A tank-type water heater includes a storage tank and a heating circuit outside of the tank. The heating circuit includes at least one heat engine and at least one pump for circulating water from the bottom of the tank through the heat engine and back to the top of the tank. A stratifier introduces the heated water from the heating circuit into the top of the tank in a diffuse manner to promote stratification of hot water in the tank.

Abstract: A water heater including a storage tank including a water inlet and a water outlet, a pump, an upper temperature sensor, a lower temperature sensor, and an electronic processor. The electronic processor is configured to receive an upper temperature signal and a lower temperature signal, compare the upper temperature signal to a sum of a setpoint temperature threshold minus a temperature differential, and compare the lower temperature signal to a high limit temperature threshold. The electronic processor is further configured to activate the pump in response to the first upper temperature signal being less than the sum of the setpoint temperature threshold minus the temperature differential and the first lower temperature signal being less than the predetermined high limit temperature threshold.

Abstract: A method and apparatus for conveying condensate from an exhaust system of a gas water heater to a drain. The method includes the steps of operating the gas water heater to produce products of combustion, operating a blower to cause the products of combustion to flow through the exhaust system to atmosphere, allowing condensate from the products of combustion to form within the exhaust system, using a drain conduit to connect a relatively high pressure zone of the exhaust system to a relatively low pressure zone of the exhaust system, using a pressure differential between the relatively high pressure zone and the relatively low pressure zone to convey condensate through the drain conduit from the relatively high pressure zone to the relatively low pressure zone, and conveying condensate from the relatively low pressure zone to the drain.