A water heater includes a first heater, a second heater, and a controller. The controller can enable different operational modes of the water heater, wherein only the first heater operates, only the second heater operates, or both the first and the second heaters operate. The controller can also be configured to enable a hybrid operational mode and a bypass operational mode. Further, in the different operational modes, the controller can direct water flow to at least one of a first conduit coupled to the first heater, a second conduit coupled to the second heater, and a bypass conduit. The controller can be configured to receive input signals relating to environmental conditions around the water heater and/or an aquatic system in which the water heater is installed.

A combustion apparatus includes a burner configured to produce flames, a first flame rod and a second flame rod, and a controller. The burner is configured to be controlled, by the controller, to be in a first output state, and a second output state in which output is smaller than in the first output state. The first flame rod makes contact with the flames produced at the burner in a normal combustion state. The second flame rod makes contact with the flames produced at the burner in the normal combustion state when the burner is being controlled to be in the first output state, and does not make contact with the flames produced at the burner in the normal combustion state when the burner is being controlled to be in the second output state.

An exhaust duct includes an upper duct being open at opposite ends thereof and a lower duct being open at a tip end thereof. One end of the upper duct is connected, inside an enclosure of a water-heating device, to an exhaust adaptor disposed on the enclosure, and an opposite end of the upper duct communicates with the tip end of the lower duct. The upper duct is connected to the lower duct so as to be slidable along a reference direction in which the lower duct extends from the tip end of the lower duct, and the upper duct is configured to be separated from the exhaust adaptor by sliding along the reference direction.

A water heater includes a heat exchanger, a heat pump, a first valve in fluid communication with the heat exchanger and the heat pump, and a controller configured to control the first valve. The first valve can be configured to direct water flow toward at least one of the gas heater or the electric heat pump. A second valve in fluid communication with the first valve and the heat pump can be provided, and the controller can be further configured to control the second valve. A water heater inlet and a water heater outlet can be included and in fluid communication with the first valve, and the controller can be configured to monitor a temperature of water entering the water heater inlet and control the first valve dependent upon the monitored temperature.

A burner system for gas-fired furnaces that includes a burner box having one or more burner heads. The burner box is linked to one or more heat exchanger tubes. A flame suppression tube extends from each of the one or more burner heads. The flame suppression tube extends in the direction of one of the one or more heat exchanger tubes. A space separates the flame suppression tube from the heat exchanger tube. A blower is configured to provide a mixture of flammable gas and air to the burner box. An air delivery means provides air in the space separating the flame suppression tube from the heat exchanger tube.

A water heater system includes a gas burner configured to selectively produce flue gases, and a heat exchanger for heating water in the water heater system. The water heater system is operable in a heating mode, and a standby mode. An exhaust assembly is in communication with the heat exchanger, and includes a condensate collector configured to receive the flue gases and condensate. A first temperature sensor is positioned to sense a temperature of the condensate within the condensate collector. The first temperature sensor is configured to detect a rate of temperature change of the condensate. A controller is configured to determine a leakage when the rate of temperature change adjusts from a first state to a second state when the water heater system is in the standby mode after the water heater system was in the heating mode.

The present application provides a temperature control device for fluids, which comprises a furnace, a fluid pipe, a plurality of regenerative members, a burner, and an air control device. The burner heats the furnace to store heat to the regenerative members inside the furnace and conduct the thermal energy to the fluid pipe. The fluid pipi outputs a heated liquid. In addition, the regenerative members further produce and transport heated air to the air control device. The air control device converts the heated air to output cooled air.

The present disclosure is directed to a tankless water heater and systems and methods of using the same. The tankless water heater embodiments of the present disclosure can be configured to have a plurality of independently operable heat exchangers that can be used individually or collectively, in any combination, to heat water based on the level of demand for hot water. Embodiments can be configured for randomly selecting which heat exchangers are used to heat the incoming water. Embodiments of the present disclosure can also be configured to flow water through heat exchangers that are not being used to heat water and direct such water to a recirculation loop.

A water heater has a water supply line, a heat exchanger in fluid communication with the water supply line, a heating element positioned proximate to the heat exchanger, such that when activated, the heating element conveys heat to the heat exchanger and thereby heating water supplied by the water supply line, an output line in fluid communication with the heat exchanger and configured to receive heated water therefrom, a flow sensor configured to cause the heating element to activate in response to sensing a predetermined water flow rate through the water heater, and a bypass flow line operably connected between the water supply line and the output line.

A heat exchanger for a heating device includes a plurality of tubes arranged in a juxtaposed configuration, and at least one first manifold member on the outside of the tubes. Each tube is wound in a spiral having a plurality of substantially co-planar turns including at least one inner turn and at least one further turn around the inner turn. At least one first tube has a first end portion, which extends starting from the inner turn towards the outside of the corresponding spiral, with at least one part of the first end portion that is superimposed on the at least one further turn in a position corresponding to a major face of the spiral, for connection to the at least one first manifold member. The at least one first tube has at least one transverse depression in which a corresponding part of the first end portion is at least partially received.