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.

A water heating system can include a first tank-based water heater having a first inlet line and a first outlet line, where the first inlet line provides unheated water to the first tank, and where the first outlet line draws heated water from the first tank. The system can also include a first tankless water heater having a second outlet line, where the second outlet line of the first tankless water heater provides the heated water to a first heated water demand. The system can also include a first valve that controls an amount of the unheated water flowing through the first inlet line to the first tank-based water heater. The system can further include a controller operatively coupled to the first valve, where the controller controls a position of the first valve based on the first heated water demand and a first capacity of the first tankless water heater.

A water heater system includes a controller configured to integrate control of both recovery and recirculation operations of a recovery pump and a recirculation pump. As such, a separate device, installation location, and power source (e.g., available outlet) is not needed with the controller. Because a single controller is configured to control both recovery and recirculation operations, additional control functions are available. The controller may be in communication with an internal controller of the water heater and configured to receive an error notification upon abnormal operation of the water heater. The controller can stop recovery and recirculation operations in response to an error notification, unlike with traditional water heating systems which may otherwise continue to function. The recovery and recirculation operations are based on a setpoint temperature of the water heater such that changes made to the setpoint temperature will automatically adjust in the recovery and recirculation operations.

A water heater includes a water tank having an inlet and an outlet, and a flue extending through the tank. A nozzle is positioned near a first end of the flue, arranged so as to emit a fuel stream into the flue, and a flame holder is located within the flue in a position to receive the fuel stream and to hold a flame entirely within the flue. A controller variably controls a flow of fuel to the nozzle according to a temperature of water in the tank.

The present description discloses a combustion type water heater that heats water by burning fuel. The combustion type water heater includes: a burner that generates combustion gas by burning the fuel; a heat exchanger that exchanges heat between the water passing through on an inside of the heat exchanger and the combustion gas flowing on an outside of the heat exchanger, an exhaust pipe that discharges the combustion gas after the heat exchange in the heat exchanger as exhaust gas; an exhaust gas temperature detector that detects a temperature of the exhaust gas flowing in the exhaust pipe as an exhaust gas temperature; a clog degree detector that detects a degree of clog in the exhaust pipe; and a scale buildup determiner that determines whether or not scale has built up inside the heat exchanger based on the exhaust gas temperature and the degree of clog in the exhaust pipe.

The present invention becomes possible to employ a main microprocessor with a relatively lower number of input ports, whereby while maintaining the performance and function of a water heater, the cost of a control apparatus is cut down. Some of sensors, adapted for measurement of various parameters which are for use in operational control of the water heater and in need of immediate response, are connected to a main microprocessor 31. The other sensors that are not in need of an immediate response, such as an ambient temperature sensor 36, are connected only to a sub microprocessor 32 if the main microprocessor 31 does not have any extra analog signal input port. The sub microprocessor converts an analog signal from the sensor 36 which is connected only to the sub microprocessor into digital data. And the sub microprocessor transmits the digital data to the main microprocessor through communication therewith.

A water heater system includes a controller configured to integrate control of both recovery and recirculation operations of a recovery pump and a recirculation pump. As such, a separate device, installation location, and power source (e.g., available outlet) is not needed with the controller. Because a single controller is configured to control both recovery and recirculation operations, additional control functions are available. The controller may be in communication with an internal controller of the water heater and configured to receive an error notification upon abnormal operation of the water heater. The controller can stop recovery and recirculation operations in response to an error notification, unlike with traditional water heating systems which may otherwise continue to function. The recovery and recirculation operations are based on a setpoint temperature of the water heater such that changes made to the setpoint temperature will automatically adjust in the recovery and recirculation operations.

A water heater system includes a controller configured to integrate control of both recovery and recirculation operations of a recovery pump and a recirculation pump. As such, a separate device, installation location, and power source (e.g., available outlet) is not needed with the controller. Because a single controller is configured to control both recovery and recirculation operations, additional control functions are available. The controller may be in communication with an internal controller of the water heater and configured to receive an error notification upon abnormal operation of the water heater. The controller can stop recovery and recirculation operations in response to an error notification, unlike with traditional water heating systems which may otherwise continue to function. The recovery and recirculation operations are based on a setpoint temperature of the water heater such that changes made to the setpoint temperature will automatically adjust in the recovery and recirculation operations.

A control system is provided for a modulated heating system including a plurality of modulating water heaters, which may be modulating boilers. A deadband control scheme provides for reduced cycling of the modulating heater when total system heat demand falls between the maximum output of one heater and the sum of the maximum output of that one point and the minimum firing point of the next subsequent heater. Condensation of flue gas products is prevented by monitoring flue exhaust temperature for each heater and controlling the modulation of each heater to maintain a minimum heater output sufficiently high to prevent condensation of flue gas products from that heater. Rapid reaction to changes in system heat demand is provided by sensing changes in flow rate in a primary loop of the system and anticipating resulting changes in temperature thus allowing for change in heater output prior to the time the change in flow rate has fully impacted system temperature.

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.