A water heater including an inflow terminal for connecting a tankless water heater to a cold water supply and an outflow terminal for connecting the tankless water heater to a tap. A fluid channel proves a fluid connection from the inflow terminal to the outflow terminal. A heat element arrangement is arranged at or within at least a section of the fluid channel for transferring heat to fluid present within the fluid channel. An electronic controller is configured to control a heating power provided to the heat element arrangement. A flow sensor is arranged at or within the fluid channel downstream the heat element arrangement. The electronic controller is further configured to detect the presence of air bubbles within the fluid channel based on a change of a flow signal provided by the flow sensor and to adapt the heating power provided to the heat element arrangement in reaction to the determination of air bubbles.

A water heater includes a heat exchanger. A controllable three-way proportional valve provides a proportionally controllable flow to the hot water inlet of the heat exchanger and a boiler return water outlet. A mixing tank mixes a cold water and a hot water. The mixing tank provides a time delayed mixed water. A temperature sensor is disposed in or on the mixing tank to measure a temperature of the time delayed mixed water to provide a time delayed mixed water temperature. A feedforward control process running on a processor adjusts a proportional operating position of the controllable three-way proportional valve to regulate a temperature of hot water at the hx domestic hot water outlet based on the temperature of the time delayed mixed water temperature. A method for controlling a hot water temperature of a water heater a water heater using a flowmeter based feedforward control are also described.

A heating and hot-water supply apparatus shortens the time taken for hot-water supply to stabilize at a set temperature in response to a request for a hot-water supply operation during a heating operation. The apparatus performs, using a common heating medium heated by a heater, a heating operation by circulating the heating medium through a heating terminal, and a hot-water supply operation of heating service water through heat exchange with the heating medium circulated through a hot-water supply heat exchanger and supplying hot water. A distribution unit (three-way valve) changes a distribution ratio of the heating medium between the heating terminal and the hot-water supply heat exchanger. A controller controls an amount of heat generated by the heater for the heating operation or the hot-water supply operation, and stops heating with the heater when the temperature of the heating medium reaches a predetermined upper-limit temperature.

A heating control method includes determining a first speed for an air circulation fan that corresponds with a temperature set point using a temperature map that maps temperatures to speeds of the air circulation fan and operating the air circulation fan at the first speed and a heating unit in a first configuration with at least one active burner from a plurality of burners where less than all of the burners are active when the heating unit is in the first configuration. The method further includes measuring a first temperature while operating the air circulation fan at the first speed, determining a temperature difference between the first temperature and the temperature set point, comparing the temperature difference to a temperature difference threshold, and updating the temperature map to map the first speed to the first temperature when the temperature difference is greater than the temperature difference threshold.

Automated systems, methods, techniques, processes, products and product components are provided to implement an advanced and energy efficient hot water heating system control scheme that incorporates an advanced hot water reset for the boilers, including condensing boilers in hydronic systems. The advanced controls are provided to substantially enhance combustion (heating) efficiency for the boilers. The disclosed schemes replace conventional linear hot water reset with a device which can stand alone or integrate with boiler control technology or an existing building automation system to create a unique (non-linear) boiler reset curve based on various inputs. The schemes allow boiler control systems to learn and adapt over time maximizing the efficiency of a condensing boiler plant, by providing an independent, intelligent, economical, monitorable and manipulable solution eliminating the need of a head end BAS control system.

As a circulation pump is activated while a hot water supply faucet is closed, an immediate hot water supply circulation path is formed to bypass the hot water supply faucet on the outside of a water heating apparatus and to pass through a heat exchanger in the inside of the water heating apparatus. A controller determines in a test mode, whether or not the immediate hot water supply circulation path has been formed by connection of a thermal water stop bypass valve, based on whether or not a temperature detector senses increase in temperature to a predetermined criterion temperature while the circulation pump and a heat source apparatus are active.

A controller assembly allows an adjusted flow of water through a hydronic emitter in order to heat or cool an environmental entity. The controller assembly operates in two phases: a calibration phase and an operational phase. During the calibration phase, the controller assembly discovers a valve position where water starts to flow through the hydronic emitter based on signals from a temperature sensor and/or a sound sensor. The temperature sensor may be mounted in close proximity of the emitter inlet so that the controller assembly can detect when the temperature starts to change. The sound sensor may be mounted on the valve body to detect a rushing water sound that is associated with a start of the water flow. The discovered valve position is subsequently used by the controller assembly to adjust water flow between a minimum flow and a maximum flow.

A water heater includes a heat exchanger. A controllable three-way proportional valve provides a proportionally controllable flow to the hot water inlet of the heat exchanger and a boiler return water outlet. A mixing tank mixes a cold water and a hot water. The mixing tank provides a time delayed mixed water. A temperature sensor is disposed in or on the mixing tank to measure a temperature of the time delayed mixed water to provide a time delayed mixed water temperature. A feedforward control process running on a processor adjusts a proportional operating position of the controllable three-way proportional valve to regulate a temperature of hot water at the hx domestic hot water outlet based on the temperature of the time delayed mixed water temperature. A method for controlling a hot water temperature of a water heater a water heater using a flowmeter based feedforward control are also described.

A system, apparatus, and method for a differential temperature managed integral, free standing, hydronic heating appliance uses a high-mass heat source coupled to a single, highly-efficient, variable speed, Electronically Commutated Motor (ECM)-driven Delta-T stand-alone system circulator which feeds one or more zone valves governing flow to one or more hydronic zones. Components are integrated into simplified, compact, assemblies. Zone valve packaging of a compact header improves hydronic performance (head pressure reduction and increased flow), complementing zone valve performance and reducing zone valve wiring labor and material content. Returns have full port valves and the boiler includes isolation valves. All manually activated valves are full port. This can include full port boiler isolation valves, circulator isolation valves and return valves. Paralleled, ganged, alignment of state-indicating-lamped zone valves provides rapid, functional indication of component and system performance while the need for a zone valve panel commonly found on hydronic heating systems is negated.

The objective of the present invention is to provide a boiler system for bath heating and hot water that is capable of performing heating and hot water preheating by using a single circulation pump for both without the need to separately include a circulation pump for heating and a circulation pump for hot water preheating. In order to achieve the above objective, the present invention provides a boiler system for both heating and hot water, comprising: a heat exchanging unit; a heating water channel connected between the heat exchanging unit and a place to be heated; a tap water supply pipe for supplying tap water to the heat exchanging unit; a hot water supply pipe for supplying hot water to a place requiring hot water from the heat exchanging unit; a hot water recirculation channel connected to the hot water supply pipe at a first branch point branched from one side of the heating water channel; a hot water bypass channel connected from the second branch point branched from the other side of the heating water channel to the tap water supply pipe; and a circulation pump disposed between the first branch point and the second branch point.