A heating and hot-water supply apparatus performs a heating operation by heating a heating medium with a heater and circulating the heating medium through a heating terminal, a hot-water supply operation by circulating the common heating medium through a hot-water supply heat exchanger, heating service water through heat exchange with the heating medium, and supplying hot water, and a simultaneous operation of the heating operation and the hot-water supply operation, and controls a distribution ratio of the heating medium between the heating terminal and the hot-water supply heat exchanger. The apparatus determines whether the heating terminal proceeding in the heating operation is a suspendible terminal to suspend the heating operation or an unsuspendible terminal not to suspend the heating operation in response to a request for the hot-water supply operation.

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.

Setting and maintaining proper pre-charge air pressure in a diaphragm or bladder-type expansion tank of any fluid system is essential for safe and efficient operation of that system. In usual practice, pre-charge air pressure checks are done by emptying the system of fluid and connecting an analog air gauge to the air input of the expansion tank. In this invention a pressure sensor that is permanently coupled to the fluid volume of the expansion tank is used to also evaluate the pre-charge air pressure in the tank. By employing a single sensor for both fluid and pre-charge air pressure evaluation, the problem of inconsistent calibration between fluid sensing and air pre-charge measuring devices is eliminated. Using the same permanently installed sensor for every test or adjustment in a given system eliminates the problem of variations in calibration between different sensors or gauges used at different testing times.

A heat pump may include a compressor configured to compress a refrigerant, a first temperature sensor provided in heating pipes connected to a heating device that heats an indoor space to sense a temperature of fluid flowing through the heating pipes, and a controller. The controller may be configured to determine whether a boiler is operating to heat an indoor space or is operating to supply hot water based on a sensing value of the first temperature sensor. The compressor may operate when the controller determines that the boiler is not operating to heat the indoor space and/or determines that the boiler is operating to supply hot water.

A combination water heating, air conditioning refrigerant system is described. The combined system includes a plurality of independently adjustable electronic expansion valves. The expansion valves can independently modulate the delivery of high-temperature, high-pressure refrigerant to either a water heat exchanger or an outside condenser. A controller can receive input signals, including temperature signals from one or more temperature sensors that indicate the temperature at various locations of the system. The temperature signals include one or more of water temperature signals, ambient air temperature signals, or refrigerant super heat temperatures signals. In response to the input signals, the controller can output control signals to one or more of the plurality of electronic expansion valves.

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 control system is provided for controlling heating and/or cooling with a conditioning load such as fan coils and chilled beams. Based on user input and ambient conditions, the control system determines a desired temperature for the liquid entering the load and combines fresh supply liquid (e.g., from a chiller or boiler) with a portion of the liquid that has passed through the load, to achieve the target load input temperature for the liquid. A recirculation pump may be used to return a portion of the liquid exiting the load for mixing with the fresh supply liquid and a control valve may be used to adjust the ratio of fresh supply liquid and recirculated liquid to achieve the targeted temperature. The control systems can be compatible with a variety of liquid supply systems such as two- and four-pipe systems.

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 fuel-fired device can include an air-moving device that mixes air and a fuel to generate a fuel-air mixture. The fuel-fired device can also include an air box that provides the air to the air-moving device, and a fuel valve that provides the fuel to the air-moving device, where the fuel valve includes a tracking port coupled to the air box, where the tracking port detects a pressure of the air box. The fuel-fired device can further provide a pressure-regulating device disposed between a pressurized component and the tracking port of the fuel valve. The flow regulating device can control, during an ignition phase of operation, an amount of the fuel provided by the fuel valve to the air-moving device.

A heat pump may include a compressor configured to compress a refrigerant, a first temperature sensor provided in heating pipes connected to a heating device that heats an indoor space to sense a temperature of fluid flowing through the heating pipes, and a controller. The controller may be configured to determine whether a boiler is operating to heat an indoor space or is operating to supply hot water based on a sensing value of the first temperature sensor. The compressor may operate when the controller determines that the boiler is not operating to heat the indoor space and/or determines that the boiler is operating to supply hot water.