A method for evaluating a sensor-detectable transient pressure difference on a gas boiler. The sensor detects a differential pressure at a measurement point upstream of the main flow restrictor (3) and downstream of the control valve (2) and a reference pressure and transmits it to the evaluation electronics. The sensor detects a differential pressure course and transmits it to the evaluation electronics, during variation of heat output and/or when the heat output is adjusted to the predetermined value. The evaluation electronics evaluates the differential pressure course over its time range and/or its frequency range. At least one characteristic value is determined and compared with a predetermined comparison value. If the characteristic value deviates from the comparison value, an error of the gas boiler is recognized.

A method for evaluating a sensor-detectable transient pressure difference on a gas boiler. The sensor detects a differential pressure at a measurement point upstream of the main flow restrictor (3) and downstream of the control valve (2) and a reference pressure and transmits it to the evaluation electronics. The sensor detects a differential pressure course and transmits it to the evaluation electronics, during variation of heat output and/or when the heat output is adjusted to the predetermined value. The evaluation electronics evaluates the differential pressure course over its time range and/or its frequency range. At least one characteristic value is determined and compared with a predetermined comparison value. If the characteristic value deviates from the comparison value, an error of the gas boiler is recognized.

A heater for a pool system, such as a swimming pool or a spa, includes a controller and a plurality of sensors for determining an operating condition of the heater. In some cases, the heater includes a gas sensor for determining at least one characteristic of gas supplied to the heater. The heater may also include a wiring sensor for determining a wiring configuration for an igniter of the heater. Additionally or alternatively, the heater may include a water inlet sensor, a water outlet sensor, and a vent sensor. The heater for the pool system may be provided with various other sensors or combination of sensors.

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 method of controlling a gas furnace comprising a gas valve for supplying a fuel gas to a manifold; a burner through which the fuel gas discharged from the manifold passes; an igniter for igniting a mixture of fuel gas passed through the burner and air; and an inducer for generating a flow in which a combustion gas generated by the burning of the mixture is discharged to an exhaust pipe via a heat exchanger, wherein the gas furnace performs a heating operation according to a heating signal or a heating stop according to a stop signal, includes the steps of: (a) receiving any one of the heating signal or the stop signal; (b) transmitting a signal to operate the inducer when the heating signal is received; (c) operating the igniter; (d) transmitting a signal to open the gas valve; (e) detecting whether the gas valve is opened or closed; (f) detecting a flow rate of the fuel gas in the manifold; and (g) displaying a normal operation of the heating operation, based on information detected in the steps (e) and (f).

A heat pump may include a compressor configured to compress a refrigerant, a first temperature sensor configured to detect an outdoor temperature, a second temperature sensor provided in heating pipes connected to a heating device that performs indoor heating and configured to detect a temperature of fluid flowing through the heating pipes, an outdoor heat exchanger configured to perform heat exchange between outdoor air and a refrigerant, a third temperature sensor configured to detect a temperature of the outdoor heat exchanger, and a controller. The controller may be configured to: control power to a boiler and/or to the compressor based on sensing values of the first, second, and third temperature sensors, calculate an expected efficiency of the heat pump based on the sensing value of the first temperature sensor and an initial target temperature, and control power to the boiler based on the expected efficiency.

An apparatus includes a high-pressure tank, a controller, a valve, controlled by the controller, and a heater.

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 water heating system can include a water heater having a tank, an inlet line, and an outlet line, where the inlet line provides unheated water to the tank, and where the outlet line draws heated water from the tank. The water heating system can also include multiple sensing devices, where each sensing device of the plurality of sensing devices measures a parameter associated with the tank. The water heating system can further include a controller communicably coupled to the plurality of sensing devices, where the controller determines an amount of heated water in the tank based on measurements made by the plurality of sensing devices.

A blower assembly is configured for use with a gas-operated heater having a burner and an exhaust port. The blower assembly has a blower and a sensor. The blower is configured to operate at two or more speeds and is configured to operatively connect to the burner in a manner to facilitate flow of combustion air into the burner and to facilitate flow of exhaust through the exhaust port. The sensor is configured to be sensitive to pressure of exhaust downstream of the blower. The sensor is operatively connected to the blower in a manner such that the blower will change speeds if said pressure exceeds a threshold pressure.