A water heater with two non-condensing flues and a condensing flue(s) having a system to prevent condensation in the non-condensing flue(s). The downwardly extending first flue is connected by a 180 degree connector to an upwardly extending second flue. Between the non-condensing and the condensing flues is positioned a temperature sensor. A controller receives input from the temperature sensor and is connected to the burner to control the minimum power setting and duration so as to prevent the combustion gases from falling below a temperature at which water will condense at the temperature sensor so no condensation occurs in the first two flues. Burner power settings are minimized near a water tank setpoint to improve efficiency by increasing condensation.

A fan heater for heating using exhaust waste heat, including: a natural exhaust tube discharging some exhaust gas from a water heater; a forced exhaust tube connected to the natural exhaust tube in a parallel structure, the remaining exhaust gas, excluding naturally discharged exhaust gas, flowing into the forced exhaust tube; a heat exchange device on the upper portion of the forced exhaust tube and supplied with high-temperature exhaust gas; a forced exhaust blower installed on the heat exchange device to draw exhaust gas from the forced exhaust tube and discharge it; a main unit having the heat exchange device embedded therein and having a circulation unit such that low-temperature indoor air circulates into the heat exchange device; a warm-air circulation blower supplying the indoor air towards the outer air circulation unit and circulating the low-temperature indoor air so the exhaust gas exchanges heat; and a control unit.

A water heater with two non-condensing flues and a condensing flue(s) having a system to prevent condensation in the non-condensing flue(s). The downwardly extending first flue is connected by a 180 degree connector to an upwardly extending second flue. Between the non-condensing and the condensing flues is positioned a temperature sensor. A controller receives input from the temperature sensor and is connected to the burner to control the minimum power setting and duration so as to prevent the combustion gases from falling below a temperature at which water will condense at the temperature sensor so no condensation occurs in the first two flues. Burner power settings are minimized near a water tank setpoint to improve efficiency by increasing condensation.

A condensate neutralizer device for treating a condensate flow, the condensate neutralizer device includes a compartment adapted to receive condensate neutralizing materials therein, the compartment having an inlet end and an outlet end, a plurality of apertures disposed only on a bottom surface of each of the inlet end and the outlet end of the compartment. The compartment is configured to receive the condensate flow traversing upwardly through the plurality of apertures at the inlet end in a direction from the inlet end to the outlet end through the condensate neutralizing materials before allowing a treated flow of the condensate flow to traverse downwardly through the plurality of apertures at the outlet end to exit the compartment as an effluent.

Provided is a method for measuring the temperature at each location of a pipe in a hot water supply system comprising a water heater, a pipe, and outlets, the method comprising checking for a temperature of a first point (T.sub.P1), which is upstream of the outlet, a temperature of a second point (T.sub.P2), which is downstream of the outlet and an outdoor temperature (T.sub.A), and confirming a length (L) of the pipe from the first point to the second point, then measuring a temperature of the pipe located at a distance of x away from the first point.

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.

A controller is configured to set total stop in which operations of all of a plurality of water heaters are stopped when an abnormal condition of a fan or an abnormal condition in communication is sensed in any of the plurality of water heaters while at least one of the plurality of water heaters is operating. The controller is further configured not to set total stop when an abnormal condition of the fan or an abnormal condition in communication is sensed in at least one of the plurality of water heaters while a sensing element for sensing a backflow of an exhaust from an exhaust path assembly is connected to the controller.

The present invention may be embodied as a biofuel heating system comprising a controller for operating a fan based on a load operating parameter such that air flows along a flow path extending through a combustion chamber, through a burn-out port, through a burn-out chamber, through a heat exchange port, through a heat exchange chamber, and out of an exhaust port. A heat exchange system transfers heat energy from air flowing through the heat exchange chamber to a working fluid. The controller operates in a char mode based at least in part on the load operating parameter, and the biofuel remains within the combustion zone during the char mode.

For the automated adjustment of a heating system (2), there is produced between an exhaust-gas measuring device (1) and a control unit (26) a data connection (6) via which data, measurement values or control or setting signals for the adjustment of the heating system (2) are transmitted at least from the exhaust-gas measuring device (1) to the control unit (26). During the adjustment of the heating system (2), at least one exhaust-gas parameter is measured in automated fashion by way of at least one exhaust-gas sensor (4) of the exhaust-gas measuring device (1), and determined measurement values are automatically detected by the exhaust-gas measuring device (1). Then, a deviation of the determined measurement value from an exhaust-gas-parameter-specific and/or installation-specific setpoint value is determined, and in a manner dependent on the determined deviation, an automated adjustment of the heating system (2) is performed, said adjustment being initiated by the control unit (26) (cf. FIG. 1).

A hot water supply device (1) includes: a fin and tube type heat exchanger (17) for aplying heat to water with combustion gas; a temperature detection means (32) for detecting an exhaust temperature after heat exchange by the heat exchanger (17); and a determination means that determines that scale is deposited within the heat exchange tubing (27) of the heat exchanger (17) if the exhaust temperature detected by the temperature detection means (32) is higher than a set temperature.