Methods and systems for determining a possible leak within a gas water heater. One system is a gas water heater including a blower and an electronic processor. The electronic processor is configured to activate the blower for a predetermined amount of time, receive, during the predetermined amount of time, a measurement of a characteristic of the blower, perform a comparison between the measurement and a predetermined characteristic threshold, and determine, based on the comparison, that a blockage is present within the water heater. The electronic processor is further configured to output a notification in response to determining the blockage is present.

The present invention provides a gas water heater, and a safety control method and system therefor. The system includes: an exhaust fan; a rotational speed detecting unit, configured to detect a rotational speed of the exhaust fan; a power obtaining unit, configured to obtain a set value for output power of the exhaust fan; a rotational speed difference obtaining unit, configured to obtain an actual value of the rotational speed and a reference value of the rotational speed according to the set value for the output power, and to calculate a difference between them; and an exhaust control unit, connected to the exhaust fan, the rotational speed detecting unit, the rotational speed difference obtaining unit and the power obtaining unit respectively, configured to correct a predetermined wind pressure curve graph at an air outlet of the exhaust fan according to the difference.

Disclosed is a boiler blockage detection system and method utilizing inputs from a pressure sensing elements. A logic circuit may determine a boiler firing rate based on an input signal from the combustion controller. An indication of the exhaust pressure level and an indication of the inlet pressure level are received. A pressure differential between the exhaust pressure level and the inlet pressure level is determined. Alternatively, a pressure differential transmitter may determine the pressure differential. The determined pressure differential is compared to a predetermined pressure level differential threshold. The predetermined pressure level differential threshold is dependent on the determined firing rate. Based on a result of the comparison of the determined pressure differential to the predetermined pressure level differential threshold, it may be determined that there is a blockage of an intake or an exhaust of the boiler. In response to the blockage determination, an interrupt signal is output.

Methods and systems for determining a possible leak within a gas water heater. One system is a gas water heater including a blower and an electronic processor. The electronic processor is configured to activate the blower for a predetermined amount of time, receive, during the predetermined amount of time, a measurement of a characteristic of the blower, perform a comparison between the measurement and a predetermined characteristic threshold, and determine, based on the comparison, that a blockage is present within the water heater. The electronic processor is further configured to output a notification in response to determining the blockage is present.

A combustion device includes a combustion control section which controls combustion in the combustion device; a setting section operated to set information indicating whether or not a plurality of combustion devices are in a common vent discharge state; and a memory section which stores therein connection configurations with the other combustion control sections to which the combustion control section is communicatively connected, and the combustion control section determines whether or not the combustion control section can communicate with a linkage control section or the other combustion control sections, and inhibits combustion in the combustion device to which the combustion control section belongs, in a case where the combustion control section determines that the combustion control section cannot communicate with the linkage control section or at least one of the other combustion control sections and the common vent discharge state is set by the setting section.

Apparatus and methods for a gas furnace are disclosed. The gas furnace includes a variable combustion control which monitors the temperature of the burner and modifies one of the amount of combustion air supplied and the amount of gas fuel supplied to the mixing chamber. The described systems can dynamically accommodate differences in air quality and gas fuel supply to provide an optimum BTU output irrespective of differences in geographic location of usage. The gas furnace can include a dynamic response unit which predicts an optimum rate of heating to maintain a target room temperature, thereby preventing unnecessary shut down and costly re-ignition sequences, and maintaining the gas furnace at an optimum BTU output level.

The present invention provides a gas water heater, and a safety control method and system therefor. The system includes: an exhaust fan; a rotational speed detecting unit, configured to detect a rotational speed of the exhaust fan; a power obtaining unit, configured to obtain a set value for output power of the exhaust fan; a rotational speed difference obtaining unit, configured to obtain an actual value of the rotational speed and a reference value of the rotational speed according to the set value for the output power, and to calculate a difference between them; and an exhaust control unit, connected to the exhaust fan, the rotational speed detecting unit, the rotational speed difference obtaining unit and the power obtaining unit respectively, configured to correct a predetermined wind pressure curve graph at an air outlet of the exhaust fan according to the difference.

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.

A control unit includes a scale detection unit for detecting, while the a burner provides combustion, occurrence of clogging with scale in a tube of a heat exchanger, and an output unit for outputting a result of a detection by the scale detection unit, a storage stores information including a numerical value representing how many times a surface temperature of the heat exchanger measured by a temperature measuring unit exceeds at least one of a plurality of threshold values. While the burner provides combustion when the surface temperature measured by the temperature measuring unit exceeds at least one of the plurality of threshold values the scale detection unit adds a predetermined value to the numerical value in the storage and when the numerical value attains a defined value or more the scale detection unit detects occurrence of clogging with scale.

A water heating apparatus includes: a water heating circuit; a heater for heating the water heating circuit; and a controller for controlling the water heating apparatus. The water heating circuit includes a heat exchanger for heating a fluid including water and hot water, and a pipe for supplying the fluid via the heat exchanger. The controller is configured to drive the heater in a cleaning mode in which a cleaning liquid for cleaning an inside of the heat exchanger is supplied to the heat exchanger through the pipe.