A heat plate for a humidifier contains a thermally conductive plate having a top surface and a bottom surface opposite the top surface. A temperature sensor is affixed to the bottom surface and a thermally conductive layer is directly-affixed to the bottom surface. A ceramic heating element is directly affixed to the thermally conductive layer. A humidifier and medical device may also contain such a heater plate.

A heat plate for a humidifier contains a thermally conductive plate having a top surface and a bottom surface opposite the top surface. A temperature sensor is affixed to the bottom surface and a thermally conductive layer is directly-affixed to the bottom surface. A ceramic heating element is directly affixed to the thermally conductive layer. A humidifier and medical device may also contain such a heater plate.

A liquid reservoir for a humidifier containing a base, a top portion opposite the base, a side wall, and a liquid presence indicator. The side wall contains a lower side wall portion adjacent to the base, and an upper side wall portion adjacent to the top portion. The liquid presence indicator interacts with the humidifier to detect the presence of liquid in the liquid reservoir. A humidifier, and/or a medical device may contain the liquid reservoir, and a method may employ the humidifier and/or medical device.

A liquid reservoir for a humidifier containing a base, a top portion opposite the base, a side wall, and a liquid presence indicator. The side wall contains a lower side wall portion adjacent to the base, and an upper side wall portion adjacent to the top portion. The liquid presence indicator interacts with the humidifier to detect the presence of liquid in the liquid reservoir. A humidifier, and/or a medical device may contain the liquid reservoir, and a method may employ the humidifier and/or medical device.

A LWCO remote monitoring and diagnosing system or device features a signal processor configured to: receive signaling containing information for running a remote low water cut off (LWCO) mobile application, and also containing information about historical data related to a LWCO circuit that monitors and controls a burner of a boiler that opens and closes to provide water to the boiler depending on the water level in the boiler; and determine corresponding signaling containing information about the historical data requested based upon the signaling received.

A method for controlling a water heater appliance includes energizing the heating element for an energization period, such as less than two seconds. During the energization period, the appliance controller measures the electrical current passing through the heating element. The measured electrical current and a base signal are passed through a correlation filter to determine a correlation value. The base signal may correspond to the electrical current passing through the heating element when the tank is full or when the tank is empty, and the correlation value may be used to determine to which base signal the measured electrical current more closely correlates. In this manner, the correlation value is used to determine whether the heating element is submerged in water.

A water boiler comprises an inner tank, an electric heating pipe, and a controller. A lower cover is attached to a mouth of the inner tank. The lower cover comprises an inlet pipe and an outlet pipe, wherein an outlet port at a lower part of the inlet pipe is in communication with lower part within the inner tank. An inlet port of a lower part of the outlet pipe is in communication with an upper part of the inner tank. The lower cover is arranged beneath the upper cover. An upper part of the inlet pipe passes through the upper cover. A cavity is formed between the lower cover and the upper cover. The cavity is partitioned into an upper chamber and a lower chamber by a diaphragm. The lower chamber is in communication with an outer space.

A method for controlling a water heater appliance includes energizing the heating element for an energization period, such as less than two seconds. During the energization period, the appliance controller measures the electrical current passing through the heating element. The measured electrical current and a base signal are passed through a correlation filter to determine a correlation value. The base signal may correspond to the electrical current passing through the heating element when the tank is full or when the tank is empty, and the correlation value may be used to determine to which base signal the measured electrical current more closely correlates. In this manner, the correlation value is used to determine whether the heating element is submerged in water.

An on-demand heater includes a plurality of heater banks disposed in series with one another between a heater fluid inlet and heater fluid outlet. Power to one or more of the heater banks is adjusted when a sensed exit fluid temperature from a heater bank differs from the partial fluid temperature increase assigned to that heater bank, such that the total desired fluid temperature increase is achieved at the heater fluid outlet in a controlled manner.

A heater system includes a heater bundle. The heater bundle includes a plurality of heater assemblies. Each heater assembly includes a plurality of heater units and an insulating material, and each heater unit defines at least one independently controlled heating zone. The heater bundle includes power conductors electrically connected to each of the independently controlled heating zones in each of the heater units. The heater bundle includes a power supply device configured to modulate power to each of the independently controlled heater zones of the heater units through the power conductors. A voltage is selectively supplied to each of the independently controlled heating zones such that a reduced number of independently controlled heating zones receives the voltage at a time or at least a subset of the independently controlled heating zones receive a reduced voltage at all times.