A fluid heater is disclosed and which has a heater, pump, and a plurality of temperature sensors which are electrically coupled with first and second temperature controlled relays, and wherein the fluid heater is operable to maintain a source of fluid used by an object of interest within a predetermined temperature range and further, is operable under given temperature conditions to discontinue operation so as to protect the object of interest and the heater from becoming damaged through overheating of the fluid which is utilized by same.

A liquid heating method and apparatus including a heat device 7 having a flow passage member forming a tubular flow passage for passing a sulfuric acid solution, a heater arranged on an outside of at least one of opposing flow passage surfaces of the tubular flow passage, a liquid draining line 10, an atmosphere opening line 12, valves 11 and 13, a liquid draining mechanism for draining the sulfuric acid solution heated at least in a heat receiving area between the opposing liquid flow passage surfaces of the tubular flow passage, a flow meter 6 for measuring a flow rate of the sulfuric acid solution, and a control unit 14 responsive to the flow meter 6 for determining a defective liquid flow in the tubular flow passage and for draining the sulfuric acid solution using the liquid draining mechanism.

An on-demand hot water dispenser includes a housing, a water heating system received in the housing, and a faucet connected to the water heating system through the housing for dispensing hot water into a container. A drip tray is positioned below the faucet and a screen covers the drip tray to support the container during dispensing of the hot water.

A temperature control unit includes a fitting, a heating wire, a first temperature sensor, and a housing, which contains the first temperature sensor and portions of the fitting and the heating wire. The fitting includes a fluid inlet, a fluid outlet, a flow channel extending from the fluid inlet to the fluid outlet, and a passage extending through a wall of the fitting to the flow channel. The heating wire extends through the passage and into the flow channel. The first temperature sensor is secured to an external surface of the fitting opposite the flow channel and is electrically connected to the heating wire.

Embodiments of the invention provide a pool heater including a housing, a first tankless heater, a second tankless heater, and a controller. The controller is configured to activate only the first tankless heater when a first condition is met, activate only the second tankless heater when a second condition is met, and activate the first and the second tankless heaters simultaneously when a third condition is met.

An inline heater includes a heater core that includes a heat spreader assembly comprising a tubular heat spreader that extends axially along a longitudinal axis and that comprises an external surface. The heat spreader assembly includes a fluid inlet and a fluid outlet. At least one conduit extends helically about the longitudinal axis of the heat spreader between the fluid inlet and the fluid outlet to define a fluid heating flow path that fluidically connects the fluid inlet and the fluid outlet. The heat spreader assembly further comprising an electrically operated heating element for heating the heat spreader.

A heater for heating liquid to boiling comprises a heating element (48; 106), a first heating region (18, 20; 100) heated by said heating element (48; 106) for heating liquid flowing therethrough to a temperature below boiling, and a second heating region (22; 102) for heating said liquid to boiling. The second region permits the exit of steam therefrom separately from heated water.

The present invention includes: a laminated structure of an insulation substrate; a resistance pattern laminated on one side of the insulation substrate with a pure metal or an alloy which is a mixture of two or more metals at a predetermined ratio and having a resistance value which is set by a pattern having a length and a cross-sectional area; a first insulator layer coated on an upper surface of the resistance pattern by a predetermined method to protect and insulate the resistance pattern; a conductor layer in which a metal material is deposited on the upper surface of the first insulator layer by a predetermined method; and a thin film protective layer deposited on the upper surface of the conductor layer to provide insulation from the conductor layer, waterproofing, corrosion resistance, and chemical resistance.

The present invention provides a hot water supply device. When a hot water supply operation is started in response to an instruction for checking a heat exchange state, a heat exchange state determiner 12 measures a post-boiling temperature Tup, which indicates the rise width of a temperature detected by a heat exchange outlet temperature sensor 26 from the point when the hot water supply operation stopped, and outputs a heat exchange success report if the post-boiling temperature Tup is lower than a first threshold temperature. Further, when the hot water supply operation is started independently of the instruction for checking a heat exchange state, the heat exchange state determiner 12 outputs a report of clogging of a heat exchanger if the post-boiling temperature Tup is higher than a second threshold temperature Bth, which is higher than the first threshold temperature Ath.

A refrigerator that may include a cabinet to define a storage space, a door to open and close the storage space, a dispenser provided in the door to dispense hot water, a hot water tank through which water flows so as to heat water introduced into the door, a heater provided in the door to heat the hot water tank, a water inflow passage through which water is supplied to the hot water tank, a water discharge passage guiding hot water discharged from the hot water tank to the dispenser, a flow rate sensor provided in the water inflow passage to measure a flow rate of water flowing through the water inflow passage, a water inflow valve provided in the water inflow passage to adjust a flow of water in the water inflow passage, a water discharge valve provided in the water outlet passage, an input provided in the door to input a temperature of the hot water to be dispensed and a hot water dispensing command, and a controller to control the water inflow valve and the water discharge valve.