Abstract: A method of operating a tankless water heater for heating a continuous supply of water. The method includes detecting a water flow condition within a heating chamber of the tankless water heater and regulating electrical current to first and second heating elements in response thereto. Both the first and second heating elements are located in the heating chamber, and respectively have first and second wattages, where second wattage is different than the first wattage. The regulating step further includes providing electrical current to the first heating element and not to the second heating element when a first flow condition is detected, and providing electrical current to the second heating element and not the first heating element when a second flow condition is detected, and providing electrical current to both of the heating elements when a third flow condition is detected.

Abstract: A tankless water heater for heating a continuous supply of water. The tankless water heater includes a housing, a water inlet and outlet ports, a heater assembly located within the housing and defining a water flow path having a heating element located therein and being coupled to the water inlet and outlet ports. A flow sensing device measures the water's flow condition between the water inlet and outlet ports. The water heater further includes a leak detection system having a water collection area defined by a portion of the housing, a water sensor configured to detect the presence of water in the collection area and being coupled to a water stoppage valve that is moveable between an open position and a closed position in response to a signal from the water sensor indicating water being present in the water collection area.

Abstract: A wall sleeve for recessed mounting into an opening in a wall. The wall sleeve includes a top sidewall, a bottom sidewall, a left sidewall, a right sidewall and a rear wall that cooperatively defines an enclosure with an enclosure opening located opposite of the rear wall. Each of the sidewalls have identical configurations, including portions defining at least one access opening and portions defining at least one mounting opening. The mounting openings having an effective diameter smaller than an effective diameter of the access openings.

Abstract: A tankless water heater system including a tankless water heater assembly and a mixing valve assembly enclosed within a system housing. The mixing valve assembly is formed by a one piece mixing valve housing that defines an unheated water path proceeding to the heater assembly and a heated water path proceeding from a hot water inlet passageway to a mixed water outlet passageway. Water flow through the mixed water passageway is controlled by mixing valve that includes a shuttle operably coupled to a thermostatic motor.

Abstract: An electric tankless water heater for heating a continuous supply of water. The electric tankless water heater includes a heater assembly having a water inlet, a water outlet and a heating chamber defining a water flow path there between. A flow sensing device is coupled to the water flow path and configured to detect an ultra-low flow condition of water within a heating chamber of the heater assembly. In response to the detection of an ultra-low flow condition, or higher flow conditions, a controller regulates the amount of electrical current flowing through to achieve the desired temperature of water at the water outlet.

Abstract: The present invention is an apparatus for controlling a water delivery system utilizing an instant flow tankless water heater. It includes a programmable microprocessor with support circuitry to achieve control of the outlet temperature of a varying flow rate and varying inlet temperature stream. The system senses a water outlet temperature and controls AC power through an on/off mechanism to regulate power to heating elements embedded in the water stream. The capabilities of the heating elements are improved through the application of using a microprocessor to perform a proportional (P), integrating (I) and derivative (D) calculation. The calculations are used to determine the operating characteristics of the heating system and to control the heating system.