Abstract: Modular tankless water heater apparatus designed for use in a system including a water supply conduit and a hot water conduit. The apparatus includes a heating tube assembly with a plurality of tubes positioned in parallel juxtaposition and connected adjacent the ends into a series connected configuration to form a continuous fluid passage. A heating element is enclosed in each tube and extends between the ends with each heating element including an electrical connector and an electrical control. A programmable electrical power controller is connected to the electrical controls of the heating elements and to flow sensor and heat sensor apparatus positioned in the continuous fluid passage. The controller is programmed to activate the electrical controls one at a time in response to a demand signal from the flow sensor and heat sensor apparatus.

Abstract: A fluid heating system with a heat exchanger includes an elongated cylindrical tube with an inlet end and an opposed end. An array of film resistive elements is positioned on the outer surface of the cylindrical tube and extends circumferentially at least partially around the outer surface. A spiral channel guide is coaxially positioned within the cylindrical tube so as to force fluid flowing in the tube into a spiral path at least partially against an inner surface of the cylindrical tube. The spiral channel guide directs fluid flowing in the cylindrical tube so as to cause turbulence to occur in the flow and increase thermal transfer from the inner surface of the cylindrical tube to the fluid flowing in the tube.

Abstract: Control circuitry is disclosed for use with a tankless water heater system including a plurality of water conduits connected in series. The control circuitry includes a plurality of water heater elements, one each associated with each of the plurality of water conduits. A controller includes a central processing unit (CPU) with an operating program and each of the plurality of water heater elements are coupled to the CPU. The CPU is programmed to individually activate one of the water heater elements to a predetermined power level in response to a demand for heated water. The number of water heater elements activated and the power level of the activation is determined by the demand for heated water.

Abstract: A tankless water heater module is disclosed and includes a casing having a first end, a second end and a plurality of conduits formed therein. A top head manifold is coupled to the first end of the casing and includes a port aligned with each of the plurality of conduits. A bottom head manifold is coupled to the second end of the casing and includes a port aligned with each of the plurality of conduits. An immersion heating element extends through each port of the top head manifold and into the conduit aligned therewith. A flow path extends through the plurality of conduits, the plurality of conduits coupled in fluid communication by channels between ports of the top head manifold and a channel between ports of the bottom head manifold.

Abstract: A tankless water heater module is disclosed and includes a casing having a first end, a second end and a plurality of conduits formed therein. A top head manifold is coupled to the first end of the casing and includes a port aligned with each of the plurality of conduits. A bottom head manifold is coupled to the second end of the casing and includes a port aligned with each of the plurality of conduits. An immersion heating element extends through each port of the top head manifold and into the conduit aligned therewith. A flow path extends through the plurality of conduits, the plurality of conduits coupled in fluid communication by channels between ports of the top head manifold and a channel between ports of the bottom head manifold.