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.