Abstract: A continuous-flow water heater has an elongated closed tank with sidewalls and end closures. The tank is arranged with its longitudinal axis substantially vertical and is provided with a vertically disposed internal tubular baffle dividing the tank into inner and outer concentric compartments which are open to each other at the top and bottom of the tank. A plurality of electric immersion heating elements are positioned within the inner compartment and extend substantially parallel to the longitudinal axis of the baffle. A jet nozzle extends into the bottom of the tank and is arranged to direct a substantially vertically directed high velocity jet of water into the tubular baffle and toward the top end closure of the tank.