Collection: Hot Water Heaters

Choosing the right marine hot water heater comes down to a handful of decisions that matter before anything else: tank capacity, shore power voltage, and whether you want a heat exchanger that runs off engine coolant. Raritan and Kuuma both offer tanks from 6 to 20 gallons, covering everything from a compact weekender to a larger liveaboard setup, and both are available in 120V and 240V configurations. If your boat runs 240V service, confirm your wiring setup before ordering because some Kuuma 240V units use L1 and L2 wiring that requires the right panel connection. Whale's Seaward heaters are built with a stainless steel tank, which adds corrosion resistance in saltwater environments where that distinction matters.

The heat exchanger question is worth thinking through carefully. Models with a heat exchanger can recover heat from the engine while underway, reducing the draw on shore power once you dock. Models without one cost less and suit boats where that secondary heating loop is not practical. Pay attention to physical dimensions and mounting orientation too, since Kuuma lists both front heat exchange and side mount variants that suit different installation constraints. Camco's replacement elements round out the category for boats that simply need a worn component swapped rather than a full unit replaced.