Excuse the boat crew while the shivers set in for the night. The sun has dropped out of sight, and the shipboard water is cold. Happily, a Webasto Isotemp Water Heater is pumping out hot water, which is then providing warmth to those chilly seafarers. Round and featureless, the drum-like marine appliance is using its 316-grade brushed stainless steel housing to conceal some fascinating tech.

A Vertically Recumbent Appliance 

Unlike the tall, upright water heating cylinders seen in most homes, Webasto Isotemp Water Heaters are designed to lay on their side. Mounted on supporting brackets, fastened so the rugged stainless steel casing can’t roll, that external casing supports an equally robust inner tank. Now, this is where this post looks beyond the toughened casing, the rigid fixing feet, and the stainless steel inner tank. There’s an extra-long corrugated coil inside the tank, which is coupled to the engine. In effect, this is a heat exchanger, a device that uses indirect water heating technology. As surplus heat leaves a boat or yacht engine, it’s collected and redirected to this heat exchanger coil.

Equipped with Marine-Grade System Redundancy 

What if the engine coolant isn’t flowing? What if the engine is offline and the yacht is sailing free. The wind is doing all the work. Well, even without the hot coolant rushing through the corrugated heat exchanger coil, there’s an immersion heating element on standby. It’s an electrically powered device, so boat batteries will keep the water hot. Then, as soon as the engine roars to life once more, the heat exchanger mode snaps back into action. It’s a best of both worlds proposition, with engine coolant heat or immersion element resistivity providing the necessary energy. Incidentally, boats are often hard to navigate, at least until a sailor gains his or her sea legs. Not to worry, there’s no chance the water will pour from a tap as a scalding hot spray, not when the Isotemp Temperature Control Safety Mixing Valve is there to protect everyone. And, should energy loss issues create anxiety, remember this marine-capable water heating unit is loaded with polyurethane insulation, which has been carefully injected into every internal nook and cranny.