A marine water heater is simply a small, insulated tank downstream of the pump. You must have a pressurized water system to operate a water heater. The pump draws water from the storage tank(s) and fills the water heater tank. Inside the water heater is an electrical heating element and usually a coiled tube called a heat exchanger. When AC power is available, the electrical element (controlled by a thermostat) heats the water. Away from the dock, the hot engine coolant is routed through the coiled tube to heat the water in the tank when the engine is running.
Water heaters have four threaded ports. The tank inlet connects via a tee-connector to the outlet hose from the pump. A check valve is required in this line or in the heater to prevent hot water from migrating back toward the pump. The outlet connection supplies heated water to the hot side of all faucets, also using tee-connectors. The other two ports are for the heat exchanger connection, which varies depending on engine installation. Use only metal fittings to plumb a water heater, never plastic. If a pressure-release valve isn’t integral, the heater will have a fifth port for this essential component.
Raritan’s 1700 Series Water Heaters are built for the long haul. A glass lined steel tank and a rust proof jacket keep the Raritan water heater looking great and lasting for many years. Research has shown that glass-lined steel tanks are more durable than tanks made from just stainless steel. To increase the longevity and fluctuations in water quality Raritan includes a sacrificial magnesium anode that ensures a long tank life.
High-density non-CFC foam insulation helps the tank to maintain the hot water longer, a plus if you don’t want to run the generator for hot water. In addition to the electric only units Raritan offers units with Heat exchangers. The heat exchanger allows the user to heat water when underway by circulating engine cooling fluid through the almost 7 foot long coil within the tank.
Raritan engineered the 1700 series from the ground up to perform in a marine environment. The dockside recovery rate is 13 gallons per hour. With a 240V heating element it can go as high as 18 gallons per hour. Because the heater includes an adjustable thermostat it can be set as high as 160o F. Hot water at 160o when mixed with cold water can greatly extend the usable capacity of the tank.
Installation of the 1700 Series Water Heaters is simple and straight-forward with all plumbing connection on one side. It retrofits without difficulty to most on board pressure systems. Hot and cold water fittings are standard ¾” male NPT and the heat exchanger’s ¾” female NPT. Available in 6, 12 or 20 gallon configurations.