Composition

• Marine water heater systems generally consist of the tank, water heater unit, pump and hoses. Valves and filters are also good things to have in the system for safer use and some systems have an accumulator that reduces pump cycling. The heater consists of an electrical heating element and a coiled tube called a heat exchanger.
  
  

Types

• There are electric and manual pumps for marine water heater systems. Electric pumps operate by pressurizing the water system pushing the water upward. Manual pumps are operated by a hand or foot pump next to the spigot being used. Manual pumps hold less water, which may be a concern for boaters away from shore for an extended period of time. Tanks may be polyethylene (a hard plastic) or made of a flexible bladder which expands to the amount of water in it.
  
  

Placement

• The water tank should be placed low in the boat so it does not affect the balance. Water is heavy and a full water tank near the top of the vessel can throw off your boat's trim. The heating element is located between the tank and the head.