This Isotemp SPA marine water heater, model SPA40, has a capacity of 40 liters and is designed for heating and storing domestic water on board. The water can be heated using the built-in 230 V/750 W electric heating element or via the heat exchanger coil when connected to the cooling water circuit of a fresh-water cooled marine engine.
The inner tank and the corrugated heat exchanger coil are made of AISI 316 stainless steel. The outer shell is made of grey polypropylene, while CFC-free polyurethane foam insulation limits heat loss. The mounting brackets are made of AISI 304 stainless steel, and the electric heating element is made of nickel-plated copper.
The SPA40 measures 640 × Ø390 mm and weighs 14 kg. The total height including mounting feet is approx. 392 mm, and the width across the feet is 390 mm. The water heater can be mounted horizontally or vertically. For vertical installation, the connections must face downwards, and the safety/drain valve must be positioned at the lowest point of the system. The mounting brackets can be moved around the tank so that the unit can be secured to a shelf or a bulkhead.
The operating thermostat is set to 75 °C, and a separate, manually resettable over-temperature cut-out is activated at 96 °C. The internal electrical connections are factory-installed. The installation must be grounded and protected by a residual current device (RCD). The tank must always be filled and bled before the power is connected.
The cold and hot water connections as well as the two connections for the engine heat exchanger have 1/2" NPT male threads. Straight G1/2 hose nipples can also be used. For the engine circuit, a heat-resistant hose with an inner diameter of at least 16 mm and a flow through the heat exchanger of at least 2 l/min is recommended. The combined safety and non-return valve is set to 6 bar, while the recommended maximum operating pressure of the fresh water pump is 3.8 bar.
A thermostatic mixing valve, item no. 50.189.58, is not included and must be purchased separately. The mixing valve regulates the outlet temperature and reduces the risk of scalding. The flexible hot water outlet hose, item no. 50.289.56, can be used as a temperature-resistant accessory at the hot water outlet. Documented service parts include, among others, heating element kit SEE00019LA, service thermostat SEA00041LA, over-temperature thermostat SEA00042LA, safety valve SFD00029AA, and mounting flange kit SGB00165AA.
If there is a risk of frost, the tank must be drained. On installations with raw-water cooled engines, the heat exchanger coil must also be drained. The safety valve should be activated regularly to check its function and remove any limescale deposits.
Key features40-liter capacity
Electric heating with 230 V/750 W heating element
Heating via engine cooling water and integrated heat exchanger coil
Inner tank and corrugated coil in AISI 316 stainless steel
CFC-free polyurethane foam insulation
Combined safety and non-return valve set to 6 bar
Operating thermostat at 75 °C and over-temperature cut-out at 96 °C
Horizontal or vertical mounting
Product dimensions: 640 × Ø390 mm
Thermostatic mixing valve purchased separately
