4 Start Up / Test
Fill the hot water tank by turning on the water pressure pump and opening a hot water tap to
allow air to bleed out of the hoses and/or plumbing.
Check the drain and pressure relief valve by turning the knob counterclockwise one notch. Wa-
ter will flow into the drain hose. Make sure the drain hose is not blocked or closed. Turn the
knob counterclockwise again and the valve will close.
Start the engine to check the circulation of the coolant. It will be necessary to add coolant to
the system to compensate for the additional volume of the exchanger and hoses. Check for air
locks in the connecting hoses and raise and lower these as necessary to clear the air from the
hoses before securing the hoses in place.
Lastly plug in the tank and turn on the circuit breaker. Check for proper operation.
5 Maintenance
5.1 Winterization
When there is a risk of freezing the tank must
be drained. This is done by opening the air
bleeder screw mounted on the mixing valve
(Fig. 5) and opening the drain valve by turning
the relief valve knob counterclockwise one
notch (Fig. 6).
If the engine is raw-water cooled the heat ex-
changer must also be drained by removing the
hoses and blowing air into the coils to drain
any water.
The tank can now be safely left in the vessel
over the winter.
6 Double Heat Exchanger
Double Heat Exchanger Water Heaters (Model
404R) have connections for second heat ex-
changer located on the back (Fig. 7).
Fig. 6
Fig. 7
Fig. 5
