737 MAX Flight Crew Operations Manual
Airplane General, Emergency
Equipment, Doors, Windows -
Systems Description
1.40.50
MN-FLT-OH-201
Hot Water
Hot and cold water is available in all lavatories. The water heater is located below
the lavatory sink. When emptied, it heats a new water charge in four minutes. An
amber light is ON when the heater is operating normally. The heater has an
overheat switch which turns off the heating element if an excess temperature is
reached. The heater may be turned off at any time by using a manual switch on the
heater. Cold water is supplied at the galleys.
Servicing
The system is serviced from an exterior panel located on the bottom right side of
the aft fuselage. Pressure filling is required. Waste water from the galleys and
lavatory wash basins is drained overboard through two heated drain masts. The
drain mast are on the bottom of the fuselage; one forward and one aft.
March 1, 2021