should adjust the fuel and air controls until the
most efficient operation of the unit is obtained.
If operating a laundry unit with a Model M-80
Normally, 60-75 psi fuel pressure with air ratio set
Water Heater (NSN 452041-162-0385) in a
for clear exhaust (approximately one-half air shut-
ter opening) will result in efficient operation of the
shelter or other enclosed area, ensure the area is
unit. This will provide a 160F (128C) water
well-ventilated. Noxious fumes may flow back
temperature at the number four position on the
through the exhaust ducts after the water reaches
temperature control for normal laundry operation.
the proper temperature and the blower shuts off.
(m) Make fuel pressure adjustments and
(e) Adjust temperature control thermal
motor corrections as listed below:
switch to position No. 4, and push the water heater
1. Adjust the fuel pressure until the
pressure gage reads approximately 85 psi (5.978 kg
per sq cm), and adjust the air shutter as necessary
registers 80 psi (5.62 kg per sq cm). If the gage
to obtain optimum heater performance.
shows less than this, check for air leaks in the
2. The blower and fuel pump electric
suction line. Vent or prime the pump as necessary.
motor are equipped with thermal overload
Adjust the pump pressure adjusting setscrew to
increase the pressure.
circuit, react by opening the circuit to the motor in
(g) Observe through the burner spark
less than 20 seconds. When this condition occurs,
sightglass (fig. 2-2) to determine that a spark is
a hum from the motor will be audible as the motor
temperature rises. After activation of the thermal
(h) Open the fuel pressure control valve
protector, it will be necessary to wait for the motor
(fig. 2-2) until the fuel pressure registers
60 to 80
to cool before the thermal protector can be reset.
psi (4.22 to 5.62 kg per sq cm).
To reset, press the button located on the endbell of
the motor. If the motor does not turn after
Be sure the Burner Shutoff Valve and the
PUMP FAILS TO
Fuel Pressure Control Valve is not opened
DELIVER FUEL and follow the listed in.
unless a spark is present. Failure to ob-
serve this warning may result in serious
injury to personnel. Turn Burner Shutoff
(5) Tumbler Starting Instruction.
Valve clockwise to OFF position, Fuel
Pressure Control Valve is turned coun-
the proper setting.
terclockwise to decrease the flow of fuel to
(b) Push the start button on the upper
the Burner and clockwise to increase the
flow of fuel to the Burner.
(c) Make certain the fuel pump rotates in
the correct direction, es indicated by the arrow on
(i) Turn the burner shutter lever until the
the fuel pump.
shutter is about halfway open.
(d) Observe the reading on the fuel gage.
(j) Open the fuel shutoff valve about one-
quarter turn, and look through the burner flame
jumps back and forth after 20 seconds of
sightglass (fig. 2-2) to determine that a flame is
operation, there is a leak in the fuel line or a
present. If a flame is present, turn the shutoff
shortage of fuel in the fuel pump. Push upper stop-
valve all the way on.
reset button, and make a thorough check of each
(k) Make adjustments as necessary to the
fitting and connection of fuel supply lines to the
shutter so that no smoke is evident in the heater
fuel container. If necessary, disconnect fitting to
make certain that screw threads are in good
(l) For normal wash water temperature set
the water temperature control thermal switch (fig.
2. Push the upper start button and
2-2) at 4. When the temperature limit is reached,
observe the reading of the fuel pressure gage. The
the heater will shutoff automatically and the fuel
gage should indicate 100 psi (7.03 kg per sq cm).
pressure gage will register zero. Observe the
If the gage does not indicate the proper pressure,
temperature gage to determine the temperature of
adjust the fuel pump,
the water when the heater cute off. The proper
(e) Observe through the burner sightglass
temperature limit for operation is 160F. (71 C). Ad-
to determine if a spark is present. The reflection of
just the thermal switch until the heater
the spark and not the spark itself, may be seen.
automatically shuts off at 160F (71 C).
(f) Push the start button of the lower
manual starter assembly (fig. 2,6).
Individual heater units will vary as to the moat ef-
ficient fuel to air ratio adjustment. The operator