Maintenance And Service; Unloader Valves; Heating Coils - Landa ENG4-2000 Operator's Manual

Spray Nozzles:
Each machine is equipped with one or more spray
nozzles, depending on the model. Different spray
nozzles are calibrated for each machine, depending on
the flow and pressure of that particular model. Spray
nozzles vary in bore size and angle of spray. Popular
spray angles are 0°, 15°, 25°, 40°. When ordering,
please specify size and angle of nozzle. Nozzle size
for each machine is located on the serial plate.

Unloader Valves:

Unloader valves relieve pressure in the line when a
spray gun is closed. Unloader valves are preset and
tested at the factory before shipping. Occasional ad-
justment of the unloader may be necessary to maintain
correct pressure. For valve adjustment contact your
nearest dealer or call technical support. Tampering
with the factory setting may cause personal injury and/
or property damage, and will void the manufacturer's
warranty.
Winterizing Procedure:
Damage due to freezing is not covered by warranty.
Adhere to the following cold weather procedures when-
ever the washer must be stored or operated outdoors
under freezing conditions.
It is necessary to protect your machine against freez-
ing when temperatures drop below 32° F. Siphoning a
small amount of antifreeze into the system is recom-
mended. This is done by pouring a 50-50 mix of anti-
freeze and water into the float tank and then siphoning
100% antifreeze through the detergent line with the
pump on. If compressed air is available, an air fitting
can be screwed into the float tank strainer fitting, and
by injecting compressed air, all water will be blown out
of the system. The use of a draft diverter will prevent
the wind chill factor from freezing the coil.
Low Pressure Diagnosis:
(Machines with spray gun)
Refer to Troubleshooting Chart for low pressure. If the
trouble is found to be either the unloader or the pump,
your next step is to determine which is the problem.
This can be done by eliminating the unloader from the
system and attaching the 50' discharge hose directly
to the pump. If high pressure is developed in this man-
ner, the pump is good and the unloader needs to be
repaired or replaced. If low pressure is still present,
then the pump needs repairing.
CAUTION: When using this procedure to test compo-
nents keep the spray gun open at all times.
High Limit Hot Water Thermostat:
For safety, each machine is equipped with a high limit
control switch. In the event the temperature of the water

MAINTENANCE AND SERVICE

ENG • 9.801-511.0 • Rev. 9/13a
should exceed its operating temperature, the high limit
control will turn the burner off until the water cools.
Pumps:
Use only SAE 20/40 weight non-detergent oil. Change
oil after first 50 hours of use. Thereafter, change oil
every three months or at 500 hour intervals. Oil level
should be checked through use of the dipstick found
on the top of the pump or by the red dot visible through
the oil gauge window. Oil should be maintained at
that level.

HEATING COILS

To Check Water Heater Coil for Leaks:
With the main burners "OFF" start the pumping unit
and allow it to run for a few minutes. Check into the
burner compartment with a drop light or flashlight. If
no leaks are visible, then water dripping from coils is
condensation from the flue gases when the burners
are on.
Condensation from Heating Coil:
When cold water is being pumped into the water heater
coils, and the burners are on, condensation will form on
the coils and drip down into the burner compartment,
giving the appearance of a leaking coil, particularly
on cold humid days.
Deliming Coils:
In alkaline water areas, lime deposits can accumulate
rapidly inside the coil pipes. This growth is increased
by the extreme heat build up in the coil. The best
prevention for liming conditions is to use high quality
cleaning detergents. In areas where alkaline water is
an extreme problem, periodic use of Mongoose Coil
Conditioner (part # 8.914-296.0) will remove lime and
other deposits before coil becomes plugged. (See the
following instructions for use of Coil Conditioner.)
Periodic flushing of coils is recommended.
1. Fill a container with 2 gallons of water, then add
1 lb. of deliming powder. Mix thoroughly.
2. Remove nozzle from spray gun assembly and put
spray gun into container. Secure the trigger on the
spray gun into the open position.
3. Attach a short section (3-5 ft.) of garden hose to
machine to siphon solution from an elevated con-
tainer, or add mixture to the float tank. Turn pump
switch on allowing solution to be pumped through
coils and back into the container. Solution should
be allowed to circulate 2-4 hours.
4. After circulating solution, flush entire system with
fresh water. Reinstall wand assembly to spray gun.
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