14
VNG/VLP SERIES PRESSURE WASHER
OPERATOR’S MANUAL
3. With a small screwdriver, rotate the adjustment screw
clockwise to increase or counterclockwise to de-
crease gas pressure.
4. Replace regulator adjustment screw cap (see Fig-
ure 6, next page).
Figure 6
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 preventa-
tive for liming conditions is to use high quality cleaning
detergents. In areas where alkaline water is an extreme
problem, periodic use of Landa Deliming Powder will re-
move lime and other deposits before coil becomes
plugged. (See Deliming Instructions for use of Landa
Deliming Powder.)
Pressure Relief Valve
Each machine is equipped with a relief valve to relieve
pressure in the system when higher than normally oper-
ating pressures are encountered. If operating pressure
of machine is found to be normal and relief valve contin-
ues to leak, repair or replace the valve. CAUTION: Re-
lief valve can become obstructed by deposits and must
be unscrewed at least once per year to allow discharge.
PROPANE GAS
General Safety Precautions
Have a qualified gas service person assist in any gas
burner installation or service. Few maintenance people
or mechanics are knowledgeable in gas controls or re-
lated safety practices. Propane gas is heavier than air;
unburned propane gas will gravitate to the floor rather
than rise out of the stack. Hence, adequate floor space
and good ventilation are especially important with pro-
pane systems.
Gas Pressure Requirements
All propane fired machines operate on vapor propane
fuel only. They are designed to operate at a pressure of
11" w.c. (between 1/3 and 1/2 of one psi), and are often
operated at even higher pressures when extra heat is
needed.
Exterior regulators are needed to control the system. Pro-
pane bottles are not included with the machine. A high
pressure regulator should be installed on the propane
bottle and a low pressure regulator attached to the pres-
sure washer.
Propane Cylinder Capacity
An important consideration with propane systems is the
capacity of the supply cylinder relative to the needs of
the burner. The burner operates on propane as a vapor
gas. As gas is used from the propane cylinder, the liquid
in the cylinder boils to maintain vapor gas pressure. This
boiling process cools the liquid, and in a heavy, continu-
ous-demand situation, the liquid temperature can fall to
the point at which it cannot provide vapor gas as rapidly
as is needed. In this case, it may be necessary to warm
the propane cylinder by directing a warm spray, not over
120°F, on the cold cylinder or by manifolding two pro-
pane bottles together to increase total vaporization ca-
pacity. It is recommended that a minimum 100 lb. vapor
propane bottle be used on the machine, depending on
the length of running time desired.
BURNER FEATURES
Operated Automatic Valve
This machine is equipped with an Intermittent Pilot Igni-
tion System. This system is designed to eliminate the
need for a constant burning pilot. Lighting of the pilot is
accomplished through electronic spark ignition each time
the burner and flow switch call for heat. The pilot is not
burning when there is no call for heat. Do not attempt to
light the appliance manually as a burn injury or electrical
shock may result. The pilot light will remain on and the
main gas valve is turned off when the spray gun is closed.
