715-721 • HDS-NG LP • 9.800-160.0 • Rev. 4/10
OPERATOR’S MANUAL
PRESSURE WASHER
10
INSTALLATION
Venting:
This machine is to be used indoors and requires
ventilation.
When venting the machine, if the machine is to be in
an enclosed area with a vent pipe, be sure it is the
same size as the stack on the machine. Poor draft will
cause the machine to soot and not operate efficiently.
When placing the machine for installation, position the
vent pipe to be as straight as possible and to protrude
through the roof of the building at a proper location and
at sufficient height to eliminate down-draft. Venting of a
gas fired machine shall be installed with a down-draft
diverter located about 3 ft. above machine.
Input - BTU Per Hour
Draft Hood & Flue Pipe
Size
250,000 - 320,000
8 inch
320,000 - 410,000
9 inch
410,000 - 600,000
10 inch
600,000 - 750,000
12 inch
NOTE: If the vent pipe exceeds 10 ft. in length, or
contains more than two elbows, use next size larger
pipe and draft diverter or the burner will not ignite. No
movable vent pipe damper should be used on any
installation.
Draft Diverter:
Install the draft diverter above the heating coil. The
diverter enhances the draft through the burner by
severing the chimney effect created in sections of vent
pipe positioned below. It also helps prevent freezing
of the coil due to wind chill factors.
Figure 3
When a room is of unusually tight construction and
has a ventilating fan, which may be used for ex-
hausting air outdoors -or has a vented exhaust — it
is recommended that combustion air be supplied to
the enclosed room through intakes extending to the
outside of the building and terminating in down-turned
fittings. These should be suitably arranged to prevent
obstruction from snow or rain, and include a protecting
screen not smaller than 1/4 inch mesh.
Figure 4
Illustration showing air openings necessary
to supply air for combustion when installed
in an enclosed room.
Water Source:
The water source for the machine should be supplied
by a 5/8" I.D. garden hose with a city water pressure of
not less than 30 PSI. If the water supply is inadequate,
or if the garden hose is kinked, the machine will run
very rough and the burner will not fire.
Water Connection:
Connect the high pressure hose by pulling the coupler
collar back and then inserting it onto the discharge
nipple. Secure it by pushing the collar forward.
Attach the wand into the spray gun using teflon tape
on the pipe threads to avoid leaks.
Inspection and Testing Gas Piping:
The building structure should not be weakened by
installing the gas piping. The piping should not be
supported by other piping, but should be firmly sup-
ported with gas hooks, straps, bands or hangers. Butt
or lap welded pipe should not be run through or in an
air duct or clothes chute.
Optional
When in a tightly closed room without ventilation open-
ings to the outdoors or other rooms, provisions shall be
made for supplying air for combustion through special
openings, one near the floor and the other near the
ceiling, each to be sized on the basis of one square
inch or more of free area for each 1,000 BTU input
per hour (see Figure 4).
Ventilating Air Opening.
1 square inch for each
1000 BTU per hour input.
