Hotsy 9452 User manual

OPERATOR’S MANUAL
For technical assistance or the dealer nearest you,
consult our web page at www.hotsy.com or call 1-800-525-1976
GAS FIRED BURNER MODULES
9452
9462
#8.914-365.0

9452 SPECIFICATIONS
 Maximum Inlet: 3200 PSI
 Machine Voltage: 120V
 Total Machine Amperage: 1 Amps
 Burner Type: Natural Gas, LP (optional)
 BTU: 540,000 BTU/Hr Max
 Exhaust Stack Size: 10"
 Machine Weight: 470 Lbs.
 Shipping Weight: 500 Lbs.
 Machine Dimensions:
Length = 32.5", Width = 25", Height = 50.5"
9462 SPECIFICATIONS
 Maximum Inlet: 3200 PSI
 Machine Voltage: 120V
 Total Machine Amperage: 1 Amps
 Burner Type: Natural Gas, LP (optional)
 BTU: 920,000 BTU/Hr Max
 Exhaust Stack Size: 12"
 Machine Weight: 880 Lbs.
 Shipping Weight: 935 Lbs.
 Machine Dimensions:
Length = 40.5", Width = 32", Height = 65"

CONTENTS
4Hosty 9452/9462GF • 8.914-365.0 • Rev. 11/08
Model Number ______________________________
Serial Number ______________________________
Date of Purchase ___________________________
The model and serial numbers will be found on a decal attached
to the machine.You should record both serial number and date of
purchase and keep in a safe place for future reference.
Introduction & General Safety Information 5-6
Component Identification 7
Installation 8-11
Pre-Start Checklist 12
Operating Instructions 13
Detergents & General Cleaning Techniques 14
Shutting Down & Clean-Up 15
Basic Facts 16
Troubleshooting 17-18
Maintenance & Service 19-20
Preventative Maintenance 21
Warranty

Hosty 9452/9462GF • 8.914-365.0 • Rev. 11/08
5
PRESSURE WASHER OPERATOR’S MANUAL
Thank you for purchasing a Hotsy Heating Module.
This manual covers the operation and maintenance
of the 9452, 9462 heating modules. All information in
this manual is based on the latest product information
available at the time of printing.
Hotsy, Inc. reserves the right to make changes at any
time without incurring any obligation.
When ordering parts, please specify model and serial
number.
Owner/User Responsibility:
The owner and/or user must have an understanding of
the manufacturer’s operating instructions and warnings
before using this Hotsy water heater. Warning infor-
mation should be emphasized and understood. If the
operator is not fluent in English, the manufacturer’s in-
structions and warnings shall be read to and discussed
with the operator in the operator’s native language by
the purchaser/owner, making sure that the operator
comprehends its contents.
Owner and/or user must study and maintain
for future reference the manufacturers’instruc-
tions.
This manual should be considered a permanent
part of the machine and should remain with it
if machine is resold.
IMPORTANT SAFETY
INFORMATION
CAUTION: To reduce the risk of
injury, read operating instruc-
tions carefully before using.
1. Read the owner's manual
thoroughly. Failure to follow
instructions could cause mal-
function of the machine and
result in death, serious bodily
injury and/or property dam-
age.
2. All installations must comply with local codes.
Contact your electrician, plumber, utility company
or the selling distributor for specific details.
WARNING: Flammable liquids
can create fumes which can
ignite causing property damage
or severe injury.
3. Risk of explosion - do not
spray flammable liquids or
operate in an explosive lo-
cation. Operate only where
open flame or torch is per-
mitted.
4. Do not attach a gasoline operated pressure
washer to this machine because gas vapors will
ignite.
WARNING: Keep water spray
away from electrical wiring or
fatal electric shock may result.
Read warning tag on electrical
cord.
5. To protect the operator from
possible electrical shock, the
machine must be electrically
grounded.
It is the responsibility of the owner to connect this
machine to a UL grounded receptacle of proper
voltage and amperage ratings. Do not spray water
on or near electrical components. Do not touch
machine with wet hands or while standing in water.
Always disconnect power before servicing.
WARNING: Spray gun kicks back. Hold with both
hands.
6. Grip cleaning wand (not included) securely with
both hands before starting the cleaner. Failure
to do this could result in injury from a whipping
wand.
WARNING: The pressure washer
attached to this equipment can
produce a high pressure stream
of fluid that can pierce skin and
its underlying tissues, leading
to serious injury and possible
amputation.
7. High pressure developed
by this machine can cause
personal injury or equipment
damage. Use caution when operating. Do not
direct discharge stream at anyone or at any part
of the body, or severe injury or death may result.
This machine is to be used only by qualified op-
erators.
8. Never make adjustments on machine while in
operation.
WARNING: High pressure can
cause paint chips or other par-
ticles to become airborne and
fly at high speeds.
9. Eye safety devices and foot
protection must be worn
when using this equipment.
WARNING
RISK OF EXPLOSION:
DO NOT SPRAY
FLAMMABLE
LIQUIDS.
WARNING
HIGH PRESSURE
SPRAY CAN PIERCE
SKIN AND TISSUES.
WARNING
KEEP WATER SPRAY
AWAY FROM
ELECTRICAL WIRING.
INTRODUCTION & SAFETY INFORMATION
WARNING
READ OPERATOR’S
MANUAL
THOROUGHLY
PRIOR TO USE.
CAUTION
WARNING
PROTECTIVE
EYEWEAR AND
CLOTHING MUST
BE WORN.

Hosty 9452/9462GF • 8.914-365.0 • Rev. 11/08
OPERATOR’S MANUAL PRESSURE WASHER
6
WARNING: Risk of asphyxi-
ation. Use this product only in
a well ventilated area.
10. When the machine is work-
ing, do not cover or place in
a closed space where venti-
lation is insufficient.
11. Protect from freezing.
12. Be certain all quick coupler
fittings are secured before
using pressure washer.
13. Do not allow acids, caustic, or abrasive fluids to
pass through the pump.
14. Inlet water must be cold and clean fresh water.
15. Do not allow CHILDREN to operate this equipment
at any time.
16. The best insurance against an accident is pre-
caution, and knowledge of the machine.
17. Do not operate this product when fatigued or under
the influence of alcohol or drugs. Keep operating
area clear of all persons.
18. Never expose a spark or flame where there may
be unburned gas present.
19. Never attempt to light pilot unless pilot manual
valve has been shut off for 5 minutes.
WARNING: Use only vapor
fuel.
20. A conversion kit, as supplied
by the manufacturer, shall be
used to convert natural gas
to propane.
21. This equipment is designed to
run on vapor fuel. Do not use
liquid fuel. Have a quaified
serviceman install and ser-
vice your equipment.
22. L.P. gases are heavier than air and will spill out
on the floor. Therefore always provide adequate
space and ventilation around these machines.
23. Hotsy will not be liable for any changes made to
our standard machines, or any components not
purchased from Hotsy.
24. Do not overreach or stand on unstable support.
Keep good footing and balance at all times.
25. Follow the maintenance instructions specified in
the manual.
26. When making repairs disconnect from electrical
source and shut off gas valve.
27. Turn burner off and cool to
100°F before turning ma-
chine off.
28. Extinguish any open flame
and test all joints with a soap
solution. If odor persists, call
your gas supplier imme-
diately.
29. This machine must be at-
tended during operation.
30. Consult local codes and ordinances for proper
stacking type and size.
31. A draft hood shall be installed on this machine and
vented to the outside of the building.
32. Inspect pressure safety relief/rupture disk for ob-
struction every three (3) months.
RISK OF EXPLOSION:
IF GAS SMELL
PRESENT TURN
OFF SUPPLY.
WARNING
WARNING
RISK OF
ASPHYXIATION.
USE ONLY IN A WELL
VENTILATED AREA.
WARNING
RISK OF FIRE OR
EXPLOSION: USE
VAPOR FUEL ONLY.
SAFETY INFORMATION

Hosty 9452/9462GF • 8.914-365.0 • Rev. 11/08
7
PRESSURE WASHER OPERATOR’S MANUAL
COMPONENT IDENTIFICATION
Fresh
Water
Inlet
Flow
Switch
Power
Cord
Gas
Valve
Fuel
Supply
Inlet
Rupture
Disk
High
Pressure
Outlet
For Detail
See Control
Box Illus.
Burner
Exhaust
Vent
Burner
Switch

Hosty 9452/9462GF • 8.914-365.0 • Rev. 11/08
OPERATOR’S MANUAL PRESSURE WASHER
8
INSTALLATION
Place machine in a convenient location providing
ample support, drainage and room for maintenance.
Location:
This machine is certified for indoor installation.
Its location should protect the machine from dam-
aging environmental conditions, such as wind, rain
and freezing.
1. The machine should be run on a level surface
where it is not readily influenced by outside sourc-
es such as strong winds, freezing temperatures,
rain, etc.The machine should be located consider-
ing accessibility of the components and the refill-
ing of detergents, adjustments and maintenance.
Normal precautions should be taken by operator of
machine to prevent excess moisture from reaching
power machine or electrical controls.
2. It is recommended that a partition be made be-
tween wash area and machine to prevent direct
spray from spray gun from coming in contact
with machine. Excess moisture reaching pres-
sure washer or electrical controls will reduce life
of machine and may cause electrical shorts.
3. During installation of machine, beware of poorly
ventilated locations or areas where exhaust fans
may cause an insufficient supply of oxygen. Suf-
ficient combustion can only be obtained when a
sufficient supply of oxygen is available for the
amount of fuel being burned. If it is necessary
to install a machine in a poorly ventilated area,
outside fresh air may have to be piped to burner
and a fan installed to bring air into area.
4. Do not locate near any combustible material.Keep
all flammable material at least 20 feet away.
Allow enough space for servicing the machine.
Local code will require certain distances from floor
and walls. (Two feet away should be adequate.)
AVOID SMALL LOCATIONS OR AREAS NEAR
EXHAUST FANS.
Gas Codes:
Confer with local gas company and with proper mu-
nicipal officials regarding any specific code or regu-
lations governing the installation.The installation must
conform to local codes.
Electrical:
The machine, when installed, must be electrically
grounded in accordance with local codes. Check for
proper power supply using a volt meter; check the
serial plate for the correct requirements.
Gas Piping:
All piping must comply with local codes and ordinances
of the National Fuel Gas Code. A sediment trap or drip
leg must be installed in the supply line to the burner.
See figure below.
A union shall be installed in the gas line adjacent to and
upstream from the control manifold and downstream
from the manual main shut-off valve.
A 1/8" N.P.T. plugged tapping accessible for test gauge
connection shall be installed immediately upstream of
the gas supply connection for the purpose of deter-
mining the gas supply pressure to the burner, and to
prevent damage to gas valve.
If a manual gas shut off valve is not in the gas supply
line within six feet of the machine and in an accessible
location, one shall be installed.
A manual shut-off valve shall be installed in the gas
supply line external to the appliance. The gas line
should be a separate supply direct from the meter to
the burner. It is recommended that new pipe be used
and located so that a minimum amount of work will
be required in future servicing. The piping should be
installed to be durable, substantial and gas tight. It
should be clear and free from cutting burrs and defects
in structure of threading. Cast iron fittings or aluminum
tubing should not be used for the main gas circuit. Joint
compounds (pipe dope) should be used sparingly on
male threads only and be approved for all gases.
3"(76.2mm)
Minimum
3"(76.2mm)
Minimum
Sediment trap (drip leg) must be
installed in the supply line.
Drop Gas
Valve
Gas
Valve

Hosty 9452/9462GF • 8.914-365.0 • Rev. 11/08
9
PRESSURE WASHER OPERATOR’S MANUAL
INSTALLATION
Propane Gas
The following pipe and stack sizes are just recom-
mendations. Always consult a local plumber and
venting contractor for local codes and regulations
during installation. The following tables are maximum
capacity of final stage pipe in thousands of BTU/Hr.
of commercial propane:
From first stage regulator (at tank) to second stage
regulator.
The chart below is based on incoming gas pressure
of 10 PSI and a pressure drop of 1 PSI. Numbers are
for straight schedule 40 pipe; fittings further reduce
capacity.
From second stage regulator to machine.
The following chart is based on incoming gas pres-
sure of 11 w.c.i. and a drop of 5 w.c.i. Numbers are
for straight schedule 40 pipe; fittings further reduce
capacity.
The chart below is based on gas pressure in the range
0-.5 PSI, specific gravity of .6, and a pressure loss of
.5 w.c.i. Numbers are for straight schedule 40 pipe;
fittings further reduce capacity.
Propane
Length of Pipe (ft.)
Iron Pipe Size
1/2" 3/4"
10 3339 6982
20 2295 4799
30 1843 3854
40 1577 3298
50 1398 2923
60 1267 2649
70 1165 2437
80 1084 2267
90 1017 2127
100 961 2009
150 772 1613
200 660 1381
250 585 1224
300 530 1109
350 488 1020
400 454 949
450 426 890
500 402 84
Propane
Length of
pipe (ft.)
Iron Pipe Size
1/2" 3/4" 1"
10 291 608 1146
20 200 418 788
30 161 336 632
40 137 287 541
50 122 255 480
60 110 231 435
70 102 212 400
80 94 198 372
90 87 185 349
100 84 175 33
Natural Gas
Length
of Pipe
(ft.)
Iron Pipe Size
3/4" 1" 1 -1/4" 1-1/2" 2"
10 360 680 1400 2100 3950
20 250 465 950 1460 2750
30 200 375 770 1180 2200
40 170 320 660 990 1900
50 151 285 580 900 1680
60 138 260 530 810 1520
70 125 240 490 750 1400
80 118 220 460 690 1300
90 110 205 430 650 1220
100 103 195 400 620 1150
150 84 160 325 500 950
200 72 135 280 430 80

Hosty 9452/9462GF • 8.914-365.0 • Rev. 11/08
OPERATOR’S MANUAL PRESSURE WASHER
10
INSTALLATION
Water Source:
The heating module was designed to accept a cold
water electric pressure washer. The water source for
the attached pressure washer 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.
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.
Before turning gas on, close all openings from which
gas can escape. Check system for leaks immediately
after turning gas on.This can be done by watching the
1/2 cubic foot test dial and allowing 5 minutes to show
any movement, or by soaping each pipe connection
and watching for bubbles. If a leak is found, make the
necessary repairs and repeat the above test.
Defective pipes or fittings should be replaced and not
repaired.Never use a flame or fire in any form to locate
gas leaks; use a soap solution.
After the piping and meter have been checked com-
pletely, purge the system of air. DO NOT bleed the air
inside an enclosed room.
The appliance and its individual shut-off valve must
be disconnected from the gas supply piping system
during the pressure testing of that system at test
pressure in excess of 1/2 psig or damage to the gas
valve will occur.
Gas Pressure
The ideal incoming gas pressure is 11 w.c" (minimum
6 w.c", maximum 14 w.c" or 1/2 psig). The correct
operating manifold pressure for natural gas is 3.5 w.c"
The operating manifold pressure for propane gas is
11 w.c" By adjusting the gas valve pressure regulator
between 3 and 4 w.c.i. for the NG and 6 and 11 w.c"
for the LPG, a side range can be achieved.
If the desired input rating cannot be obtained within the
above manifold pressure adjusting range, the next size
larger or smaller burner orifice should be used.
Venting:
If the machine is used indoors, regulations or venti-
lation concerns may call for a chimney or furnace
pipe.
When venting, if the heating module is to be in an en-
closed area with a chimney on it, be sure the chimney
is the same size as the stack on the module. Poor draft
will cause the machine to soot and not operate effi-
ciently.When installing, keep in mind that the machine
should be positioned in such a manner that the stack
will be as straight as possible and protrude through the
roof of the building at a proper location and at sufficient
height to eliminate downdraft. The chimney shall be
installed with a down draft diverter.
Draft Diverter:
The draft diverter shall be installed at least three
(3) feet above the heating coil. The diverter serves
to sever the chimney effect created in all sections of
furnace pipe positioned below to enhance the draft
through the burner. It also helps prevent freezing of
the coil due to wind chill factors.
Figure 3. Draft Diverter (Optional)
When a room is of unusually tight construction and
has a kitchen and/or bathroom ventilating fan, which
may be used for exhausting air to outdoors - or has a
vented fireplace - it is recommended that combustion
air be supplied to the enclosed room through intakes
extending to the outside of the building and terminating
in downturned fittings, suitably arranged to prevent ob-
struction from snow or rain, and including 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 en-
closed room.
Ventilating air openings - 1/2 square inch for
each 1000 BTU per hour input for make-up air
from outside the building.

Hosty 9452/9462GF • 8.914-365.0 • Rev. 11/08
11
PRESSURE WASHER OPERATOR’S MANUAL
WARNING & CHECK LIST
1. Installation or servicing of
gas appliances and controls
must only be performed
by qualified personnel. Af-
ter installation or servicing,
test manual valve, operating
valves, pressure regulation,
and automatic shut-off valve
for proper operation.
2. Install in a suitable
dry location. The machine must be located in an
area properly protected from the weather.
3. Shut off gas and electricity before starting instal-
lation or service. Turn back on to test or operate.
4. DO NOT connect appliances before pressure
testing the gas piping. Damage to gas valve may
result. (6 - 14 w.c.i. or 1/2 psig)
5. DO NOT insert any object other than suitable pipe
or tubing in the inlet or outlet of the gas valve.
Internal damage may occur and result in a haz-
ardous condition.
6. DO NOT grip gas valve body with a pipe wrench or
vise.Damage may result causing gas leakage.Use
inlet or outlet bosses or a special body wrench.
INSTALLATION
7. DO NOT short the gas valve terminals.
8. DO NOT allow any flame to impinge on the regu-
lator vent tubing if supplied.It may clog and cause
gas valve malfunction.
9. DO NOT use the gas cock to adjust gas flow.
10. If main burner fails to shut off, turn off gas sup-
ply.
11. Keep all combustible materials away from gas
appliances. DO NOT allow lint or dust to collect
in burner area.
12. Dials must only be operated by hand. Never use
pliers, wrenches or other tools to turn dials.
13. After installation or servicing, test for leaks with a
soap solution. With the main burner on, coat pipe
and tubing joints, gaskets, etc. Bubbles indicate
leaks.
14. If the machine is installed in an enclosed room,
care should be taken to ensure that an adequate
supply of air is available for combustion and venti-
lation. (1 sq. inch per 1000 BTU)
WARNING
READ OPERATOR’S
MANUAL
THOROUGHLY
PRIOR TO USE.

Hosty 9452/9462GF • 8.914-365.0 • Rev. 11/08
OPERATOR’S MANUAL PRESSURE WASHER
12
CHECKLIST PRIOR TO OPERATION
WARNING
HAS ELECTRONIC
SPARK IGNITION. DO
NOT ATTEMPT TO
LIGHT MANUALLY.
CAUTION: If “NO" has been checked on any of the
above questions, do not operate the machine.
CAUTION: This machine is
equipped with an electronic
ignition system. Lighting of the
pilot is accomplished through
electronic spark ignition. Do not
attempt to light the appliance
manually as a burn injury or
electrical shock may result.
FOR YOUR SAFETY READ BEFORE LIGHTING
WARNING
If you do not follow these instructions exactly, a fire or
explosion may result causing property damage, personal
injury or loss of life.
A. This appliance has an electronic ignition system.
When lighting the pilot, follow these instructions
exactly.
B. BEFORE LIGHTING smell all around the appliance
area for gas. Be sure to smell next to the floor
because some gas is heavier than air and will settle
on the floor.
FOR YOUR SAFETY
"WHAT TO DO IF YOU SMELL GAS"
•Do not try to light any appliance.
•Do not touch any electrical switch, do not use any phone
in your building.
•Immediately call your gas supplier from a neighbor's
phone. Follow the gas supplier's instructions.
•If you cannot reach your gas supplier, call the fire de-
partment.
C. Use only your hand to turn the gas control. Never use
tools. If the knob will not push in or turn by hand, don't
try to repair it; call a qualified service technician.Forced
or attempted repair may result in a fire or explosion.
D. Do not use this appliance if any part has been under
water. Immediately call a qualified service technician
to inspect the appliance and to replace any part of the
control system and any gas control which has been
under water.
YES NO
Has gas supply been inspected by an
authorized contractor to meet local
codes?
Is machine protected from downdraft
and excessive wind?
Is machine shielded from moisture or
water spray?
Is the voltage correct and are the
circuit breaker and supply cord
adequate according to specifications
and serial plate notation?
Is the machine electrically grounded?
Is there ample water supply?
Have all flammable liquids or gases
been removed from installation loca-
tion?
Is there adequate gas supply for the
BTU rating of the burner?
Is incoming gas supply pressure
between 6 - 14 water column inches
or 1/2 PSIG?
Has the proper gas regulator been
installed for pressure and volume?
Is the machine properly vented to al-
low adequate air flow?
Are propane tanks large enough, ac-
cording to rating to prevent freezing?
Have gas lines been checked for gas
leaks?
Have gas lines been checked with
local codes?
Have all operators using this machine
been instructed properly & have they
read the manual?
Has machine been installed accord-
ing to operator's manual instructions?

Hosty 9452/9462GF • 8.914-365.0 • Rev. 11/08
13
PRESSURE WASHER OPERATOR’S MANUAL
STEP 1: Review installation in-
structions prior to connecting water
supply.
STEP 2: Connect accompanying
pressure washer and burner module
to appropriate power supply.
STEP 3: Connect high pressure
hose from attached pressure
washer (not included) to burner
module. .
STEP 4: Connect high pressure
hose to burner module outlet.
STEP 5: Assemble spray gun to
high pressure outlet hose. Attach
desired nozzle to end of wand and
secure it in place.
STEP 6: Turn on burner switch. Pilot
ignition will begin to spark. Confirm
pilot light ignition, if unsuccessful,
turn of switch and turn on again. If
pilot continues to spark, but not light,
consult troubleshooting guide.
STEP 7: Start attched pressure
washer according to manufacturer’s
safety and operation instructions
then pull trigger on spray gun to al-
low water flow.
OPERATION INSTRUCTIONS

Hosty 9452/9462GF • 8.914-365.0 • Rev. 11/08
OPERATOR’S MANUAL PRESSURE WASHER
14
Pre-rinse cleaning surface with fresh water. Place de-
tergent suction tube directly into cleaning solution and
apply to surface at low pressure (for best results, limit
your work area to sections approximately 6 feet square
and always apply detergent from bottom to top). Allow
detergent to remain on surface 1-3 minutes. Do not al-
low detergent to dry on surface. If surface appears to
be drying, simply wet down surface with fresh water.
If needed, use brush to remove stubborn dirt. Rinse at
high pressure from top to bottom in an even sweeping
motion keeping the spray nozzle approximately 1 foot
from cleaning surface. Use overlapping strokes as you
clean and rinse any surface. For best surface cleaning
action spray at a slight angle.
Recommendations:
• Before cleaning any surface, an inconspicuous
area should be cleaned to test spray pattern and
distance for maximum cleaning results.
• If painted surfaces are peeling or chipping, use
extreme caution as pressure washer may re-
move the loose paint from the surface.
DETERGENTS AND GENERAL CLEANING TECHNIQUES
• Keep the spray nozzle a safe distance from the
surface you plan to clean. High pressure wash a
small area, then check the surface for damage. If
no damage is found, continue to pressure wash-
ing.
CAUTION - Never use:
• Bleach, chlorine products and other corrosive
chemicals
• Liquids containing solvents (i.e., paint thinners,
gasoline, oils)
• Tri-sodium phosphate products
• Ammonia or Acid-based products
These chemicals will harm the machine and will dam-
age the surface being cleaned.
RINSING
It will take a few seconds for the detergent to clear.
Apply safety latch to spray gun. Select and install de-
sired high pressure nozzle. NOTE: You can also stop
detergent from flowing by removing detergent siphon
tube from bottle.

Hosty 9452/9462GF • 8.914-365.0 • Rev. 11/08
15
PRESSURE WASHER OPERATOR’S MANUAL
SHUTTING DOWN AND CLEAN-UP
STEP 1: To clean detergent from
hose and wand, insert end of
detergent hose in clean bucket of
water and run for a few minutes
until steady stream of clean water
is evident.
STEP 4: Open spray gun to relieve
remaining pressure.
STEP 2: Turn burner switch “Off"
and continue spraying water until
temperature reaches 100°.
STEP 3: Turn water off.

Hosty 9452/9462GF • 8.914-365.0 • Rev. 11/08
OPERATOR’S MANUAL PRESSURE WASHER
16
BASIC FACTS
PRESSURE EQUIVALENTS
Simply stated, pressure is the force exerted by a gas or liquid attempting to escape from a container. It is useful
to know how strong this "attempt to escape" is. Pressure can be measured with a manometer or with a pressure
gauge. At the lower levels, it is expressed in "water column inches" i.e. 1 w.c.i. Higher pressures are expressed
in terms of the force exerted against a square inch of area. For example, 125 lbs. per square inch (125 psi).
Based on 60°F Propane Butane
Formula C3H8 C4H10
Vaporization Point (oF) -43.7 31.1
Specific Gravity (Vapor) 1.522 2.006
Specific Gravity (Liquid) 0.508 0.584
Lbs. Per Gallon (Liquid) 4.23 4.87
B.T.U. Per Cubic Foot (Vapor) 2.563 3.39
B.T.U. Per Lb. (Vapor) 21.663 21/3-9
B.T.U. Per Gallon (Liquid) 91.74 1-3/93
Cubic Feet Per Lb. (Liquid) 8.607 7/53
Cubic Feet Per Gallon (Liquid) 3.45 31/9
Octane Number 125 1
Molecular Weight 44.09 58.12
To calculate running cost:
1 cubic Ft./1,000 B.T.U.
100 cubic Ft./Therm
Therm/Hour
50¢ Therm
Example: Using natural gas
400,000 BTU Machine
400 cubic feet
4 Therms/hour
4 x .50 = $2.00/hour to run
1 Water Column Inch = 50 Oz./Sq. In. 11 Water Column Inches = 6.35 Oz./Sq. In.
11 Water Column Inches = 4 Lb./Sq. In. 1 Lb./Sq. In. = 27.71 Water Column Inches
1 Lb./Sq. In. = 2.04" Mercury 1" Mercury = .39 Lb./Sq. In.
1 Std. Atmosphere = 14.73 Lbs./Sq. In

Hosty 9452/9462GF • 8.914-365.0 • Rev. 11/08
17
PRESSURE WASHER Troubleshooting Guide
TROUBLESHOOTING
PROBLEM POSSIBLE CAUSE SOLUTION
FLOW & BURNER
SWITCH ON; NO
SPARK, NO PILOT
GAS
A. No main power With power switch on, open trigger on spray
gun and set your test meter to the 24 volt scale.
Probe terminals 24V and 24V(GND). If you do
not read 24 volts, the problem is not the ignition
system. Perform normal system checks of main
power, transformer, thermostat and the limit con-
trol. If you do read 24 volts at TH and GND, the
problem is in the ignition system. Check for loose
or defective wiring. If wiring is good, replace the
ignition control unit.
B. Faulty transformer
C. Faulty burner & flow switch
D. Faulty ignition control unit
HAVE SPARK, NO
PILOT GAS FLOW
Main gas supply turned off Set test meter to 24 volt scale.
1. Be sure main gas valve (gas cock or selector
arm) is turned on.
2. With gas on and system sparking, probe
terminals PV and 24V(GND). If pilot gas does
not flow with 24 volts at these terminals, replace
gas valve.
3. Probe terminals PV and MV/PV. If 24 volts
not present, replace ignition control box.
HAVE PILOT GAS,
NO SPARK
A. Defective ignitor/sensor and
or its wiring
Set test meter to ohm scale.
1. Disconnect the wire from the IGN terminal on
the ignition control unit.
B. Faulty ignition control unit 2. Touch one meter probe to the tip of the
ignitor/sensor rod in the pilot. Touch the other
probe to the quick connect at the other end of
ignitor/sensor wire.
3. If you have continuity from the tip of the ig-
nitor/sensor rod to the connector and no spark,
replace the ignition control unit.
4. If you do not have continuity through wire and
the ignitor/sensor, check for a loose wire con-
nection in the wire. Repair as needed.
5. Check to see if spark shorts to burner ring
through a cut in the ignitor wire.

Hosty 9452/9462GF • 8.914-365.0 • Rev. 11/08
PRESSURE WASHER Troubleshooting Guide
18
TROUBLESHOOTING
PROBLEM POSSIBLE CAUSE SOLUTION
HAVE PILOT FLAME,
MAIN BURNER WILL
NOT TURN ON
Faulty main valve coil in the gas
valve
Set test meter to 24 volt scale.
Faulty ignitor/sensor and/or its
wiring
With pilot flame on ignitor/sensor, probe terminals
MV and MV/PV on the ignition control unit. If you
read 24 volts here, but not at the gas valve, there
is a loose wiring connection. Repair or replace a
as needed.
Ground wire not attached to
machine chassis
If you do read 24 volts at MV and MV/PV and the
pilot flame is impinging on the ignitor/sensor rod,
the problems may be:
Faulty ignition control unit a. Faulty ignitor/sensor and/or its wiring.
b. Faulty ignition control unit.
Set test meter to the ohm scale. Turn burner switch
off.
Check continuity through the green ground wire
and its connections.
Reconnect the ignitor/sensor wire and the ground
wire.
Turn burner switch on. With the pilot burning and
the flame on the ignitor/sensor rod, the main
burner should turn on. If it does not, replace the
ignition control unit.
SHORT-CYCLING
OF MAIN BURNER.
MAIN BURNER
TURNS OFF
BEFORE THE
BURNER SWITCH
OR FLOW SWITCH
IS TURNED OFF
Draft condition pulls flame away
from ignitor/sensor rod.
Check the thermostat by bypassing at terminals
P1 & 1.
Set thermostat high. With main burner on, observe
the pilot flame impingement on the ignitor/sensor.
Faulty thermostat or water
temperature is too high
If pilot flame is small and draft condition pulls flame
from ignitor sensor rod, the burner will turn off and
then on again.
a. Adjust pilot flame higher or clean pilot oriface.
b. Bend ignitor/sensor rod closer to pilot flame.
If flame impingement on the ignitor/sensor is stable
and the system short-cycles, check the limit switch.
Set test meter to 110 volt scale
a. When the system cycles off, probe the switch
terminals of the limit switch.
b. If you read 24V accross the switch terminals the
limit switch is open. Replace the limit switch.
A pilot flame set too high will also cause burner to
short cycle. Pilot flame lifts over ignitor/sensor.

Hosty 9452/9462GF • 8.914-365.0 • Rev. 11/08
19
PRESSURE WASHER OPERATOR’S MANUAL
MAINTENANCE & SERVICE
PREVENTATIVE MAINTENANCE
1. Follow Winterizing Procedures to prevent freeze
damage to the pump and coils.
2. Always neutralize and flush detergent from system
after use.
3. If water is known to be high in mineral content, use
a water softener in your water system or de-scale
as needed.
4. Do not allow acidic, caustic or abrasive fluids to
be pumped through system.
5. Always use high grade quality Hotsy cleaning
products.
6. Always cool the heating module.
7. Periodically delime coils per instructions.
It is advisable, periodically, to visually inspect the
burner. Check air inlet to make sure it is not clogged
or blocked.Wipe off any oil spills and keep this equip-
ment clean and dry.
The areas around the Hotsy heating module should be
kept clean and free of combustible materials, gasoline
and other flammable vapors and liquids.
The flow of combustion and ventilating air to the burner
must not be blocked or obstructed in any manner.
MAINTENANCE AND SERVICE
Winterizing Procedure:
Damage due to freezing is not covered by warranty.
Follow these cold weather procedures whenever the
washer must be stored or operated outdoors under
freezing conditions.
If the water heater will be exposed to freezing weather,
an anti-freeze solution should be circulated through the
coils by whatever means are available for the particular
system the water heater is used on. If compressed
air is available, an air fitting can be screwed into the
discharge coupling 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.
HEATING COILS
To Check Water Heater Coil for Leaks
With the main burners “OFF" start the attached pres-
sure washer 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 coil is from condensation in the flue gases when
the burner is on.
Condensation from Heating Coil
When cold water is being pumped into the water heater
coils, and the burner is on, condensation will form on
the coil 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 Deliming Pow-
der will remove lime and other deposits before coil
becomes plugged.
Periodic flushing of coils is recommended.
1. Fill a container with 4 gallons of water, then add 1
lb. of deliming powder. Mix thoroughly and check
label for proper solution mixing ratio.
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 nozzle in spray gun.

Hosty 9452/9462GF • 8.914-365.0 • Rev. 11/08
OPERATOR’S MANUAL PRESSURE WASHER
20
MAINTENANCE & SERVICE
GAS VALVE
REGULATOR ADJUSTMENT:
Adjustment of the built-in regulator isn’t normally nec-
essary, since it is preset at the factory. However, field
adjustment may be accomplished as follows:
1. Attach manometer at pressure tap port.
2. Remove regulator adjustment screw cap.
3. With small screwdriver, rotate adjustment screw
clockwise to increase or counterclockwise to de-
crease gas pressure.
Pressure Relief Valve
Each machine is equipped with a relief valve to relieve
pressure in the system when higher than normal
operating pressures are encountered. If operating
pressure of machine is found to be normal and relief
valve continues to leak, repair or replace the valve.
CAUTION: Relief valve can become obstructed by
deposits and must be unscrewed at least once per
year to allow discharge.
PROPANE GAS
(OPTIONAL CONVERSION KIT)
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
related 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 propane systems.
Gas Pressure Requirements
All propane fired machines operate on gas phase only.
They are designed to operate at a pressure of 11 water
column inches (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.
Propane bottles are not included with machine. A high
pressure regulator should be installed on propane
bottle and a low pressure regulator attached to the
pressure 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
gas. As gas is used from the propane cylinder, the
liquid in the cylinder boils to maintain gas pressure.
This boiling process cools the liquid, and in a heavy,
continuous-demand situation, the liquid temperature
can fall to the point at which it cannot provide 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°, on the cold cylinder, or by
manifolding two propane bottles together to increase
total vaporization capacity. It is recommended that
a minimum 100 lb. 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
Ignition 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.
Care of Main Burner
Due to condensation from heater coils dripping down
on the burners, scale build-up may occur in the burner
jet orifices.
1. TO REMOVE BURNER MANIFOLD FROM WA-
TER HEATER COIL:
Turn off the gas at the main burner by turning the
knob to the “OFF" position on the gas valve and
main gas supply.
Disconnect the pilot and ignition lines from the gas
valve. Disconnect union in main burner line. Slide
burner manifold out through shell opening.
2. TO CLEAN BURNER JETS:
Select proper size drill for type of gas involved. Use
pine vise to hold drill and then ream out each jet
orifice.
CAUTION: Do not ream out orifices to a larger
size.
Adjustment
Screw
Pressure Tap
Port

Hosty 9452/9462GF • 8.914-365.0 • Rev. 11/08
21
PRESSURE WASHER OPERATOR’S MANUAL
PREVENTATIVE MAINTENANCE
This pressure washer was produced with the best available materials and quality craftsmanship. However, you
as the owner have certain responsibilities for the correct care of the equipment. Attention to regular preventative
maintenance procedures will assist in preserving the performance of your equipment. Contact your Hotsy, Inc.
dealer for maintenance. Regular preventative maintenance will add many hours to the life of your pressure
washer. Perform maintenance more often under severe conditions.
OIL CHANGE RECORD
MAINTENANCE SCHEDULE
Remove Burner Soot From Heating Coil Annually
Descale Coil Annually - (more often if required)
Replace Quick Connects Annually
Clean Water and Detergent Screen/Filter Weekly
Clean Float/Supply Tank Every 6 months
Replace HP Hose If there is any sign of wear
Grease Motor Every 10,000 hours
Check Burner Pilot Jets Annually
Pressure Relief Valve Annually
Date Oil Changed
Month/Day/Year
Estimated Operating
Hours Since Last Oil
Change