ESA 125T User manual

PORTABLE FORCED AIR
HEATERS OWNER’S MANUAL
HEATER SIZES:
125,000, 170,000 AND 200,000 BTU/HR
KEROSENE/DIESEL HEATER WITH BUILT-IN THERMOSTAT
IMPORTANT: Read and understand this manual before
assembling, starting or servicing heater. Improper use
of heater can cause serious injury. Keep this manual for
future reference.
TABLE OF CONTENTS
Safety Information .............................................2
Unpacking .........................................................3
Fuels .................................................................3
Product Identification ........................................3
Theory of Operation ..........................................4
Ventilation .........................................................4
Assembly ..........................................................4
Operation ..........................................................5
Operation with Portable Generator ...................7
Storing, Transporting or Shipping .....................7
Preventative Maintenance Schedule...................8
Troubleshooting...................................................8
Service Procedures .........................................10
Specifications ..................................................15
Wiring Diagrams ..............................................16
Technical Service ............................................17
Replacement Parts ..........................................17
Accessories .....................................................17
Illustrated Parts Breakdown and Parts List ......18
Warranty and Repair Service ..........................28
Fill In For Your Records
Model No.
(Located on side panel)
Serial No.
(Located on fuel tank)
Date of Purchase:
Save this manual for future reference.
For more information, visit www.desatech.com

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SAFETY
INFORMATION
WARNING:Thisproductcon-
tainsand/orgenerateschemicals
known to the State of California
to cause cancer or birth defects
or other reproductive harm.
IMPORTANT: Read this owner’s
manual carefully and completely
beforetryingtoassemble,operate
or service this heater. Improper
useofthis heatercan cause seri-
ousinjuryordeathfromburns,fire,
explosion, electrical shock and
carbonmonoxidepoisoning.
DANGER: Carbon monoxide
poisoning may lead to death!
Carbon Monoxide Poisoning: Early signs of
carbon monoxide poisoning resemble the flu,
with headaches, dizziness and/or nausea. If you
have these signs, the heater may not be working
properly. Get fresh air at once! Have heater ser-
viced. Some people are more affected by carbon
monoxide than others. These include pregnant
women, persons with heart or lung disease or
anemia, those under the influence of alcohol and
those at high altitudes.
Make certain you read and understand all warn-
ings. Keep this manual for reference. It is your
guide to safe and proper operation of this heater.
1. Use only kerosene, #1/#2 diesel/fuel oil, JETA
or JP-8 fuels to avoid risk of fire or explosion.
Never use gasoline, naphtha, paint thinners,
alcohol or other highly flammable fuels.
2. Fueling
a) Personnel involved with fueling shall be
qualified and thoroughly familiar with the
manufacturer's instructions and applicable
regulations regarding the safe fueling of
heating units.
b) Only the type of fuel specified on the
heater's data plate shall be used.
c) All flame, including the pilot light, if
any, shall be extinguished and the heater
allowed to cool, prior to fueling.
d) During fueling, all fuel lines and fuel-line
connections shall be inspected for leaks.
Any leaks shall be repaired prior to
return- ing the heater to service.

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e) At no time shall more than one day's
sup- ply of heater fuel be stored inside
a build- ing in the vicinity of the
heater. Bulk fuel storage shall be
outside the structure.
f) All fuel storage shall be located a
mini- mum of 762 cm (25 feet) from
heaters, torches, welding equipment
and similar sources of ignition
(exception: the fuel reservoir integral
with the heater unit).
g) Whenever possible, fuel storage shall
be confined to areas where floor
penetrations do not permit fuel to drip
onto or be ignited by a fire at lower
elevation.
h) Fuel storage shall be in accordance
with the authority having jurisdiction.
3. Use only the electrical voltage and
frequency specified on model plate.
4. Heater must be grounded. Use only a
properly grounded three-wire extension
cord.Plug into grounded outlet only.
5. Use only in areas free of flammable vapors
or high dust content.
6. Minimum clearance from any
combustible materials: 8 feet (244 cm)
from hot air outlet; 6 feet (183 cm) from
top; and 4 feet (120 cm) from sides and
inlet.
7. Locate heater on a stable and level
surface while hot or operating or a fire
may occur.
8. Use only in well-vented areas. Before
using heater, provide at least a 2800 square
cm (three- square-foot) opening of fresh,
outside air for each 30 kw (100,000
Btu/Hr) of rating.
9. Keep children and animals away from
heater at all times.
10. Never start heater when combustion
chamber is hot or if fuel has accumulated in
combustion chamber.
11. When used with thermostat, heater may
start at anytime.
12. When heater is moved or stored, it must be
in a level position or fuel spillage may
occur.
13. Use heater only in accordance with
local ordinances and codes.
14. Never use gasoline, crankcase
drainings, naphtha, paint thinners, alcohol
orotherhighly flammable fuels.
15. Never use heater where gasoline, paint
thinner or other highly flammable vapors are
present.
16. Never use heater in living or sleeping areas.
17. Never leave a heater plugged in without adult
supervision if children or animals are likely to
be present.

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SAFETY INFORMATION
Continued
18. Never move, handle, refuel or service a hot,
operating or plugged-in heater.
19. Never attach duct work to front or rear of heater.
20. Never attach heater to external fuel tank.
21. Heaters used in the vicinity of tarpaulins,
canvas or similar enclosure materials shall be
located a safe distance from such
materials. The recommended minimum safe
distance is
304.8 cm(10 feet). It is further recommended
that these enclosure materials be of a fire
retardant nature. These enclosure materials
shall be securely fastened to prevent them
from igniting or from upsetting the heater due
to wind action.
22. Unplug heater when not in use.
23. Never block air inlet (rear) or air outlet (front)
of heater.
24. Warning to New York City Residents
For Use Only At Construction Sites in ac-
cordance with applicable NYC codes under
NYCFDcertificateofapproval#4803, #4899,
#4908, #4909 or #4934.
UNPACKING
1. Remove all packing items applied to heater
for shipment.
2. Remove all items from carton.
3. Check items for any shipping damage. If
heater is damaged, promptly inform dealer
where you bought heater.
FUELS
WARNING: Use only kero-
sene, #1/#2 diesel/fuel oil, JET
A or JP-8 fuels to avoid risk
of fire or explosion. Never
use gasoline, oil drained from
crankcases, naphtha, paint
thinners,alcoholorotherhighly
flammable fuels.
Use only kerosene, #1/#2 diesel/fuel oil, JET A
or JP-8 fuels. Heavier fuels such as No. 2 fuel
oil or No. 2 diesel fuel may also be used but will
result in:
•noticeable odor
•additional fuel filter maintenance
•theneedfornontoxic,anti-icer additivesinvery
cold weather
Do not use fuels heavier than No. 2 grade or
heavy oils such as oil drained from crankcases.
These heavy oils will not ignite properly and will
contaminate the heater.
IMPORTANT:Use a KEROSENE ONLY (blue)
or DIESEL ONLY (yellow) storage container.
Be sure storage container is clean. Foreign matter
such as rust, dirt or water will cause the ignition
control assembly to shut down heater. Foreign
matter may also require heater's fuel system to be
frequently cleaned.
PRODUCT IDENTIFICATION
Hot Air
Outlet
Lower
Shell
Upper Shell ON/OFF
Switch Thermostat
Knob
Fan
Handle
Fuel Cap/
Gauge Guard
Extension
Cord Wrap
Shroud
Control Cover
Ignition Control
Assembly (On
Inside of Control
Cover)
Fuel Tank
Rear Panel
Figure 1 - 125T, 170T and 200T Models

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THEORY OF OPERATION
The Fuel System: The air pump forces air through the air line. The air is then pushed through the
nozzle. This air causes fuel to be lifted from the tank. A fine mist of fuel is sprayed into the combus-
tion chamber.
The Air System: The motor turns the fan. The fan pushes air into and around the combustion chamber.
This air is heated and provides a stream of clean, hot air.
The Ignition System: The ignition control assembly provides power to the ignitor. This ignites the
fuel/air mixture in the combustion chamber.
The Flame-Out Control System: This system causes the heater to shut down if the flame goes out.
Combustion Chamber Ignitor
Clean
Heated
Air Out
Fan Motor Air Pump Air Intake
Filter Cool Air In
Air Output Filter
Fuel
Tank
Nozzle
Air For Fuel
System
Fuel
Filter
Air Line
To Burner
Air For
Combustion
And Heating
Ignition
Control
Assembly
Fuel
Figure 2 - Cross Section Operational View
VENTILATION
WARNING:Provideafreshair
opening of at least three square
feet (2,800 square cm) for each
100,000 BTU/HR rating. Provide
extra fresh air if more heaters
are being used. The minimum
ventilationrequirementsmustbe
followedtoavoidrisksassociated
withcarbonmonoxidepoisoning.
Make certain these requirements
aremet prior to operatingheater.
Example: A 58.6 kw (200,000 Btu/Hr) heater
requires one of the following:
•a two-car garage door [4.88 meter (16 feet)
opening] raised 12.7 cm (5 inches)
•a single-car garage door [2.74 meter (9 feet)
opening] raised 20.3 cm (8 inches)
•two,76.2 cm(30 inch) windows raised 38.1 cm
(15 inches)
ASSEMBLY
These models are furnished with wheels and a rear
handle. Wheels, handle and the mounting hardware
are found in the shipping carton.
Tools Needed
•Medium Phillips Screwdriver
•Rubber Mallet/Hammer
•Flat Blade Screwdriver
1. Slide axle through holes in shroud. Install
washers, wheel spacers and wheels on axle
as shown in Figure 3, page 5.
IMPORTANT: When installing wheels, point
extended hub of wheels toward shroud (see
Figure 3, page 5).
2. Place cap nuts on axle ends. Gently tap with
hammer to secure.
3. Install extension cord wraps into handle.
4. Slide handle onto shroud leaving a one inch
gap between parts.
5. Place washers onto screws and insert
screws into holes in handles.
6. Visually confirm that all six screws are
threaded into the shroud. Push the handle
completely into the shroud.
7. Tighten all screws.

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Hot Air Outlet
ASSEMBLY
Continued
Shroud
Shroud
Axle Hole
Wheel
Spacer
Washer
Air Inlet Rear Panel
Handle
Washer
Extension
Cord Wrap
Wheel
Cap Nut
Axle
Extended Hub Screw
Figure 3 - Wheel and Handle Assembly
OPERATION
IMPORTANT:Reviewandunder-
standthewarningsintheSafety
Information section, page 2.
They are needed to safely oper-
ate this heater. Follow all local
ordinances and codes when
using this heater.
TO START HEATER
1. Follow all ventilation and safety information.
2. Locate heater to provide maximum circulation
of the heated air. Follow all location require-
ments noted in Safety Information, page 2.
3. Fill fuel tank with fuel. Use only kerosene,
#1/#2 diesel/fuel oil, JET A or JP-8 fuels to
avoid risk of fire or explosion. Never use
gasoline, naphtha, paint thinners, alcohol or
other flammable fuels.
4. Attach fuel cap/gauge.
5. Plug heaterʼs power cord into
approved, grounded, three-wire extension
cord. Extension cord must be at least six feet
(1.8 meters) long.
Extension Cord Size Requirement
6 to10 feet(1.8to 3 meters)long,use 18AWG
(0.75 mm2) rated cord
11 to 100 feet (3.3 to 30.5 meters) long, use
16 AWG (1.0 mm2) rated cord
101 to 200 feet (30.8 to 61 meters) long, use
14 AWG (1.5 mm2) rated cord
6. Plug extension cord into standard 120 volt/60
hertz, 3-prong grounded outlet.
7. Turn thermostat knob to the right (clockwise)
to the warmest position.
8. Push ON/OFF switch to the ON (|) position.
Lightwillcomeon.Note:Ignitorwill preheat
for five seconds, then heater will start.
9. Afterheater is running, adjust thermostat knob
to the desired setting. Note:Acold heater may
affectthe thermostat setting. This thermostat is
a general-heating control. It is not intended for
precise temperature control. Adjust thermostat
until heater cycles at the desired setting.
TO STOP HEATER
1. Push ON/OFF switch to the OFF (O) position.
2. Unplug heater.
TO RESET HEATER
1. Push ON/OFF switch to the OFF (O) position
and wait 10 seconds. (Wait two minutes if
heater has been running.)
2. Repeat steps under To Start Heater.

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OPERATION
Continued
RL, RE AND PKHD SERIES MODELS
ONLY
Temperature Display
These models are equipped with a digital tem-
perature display. The temperature being shown
represents the air nearest to the control cover. The
temperature of the air in surrounding areas may
be much different from the temperature being
displayed. The display may show [ - - ] when the
thermostat control or temperature sensor are dis-
connected from the ignition control or if they are
or damaged. If this occurs, the safety control will
continue to operate as before, however, the unit
will not cycle off during operation. See Figure 4.
Lighted ON/OFF
Switch Thermostat
Control
Temperature
Display
LED Indicator Lights
These modelsare equipped withLED lightsin order
to help monitor your heater and to help diagnose
any potential problems associated with your heater.
Make sure you have read all of the instructions and
see Troubleshooting, page 8, before attempting to
rectify any problems with your heater.
WARNING: Never service
heater while it is plugged in,
operating or hot. Severe burns
and electrical shock can occur.
LOGIC ENHANCED IGNITION
These models have an electronically controlled
ignition system that is able to detect problems
during startup and is able to apply an automatic
“choke” to increase the likelihood of ignition. If
the heater does not ignite within the first second
the motor will slow down momentarily. If your
heater does not light after the first “choke” it will
repeat once. If the heater does not ignite after the
second “choke” it will shutdown and remain in
shutdown mode until the unit is reset. Please refer
to Troubleshooting, page 8 in order to properly
diagnose the problem.
Figure 4 - Control Cover with
Temperature Display
Ignitor - indicates a problem with
the ignitor and can be caused by
a damaged or broken ignitor or an
ignitor that is wired incorrectly.
Flame - will illuminate after heater
is shut down due to problems
associated with the flame or the
photocell that monitors the flame.
3
4
2 5
Temperature
Temperatura
1 6
LO Thermostat
Termostato
HI
112935-01
Temperature
Display
Voltage - monitors line voltage during
normal operation and indicates
improper line voltage. If line voltage
falls below 108V or above 132V the
heater will shut down.
Start/Run - blinks during
“preheat” for 10-15 seconds
before ignition and will stay on
during normal operation.
Figure 5 - LED Indicator Lights

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OPERATION WITH
PORTABLE GENERATOR
WARNING: Before operating
heater or any appliance from a
portable generator, verify that
generatorhasbeenproperlycon-
nectedtoearthground.Improper
grounding or failure to ground
generator can result in electro-
cution if a ground fault occurs.
Refertoowner’smanualsupplied
by generator manufacturer for
proper grounding procedures.
The operating voltage range of the heater is 108 to
132 Volts (120 Volts +/- 10%). Prior to plugging
heater into generator the output voltage should be
verified (if generator is equipped with theautomatic
idle feature, the output voltage should be measured
with the generator running at full speed). If the volt-
age does not measure in this range theheatershould
not be plugged into the generator.
Refer to Operation, page 5, for starting, stopping
and resetting heater procedures.
Alternator
STORING,
TRANSPORTING
OR SHIPPING
Note: If shipping, transport companies require
fuel tanks to be empty.
1. Remove drain plug from bottom side of fuel
tank and drain all fuel.
2. Replace drain plug.
3. If any debris is noted in old fuel, add 1 or 2
quarts of clean kerosene to tank, stir and drain
again. This will prevent excess debris from
clogging filters during future use.
4. Properly dispose of old and dirty fuel. Check
with local automotive service stations that
recycle oil.
5. If storing, store heater in dry place. Make sure
storage place is free of dust and corrosive
fumes.
IMPORTANT: Do not store kerosene over sum-
mer months for use during next heating season.
Using old fuel could damage heater.
Ground Lug
Copper
or Brass
Grounding
Point
Ground Wire (#10 AWG
- Stranded-Copper)
Figure 6 - Typical Generator Grounding
Method (Generator construction may
vary from that shown)

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PREVENTATIVE MAINTENANCE SCHEDULE
WARNING: Never service heaterwhile it is plugged in, operating
or hot. Severe burns and electrical shock can occur.
Item
Fuel tank
Air output and lint filters
Air intake filter
Fuel filter
Ignitor
Fan blades
How Often
Flushevery150-200hoursofoperation
or as needed
Replace every 500 hours of operation
or once a year
Washanddrywithsoapandwaterevery
500 hours of operation or as needed
Clean twice a heating season or as
needed
No maintenance required
Clean every season or as needed
How To
See Storing, Transporting, or
Shipping, page 7
See Air Output, Air Intake and
Lint Filters, page 10
See Air Output, Air Intake and
Lint Filters, page 10
See Fuel Filter, page 11
See Fan, page 10
Motor Not
required/permanently
lubricated
TROUBLESHOOTING
WARNING: Never service heaterwhile it is plugged in, operating
or hot. Severe burns and electrical shock can occur.
FAULT CONDITION
Motor does not start five seconds
after heater is plugged in
INDICATOR LIGHT
•Ignitor
POSSIBLE CAUSE
1. No power to heater
2. ON/OFF switch not in theON
(|) position
3. Thermostat setting is too low
REMEDY
1. Check circuit breaker in elec-
trical panel
2. VerifytheON/OFFswitchisin
ON (|) position and light is on
3. Turn thermostat knob to a
higher setting
WARNING: High voltage!
4. Bad electrical connection be-
tween motor and ignition con-
trol assemblyorignitioncontrol
assembly and power cord
5. Binding pump rotor
6. Blownfuseon ignitioncontrol
assembly
7. Defective ignition control
assembly
8. Defective motor
4. Check all electrical connec-
tions. See Wiring Diagrams,
page 16
5. If fan does not turn freely, see
Pump Rotor, page 14
6. SeeIgnitionControlAssembly,
page 14
7. Replace ignition control
assembly
8. Replace motor

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TROUBLESHOOTING
Continued
FAULT CONDITION
Motor starts and runs but heater
does not ignite
INDICATOR LIGHT
•Flame
POSSIBLE CAUSE
1. No fuel in tank
2. Pump pressure incorrect
3. Dirty fuel filter
4. Obstruction in nozzle
5. Water in fuel tank
REMEDY
1. Fill tank with kerosene
2. See Pump Pressure Adjust-
ment, page 10
3. See Fuel Filter, page 11
4. See Nozzle Assembly, page 12
5. Drain and flush fuel tank with
clean kerosene. See Storing,
Transporting or Shipping,
page 7
WARNING: High voltage!
•Ignitor 6. Bad electrical connection 6. Check electrical connections.
between ignitor and ignition
control assembly
7. Defective ignitor
8. Defective ignition control
assembly
See Wiring Diagrams, page 16
7. Replace ignitor, see page 11
8. Replace ignition control
assembly
•Voltage 9. Line voltage is below 108V or 9. Check for proper line voltage
above 132v
Heaterignitesbutignitioncontrol
assembly shuts heater off after a
short period of time
INDICATOR LIGHT
•Flame
1. Pump pressure incorrect 1. See Pump Pressure Adjust-
ment, page 10
2. Dirty air intake, air output 2. See Air Output, Air Intake and
and/or lint filter
3. Dirty fuel filter
4. Obstruction in nozzle
Lint Filters, page 10
3. See Fuel Filter, page 11
4. See Nozzle Assembly, page 12
5. Photocellassemblynotproperly 5. Make sure photocell boot is
installed (not seeing the flame)
6. Dirty photocell lens properly seated in bracket 6. Clean photocell lens
WARNING: High voltage!
•Voltage 7. Bad electrical connection be- 7. Check electrical connections.
tween photocell and ignition
control assembly
8. Defective photocell
9. Defective ignition control
assembly
See Wiring Diagrams, page 16
8. Replace photocell
9. Replace ignition control
assembly
10. Linevoltageis below108Vor 10.Check for proper line
voltage.
above 132v Disconnect power equipment
that may be used on same
line

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SERVICE PROCEDURES
WARNING: To avoid risk of
burnandelectricalshock,never
attempttoserviceheaterwhileit
is plugged in, operating or hot.
UPPER SHELL REMOVAL
1. Remove screws along each side of heater using
phillipsscrewdriver.Thesescrewsattachupper
and lower shells together. See Figure 7.
2. Lift upper shell off.
3. Remove fan guard.
AIR OUTPUT, AIR INTAKE AND LINT
FILTERS
1. Remove upper shell (see Figure 7).
2. Remove filter end cover screws using 5/16"
nut-driver (see Figure 10).
3. Remove filter end cover.
4. Replace air output and lint filters.
5. Washorreplaceairintakefilter(seePreventa-
tive Maintenance Schedule, page 8).
6. Replace filter end cover.
7. Replace upper shell.
IMPORTANT: Do not oil filters.
Screw
2
Upper Shell Air Intake
Filter Filter
End
1
Cover
Lint Filter
FAN
Figure 7 - Upper Shell Removal
Air Output Filter
Figure 10 - Air Output, Air Intake and Lint
Filters
IMPORTANT: Remove fan from motor shaft
before removing motor from heater. The weight
of the motor resting on the fan could damage the
fan pitch (see Figure 8).
1. Remove upper shell (see Figure 7).
2. Use 1/8" allen wrench to loosen setscrew
which holds fan to motor shaft.
3. Slip fan off motor shaft.
4. Clean fan using a soft cloth moistened with
kerosene or solvent.
5. Dry fan thoroughly.
6. Replacefanonmotorshaft.Placefanhubflush
with end of motor shaft (see Figure 9).
7. Placesetscrewonflatofshaft.Tightensetscrew
firmly (40-50 inch-pounds/4.5-5.6 n-m).
8. Replace upper shell.
PUMP PRESSURE ADJUSTMENT
1. Remove fan guard using medium phillips
screwdriver.
2. Remove pressure gauge plug from filter end
cover (see Figure 11).
3. Install accessory pressure gauge (part number
HA1180).
4. Start heater (see Operation, page 5). Allow
motor to reach full speed.
Relief
Valve
Pressure
Setscrew
Fan Setscrew
Motor Fan Gauge
Plug
Flush Figure 11 - Pressure Gauge Plug
Removal
Motor Shaft
Figure 8 - Fan, Motor
Shaft and Setscrew
Location
Motor
Shaft
Figure 9 - Fan
Cross Section

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SERVICE PROCEDURES
Continued
5. Adjust pressure. Turn relief valve to right to
increase pressure. Turn relief valve to left to
decrease pressure. See specifications below
for correct pressure (see Figure 12).
6. Remove pressure gauge. Replace pressure
gauge plug in filter end cover.
WARNING: HIGH VOLTAGE
WARNING:Toavoidriskofburn
and electrical shock, never at-
tempttoserviceheaterwhileitis
plugged in, operating or hot.
IGNITOR
Pump
Model Pressure
125T 6.0 PSI
170T 6.0 PSI
200T 6.2 PSI
Pressure
Gauge 1. Remove upper shell (See Upper Shell Re-
moval, page 10).
2. Remove fan (see page 10).
3. Remove 2 control cover screws with a phil-
lips screwdriver. Remove control cover (see
Figure 13).
4. Disconnect ignitor wires from ignition control
assembly (see Figure 14). Pull the ignitor
wires up through the hole in the lower shell.
5. Disconnect fuel line hose and air line hose.
Removephotocellfromphotocellbracket (see
Figure 12 - Adjusting Pump Pressure
FUEL FILTER
1. Unplug heater.
2. Remove control cover screws using medium
phillips screwdriver.
3. Remove control cover.
4. Pull upper fuel line off fuel filter neck (see
Figure 13).
5. Carefully pry bushing, fuel filter and lower
fuel line out of fuel tank (see Figure 13).
6. Wash fuel filter with clean fuel and replace in
Figure 14).
6. Remove combustion chamber. Stand com-
bustion chamber on end with nozzle adapter
bracket on top (see Figure 15, page 12).
7. Remove ignitor screw with a 1/4" nut driver
for models using ignitor HA1000 or 5/16"
nut driver for models using ignitor HA1100.
Carefully remove ignitor from nozzle adapter
bracket.
8. Carefully remove replacement ignitor from
styrofoam packing. Nozzle Adapter
tank.
7. Attach upper fuel line to fuel filter neck.
8. Replace control cover.
Screw
Control Cover
3 4
Combustion
Chamber
Air Line Hose
Photocell
Bracket
Bracket
Ignitor
Ignitor
Wire
2 5
Temperature
Temperatura 1 6
Fuel Filter,
Bushing and
Lower Fuel Line
Upper Fuel Line
HI
LO
Thermostat
Termostato Fuel Line
Hose
Photocell
Assembly
Ignitor
Wire
Control Cover Ignition
Control
Assembly
Figure 13 - Fuel Filter Removal

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Figure 14 - Disconnecting
Ignitor Wires from Ignition
Control Assembly
(170T Model Shown)

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SERVICE PROCEDURES
Continued
CAUTION: Do not bend or
strike ignitor element. Handle
with care.
9. Carefully guide ignitor into opening in nozzle
adapter bracket. Do not strike ignitor element.
Attach ignitor to nozzle adapter bracket with
screw using a 1/4" nut driver for models using
ignitor HA1000 (see Figure 15) or 5/16" nut
driver for models using HA1100 ignitor (see
Figure 16). Torque .90 to 1.69 N-m (8 to 15
in-lbs) Do not over torque.
10. Replace combustion chamber.
Ignitor Element
Photocell
Bracket
Nozzle Adapter
Bracket Opening
Ignitor
Nozzle
Adapter
Bracket
Combustion
Chamber
11. Route the ignitor wires back down through
the hole in the lower shell. Connect wires to
the ignition control assembly (see Figure 14,
page 11).
12. Replace control cover (see Figure 13, page 11).
13. Connect and route fuel line hose and air line
hose to nozzle adapter assembly. See Fuel and
Air Line Replacement and Proper Routing,
page 13.
14. Replace photocell in photocell bracket. Route
wires as shown in Figure 17.
Figure 16 - Ignitor HA1100 Replacement
NOZZLE ASSEMBLY
125T and 170T Models Only
1. Remove upper shell (see Upper Shell Re-
moval, page 10).
2. Remove fan (see Fan, page 10).
3. Remove fuel and air line hoses from nozzle
assembly (see Figure 17).
4. Turn nozzle assembly 1/4 turn to left and pull
toward motor to remove (see Figure 18).
15. Replace fan (see page 10).
16. Replace upper shell (see page 10).
Ignitor Screw/Washer
Assembly Ignitor
Ignitor Element
Combustion
Chamber
Nozzle
Adapter
Bracket
Photocell
Bracket
Nozzle/
Adapter
Assembly
Photocell
Bracket
Nozzle
Adapter
Bracket
Fuel Line
Hose
Air Line Hose
Figure 17 - Removing Air and Fuel Line
Hoses (125T and 170T Models Only)
Combustion
Combustion
Chamber Nozzle Adapter
Bracket Opening Chamber Nozzle/
Adapte
r
Figure 15 - Ignitor HA1000 Replacement Assembly
Figure 18 - Removing Nozzle/Adapter

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Assembly

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SERVICE PROCEDURES
Continued
5. Place plastic hex-body into vise and lightly
tighten.
6. Carefullyremovenozzlefromthenozzleadapter
using5/8" socket wrench (see Figure 19).
7. Blow compressed air through face of nozzle.
This will free any dirt in nozzle area.
8. Inspect nozzle sleeve for damage.
9. Replace nozzle into nozzle adapter until
nozzle seats. Tighten 1/3 turn more using 5/8"
socketwrench4.5to 5.1N-m(40 to45in-lbs).
See Figure 19).
Combustion
Chamber
Nozzle
Adapter
Bracket
Photocell
Bracket
Air Line
Hose
Nozzle/
Adapter
Assembly
Fuel Line Hose
10. Attach nozzle assembly to nozzle adapter
bracket (see Figure 18, page 12).
11. Attach fuel and airline hoses to nozzle as-
Figure 20 - Removing Air and Fuel Line
Hoses (200T Model Only)
sembly. See Fuel and Airline Replacement
and Proper Routing.
12. Replace fan (see Fan, page 10).
13. Replaceuppershell(seeUpperShell Removal,
page 10).
Nozzle Face Nozzle Sleeve
Nozzle
Face
Nozzle
Nozzle
Adapter
Nozzl
e
Sleev
e
Nozzle
Adapter
Nozzle
Adapter Bracket Air Line
Fitting
Fuel
Line
Fitting
Nozzle
Air Line Fitting
Fuel Line Fitting
Figure 19 - Nozzle and Nozzle Adapter
200T Model Only
1. Remove combustion chamber and ignitor by
following steps 1 through 7 under Ignitor,
page 11.
2. Carefully place the ignitor in a safe location.
3. Remove two nozzle adapter bracket screws
(see Figure 20).
4. Place hex-shaped aluminum nozzle adapter
into vise (do not overtighten).
5. Carefully remove nozzle from nozzle adapter
using 5/8" socket wrench (see Figure 21).
6. Blow compressed air through face of nozzle.
This will remove any debris in nozzle.
7. Inspect nozzle seal for damage.
8. Replace nozzle into nozzle adapter until
nozzle seats. Tighten 80-110 inch-pounds.
9. Attach nozzle adapter bracket to combustion
chamber with two screws removed in step 3.
10. Repeat steps 9 through 16 under Ignitor,
page 11.

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Figure 21 - Nozzle and Nozzle Adapter
FUEL AND AIR LINE REPLACEMENT
AND PROPER ROUTING
1. Remove upper shell (see Upper Shell
Re- moval, page 10).
2. Remove control cover screws using
phillips screwdriver (see Figure 13, page
11).
3. Remove control cover.
4. Inspect fuel and air line hoses for cracks
and/or holes. If fuel line hose is damaged,
disconnect from nozzle adapter (see Figure
17, page 12 or Figure 20 according to
model) and from fuel filter (see Fuel Filter,
page 11). If air line hose is damaged,
disconnect from nozzle adapter (see
Figure 17, page 12 or Figure 20 according to
model and from barb fitting on pump end
cover (see Figure 22, page 14).
5. Install new air and/or fuel line. Attach one
end of air line hose to barb fitting on
pump end cover (see Figure 22, page 14)
and the other end to nozzle adapter (see
Figure 17, page 12 or Figure 20 according
to model). Attach one end of fuel line
hose to fuel filter (see Fuel Filter, page
11) and the other end to nozzle adapter
(see Figure 17, page 12 or Figure 20
according to model).

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SERVICE PROCEDURES
Continued
Note:Route hoses as shown in Figure 17, page
12 or Figure 20 according to model. Hoses are
not to touch photocell bracket.
6. Replace control cover.
7. Replaceuppershell(seeUpperShellRemoval,
page 10).
Pump End
Insert
Rotor
Air Output Filter
Pump Plate
Blade Air
Intake
Filter Filter End
Cover
Cover
Air Hose
Barb
Fitting
Figure 23 - Rotor Location
Gap Adjusting Screw .003"/.004"
(.076-.101 mm)
Gap Measured
Figure 22 - Air Hose to Barb Fitting
PUMP ROTOR
(Procedure if Rotor is Binding)
1. Remove upper shell (see Upper Shell Re-
moval, page 10).
2. Remove fan guard.
3. Remove filter end cover screws using 5/16"
nut driver (see Figure 23).
4. Remove filter end cover and air filters.
5. Remove pump plate screws using 5/16" nut-
driver.
6. Remove pump plate.
7. Remove rotor, insert and blades (see
Figure 23).
8. Check for debris in pump. If debris is found,
blow out with compressed air.
9. Install insert and rotor.
10. Check gap on rotor. Adjust to .076/.101 mm
(.003"/.004") if needed (see Figure 24).
Note: Rotate rotor one full turn to ensure the
gap is .076/.101 mm (.003"/.004") at tightest
position. Adjust if needed.
11. Install blades, pump plate, air filters and filter
end cover.
12. Replace fan guard and upper shell (see Upper
Shell Removal, page 10).
13. Adjust pump pressure (see Pump Pressure
Adjustment, page 10).
With Feeler
Gauge
Rotor
Blade
Gap Adjusting Screw
Figure 24 - Gap Adjusting Screw
Locations
Sandpaper
Figure 25 - Sanding Rotor
IGNITION CONTROL ASSEMBLY
WARNING: High voltage!
1. Unplug heater.
2. Remove control cover screws (2) using phil-
lips screwdriver to expose ignition control
assembly (see Figure 11, page 10).
3. Remove fuse from fuse holder.
4. Replace with new fuse (DESA Heating
Prod- ucts part number 113752-01). Do not
substitute a fuse with a higher current
rating. Use an equivalent 6.3 amp time lag, 5
x 20 mm fuse.
5. Replace control cover (see Figure 11,
page 10). Fuse Holder
Note: If rotor is still binding, proceed as follows.
14. Perform steps 1 through 6.
15. Place fine grade sandpaper (600 grit) on flat
surface. Sand rotor lightly in “figure 8”
motion four times (see Figure 25).
16. Reinstall insert and rotor.
17. Perform steps 10 through 12.
Fuse
Figure 26- Replacing Fuse

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SPECIFICATIONS
Model Size
125T
170T
200T
Output Rating (Btu/Hr)
125,000
170,000
200,000
Fuel Use only kerosene, #1/#2 diesel/fuel oil, JET A or JP-8 fuels*
Fuel Tank Capacity (U.S. Gal./Liters)
Fuel Consumption
13.5/51
13.5/51
13.5/51
(Gal. Per Hr/Liters Per Hr)
.90/3.41
1.25/4.73
1.4/5.3
Pump Pressure (psi)
6.0
6.0
6.2
Electric Requirements
120 V/60 HZ
120 V/60 HZ
120 V/60 HZ
Amperage (Normal Run)
3.6
3.6
3.6
Maximum Motor Speed (RPM)
3400
3400
3400
Hot Air Output (CFM)
520
580
600
Motor Horsepower
1/5
1/5
1/4
Shipping Weight
81/36.74
82/37.2
87/39.46
(Approximate Pounds/Kilograms)
Heater Weight without Fuel 73/33.11 74/33.57
79/35.86 (Approximate
Pounds/Kilograms)
* Use of #2 diesel/fuel oil will result in noticeable odor and could require additional fuel filter mainte-
nance. Use in extreme cold temperatures may require nontoxic anti-icer additive