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
Illustrated Parts Breakdown and Parts List ....... 18
Warranty and Repair Service ............................ 28
8
15
17
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
SAFETY INFORMATION
WARNING: This product contains and/or generates chemicals
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
before trying to assemble, operate
or service this heater. Improper
use of this heater can cause serious injury or death from burns, fire,
explosion, electrical shock and
carbon monoxide poisoning.
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, JET A
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.
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 (threesquare-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 or other highly
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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113170-01E
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
NYCFD certificate of approval #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.
PRODUCT IDENTIFICATION
Hot Air
Outlet
Lower
Shell
Fuel Cap/
Gauge
Upper Shell
ON/OFF
Switch
FUELS
WARNING: Use only kerosene, #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, alcohol or other highly
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
• the need for nontoxic, anti-icer additives in very
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.
Thermostat
Knob
Handle
Fan
Guard
Extension
Cord Wrap
Shroud
Ignition Control
Control Cover
113170-01E3
Assembly (On
Inside of Control
Cover)
Figure 1 - 125T, 170T and 200T Models
www.desatech.com
Fuel Tank
Rear Panel
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 combustion 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.
Fan
Motor
Combustion Chamber
Ignitor
Air Pump
Air Intake Filter
Clean
Heated
Air Out
Fuel
Tank
Nozzle
Air For Fuel
System
Figure 2 - Cross Section Operational View
Fuel
Filter
VENTILATION
WARNING: Provide a fresh air
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
ventilation requirements must be
followed to avoid risks associated
with carbon monoxide poisoning.
Make certain these requirements
are met prior to operating heater.
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)
Cool Air In
Air Output Filter
Air Line
To Burner
Air For
Combustion
And Heating
Ignition Control
Assembly
Fuel
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.
4
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113170-01E
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Hot Air Outlet
ASSEMBLY
Continued
Shroud
Shroud
Axle Hole
Wheel
Spacer
Washer
Wheel
Cap Nut
Extended Hub
Axle
Figure 3 - Wheel and Handle Assembly
OPERATION
IMPORTANT: Review and understand the warnings in the Safety 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 requirements 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 Requirement6 to 10 feet (1.8 to 3 meters) long, use 18 AWG
2
(0.75 mm
11 to 100 feet (3.3 to 30.5 meters) long, use
16 AWG (1.0 mm
101 to 200 feet (30.8 to 61 meters) long, use
14 AWG (1.5 mm
) rated cord
2
) rated cord
2
) rated cord
-
Air Inlet
Rear Panel
Handle
Washer
Extension
Cord Wrap
Screw
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.
Light will come on. Note: Ignitor will preheat
for five seconds, then heater will start.
9. After heater is running, adjust thermostat knob
to the desired setting. Note: A cold heater may
affect the 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
.
113170-01E5
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OPERATION
Temperature
Temperatura
Thermostat
Termostato
LO
HI
Ignitor • Encended
or
Allumeu
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Vo
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Te
nsión
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Flame • Llama • Flamme
Star
t/Run
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Démarre/
Ma
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112935-01
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 disconnected 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
Temperature
Display
Thermostat
Control
LED Indicator Lights
These models are equipped with LED lights in 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.
Temperature
Display
6
Voltage - monitors line voltage during
no rmal op erat i on a nd i n dica t es
improper line voltage. If line voltage
falls below 108V or above 132V the
heater will shut down.
Flame - will illuminate after heater
is shut down due to problems
associated with the flame or the
photocell that monitors the flame.
Figure 5 - LED Indicator Lights
www.desatech.com
Start/Run - b l ink s d u rin g
“preheat” for 10-15 seconds
before ignition and will stay on
during normal operation.
113170-01E
FUEL
F
OPERATION WITH
PORTABLE GENERATOR
WARNING: Before operating
heater or any appliance from a
portable generator, verify that
generator has been properly connected to earth ground. Improper
grounding or failure to ground
generator can result in electrocution if a ground fault occurs.
Refer to owner’s manual supplied
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 the automatic
idle feature, the output voltage should be measured
with the generator running at full speed). If the voltage does not measure in this range the heater should
not be plugged into the generator.
Operation, page 5, for starting, stopping
Refer to
and resetting heater procedures.
Alternator
Ground Lug
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 summer months for use during next heating season.
Using old fuel could damage heater.
Copper
or Brass
Grounding
Point
Ground Wire (#10 AWG
- Stranded-Copper)
Figure 6 - Typical Generator Grounding
Method (Generator construction may
vary from that shown)
113170-01E7
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PREVENTATIVE MAINTENANCE SCHEDULE
WARNING: Never service heater while 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
Motor
How Often
Flush every 150-200 hours of operation
or as needed
Replace every 500 hours of operation
or once a year
Wash and dry with soap and water every
500 hours of operation or as needed
Clean twice a heating season or as
needed
No maintenance required
Clean every season or as needed
Not required/permanently
lubricated
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
TROUBLESHOOTING
WARNING: Never service heater while 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 the ON
(|) position
3. Thermostat setting is too low
REMEDY
1. Check circuit breaker in electrical panel
2. Verify the ON/OFF switch is in
ON (|) position and light is on
3. Turn thermostat knob to a
higher setting
WARNING: High voltage!
4. Bad electrical connection between motor and ignition con
trol assembly or ignition control
assembly and power cord
5. Binding pump rotor
6. Blown fuse on ignition control
assembly
7. Defective ignition control
assembly
8. Defective motor
8
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4. Check all electrical connec
-
tions. See Wiring Diagrams,
page 16
5. If fan does not turn freely, see
Pump Rotor, page 14
6. See Ignition Control Assembly,
page 14
7. Replace ignition control
assembly
8. Replace motor
113170-01E
-
FAULT CONDITION
Motor starts and runs but heater
does not ignite
INDICATOR LIGHT
• Flame
TROUBLESHOOTING
Continued
POSSIBLE CAUSE
1. No fuel in tank
2. Pump pressure incorrect
3. Dirty fuel filter
4. Obstruction in nozzle
5. Water in fuel tank
WARNING: High voltage!
REMEDY
1. Fill tank with kerosene
2. See Pump Pressure Adjustment, 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,
Tran sport in g or Shi pping ,
page 7
-
• Ignitor
• Voltage
Heater ignites but ignition control
assembly shuts heater off after a
short period of time
INDICATOR LIGHT
• Flame
• Voltage
6. Bad electrical connectio n
between ignitor and ignition
control assembly
7. Defective ignitor
8. Defective ignition control
assembly
9. Line voltage is below 108V or
above 132v
1. Pump pressure incorrect
2. Dirty air intake, air output
and/or lint filter
3. Dirty fuel filter
4. Obstruction in nozzle
5. Photocell assembly not properly
installed (not seeing the flame)
6. Dirty photocell lens
WARNING: High voltage!
7. Bad electrical connection be
tween photocell and ignition
control assembly
8. Defective photocell
9. Defective ignition control
assembly
10.Line voltage is below 108V or
above 132v
6. Check electrical connections.
See Wiring Diagrams, page 16
7. Replace ignitor, see page 11
8. Replace ignition control
assembly
9. Check for proper line voltage
1. See Pump Pressure Adjustment, page 10
2. See Air Output, Air Intake and Lint Filters, page 10
3. See Fuel Filter, page 11
4. See Nozzle Assembly, page 12
5. Make sure photocell boot is
properly seated in bracket
6. Clean photocell lens
-
7. Check electrical connections.
See Wiring Diagrams, page 16
8. Replace photocell
9. Replace ignition control
assembly
10.Check for proper line voltage.
Disconnect power equipment
that may be used on same
line
-
113170-01E9
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SERVICE PROCEDURES
2
1
WARNING: To avoid risk of
burn and electrical shock, never
attempt to service heater while it
is plugged in, operating or hot.
UPPER SHELL REMOVAL
1. Remove screws along each side of heater using
phillips screwdriver. These screws attach upper
and lower shells together. See Figure 7.
2. Lift upper shell off.
3. Remove fan guard.
Screw
Figure 7 - Upper Shell Removal
FAN
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. Replace fan on motor shaft. Place fan hub flush
with end of motor shaft (see Figure 9).
7. Place setscrew on flat of shaft. Tighten setscrew
firmly (40-50 inch-pounds/4.5-5.6 n-m).
8. Replace upper shell.
Setscrew
Fan
Upper Shell
Setscrew
Motor
Fan
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. Wash or replace air intake filter (see Preventative Maintenance Schedule, page 8).
6. Replace filter end cover.
7. Replace upper shell.
IMPORTANT: Do not oil filters.
Air Intake
Filter
Lint Filter
Air Output Filter
Figure 10 - Air Output, Air Intake and Lint
Filters
Filter
End
Cover
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
motor to reach full speed.
Pressure
Gauge
Plug
Operation, page 5). Allow
Relief
Valve
-
Motor Shaft
Figure 8 - Fan, Motor
Shaft and Setscrew
Location
10
Motor
Shaft
Figure 9 - Fan
Cross Section
www.desatech.com
Flush
Figure 11 - Pressure Gauge Plug
Removal
113170-01E
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SERVICE PROCEDURES
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•
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•
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Fl
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•
L
la
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a
• F
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/
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D
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/
M
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5
6
4
3
2
1
1
1
2
93
5
0
1
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.
Pump
Model Pressure
125T 6.0 PSI
170T 6.0 PSI
200T 6.2 PSI
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
tank.
7. Attach upper fuel line to fuel filter neck.
8. Replace control cover.
Control Cover
Fuel Filter,
Bushing and
Lower Fuel Line
Upper Fuel Line
Pressure
Gauge
Screw
WARNING: HIGH VOLTAGE
WARNING: To avoid risk of burn
and electrical shock, never attempt to service heater while it is
plugged in, operating or hot.
IGNITOR
1. Remove upper shell (See Upper Shell Removal, 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.
Remove photocell from photocell bracket (see
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.
Combustion
Chamber
Air Line Hose
Photocell
Bracket
Fuel Line
Hose
Photocell
Assembly
Nozzle Adapter
Bracket
Ignitor
Ignitor
Wire
Ignitor
Wire
-
-
Ignition
Control Cover
Control
Assembly
Figure 14 - Disconnecting Ignitor Wires
from Ignition Control Assembly
Figure 13 - Fuel Filter Removal
113170-01E11
www.desatech.com
(170T Model Shown)
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.
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.
15. Replace fan (see page 10).
16. Replace upper shell (see page 10).
Ignitor Screw/Washer
Assembly
Ignitor
Ignitor Element
Photocell
Bracket
Nozzle
Adapter
Bracket
Ignitor
Ignitor Element
Photocell
Bracket
Nozzle Adapter
Bracket Opening
Figure 16 - Ignitor HA1100 Replacement
Nozzle
Adapter
Bracket
Combustion
Chamber
NOZZLE ASSEMBLY
125T and 170T Models Only
1. Remove upper shell (see Upper Shell Re
moval, page 10).
2. Remove fan (see
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).
Combustion
Chamber
Nozzle
Adapter
Bracket
Photocell
Bracket
Fan, page 10).
Nozzle/
Adapter
Assembly
Fuel Line
Hose
-
Combustion
Chamber
Figure 15 - Ignitor HA1000 Replacement
12
Nozzle Adapter
Bracket Opening
www.desatech.com
Air Line Hose
Figure 17 - Removing Air and Fuel Line
Hoses (125T and 170T Models Only)
Combustion
Chamber
Figure 18 - Removing Nozzle/Adapter
Assembly
Nozzle/
Adapter
Assembly
113170-01E
SERVICE PROCEDURES
Continued
5. Place plastic hex-body into vise and lightly
tighten.
6. Carefully remove nozzle from the nozzle adapter
using 5/8" 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"
socket wrench 4.5 to 5.1 N-m (40 to 45 in-lbs).
See Figure 19).
10. Attach nozzle assembly to nozzle adapter
bracket (see Figure 18, page 12).
11. Attach fuel and airline hoses to nozzle as
sembly. See Fuel and Airline Replacement and Proper Routing.
12. Replace fan (see
13. Replace upper shell (see Upper Shell Removal
page 10).
Nozzle Face
Nozzle
Air 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.
Fan, page 10).
Nozzle Sleeve
Nozzle
Adapter
Fuel Line Fitting
Combustion
Chamber
Nozzle
Adapter
Bracket
Photocell
Bracket
Air Line
Hose
Figure 20 - Removing Air and Fuel Line
-
Nozzle Face
,
Hoses (200T Model Only)
Nozzle
Sleeve
Nozzle
Nozzle
Adapter
Bracket
Figure 21 - Nozzle and Nozzle Adapter
Air Line
Fitting
Nozzle/
Adapter
Assembly
Fuel Line Hose
Nozzle
Adapter
Fuel Line
Fitting
FUEL AND AIR LINE REPLACEMENT
AND PROPER ROUTING
1. Remove upper shell (see Upper Shell Removal, 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
Filter, page 11) and the other end to nozzle
adapter (see Figure 17, page 12 or Figure 20
according to model).
Fuel
113170-01E13
www.desatech.com
T
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•
T
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•
T
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Flame
•
L
la
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a
•
Flam
m
e
S
ta
rt
/
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En
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n
d
a/
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ac
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D
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/
M
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c
he
5
6
4
3
2
1
1
1
2
93
5
0
1
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. Replace upper shell (see Upper Shell Removal
page 10).
Pump End
Cover
Air Hose
Figure 22 - Air Hose to Barb Fitting
PUMP ROTOR
(Procedure if Rotor is Binding)
1. Remove upper shell (see Upper Shell Removal, 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" nutdriver.
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
Shell Removal, page 10).
13. Adjust pump pressure (see Pump Pressure Adjustment, page 10).
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.
14
Barb
Fitting
www.desatech.com
Upper
Pump Plate
Blade
Air
Intake
Filter
Insert
,
Rotor
Air Output Filter
Figure 23 - Rotor Location
Gap Adjusting Screw
.003"/.004"
(.076-.101 mm)
Gap Measured
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
Figure 26- Replacing Fuse
113170-01E
Filter End
Cover
-
-
Fuse
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) 13.5/51 13.5/51 13.5/51
Fuel Consumption
(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 additives.
-
113170-01E15
www.desatech.com
Power Plug
120V/60Hz
Blue
Blue
White
Photocell
Ignition Control Assembly
11
3471-01
Green
Black
Green
Red
Black
Yellow/Tan
Yellow/Tan
Motor
Ignitor
Photocell
Photocell
Ignitor
Temp.
Temp
.
Motor Return
AC Neutral (L2)
120V (L1)
Ignitor
Motor
White
ON/OFF Switch
with Light
5
4
1
Thermostat
Control
Te
mperature
Sensor
Power Plug
120V/60Hz
Blue
Blue
White
Photocell
Ignition Control Assembly
Green
Black
Black
Green
Red
Black
Yellow
Yellow
Motor
Ignitor
Thermostat
Photocell
Photocell
Ignitor
Motor Return
AC Neutral (L2)
120V (L1)
Ignitor
Motor
White
ON/OFF Switch
with Light
5
4
1
WIRING DIAGRAMS
MODELS RH125AT, M125AT, RH170AT, M170AT AND M200AT ONLY
You may have further questions about installation,
operation or troubleshooting. If so, contact DESA
Heating Productsʼ Technical Service Department
at 1-866-672-6040. When calling please have your
model and serial numbers of your heater ready.
You can also visit DESA Heating Productsʼ techni
cal services web site at www.desatech.com.
REPLACEMENT PARTS
Note: Use only original replacement parts. This
will protect your warranty coverage for parts
replaced under warranty.
PARTS UNDER WARRANTY
Contact authorized dealers of this product. If they
canʼt supply original replacement part(s), call
DESA Heating Productsʼ Technical Service Dept.
at 1-866-672-6040.
When calling DESA Heating Products, have
ready:
• your name
• your address
• model and serial numbers of your heater
• how heater was malfunctioning
• purchase date
Usually, we will ask you to return the part to the
factory.
PARTS NOT UNDER WARRANTY
Contact authorized dealers of this product. If they
canʼt supply original replacement part(s), call
DESA Heating Products at 1-866-672-6040 for
referral information. Parts dealers are listed in
the Authorized Service Center booklet supplied
with heater.
When calling DESA Heating Products, have
ready:
• model and serial numbers of your heater
• the replacement part number
ACCESSORIES
Purchase accessories and parts from your nearest
dealer or service center. If they can not supply
these accessories or parts, either contact your
nearest parts dealer or DESA Heating Products
at 1-866-672-6040 for referral information. Parts
Centrals are listed in the Authorized Service Center
booklet supplied with heater.
AIR GAUGE KIT - HA1180
For all model s. Special tool to check pump
pressure.
IGNITION CONTROL ASSEMBLY/
PHOTOCELL TESTER - HA1170
For all models. Special tool used to test the ignition control assembly and photocell.