Desa R60A, PK55, UK55, TK50, TK55 Owner's Manual

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.

Save this manual for future reference.

For more information, visit www.desatech.com

HEATER SIZES: 40,000 50,000 55,000 60,000 70,000 110,000

115,000 155,000 165,000 AND 200,000 BTU/HR MODELS

H.S.I. SERIES

KEROSENE/DIESEL PORTABLE FORCED AIR HEATERS

OWNER’S MANUAL

New

Straight

Shell

Design

Fill In For Your Records

Model No. _______________________

(Located on side panel)

Serial No. _______________________

(Located on fuel tank)

Date of Purchase: _________________

TABLE OF CONTENTS

Safety Information ............................................... 2

Unpacking ........................................................... 3

Product Identification .......................................... 3

Fuels ................................................................... 4

Ventilation ........................................................... 4

Theory of Operation ............................................ 4

Assembly ............................................................ 5

Operation ............................................................ 5

Operation With Portable Generator ..................... 6

Storing, Transporting, or Shipping ....................... 6

Preventative Maintenance Schedule ................... 7

Troubleshooting ................................................... 7

Service Procedures ............................................. 9

Specifications .................................................... 15

Wiring Diagrams ............................................... 16

Illustrated Parts Breakdown and Parts List ....... 18

Replacement Parts ........................................... 30

Technical Service .............................................. 31

Accessories ....................................................... 31

Warranty and Repair Service ............. Back Cover

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2

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 serviced. 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 warn­ings. Keep this manual for reference. It is your
guide to safe and proper operation of this heater.

• 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.

• 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 returning the
heater to service.

e) At no time shall more than one day's supply

of heater fuel be stored inside a building in
the vicinity of the heater. Bulk fuel storage
shall be outside the structure.

f) All fuel storage shall be located a minimum

of 25 feet (762cm) 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 con-

fined 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.

• Use only the electrical voltage and frequency
specified on model plate.

• Heater must be grounded. Use only a properly
grounded three-wire extension cord. Plug into
grounded outlet only.

• Use only in areas free of flammable vapors or
high dust content.

• Minimum clearance from any combustible
materials: 8 feet (244 cm) from hot air outlet; 4
feet (122 cm) from top; and 4 feet (122 cm)
from sides and inlet.

• Locate heater on a stable and level surface while
hot or operating or a fire may occur.

• Use only in well-vented areas. Before using
heater, provide at least a three-square-foot (2800
square cm) opening of fresh, outside air for each
100,000 Btu/Hr (30 kw) of rating.

• Keep children and animals away from heater
at all times.

• Never start heater when combustion chamber
is hot or if fuel has accumulated in combustion
chamber.

• When used with thermostat, heater may start at
anytime.

• When heater is moved or stored, it must be in a
level position or fuel spillage may occur.

• Use heater only in accordance with local ordi­nances and codes.

• Never use gasoline, crankcase drainings, naph­tha, paint thinners, alcohol, or other highly flam­mable fuels.

• Never use heater where gasoline, paint thinner,
or other highly flammable vapors are present.

• Never use heater in living or sleeping areas.

• Never leave a heater plugged in without adult
supervision if children or animals are likely to
be present.

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113282-01C 3

• Never move, handle, refuel, or service a hot,
operating, or plugged-in heater.

• Never attach duct work to front or rear of heater.

• Never attach heater to external fuel tank.

• 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 10 feet
(304.8cm). 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.

• Unplug heater when not in use.

• Never block air inlet (rear) or air outlet (front)
of heater.

• Warning to New York City Residents
For Use Only At Construction Sites in accor-

dance 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

SAFETY INFORMATION

Continued

Side Cover

Fuel
Cap/
Gauge

Hot Air Outlet

Side Cover

Fuel
Tank

Hot Air
Outlet

Fan Guard

Air Filter
End
Cover

Fuel Cap/Gauge

Ignition Control
Assembly (On
Inside of Side
Cover)

Ignition Control
Assembly (On Inside
of Side Cover)

Figure 2 - 50/55/60/70 Models

Figure 3 - 110/115/155/165 Models

Thermostat Knob
(Thermostat
Models Only)

Fuel
Tank

Fan Guard

Thermostat Knob
(Thermostat
Models Only)

Figure 4 - 200 Model

Hot Air Outlet

Side Cover

Fuel Cap/
Gauge

Ignition Control
Assembly (On
Inside of Side
Cover)

Fan
Guard

Thermostat Knob
(Thermostat Models Only)

Fuel
Tank

Side Cover

Fuel
Tank

Hot Air
Outlet

Fan Guard

Air Filter
End
Cover

Fuel
Cap

Ignition Control
Assembly (On Inside
of Side Cover)

Figure 1 - 40 Models

Thermostat Knob
(Thermostat
Models Only)

ON/OFF Switch
with Light

ON/OFF Switch
with Light

ON/OFF Switch
with Light

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4

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.

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.

Figure 5 - Cross Section Operational View

Clean
Heated
Air Out

Fuel
Filter

Air Line
To Burner

Air Output
Filter

Air Pump

Air Intake Filter

Cool
Air
In

Fan

Combustion
Chamber

Ignitor

Ignition Control
Assembly

Air For Fuel
System

Air For
Combustion
And Heating

Fuel

Nozzle

Fuel
Tank

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 200,000 Btu/Hr (58.6kw) heater re-

quires one of the following:

• a two-car garage door [16 feet (4.88 meter)
opening] raised 5 inches (12.7 cm)

• a single-car garage door [9 feet (2.74 meter)
opening] raised 8 inches (20.3 cm)

• two, 30 inch (76.2 cm) windows raised 15
inches (38.1 cm)

Motor

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113282-01C 5

ASSEMBLY

(FOR 110/115/155/165/200 MODELS
ONLY)

These models are furnished with wheels and a
handle. Some models are furnished with a second
handle also. Wheels, handle(s), and the mounting
hardware are found in the shipping carton.

Tools Needed

• Medium Phillips Screwdriver

• 3/8" Open or Adjustable Wrench

• Hammer

1. Slide axle through wheel support frame. Install
wheel spacers if provided. Install wheels on axle.

IMPORTANT:

When installing wheels, point
extended hub of wheels toward wheel support
frame (see Figure 6).

2. Place cap nuts on axle ends. Gently tap with
hammer to secure.

3. Place heater on wheel support frame. Line up
holes on fuel tank flange with holes on wheel
support frame.

4. Place handle(s) on top of fuel tank flange. In­sert screws through handle(s), fuel tank flange,
and wheel support frame. Attach nut finger
tight after each screw is inserted.

5. After all screws are inserted, tighten nuts
firmly.

Figure 6 - Wheel and Handle Assembly,

110/115/155/165/200 Models Only

Wheel Support
Frame

Fuel
Tank
Flange

Cap Nut

Wheel

Nut

Axle

Extended
Hub

Air
Inlet

Handle

Hot Air
Outlet

Screw

OPERATION

IMPORTANT: Review and under­stand the warnings in the

Safety

Information

section, page 2.
They are needed to safely oper­ate 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 kerosene, #1#2 diesel/fuel
oil, JET A or JP-8 fuel.

4. Attach fuel cap.

5. For thermostat models, turn thermostat knob
clockwise to the high position.

6. Plug heater’s 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 to 10 feet (1.8 to 3 meters) long, use 18 AWG
(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

7.

Plug extension cord into standard 120 volt/60
hertz, 3-prong grounded outlet.

Note:

For heater without ON/OFF switch, ig­nitor will preheat for five seconds, then heater
will start.

Note:

For heater with ON/OFF switch, push
switch to ON(|) position and heater should start
in 5 seconds. If heater does not start, see
Troubleshooting, page 7.

8. For thermostat models, 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

Without ON/OFF Switch

Unplug extension cord from outlet.

With ON/OFF Switch

Push ON/OFF switch to OFF (O) position. Un­plug heater when not in use.

Wheel Spacer
(If Provided)

Cord Cleat with Bolts
and Nuts (If Provided ­Set of Two for Right or
Left Side)

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6

Figure 9 - Typical Generator Grounding

Method (Generator construction may

vary from that shown)

Ground Lug

Ground Wire (#10
AWG - Stranded­Copper)

Alternator

Copper or
Brass
Grounding
Point

TO RESTART HEATER

Wthout ON/OFF Switch

1. Unplug extension cord from outlet and wait
10 seconds. (Wait two minutes if heater has
been running.)

2. Repeat steps under To Start Heater.

With ON/OFF Switch

1. Push ON/OFF switch to OFF (O) position
and wait 10 seconds (2 minutes if heater has
been running).

2. Repeat steps under To Start Heater, page 5.

OPERATION

Continued

Figure 7 - ON/OFF Switch, 50/55/60/70 Models

Figure 8 - ON/OFF Switch, 110/115/155/

165/200 Models

ON/OFF
Switch with
Light

ON/OFF
Switch with
Light

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.

Refer to Operation, page 5, for starting, stopping,
and resetting heater procedures.

STORING,

TRANSPORTING, OR

SHIPPING

Note:

If shipping, transport companies require fuel

tanks to be empty.

1. Drain fuel tank.

Note:

Some models have
drain plug on underside of fuel tank. If so,
remove drain plug to drain all fuel. If heater
does not have drain plug, drain fuel through
fuel cap opening. Be sure all fuel is removed.

2. Replace drain plug if provided.

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. Replace fuel cap or drain plug. 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.

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113282-01C 7

PREVENTATIVE MAINTENANCE SCHEDULE

WARNING: Never service heater while it is plugged in, operating,

or hot. Severe burns and electrical shock can occur.

How To

See Storing, Transporting, or
Shipping, page 6

See Air Output, Air Intake, and
Lint Filters, page 9

See Air Output, Air Intake, and
Lint Filters, page 9

See Fuel Filter, page 10

See Fan, page 9

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

TROUBLESHOOTING

WARNING: Never service heater while it is plugged in, operating,

or hot. Severe burns and electrical shock can occur.

POSSIBLE CAUSE

1. No power to heater

2. ON/OFF switch not in the
ON(|) position

3. If equipped, thermostat setting
is too low

4. Bad electrical connection be­tween motor and ignition con­trol assembly or ignition con­trol assembly and power cord

5. Binding pump rotor

6. Defective ignition control as­sembly

7. Defective motor

8. Blown fuse or ignitor control
assembly

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

4. Check all electrical connec­tions. See Wiring Diagrams,
page 16

5. If fan does not turn freely, see
Pump Rotor, page 14

6 Replace ignition control as-

sembly

7. Replace motor

8. See Ignition Control Assem-
bly, page 15

FAULT CONDITION

Motor does not start five sec­onds after heater is plugged in

WARNING: High voltage!

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8

POSSIBLE CAUSE

1. No fuel in tank

2. Pump pressure incorrect

3. Dirty fuel filter

4. Obstruction in nozzle

5. Water in fuel tank

6. Bad electrical connection be­tween ignitor and ignition con­trol assembly

7. Defective ignitor

8. Defective ignition control as­sembly

9. 200 Model Only: Defective
fuel valve (Models equipped
with fuel valve only)

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

7. Bad electrical connection be­tween photocell and ignition
control assembly

8. Defective photocell

9. Defective ignition control as­sembly

REMEDY

1. Fill tank with kerosene

2. See Pump Pressure Adjust-
ment, page 10

3. See Fuel Filter, page 10

4. See Nozzle Assembly, page 13

5. Drain and flush fuel tank with
clean kerosene. See Storing,

Transporting, or Shipping,

page 6

6. Check electrical connections.
See Wiring Diagrams, page 16

7. Replace ignitor, see page 11

8. Replace ignition control as­sembly

9. See Fuel Valve, page 11

1. See Pump Pressure Adjust-
ment, page 10

2. See Air Output, Air Intake, and
Lint Filters, page 9

3. See Fuel Filter, page 10

4. See Nozzle Assembly, page 13

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

FAULT CONDITION

Motor starts and runs but heater
does not ignite

Heater ignites but ignition con­trol assembly shuts heater off
after a short period of time

WARNING: High voltage!

TROUBLESHOOTING

Continued

WARNING: High voltage!

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113282-01C 9

SERVICE PROCEDURES

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
5/16" nut-driver. These screws attach upper and
lower shells together. See Figure 10 or 11.

2. Lift upper shell off.

3. Remove fan guard.

Upper Shell

Fan Guard

Figure 10 - Upper Shell Removal,

40/50/55/60/70 Models Only

Figure 11 - Upper Shell Removal,
110/115/155/165/200 Models Only

Fan
Guard

Upper Shell

Screw

Screw

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 12).

1. Remove upper shell (see Figure 10 or 11).

2. Use 1/8" allen wrench to loosen setscrew

which holds fan to motor shaft.

3. Slip fan off motor shaft.

Motor Shaft

Setscrew

Figure 12 - Fan, Motor Shaft, and

Setscrew Location

Motor
Shaft

Fan

Setscrew

Figure 13 - Fan Cross Section

Fan

Flush

Motor

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 13).

7. Place setscrew on flat of shaft. Tighten setscrew
firmly (40-50 inch-pounds/4.5-5.6 n-m).

8. Replace fan guard and upper shell.

AIR OUTPUT, AIR INTAKE AND LINT
FILTERS

1. Remove upper shell (see Figure 10 or 11).

2. Remove filter end cover screws using 5/16" nut­driver (see Figure 14 or Figure 15, page 10).

3. Remove filter end cover.

4. Replace air output and lint filters.

5. Wash or replace air intake filter (see Preven-
tative Maintenance Schedule, page 7).

Air Intake Filter

Lint Filter

Filter End
Cover

Air Output Filter

Figure 14 - Air Output, Air Intake, and

Lint Filters, 40/50/55/60/70 Models Only

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10

SERVICE PROCEDURES

Continued

Figure 15 - Air Output, Air Intake, and Lint

Filters, 110/115/155/165/200 Models Only

Air Intake Filter

Filter End
Cover

Lint Filter

Air Output Filter

6. Replace filter end cover.

7. Replace fan guard and upper shell.

IMPORTANT:

Do not oil filters.

PUMP PRESSURE ADJUSTMENT

1. Remove pressure gauge plug from filter end
cover (see Figure 16).

2. Install accessory pressure gauge (part num­ber HA1180).

3. Start heater (see Operation, page 5). Allow
motor to reach full speed.

4. Adjust pressure. Turn relief valve to right to
increase pressure. Turn relief valve to left to
decrease pressure. See specifications correct
pressure for each model (see Figure 17).

5. Remove pressure gauge. Replace pressure
gauge plug in filter end cover.

Figure 16 - Pressure Gauge Plug

Removal (40/55/60/70 Models Shown)

Pressure
Gauge
Plug

Pressure
Gauge

Figure 17 - Adjusting Pump Pressure

(40/50/55/60/70 Models Shown)

Relief
Valve

Pump

Model Pressure

40 3.0 PSI
50 3.4 PSI
55 3.4 PSI
60 3.4 PSI

70 4.7 PSI
110 5.1 PSI
115 5.1 PSI
155 5.2 PSI
165 5.6 PSI
200 6.2 PSI

FUEL FILTER

1. Remove side cover screws using 5/16" nut­driver.

2. Remove side cover.

3. Pull upper fuel line off fuel filter neck (see
Figure 18 or 19).

4. Carefully pry bushing, fuel filter, and lower
fuel line (110/115/155/165/200 Models only)
out of fuel tank (see Figure 19).

5.

Wash fuel filter with clean fuel and replace in tank.

6. Attach upper fuel line to fuel filter neck.

7. Replace side cover.

Figure 18 - Fuel Filter Removal,

40/50/55/60/70 Models

Fuel Filter and
Bushing

Side Cover

Upper Fuel Line

Fuel Filter, Bushing,
and Lower Fuel Line

Upper Fuel Line

Side
Cover

Figure 19 - Fuel Filter Removal,

110/115/155/165/200 Models