Desa B350D User manual

Technical Service Department • P.O. Box 90004 • 2701 Industrial Drive • Bowling Green, Kentucky 42102-9004
SERVICE MANUAL
HIGH PRESSURE
PORTABLE FORCED AIR HEATERS
600 SIDE PFA/PV 009
350 SIDE PFA/PV 008
INTERNATIONAL
DESA

HIGH PRESSURE PORTABLE FORCED AIR HEATER SERVICE MANUAL
2
TABLE
OF
CONTENTS
Section 1 - Safety Information.................................................................................3
Section 2 - Introduction
Arrangement of Manual......................................................................................4
Technical Service Department ...........................................................................4
Service Preparation............................................................................................4
Tools Required...................................................................................................4
Section 3 - General Specifications and Applications Information
Fuel Section .......................................................................................................5
Electrical.............................................................................................................5
Ventilation ..........................................................................................................5
Heater Sizing......................................................................................................5
Heater Performance Specifications....................................................................6
Wiring Diagrams.................................................................................................6
Section 4 - Component Operation
All Systems Working Together...........................................................................8
Fuel System .......................................................................................................8
Fuel Pump......................................................................................................8
Fuel Filters .....................................................................................................9
Nozzle ............................................................................................................9
Electrical System................................................................................................10
Motor ..............................................................................................................10
Flame Control Assembly ................................................................................10
Ignition Transformer .......................................................................................11
Fuel Solenoid Valve .......................................................................................11
Fan Switch .....................................................................................................11
Section 5 - Troubleshooting
Safety Requirements .........................................................................................12
Using an Ohmmeter...........................................................................................12
Setting Up the Ohmmeter ..................................................................................12
Calibrating the Ohmmeter..................................................................................12
Diagnostic Information .......................................................................................12
Problem Conditions
Frequent Spark Plug Fouling/Delayed Ignition ..............................................13
Spark Plug Sparks, but Motor Does Not Start ...............................................14
Motor Starts, but Heater Will Not Ignite .........................................................15
Heater Ignites, and Flame Is Established, However, Flame Control Trips,
and Heater Shuts Off .................................................................................18
Heater Does Not Start. Motor and Transformer Do Not Operate...................21
Carbon Build-Up Inside Combustion Chamber..............................................22
Section 6 - Accessories and Service Information....................................................23

HIGH PRESSURE PORTABLE FORCED AIR HEATER SERVICE MANUAL
3
SAFETY INFORMATION
Safety Requirements
Thisservicemanualisintendedforusebyindividualswithadequateelectricalandmechanical
skills. Attempts to repair this heater by individuals without those skills can result in personal
injury as well as property damage.
1
SECTION
IMPORTANT: ReadtheOwner’sManual carefully andcompletelybeforetryingto 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.
Make certain you read and understand all Warnings.
Warnings
!
WARNING ICON G 001
• Use only kerosene or No. 1 fuel oil to avoid risk of fire or explosion. Never use gasoline,
naphtha, paint thinners, alcohol, or other highly flammable fuels.
• Never use heater where gasoline, paint thinner, or other highly flammable vapors are
present.
• Follow all local ordinances and codes when using heater.
• Use only in well vented areas. Provide at least three (3) square feet of fresh, outside air for
each 100,000 BTU/Hr of rating. This heater produces carbon monoxide, which is listed by
the State of California as a reproductive toxin under Proposition 65.
• Use only in places free of flammable vapors or high dust content.
• Use only with the electrical voltage and frequency specified on model plate.
• Use only a three-prong, grounded extension cord.
• Minimum heater clearances from combustibles:
Outlet: 8 Ft. Sides: 4 Ft. Top: 4 Ft. Rear: 4 Ft.
• Locate heater on a stable and level surface while hot or running or a fire may occur.
• When moving or storing, heater must be in a level position or fuel spillage may occur.
• Keep children and animals away from heater.
• Unplug heater when not in use.
• This heater is equipped with a thermostat. When plugged in, heater may start anytime.
• Never use heater in living or sleeping areas.
• Never block air inlet (rear) or air outlet (front) of heater.
• Never move, handle, refuel, or service a hot, operating, or plugged in heater.
• Never attach duct work to front or rear of heater.

HIGH PRESSURE PORTABLE FORCED AIR HEATER SERVICE MANUAL
4
2
SECTION
Pressure Gage
INTRODUCTION
Arrangement Of Manual
This manual contains information and serv-
ice procedures that help the service person
understand and correct problems on the
DESA International High Pressure Portable
ForcedAirHeater.Thefirstpartofthismanual
contains basic information about the opera-
tion of different parts of the heater. Review
this information. It provides a basic under-
standing of how the parts function in the
working system. The last part of this manual
is a troubleshooting section. It provides a
quickreferenceconcerningconditionswhich
may result in customer complaints. These
procedures will help the service person
quickly diagnose a malfunctioning heater.
The illustrations in this manual may not nec-
essarilydepicttheactualheatermodel.They
are intended for reference only.
Technical Service Department
The Technical Service Department, located
inBowlingGreen,Kentucky,is committed to
helpincreasetheserviceknowledgeofthose
who service these heaters. This will enable
service people to provide prompt, efficient
service.Thisservicemanualcoversthemajor
problems that can occur with the heaters.
However, as with any product, certain prob-
lems can arise which this manual does not
cover.Ifsuchproblemsarise,pleasecallthe
TechnicalServiceDepartmentat1-800-323-
5190. The Technical Service Department is
openfrom8:00amto4:00pmCentralTime.
This number is only for servicing problems
andcannotbeusedfororderingparts,billing
questions, etc.
Service Preparation
A clean work area at the start of each job is
essential for efficient service work. Clean
extremely dirty heaters before servicing.
Cleaning will sometimes uncover the prob-
lem area. Gather tools needed for the job
beforeworkisstarted.Havingtolocatetools
causes delays that lead to lost time and
wages.
Always use clean fuel when testing heater.
Many problems are often caused by the
wrong type of fuel or dirty fuel.
Usecautionandcommonsensewhenwork-
ing on heater. Always remember:
• Kerosene is combustible.
• Guard against electrical shock.
• Heater parts get hot during operation.
Touching these parts can cause severe
burns.
Tools Required
In addition to common hand tools, the serv-
iceshopshouldhavethefollowingtoolsand
instruments to properly repair the heater.
These tools and instruments will be referred
to throughout this manual.
Tool/ Part
Instrument Range Number
Volt Ohmmeter RX1/AC 250V *
Feeler Gage .001 to .1 inch **
Pressure Gage 0-200 PSI M4574
Flame Control/
Photocell Tester HA1170
* Available at most electronic stores.
** Available at any auto parts store.
CAUTION: OBSERVE SAFETY RULES
V- MA
0
1000300
100
30
10
3
1000
300
100
30
10
3
1
.1
10
1000
100
x1
x10
x100
x1K
x10K
D
C
V
D
M
C
A
COM-
A
C
V
T
E
S
T
5
10
15
20
25
30
1
2
3
4
5
8
6
9
10
7
OFF
Volt Ohmmeter
.025
.0015
Feeler Gage

HIGH PRESSURE PORTABLE FORCED AIR HEATER SERVICE MANUAL
5
Fuel Selection
One of the most critical specifications for
trouble-free operation is the use of a clean,
acceptable fuel. Listed below are guidelines
andcommentsconcerningoperationofheat-
ers with different fuels.
Recommended
Fuels Comments
Kerosene Best overall results. Mini-
Fuel Oil No. 1 mum odor and minimum
Jet “A” maintenance.Noadditives
necessaryforcoldweather
operation.
Alternate Fuels Comments
Fuel Oil No. 2 Noticeable increase in
Diesel No. 1 odor. Requires frequent
Diesel No. 2 maintenance of fuel filter,
nozzle and spark plug.
Cannot be used at tem-
peratures below +20°F.
Electrical
Connectheatertoastandardelectricaloutlet
(120V/60Hz) to operate. For safety, all heat-
ers have a three-prong, grounded power
cord. Plug power cord of heater into three-
prong, grounded extension cord. Extension
cordmustbeatleastsixfeetlong.Makesure
youuseextensioncordlargeenoughtocarry
the voltage the heater requires. Use the
following chart to determine the proper size
extension cord for heater.
Length of Cord Wire Size (AWG)
100 ft. No. 14
200 ft. No. 12
300 ft. No. 10
400 ft. No. 8
500 ft. No. 6
3
SECTION
Ventilation
Onlyuseheaterinwell-ventilatedareas.The
following chart shows the minimum fresh,
outside air opening needed for proper venti-
lation.
Heater Size Square Foot
(BTU/Hr) Opening
250,000 7.5
300,000 9.0
350,000 10.5
600,000 18.0
The above chart is based on ventilation re-
quirementsofatleasta three (3)squarefoot
fresh, outside air opening for each 100,000
BTU/Hr of rating. Provide extra fresh air if
usingmoreheaters.Ifpossible,providecross-
ventilation for better air movement. This
heater produces carbon monoxide, which is
listed by the State of California as a repro-
ductive toxin under Proposition 65.
Heater Sizing
Use heater which is properly sized for the
area to be heated. Listed below is a simple
formula that allows you to determine heater
BTU/Hr size requirements.
Cubic Feet of Area x .133 x Desired
Temperature Rise °F = BTU size
Example
Area: 100' x 100' x 8' = 80,000 Cubic Feet
Desired Temperature Rise: 30°F
80,000 (Cubic Feet)
x .133 (Factor)
10,640
x 30 (Temperature Rise)
319,200 (BTUs/Hr Needed)
Answer: Use a 350,000 BTU/Hr
heater for this heating example.
GENERAL SPECIFICATIONS AND APPLICATIONS INFORMATION

HIGH PRESSURE PORTABLE FORCED AIR HEATER SERVICE MANUAL
6
Heater Performance Specifications
350,000 BTU/Hr 600,000 BTU/Hr
Output Rating (BTU/Hr) 350,000 600,000
Fuel Use only kerosene or No. 1 fuel oil
Fuel Tank Capacity (U.S. Gallons) 30 36
Fuel Consumption (Gallons Per Hour) 2.5 4
Electric Requirements 120V/60Hz 120V/60Hz
Amperage (Normal Run) 7.1 11.5
Motor RPM 1725 1725
Fuel Pump Pressure (PSI) 100 110
Spark Plug Gap .050/.060" .050/.060"
Weight (Approx. Lbs.)
Dry 180 285
With Full Fuel Tank 390 550
Wiring Diagrams
Wiring Diagram for Non-Terminal Block Heater with Standard Flame Control
1
2
3
RELAY
AB
75
FLAME
CONTROL
WHITE
ORANGE
RED
GREEN
MOTOR
PHOTO-
CELL
BLUE
BLACK
SPARK PLUG
BLACK
BLACK
BLACK
BLACK
BLACK
WHITE
WHITE
WHITE
WHITE
WHITE
RED
RED
RED
WHITE
BLUE
FAN
SWITCH
T
R
A
N
S
F
O
R
M
E
R
ORANGE
YELLOW YELLOW
THERMOSTAT
SOLENOID
VALVE
R
B
WHITE

HIGH PRESSURE PORTABLE FORCED AIR HEATER SERVICE MANUAL
7
Wiring Diagram for Terminal Block Heater with Standard Flame Control
Wiring Diagram for Non-Terminal Block Heater with White-Rogers/Robert Shaw Flame Control
FAN
SWITCH
SPARK PLUG
ORANGE
BLACK
FLAME
CONTROL
WHITE
THERMOSTAT
WHITE
WHITEBLUE
PHOTO
CELL WHITE
GREEN
BLACK
BLACK
WHITE
ORANGE
ORANGE
RED
RED
RED
YELLOWYELLOW
SOLENOID
VALVE WHITE
MOTOR
T
R
A
N
S
F
O
R
M
E
R
32
1
WHITE
WHITE
BLACK
WHITE WHITE
1
3
2
FAN
SWITCH
75
BA
MOTOR
RELAY
WHITE
RED ORANGE
ORANGE
RED
BLACK
WHITE
BLACK
WHITE
BLUE
BLUEWHITE
BLACK BLACK
THERMOSTAT B
R
FLAME
CONTROL RESET
BUTTON
RED
YELLOW
YELLOW RED
WHITE
SOLENOID
VALVE
WHITE
TERMINAL
BOARD
TERMINAL
BOARD
TRANSFORMER
WHITE
SPARK
PLUG
PHOTOCELL
BLACK
WHITE
GREEN
YELLOW
WHITE

HIGH PRESSURE PORTABLE FORCED AIR HEATER SERVICE MANUAL
8
COMPONENT OPERATION
All Systems Working Together
There are four basic systems within the
heater: the fuel system, the air system, the
ignition system, and the flame control sys-
tem.
The Fuel System: The fuel pump pulls fuel
fromthefueltankandpressurizesit.Thefuel
pump pushes fuel through a filter and a
solenoid valve and out the burner head
nozzle. 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
4
SECTION
FUEL SYSTEM
Fuel Pump
The fuel pump is a single stage gear-type
pumpdesignedfortwo-pipeusage.Theterm
“two-pipeusage”meansthatprovisionsmust
bemadetoreturnexcessfuelfromthepump
backtosupplytank.Figure1showsposition
of pump on heater.
Thefuelpumpisdirectly connected tomotor
shaft. When motor on heater runs, the fuel
pump starts working. The fuel pump draws
fuel into one of the ports marked “INLETS.”
After fuel pump draws fuel into INLET port,
thefuelisthenpressurizedin the pump. The
fuelpumpthenforcesfueltotheburnerhead
nozzle thru the port marked NOZZLE.
The port marked “PRESS ADJ” contains an
adjustment screw. Turning this screw will
increase or decrease the fuel pump pres-
sure.Checkfuelpumppressurebyattaching
high pressure gauge into the port marked
“GAGE.”
As mentioned above, the port marked “RE-
TURN” is used to return excess fuel back to
supply tank.
Be careful when working on fuel pump. Fuel
pump operates under high pressure. Figure 1 - Fuel Pump
PUMP
MODEL PRESSURE
350,000 BTU/Hr. 100 psi
600,000 BTU/Hr. 110 psi
combustion chamber. The air that goes into
the combustion chamber mixes with the fuel
for combustion. The air is heated and pro-
vides a stream of clean, hot air.
TheIgnitionSystem:Thetransformersends
voltage to the spark plug. The spark plug
ignites the fuel and air mixture.
The Flame Control System: This system
causes the heater to shut down if the flame
goes out. It also allows the fan to continue
running after normal shutdown of heater.
This cools the combustion chamber.

HIGH PRESSURE PORTABLE FORCED AIR HEATER SERVICE MANUAL
9
Fuel Filters
The fuel filtering system has two filters. The
first filter is a 50-mesh screen type. It is
located in the fuel tank below the grommet
where fuel suction and return lines enter the
tank. The filter is connected to both the fuel
input (suction side) and the return line from
thefuelpump.Thisuniquedesignallowsthe
filter to backflush or clean itself of sediment
by the action of the excess flow returning
from the pump.
The second filter is a canister type. The two-
piece canister contains a replaceable drop-in
filterelement.Thisfilterwillfilteroutverysmall
particles which may be present in the fuel
system.Thishighdegreeoffilteringisneeded
to prevent any sediment or foreign material
from reaching the nozzle. Make sure to clean
orreplacethisfilterelementevery250hoursof
operation. Clean or replace this filter more
often if fuel quality is bad.
Nozzle
The nozzle could be classified as the heart of
the fuel system. The nozzle works similar to a
standard garden hose nozzle. The kerosene
passes through the nozzle. Under pressure,
the oil expands through the nozzle orifice and
breaksintoa fine spray. The flow rate and the
spray angle is designed into each nozzle. Do
not substitute with a nozzle having a different
flow rate or spray pattern. Use only replace-
ment parts supplied by DESA International.
Figure 3 - Canister Type Fuel Filter
Figure 2 - Fuel Filter in Fuel Tank
Filter
Figure 4 - Nozzle

HIGH PRESSURE PORTABLE FORCED AIR HEATER SERVICE MANUAL
10
Flame Control Assembly
Theheaterisequippedwithoneoftwoflame
controls — a White-Rogers/Robert Shaw or
a standard flame control. The flame control
monitors the combustion chamber flame.
The control will shut off power to the heater
if the combustion flame goes out or if an
inside the motor. The centrifugal switch also
supplies voltage to the fuel solenoid valve.
The motor also has a temperature/current
sensitive thermal protector wired in series
with both windings. This device protects the
motorfromoverheatingifthefan/pumplocks
up. If the fan/pump locks up, this device will
shut the motor off. Before motor will run
again, press red reset button located on top
of the motor housing (see Figure 5).
Figure 6 - White-Rogers/Robert Shaw
Flame Control Figure 7 - Standard Flame Control
RESET
ELECTRICAL SYSTEM
Motor
The motor is a fractional horsepower motor.
The motor drives the fuel pump and rotates
the fan. The turning fan delivers air into and
around the combustion chamber.
The motor contains two separate internal
windings. The first winding is the start wind-
ing.Thesecondwindingisthemainwinding.
The motor switches power from the start
winding to the main winding after the motor
reaches75%ofitsratedspeed.Thisswitch-
ing is done by a centrifugal switch located
unusual flame color is present. A photocell
(attached to the burner head) monitors light
within the chamber. If the photocell detects
improper combustion or loss of flame, the
flamecontrolwillshutoffpowertotheheater.
Reset Button
Figure 5 - Motor