Desa VN18B Original instructions

UNVENTED (VENT-FREE) INFRARED GAS HEATER
SAFETY INFORMATION AND INSTALLATION MANUAL
MODELS VN18B, VN18TB, VP16B, VP16TB,
VP26B, VP26TB, VN30B AND VN30TB
Model VN30B Shown
For more information, visit www.desatech.com
WARNING: If the information in this manual is not fol-
lowed exactly, a re or explosion may result causing
property damage, personal injury or loss of life.
— Do not store or use gasoline or other ammable
vapors and liquids in the vicinity of this or any other
appliance.
— WHAT TO DO IF YOU SMELL GAS
• Do not try to light any appliance.
• Do not touch any electrical switch; do not use any
phone in your building.
• Immediately call your gas supplier from a neighbor’s
phone. Follow the gas supplier’s instructions.
• If you cannot reach your gas supplier, call the re
department.
— Installation and service must be performed by a quali-
ed installer, service agency or the gas supplier.
INSTALLER: Leave this manual with the appliance.
CONSUMER: Retain this manual for future reference.

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SAFETY INFORMATION
WARNING: Improper in-
stallation, adjustment, al-
teration, service or mainte-
nance can cause injury or
property damage. Refer to
this manual for correct in-
stallation and operational
procedures. For assis-
tance or additional infor-
mation consult a qualied
installer, service agency or
the gas supplier.
WARNING: This is an
unvented gas-red heater.
It uses air (oxygen) from the
room in which it is installed.
Provisions for adequate
combustion and ventila-
tion air must be provided.
Refer to Air for Combustion
and Ventilation section on
page 5 of this manual.
This appliance is only for
use with the type of gas
indicated on the rating
plate. This appliance is
not convertible for use
with other gases.
This appliance may be in-
stalled in an aftermarket,*
permanently located,
manufactured (mobile)
home, where not prohib-
ited by local codes.
* Aftermarket: Completion of sale, not for
purpose of resale, from the manufacturer
WARNING: This product con-
tains 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 car-
bon monoxide poisoning resemble the u, with
headaches, dizziness 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, people with heart or lung
disease or anemia, those under the inuence
of alcohol and those at high altitudes.
TABLE OF CONTENTS
Safety Information ............................................... 2
Local Codes......................................................... 4
Product Identication ........................................... 4
Unpacking............................................................ 4
Product Features ................................................. 4
Air For Combustion and Ventilation ..................... 5
Installation ........................................................... 7
Operating Heater ............................................... 14
Inspecting Heater .............................................. 16
Cleaning and Maintenance ................................ 17
Troubleshooting ................................................. 18
Specications .................................................... 21
Illustrated Parts Breakdown and Parts List........ 22
Replacement Parts ............................................ 26
Service Hints ..................................................... 26
Technical Service............................................... 26
Accessories ....................................................... 26
Service Publications .......................................... 26
Parts Central...................................................... 27
Warranty Information ...........................Back Cover

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Natural and Propane/LP Gas: Natural and Pro-
pane/LP gases are odorless. An odor-making
agent is added to these gases. The odor
helps you detect a gas leak. However, the
odor added to the gas can fade. Gas may be
present even though no odor exists.
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.
WARNING: Any change to
this heater or its controls can
be dangerous.
WARNING: Do not use a blow-
er insert, heat exchanger insert
or other accessory not approved
for use with this heater.
Due to high temperatures, the
appliance should be located out
of trafc and away from furniture
and draperies.
Do not place clothing or other
ammable material on or near
the appliance. Never place any
objects on the heater.
Surface of heater becomes very
hot when running heater. Keep
children and adults away from
hot surface to avoid burns or
clothing ignition. Heater will
remain hot for a time after shut-
down. Allow surface to cool
before touching.
Carefully supervise young chil-
dren when they are in the same
room with heater.
Make sure grill guard is in place
before running heater.
Keep the appliance area clear
and free from combustible ma-
terials, gasoline and other am-
mable vapors and liquids.
1. This appliance is only for use with the type
of gas indicated on the rating plate. This
appliance is not convertible for use with
other gases.
2. Do not place propane/LP supply tank(s)
inside any structure. Locate propane/LP
supply tank(s) outdoors.
3. This heater shall not be installed in a
bedroom or bathroom.
4. If you smell gas
• Shut off gas supply
• Do not try to light any appliance
• Do not touch any electrical switch; do
not use any phone in your building
• Immediately call your gas supplier from
a neighbor’s phone. Follow the gas
supplier’s instructions
• If you cannot reach your gas supplier,
call the re department
5. Always run heater with plaque control
knob at the 1, 2, 3 or 4 locked positions.
Never set control knob between locked
positions. Poor combustion and higher
levels of carbon monoxide may result.
6. This heater needs fresh, outside air ven-
tilation to run properly. This heater has an
Oxygen Depletion Sensing (ODS) safety
shutoff system. The ODS shuts down the
heater if not enough fresh air is available.
See Air for Combustion and Ventilation,
page 5.
7. Keep all air openings in front and bottom
of heater clear and free of debris. This will
insure enough air for proper combustion.
8. If heater shuts off, do not relight until you
provide fresh, outside air. If heater keeps
shutting off, have it serviced.
9. Do not run heater
• where ammable liquids or vapors are
used or stored
• under dusty conditions
10. Do not use heater if any part has been
under water. Immediately call a qualied
service technician to inspect the room
heater and to replace any part of the
control system and any gas control which
has been under water.
SAFETY INFORMATION
Continued

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11. Turn off and unplug heater and let cool
before servicing. Only a qualied service
person should service and repair heater.
12. Operating heater above elevations of
4,500 feet could cause pilot outage.
13. To prevent performance problems, do not use
propane/LP fuel tank of less than 100 lbs.
capacity.
14. Before using furniture polish, wax, carpet
cleaner or similar products, turn heater off. If
heated, the vapors from these products may
create a white powder residue within burner
box or on adjacent walls or furniture.
15. Provide adequate clearances around air
openings.
LOCAL CODES
Install and use heater with care. Follow all
local codes. In the absence of local codes,
use the latest edition of The National Fuel
Gas Code, ANSI Z223.1/NFPA 54*.
*Available from:
American National Standards Institute, Inc.
1430 Broadway
New York, NY 10018
National Fire Protection Association, Inc.
Batterymarch Park
Quincy, MA 02269
State of Massachusetts: The installation
must be made by a licensed plumber or
gas tter in the Commonwealth of Mas-
sachusetts.
Sellers of unvented propane or natural
gas-red supplemental room heaters shall
provide to each purchaser a copy of 527
CMR 30 upon sale of the unit.
Vent-free gas products are prohibited for
bedroom and bathroom installation in the
Commonwealth of Massachusetts.
SAFETY INFORMATION
Continued
Heater Cabinet
Front Panel
Grill
Guard
Ignitor Button Control
Knob
Plaque
Figure 1 - Vent-Free Gas Heater
PRODUCT
IDENTIFICATION
UNPACKING
1. Remove heater from carton.
2. Remove all protective packaging applied
to heater for shipment.
3. Check heater for any shipping damage.
If heater is damaged, promptly return to
where you bought heater.
PRODUCT FEATURES
SAFETY DEVICE
This heater has a pilot with an Oxygen Deple-
tion Sensing (ODS) safety shutoff system. The
ODS/pilot is a required feature for vent-free
room heaters. The ODS/pilot shuts off the
heater if there is not enough fresh air.
IGNITION SYSTEM
This heater has an electronic ignitor to light
heater fuel supply.
THERMOSTATIC HEAT CONTROL
(Thermostat Models Only)
Thermostat models have a thermostat sensing
bulb and a control valve. This results in the
greatest heater comfort. This can also result
in lower gas bills.

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AIR FOR COMBUSTION
AND VENTILATION
WARNING: This heater shall
not be installed in a conned space
or unusually tight construction
unless provisions are provided
for adequate combustion and
ventilation air. Read the following
instructions to insure proper fresh
air for this and other fuel-burning
appliances in your home.
Today’s homes are built more energy efcient
than ever. New materials, increased insulation
and new construction methods help reduce
heat loss in homes. Home owners weather
strip and caulk around windows and doors to
keep the cold air out and the warm air in. Dur-
ing heating months, home owners want their
homes as airtight as possible.
While it is good to make your home energy
efcient, your home needs to breathe. Fresh
air must enter your home. All fuel-burning ap-
pliances need fresh air for proper combustion
and ventilation.
Exhaust fans, replaces, clothes dryers and
fuel burning appliances draw air from the house
to operate. You must provide adequate fresh
air for these appliances. This will insure proper
venting of vented fuel-burning appliances.
PROVIDING ADEQUATE
VENTILATION
The following are excerpts from National Fuel
Gas Code, ANSI Z223.1/NFPA 54, Section
5.3, Air for Combustion and Ventilation.
All spaces in homes fall into one of the three
following ventilation classications:
1. Unusually Tight Construction
2. Unconned Space
3. Conned Space
The information on pages 5 through 7 will help
you classify your space and provide adequate
ventilation.
Unusually Tight Construction
The air that leaks around doors and windows
may provide enough fresh air for combustion
and ventilation. However, in buildings of un-
usually tight construction, you must provide
additional fresh air.
Unusually tight construction is dened as
construction where:
a. walls and ceilings exposed to the outside
atmosphere have a continuous water
vapor retarder with a rating of one perm
(6 x 10-11 kg per pa-sec-m2) or less with
openings gasketed or sealed and
b. weather stripping has been added on
openable windows and doors and
c. caulking or sealants are applied to areas
such as joints around window and door
frames, between sole plates and oors,
between wall-ceiling joints, between wall
panels, at penetrations for plumbing, electri-
cal and gas lines and at other openings.
If your home meets all of these three criteria,
you must provide additional fresh air. See
Ventilation Air From Outdoors, page 7.
If your home does not meet all of the three
criteria above, proceed to Determining Fresh-
Air Flow For Heater Location, page 6.
Conned and Unconned Space
The National Fuel Gas Code, ANSI Z223.1/
NFPA 54 denes a conned space as a space
whose volume is less than 50 cubic feet per
1,000 Btu per hour (4.8 m3 per kw) of the ag-
gregate input rating of all appliances installed
in that space and an unconned space as a
space whose volume is not less than 50 cubic
feet per 1,000 Btu per hour (4.8 m3 per kw)
of the aggregate input rating of all appliances
installed in that space. Rooms communicating
directly with the space in which the appliances
are installed*, through openings not furnished
with doors, are considered a part of the un-
conned space.
* Adjoining rooms are communicating only if
there are doorless passageways or ventilation
grills between them.

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DETERMINING FRESH-AIR FLOW
FOR HEATER LOCATION
Determining if You Have a Conned or
Unconned Space
Use this work sheet to determine if you have
a conned or unconned space.
Space: Includes the room in which you will install
heater plus any adjoining rooms with doorless
passageways or ventilation grills between the
rooms.
1. Determine the volume of the space (length
x width x height).
Length x Width x Height =__________cu. ft.
(volume of space)
Example: Space size 20 ft. (length) x 16 ft.
(width) x 8 ft. (ceiling height) = 2560 cu. ft.
(volume of space)
If additional ventilation to adjoining room
is supplied with grills or openings, add the
volume of these rooms to the total volume
of the space.
2. Multiply the space volume by 20 to determine
the maximum Btu/Hr the space can support.
________ (volume of space) x 20 = (Maxi-
mum Btu/Hr the space can support)
Example: 2560 cu. ft. (volume of space) x 20
= 51,200 (maximum Btu/Hr the space can
support)
3. Add the Btu/Hr of all fuel burning appliances
in the space.
Vent-free heater ___________Btu/Hr
Gas water heater* ___________Btu/Hr
Gas furnace ___________Btu/Hr
Vented gas heater ___________Btu/Hr
Gas replace logs ___________Btu/Hr
Other gas appliances* +__________Btu/Hr
Total =__________Btu/Hr
* Do not include direct-vent gas appliances.
Direct-vent draws combustion air from the
outdoors and vents to the outdoors.
Example:
Gas water heater __________ Btu/Hr
Vent-free heater + _________ Btu/Hr
Total = _________ Btu/Hr
AIR FOR COMBUSTION
AND VENTILATION
Continued
4. Compare the maximum Btu/Hr the space can
support with the actual amount of Btu/Hr used.
_______ Btu/Hr (maximum can support)
_______ Btu/Hr (actual amount used)
Example: 51,200 Btu/Hr (maximum the
space can support)
60,000 Btu/Hr (actual amount of
Btu/Hr used)
The space in the above example is a conned
space because the actual Btu/Hr used is more
than the maximum Btu/Hr the space can sup-
port. You must provide additional fresh air. Your
options are as follows:
A. Rework worksheet, adding the space of an
adjoining room. If the extra space provides an
unconned space, remove door to adjoining
room or add ventilation grills between rooms.
See Ventilation Air From Inside Building.
B. Vent room directly to the outdoors. See
Ventilation Air From Outdoors, page 7.
C. Install a lower Btu/Hr heater, if lower Btu/Hr
size makes room unconned.
If the actual Btu/Hr used is less than the maxi-
mum Btu/Hr the space can support, the space is
an unconned space. You will need no additional
fresh air ventilation.
WARNING: If the area in
which the heater may be oper-
ated is smaller than that dened
as an unconned space or if the
building is of unusually tight
construction, provide adequate
combustion and ventilation air
by one of the methods described
in the National Fuel Gas Code,
ANSI Z223.1/NFPA54 Section 5.3
or applicable local codes.
VENTILATION AIR
Ventilation Air From Inside Building
This fresh air would come from an adjoining
unconned space. When ventilating to an
adjoining unconned space, you must provide
two permanent openings: one within 12" of the
ceiling and one within 12" of the oor on the
wall connecting the two spaces (see options 1
and 2, Figure 2, page 7). You can also remove
door into adjoining room (see option 3, Figure
2, page 7). Follow the National Fuel Gas
Code, ANSI Z223.1/NFPA 54, Section 5.3, Air
for Combustion and Ventilation for required
size of ventilation grills or ducts.
40,000
20,000
60,000

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AIR FOR COMBUSTION
AND VENTILATION
Continued
Ventilation Air From Outdoors
Provide extra fresh air by using ventilation
grills or ducts. You must provide two perma-
nent openings: one within 12" of the ceiling
and one within 12" of the oor. Connect these
items directly to the outdoors or spaces open
to the outdoors. These spaces include attics
and crawl spaces. Follow the National Fuel
Gas Code, ANSI Z223.1/NFPA 54, Section
5.3, Air for Combustion and Ventilation for
required size of ventilation grills or ducts.
IMPORTANT: Do not provide openings for
inlet or outlet air into attic if attic has a thermo-
stat-controlled power vent. Heated air entering
the attic will activate the power vent.
Figure 2 - Ventilation Air from Inside
Building
Figure 3 - Ventilation Air from Outdoors
INSTALLATION
NOTICE: This heater is intended
for use as supplemental heat. Use
this heater along with your primary
heating system. Do not install this
heater as your primary heat source.
If you have a central heating system,
you may run system’s circulating
blower while using heater. This will
help circulate the heat throughout
the house. In the event of a power
outage, you can use this heater as
your primary heat source.
WARNING: A qualied ser-
vice person must install heater.
Follow all local codes.
CHECK GAS TYPE
Use only the correct type of gas (natural or
propane/LP). If your gas supply is not the correct
gas type, do not install heater. Call dealer where
you bought heater for proper type heater.
This appliance is only for use with
the type of gas indicated on the rat-
ing plate. This appliance is not con-
vertible for use with other gases.
WARNING: This appliance
is equipped for (natural or pro-
pane/LP) gas. Field conversion
is not permitted.
INSTALLATION ITEMS
Before installing heater, make sure you have
the items listed below.
• for propane/LP gas, external regulator
(supplied by installer)
• piping (check local codes)
• sealant (resistant to propane/LP gas)
• equipment shutoff valve *
• ground joint union
• sediment trap
• tee joint
• pipe wrench
• for natural gas, test gauge connection*
* A CSA design-certied equipment shutoff valve
with 1/8" NPT tap is an acceptable alternative to
test gauge connection. The optional CSA design-
certied equipment shutoff valve can be purchased
from your dealer. See Accessories, page 26.
Outlet
Air
Ventilated
Attic
Outlet
A
ir
Inlet
Air
Inlet Air Ventilated
Crawl Space
To
Crawl
Space
To Attic
Or
Remove
Door into
Adjoining
Room,
Option 3
Ventilation Grills
Into Adjoining Room,
Option 2
12"
12"
Ventilation
Grills into
Adjoining
Room,
Option 1

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CAUTION: This heater cre-
ates warm air currents. These
currents move heat to wall sur-
faces next to heater. Installing
heater next to vinyl or cloth wall
coverings or operating heater
where impurities (such as, but
not limited to, tobacco smoke,
aromatic candles, cleaning u-
ids, oil or kerosene lamps, etc.) in
the air exist, may discolor walls
or cause odors.
IMPORTANT: Vent-free heaters add moisture
to the air. Although this is benecial, installing
heater in rooms without enough ventilation
air may cause mildew to form from too much
moisture. See Air for Combustion and Ventila-
tion, page 5. If high humidity is experienced,
a dehumidier may be used to help lower the
water vapor content in the air.
For convenience and efciency, install heater
• where there is easy access for operation,
inspection and service
• in coldest part of room
An optional fan kit is available from your
dealer. See Accessories, page 26. If planning
to use fan, locate heater near an electrical
outlet.
THERMOSTAT SENSING BULB
(Thermostat Models Only)
The thermostat sensing bulb has been placed
below the heater.
1. Place clamp on thermostat sensing bulb
as shown in Figure 5. Clamp is provided
in hardware package.
2. Snap clamp into upper mounting hole
as shown in Figure 5. Mounting hole is
located on lower left edge on back of
heater. Make sure the thermostat sensing
bulb is pointing up.
INSTALLATION
Continued
Figure 5 - Attaching Thermostat Sensing
Bulb
Clamp
Thermostat
Sensing
Bulb
LOCATING HEATER
WARNING: Maintain the
minimum clearances shown
in Figure 4. If you can, provide
greater clearances from oor,
ceiling and joining wall.
You can locate heater on the oor, away from
a wall. A wall mounting bracket and oor base
stand are included with this heater. Determine
which method is best for your application.
WARNING: Never install the
heater
• in a bedroom or bathroom
• in a recreational vehicle
• wherecurtains,furniture,cloth-
ing or other ammable objects
are less than36" from the front,
top or sides of the heater
• as a replace insert
• in high trafc areas
• in windy or drafty areas
CAUTION: If you install the
heater in a home garage
• heater pilot and burner must
be at least 18" above oor
• locate heater where moving
vehicle will not hit it
Figure 4 - Mounting Clearances As
Viewed From Front of Heater
Minimum
From
Sides Of
Heater
36"
2"
FLOOR
CEILING
Minimum
Minimum To
Top Surface
Of Carpeting,
Tile Or Other
Combustible
Material
Left
Side
Right
Side
10"

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INSTALLING HEATER TO WALL
Mounting Bracket
Locate mounting bracket in heater carton. Re-
move mounting bracket from heater carton.
Figure 6 - Mounting Bracket
INSTALLATION
Continued
Removing Front Panel Of Heater
1. Remove the four painted screws, two on
each side of front panel.
2. Pull bottom of front panel forward, then out.
3. Remove any remaining packaging materials.
Figure 7 - Removing Front Panel Of
Heater
Screw
Front Panel
Marking Screw Locations
1. Tape mounting bracket to wall where
heater will be located. Make sure mount-
ing bracket is level.
WARNING:Maintainminimum
clearances shown in Figure 8. If
you can, provide greater clearanc-
es from oor and joining wall.
2. Mark screw locations on wall (see Figure 8).
Note: Only mark last hole on each end of
mounting bracket. Insert mounting screws
through these holes only.
3. Remove tape and mounting bracket from
wall.
4 and 5 Plaque Heaters
3 Plaque Heater
Figure 8 - Mounting Bracket Clearances
Attaching Mounting Bracket To Wall
Note: Wall anchors, mounting screws and
spacers are in hardware package. The hard-
ware package is provided with heater.
16"
Min.
14"
12"
Min.
Adjoining Wall
14"
Adjoining Wall
Only Insert Mounting
Screws Through Last
Hole On Each End
Only Insert Mounting
Screws Through Last
Hole On Each End
Floor Floor
25 3/4"
Optional
19 3/4"
Min.
25 3/4"
Optional
19 3/4"
Min.
16"
Min.
14"
12"
Min.
Adjoining Wall
14"
Adjoining Wall
Only Insert Mounting
Screws Through Last
Hole On Each End
Only Insert Mounting
Screws Through Last
Hole On Each End
Floor Floor
25
3
/ 4 "
Optional
19
3
/ 4 "
Min.
25
3
/ 4 "
Optional
19
3
/ 4 "
Min.
Methods For Attaching Mounting Bracket
To Wall
Only use last hole on each end of mounting
bracket to attach bracket to wall. These two
holes are 14" apart from their centers. Attach
mounting bracket to wall in one of two ways:
1. Attaching to wall stud
2. Attaching to wall anchor
Attaching to Wall Stud: This method provides
the strongest hold. Insert mounting screws
through mounting bracket and into wall
studs.
Attaching to Wall Anchor: This method allows
you to attach mounting bracket to hollow walls
(wall areas between studs) or to solid walls
(concrete or masonry).
Decide which method better suits your needs.
Either method will provide a secure hold for
the mounting bracket.

www.desatech.com 119342-01B10
Attaching To Wall Stud Method
For attaching mounting bracket to wall studs
1. Drill holes at marked locations using 9/64"
drill bit.
2. Place mounting bracket onto wall. Line
up last hole on each end of bracket with
holes drilled in wall.
3. Insert mounting screws through bracket
and into wall studs.
4. Tighten screws until mounting bracket is
rmly fastened to wall studs.
Attaching To Wall Anchor Method
For attaching mounting bracket to hollow
walls (wall areas between studs) or solid walls
(concrete or masonry)
1. Drill holes at marked locations using
5/16" drill bit. For solid walls (concrete or
masonry), drill at least 1" deep.
2. Fold wall anchor as shown in Figure 9.
3. Insert wall anchor (wings rst) into hole.
Tap anchor ush to wall.
4. For thin walls (1/2" or less), insert red key
into wall anchor. Push red key to “pop” open
anchor wings. IMPORTANT: Do not ham-
mer key! For thick walls (over 1/2" thick) or
solid walls, do not pop open wings.
5. Place mounting bracket onto wall. Line up
last hole on each end of bracket with wall
anchors.
6. Insert mounting screws through bracket
and into wall anchors.
7. Tighten screws until mounting bracket is
rmly fastened to wall.
INSTALLATION
Continued
Figure 9 - Folding
Anchor
Figure 10 - Popping
Open Anchor Wings
For Thin Walls
Figure 11 - Mounting Heater Onto
Mounting Bracket
Mounting
Bracket
(attached
to wall)
Horizontal Slots
Stand-Out Tab
Placing Heater On Mounting Bracket
1. Locate two horizontal slots on back panel
of heater.
2. Place heater onto mounting bracket. Slide
horizontal slots onto stand-out tabs on
mounting bracket.
Installing Bottom Mounting Screws
1. Locate two bottom mounting holes. These
holes are near bottom on back panel of
heater (see Figure 12).
2. Mark screw locations on wall.
3. Remove heater from mounting bracket.
4. If installing bottom mounting screws into
hollow or solid wall, install wall anchors.
Follow steps 1 through 4 under Attaching
To Wall Anchor Method.
If installing bottom mounting screw into wall
stud, drill holes at marked locations using
9/64" drill bit.
5. Replace heater onto mounting bracket.
6. Place spacers between bottom mounting
holes and wall anchor or drilled hole.
7. Hold spacer in place with one hand. With other
hand, insert mounting screw through bottom
mounting hole and spacer. Place tip of screw
in opening of wall anchor or drilled hole.
8. Tighten both screws until heater is rmly
secured to wall. Do not over tighten.
Note: Do not replace front panel at this
time. Replace front panel after making
gas connections and checking for leaks
(see page 11).
Figure 12 - Installing Bottom Mounting
Screws
Side View
Front View
Wall
Spacer
Heater

www.desatech.com 11119342-01B
CONNECTING TO GAS SUPPLY
WARNING: This appliance
requires a 3/8" NPT (National
Pipe Thread) inlet connection to
the pressure regulator.
WARNING: A qualied service
person must connect heater to gas
supply. Follow all local codes.
WARNING: For natural
gas, never connect heater to
private (non-utility) gas wells.
This gas is commonly known
as wellhead gas.
IMPORTANT: For natural gas, check gas line
pressure before connecting heater to gas line.
Gas line pressure must be no greater than
10.5" of water. If gas line pressure is higher,
heater regulator damage could occur.
CAUTION: For propane/LP
gas, never connect heater di-
rectly to the propane/LP supply.
This heater requires an external
regulator (not supplied). Install
the external regulator between the
heater and propane/LP supply.
For propane/LP gas, the installer must supply
an external regulator. The external regulator
will reduce incoming gas pressure. You must
reduce incoming gas pressure to between 11"
and 14" of water. If you do not reduce incom-
ing gas pressure, heater regulator damage
could occur. Install the external regulator with
the vent pointing down as shown in Figure
14. Pointing the vent down protects it from
freezing rain or sleet.
INSTALLATION
Continued
MOUNTING HEATER TO FLOOR
Mounting Base Feet to Heater
1. Lay heater cabinet on its back on a table
with the heater bottom overhanging the
table edge.
2. Align holes in base foot with mounting holes
on bottom of cabinet (see Figure 13).
3. Secure base foot to heater using sheet
metal screws.
4. Repeat for other side.
Mounting Base Feet to Floor
1. Remove front cover (see Removing Front
Panel of Heater, page 9).
2. Position heater with base feet in desired
location. Mark holes for drilling. Remove
heater with base.
3. For carpeted oors, make a small cut with
a sharp knife at marked locations prior to
drilling. If mounting base to a wood oor,
drill 1/8" diameter hole, 3/4" deep. (Do not
use anchors in wood oors).
If mounting base to a concrete oor, drill
with 1/4" diameter concrete drill bit, 13/8"
into oor. Insert anchors completely into
holes.
4. Reposition heater with base feet over
holes. Secure base to oor with wood
screws. See Figure 13.
Figure 13 - Installing Base Feet
Wood
Screw
Sheet Metal Screw
Base Foot
Figure 14 - External Regulator With Vent
Pointing Down
External
Regulator
With Vent
Pointing
Down
Propane/LP
Supply Tank

www.desatech.com 119342-01B12
Tee Pipe Cap
Joint Nipple
CAUTION: Use only new,
black iron or steel pipe. Inter-
nally-tinned copper tubing may
be used in certain areas. Check
your local codes. Use pipe of
large enough diameter to allow
proper gas volume to heater. If
pipe is too small, undue loss of
volume will occur.
Typical Inlet Pipe Diameters
16,000 and 18,000 Btu/hr - 3/8" or greater
26,000 and 30,000 Btu/hr - 1/2" or greater
Installation must include equipment shutoff
valve, union and plugged 1/8" NPT tap. Locate
NPT tap within reach for test gauge hook up.
NPT tap must be upstream from heater (see
Figure 15).
IMPORTANT: Install an equipment shutoff
valve in an accessible location. The equip-
ment shutoff valve is for turning on or shutting
off the gas to the appliance.
Apply pipe joint sealant lightly to male NPT
threads. This will prevent excess sealant from
going into pipe. Excess sealant in pipe could
result in clogged heater valves.
WARNING: Use pipe joint
sealant that is resistant to liquid
petroleum (LP) gas.
Install sediment trap in supply line as shown
in Figure 15. Locate sediment trap where it
is within reach for cleaning. Locate sediment
trap where trapped matter is not likely to
freeze. A sediment trap traps moisture and
contaminants. This keeps them from going
into heater controls. If sediment trap is not
installed or is installed wrong, heater may
not run properly.
IMPORTANT: Hold the pressure regulator
with wrench when connecting it to gas pip-
ing and/or ttings. Do not over tighten pipe
connection to regulator. The regulator body
could be damaged.
INSTALLATION
Continued
Tee Joint
Reducer
Bushing to
1/8" NPT
1/8" NPT
Plug Tap
* A CSA design-certied equipment shutoff
valve with 1/8" NPT tap is an acceptable al-
ternative to test gauge connection. Purchase
the optional CSA design-certied equipment
shutoff valve from your dealer. See Acces-
sories, page 26.
Figure 15 - Gas Connection
Pressure
Regulator
Test Gauge Connection*
Heater
Cabinet
Sediment Trap
Equipment
Shutoff Valve*
3"
Min.
Natural Gas
From Gas
Meter (7" W.C.
to 10.5" W.C.
Pressure)
Propane/LP
From External
Regulator
(11" W.C. to 14"
W.C. Pressure)
Regulator
Bracket
Ground
Joint
Union
3/8" NPT
Pipe
Nipple
CHECKING GAS CONNECTIONS
WARNING: Test all gas piping
and connections, internal and
external to unit, for leaks after
installing or servicing. Correct
all leaks at once.
WARNING: Never use an
open ame to check for a leak.
Apply a noncorrosive leak detec-
tion uid to all joints. Bubbles
forming show a leak. Correct all
leaks at once.
CAUTION: For propane/LP
gas, make sure external regula-
tor has been installed between
propane/LP supply and heater.
See guidelines under Connect-
ing to Gas Supply, page 11.

www.desatech.com 13119342-01B
INSTALLATION
Continued
PRESSURE TESTING GAS SUPPLY
PIPING SYSTEM
Test Pressures In Excess Of 1/2 PSIG
(3.5 kPa)
1. Disconnect appliance with its appliance
main gas valve (control valve) and equip-
ment shutoff valve from gas supply piping
system. Pressures in excess of 1/2 psig
will damage heater regulator.
2. Cap off open end of gas pipe where equip-
ment shutoff valve was connected.
3. Pressurize supply piping system by either
opening propane/LP supply tank valve
for propane/LP gas or opening main gas
valve located on or near gas meter for
natural gas or using compressed air.
4. Check all joints of gas supply piping sys-
tem. Apply a noncorrosive leak detection
uid to all joints. Bubbles forming show a
leak.
5. Correct all leaks at once.
6. Reconnect heater and equipment shutoff
valve to gas supply. Check reconnected
ttings for leaks.
Test Pressures Equal To or Less Than 1/2
PSIG (3.5 kPa)
1. Close equipment shutoff valve (see Fig-
ure 16).
2. Pressurize supply piping system by either
opening propane/LP supply tank valve
for propane/LP gas or opening main gas
valve located on or near gas meter for
natural gas or using compressed air.
3. Check all joints from gas meter for natural
gas (see Figure 17) or propane/LP supply
tank for propane/LP gas, to equipment
shutoff valve (see Figure 18). Apply a
noncorrosive leak detection uid to all
joints. Bubbles forming show a leak.
4. Correct all leaks at once.
PRESSURE TESTING HEATER GAS
CONNECTIONS
1. Open equipment shutoff valve (see Fig-
ure 16).
2. For natural gas open main gas valve
located on or near gas meter. For pro-
pane/LP gas open propane/LP supply
tank valve.
3. Make sure control knob of heater is in the
OFF position.
4. Check all joints from equipment shutoff
valve to thermostat gas valve (see Figure
17 or 18). Apply a noncorrosive leak de-
tection uid to all joints. Bubbles forming
show a leak.
5. Correct all leaks at once.
6. Light heater (see Operating Heater, page
14). Check all other internal joints for
leaks.
7. Turn off heater (see To Turn Off Gas to
Appliance, page 15).
8. Replace front panel.
Figure 18 - Checking Gas Joints for
Propane/LP Gas
Figure 16 - Equipment Shutoff Valve
Equipment
Shutoff
Valve
Propane/LP
Supply Tank
Thermostat Gas Valve
Open
Closed
Equipment
Shutoff Valve
Figure 17 - Checking Gas Joints for
Natural Gas
Equipment
Shutoff Valve
Gas
Meter
Thermostat Gas Valve

www.desatech.com 119342-01B14
OPERATING HEATER
FOR YOUR SAFETY READ
BEFORE LIGHTING
WARNING: If you do not fol-
low these instructions exactly,
a re or explosion may result
causing property damage, per-
sonal injury or loss of life.
A. This appliance has a pilot which must
be lighted by hand. When lighting the pi-
lot, follow these instructions exactly.
B. BEFORE LIGHTING smell all around
the appliance area for gas. Be sure to
smell next to the oor because some
gas is heavier than air and will settle
on the oor.
WHAT TO DO IF YOU SMELL GAS
• Do not try to light any appliance.
• Do not touch any electric switch; do
not use any phone in your building.
• Immediately call your gas supplier
from a neighbor’s phone. Follow the
gas supplier’s instructions.
• If you cannot reach your gas supplier,
call the re department.
C. Use only your hand to push in or turn
the gas control knob. Never use tools.
If the knob will not push in or turn by
hand, don’t try to repair it, call a qualied
service technician. Force or attempted
repair may result in a re or explosion.
D. Do not use this appliance if any part
has been under water. Immediately call
a qualied service technician to inspect
the appliance and to replace any part of
the control system and any gas control
which has been under water.
LIGHTING
INSTRUCTIONS
1. STOP! Read the safety information above.
2. Make sure equipment shutoff valve is fully
open.
3. Turn off any electric power to the appli-
ance if service is to be performed.
4. Turn control knob clockwise to the
OFF position.
5. Wait ve (5) minutes to clear out any
gas. Then smell for gas, including near
the oor. If you smell gas, STOP! Follow
“B” in the safety information above. If you
don’t smell gas, go to the next step.
6. Thermostat Models: Turn control knob
counterclockwise to the PILOT
position. Press in control knob for ve (5)
seconds.
Manual Models: Press in and turn control
knob counterclockwise to the PI-
LOT position. Keep control knob pressed
in for ve (5) seconds.
7. With control knob pressed in, push down
and release ignitor button. This will light
pilot. The pilot is attached to the front of
burner.
Note: You may be running this heater
for the rst time after hooking up to gas
supply. If so, the control knob may need
to be pressed in for 30 seconds or more.
This will allow air to bleed from the gas
system.
If needed, keep pressing ignitor button
until pilot lights. If ignitor does not light
pilot, refer to Troubleshooting, page 18
or contact a qualied service person or
gas supplier for repairs. Until repairs are
made, light pilot with match. See Manual
Lighting Procedure, page 15.
8. Keep control knob pressed in for 30 sec-
onds after lighting pilot. After 30 seconds,
release control knob.
• If control knob does not pop up when
released, contact a qualified service
person or gas supplier for repairs.
Note: If pilot goes out, repeat steps 4 thru
7. Thermostat models have a safety inter-
lock system. Wait one (1) minute before
lighting pilot again.
9. Turn control knob counterclockwise
to desired heating level. The main
burner should light. Manual control heat-
ers should be used in locked positions.
WARNING: Always operate
manual control heaters at the
locked positions. Operation
between these positions may
create a possible health hazard
if used in a poorly ventilated
room. Read owner’s manual for
complete instructions.
CAUTION: Do not try to ad-
just heating levels by using the
equipment shutoff valve.

www.desatech.com 15119342-01B
OFF
Ignitor Button Control Knob
Figure 19 - Control Knob In The OFF
Position (Manual Controlled Models)
Figure 21 - Pilot
Ignitor Electrode
Pilot
Burner
Thermocouple
OPERATING HEATER
Continued
O
F
F
P
I
L
O
T
Figure 20 - Control Knob In The OFF
Position (Thermostat Models)
Control Knob
Ignitor Button
TO TURN OFF GAS
TO APPLIANCE
Shutting Off Heater
1. Turn control knob clockwise to the
OFF position.
2. Turn off any electric power to the appli-
ance if service is to be performed.
Shutting Off Burner Only (pilot stays lit)
Turn control knob clockwise to the
PILOT position.
MANUAL LIGHTING
PROCEDURE
1. Remove front panel (see page 9).
2. Follow steps 1 through 7 under Lighting
Instructions, page 14.
3. With control knob pressed in, strike match.
Hold match to pilot until pilot lights.
4. Keep control knob pressed in for 30 sec-
onds after lighting pilot. After 30 seconds,
release control knob. Now follow step 9,
under Lighting Instructions, page 14.
5. Replace front panel.
THERMOSTAT
OPERATION
The thermostatic control used on these
models differs from standard thermostats.
Standard thermostats simply turn on and off
the burner. The thermostat used on this heater
senses the room temperature. At times the
room may exceed the set temperature. If so,
the burner will shut off. The burner will cycle
back on when room temperature drops below
the set temperature. The control knob can be
set to any heating level between 1 and 5. All
plaques will turn off and on.
Note: The thermostat sensing bulb mea-
sures the temperature of air near the heater
cabinet. This may not always agree with
room temperature (depending on housing
construction, installation location, room size,
open air temperatures, etc.) Frequent use of
your heater will let you determine your own
comfort levels.
TO SELECT
HEATING LEVEL
WARNING: When running
heater, set control knob at LOW,
MEDIUM or HIGH locked posi-
tions. Never set control knob
between locked positions. Poor
combustion and higher levels of
carbon monoxide may result.
CAUTION: Do not try to ad-
just heating levels by using the
equipment shutoff valve.

www.desatech.com 119342-01B16
OPERATING HEATER
Continued
Slightly press in control knob and turn coun-
terclockwise to the LOW, MED or HI
positions (see Figure 22 or 23).
IMPORTANT: Release downward pressure
while turning control knob. Control knob will
lock at the desired position.
LOW
HI
OFF
MED
Control 16,000 & 26,000 &
Knob 18,000 Btu/Hr 30,000 Btu/Hr
Figure 22 - Burner Patterns for Manual
Controlled Models
Figure 23 - Burner Patterns for
Thermostat Models
Control 16,000 & 26,000 &
Knob 18,000 Btu/Hr 30,000 Btu/Hr
Thermocouple Pilot Burner
Pilot Burner
Thermocouple
Blue Flame
Yellow Flame
Figure 24 - Correct Pilot Flame Pattern
Figure 25 - Incorrect Pilot Flame Pattern
Figure 26 - Correct Burner Flame Pattern
INSPECTING HEATER
Check pilot ame pattern and burner ame
pattern often.
PILOT FLAME PATTERN
Figure 24 shows a correct pilot ame pattern.
Figure 25 shows an incorrect pilot ame pat-
tern. The incorrect pilot ame is not touching
the thermocouple. This will cause the thermo-
couple to cool. When the thermocouple cools,
the heater will shut down.
If pilot ame pattern is incorrect, as shown
in Figure 25 Figure 27 - Incorrect Burner Flame
Pattern
• turn heater off (see To Turn Off Gas to Ap-
pliance, page 15)
• see Troubleshooting, page 18
Note: The pilot ame on natural gas units will
have a slight curve, but ame should be blue
and have no yellow or orange color.
BURNER FLAME PATTERN
Figure 26 shows a correct burner ame pat-
tern. Figure 27 shows an incorrect burner
ame pattern.
If burner ame pattern is incorrect, as shown
in Figure 27
• turn heater off (see To Turn Off Gas to Ap-
pliance, page 15)
• see Troubleshooting, page 18

www.desatech.com 17119342-01B
CLEANING AND
MAINTENANCE
WARNING: Turn off heater
and let cool before cleaning.
CAUTION: You must keep
control areas, burner and circu-
lating air passageways of heater
clean. Inspect these areas of
heater before each use. Have
heater inspected yearly by a
qualied service person. Heater
may need more frequent clean-
ing due to excessive lint from
carpeting, bedding material, pet
hair, etc.
WARNING: Failure to keep
the primary air opening(s) of
the burner(s) clean may result in
sooting and property damage.
ODS/PILOT AND BURNER
Use a vacuum cleaner, pressurized air or
small, soft bristled brush to clean.
BURNER PILOT AIR INLET
The primary air inlet holes allow the proper
amount of air to mix with the gas. This pro-
vides a clean burning ame. Keep these holes
clear of dust, dirt and lint. Clean these air inlet
holes prior to each heating season. Blocked
air holes will create soot. We recommend that
you clean the unit every three months during
operation and have heater inspected yearly
by a qualied service person.
We also recommend that you keep the burner
tube and pilot assembly clean and free of dust
and dirt. To clean these parts we recommend
using compressed air no greater than 30 PSI.
Your local computer store, hardware store or
home center may carry compressed air in a
can. If using compressed air in a can, please
follow the directions on the can. If you don’t
follow directions on the can, you could dam-
age the pilot assembly.
1. Shut off the unit, including the pilot. Allow
the unit to cool for at least thirty min-
utes.
2. Inspect burner, pilot for dust and dirt.
3. Blow air through the ports/slots and holes
in the burner.
4. Never insert objects into the pilot tube.
Clean the pilot assembly also. A yellow tip on
the pilot ame indicates dust and dirt in the
pilot assembly. There is a small pilot air inlet
about two inches from where the pilot ame
comes out of the pilot assembly (see Figure
28). With the unit off, lightly blow air through
the air inlet. You may blow through a drinking
straw if compressed air is not available.
CABINET
Air Passageways
Use pressurized air to clean.
Exterior
Use a soft cloth dampened with a mild soap
and water mixture. Wipe the cabinet to re-
move dust.
Figure 28 - Pilot Air Inlet
Pilot Assembly
Pilot Air Inlet

www.desatech.com 119342-01B18
TROUBLESHOOTING
WARNING: Turn off and unplug heater and let cool before servicing.
Only a qualied service person should service and repair heater.
CAUTION: Never use a wire, needle or similar object to clean
ODS/pilot. This can damage ODS/pilot unit.
Note: All troubleshooting items are listed in order of operation.
POSSIBLE CAUSE
1. Ignitor electrode positioned
wrong
2. Ignitor electrode broken
3. Ignitor electrode not con-
nected to ignitor cable
4. Ignitor cable pinched or
wet
5. Broken ignitor cable
6. Bad ignitor
7. Battery not installed, battery
power low or battery not
installed correctly
1. Gas supply turned off or
equipment shutoff valve
closed
2. Control knob not fully
pressed in while pressing
ignitor button
3. Air in gas lines when in-
stalled
4. Depleted gas supply (pro-
pane/LP gas)
5. ODS/pilot is clogged
6. Gas regulator setting is not
correct
7. Control knob is not in pilot
position
REMEDY
1. Replace pilot assembly
2. Replace pilot assembly
3. Reconnect ignitor cable
4. Free ignitor cable if pinched
by any metal or tubing.
Keep ignitor cable dry
5. Replace ignitor cable
6. Replace ignitor
7. Install new alkaline battery
in electronic ignitor. Verify
battery is installed correctly
1. Turn on gas supply or open
equipment shutoff valve
2. Turn to PILOT position. Fully
press in control knob while
pressing ignitor button
3. Continue holding down
control knob. Repeat ignit-
ing operation until air is
removed
4. Contact local propane/LP
gas company
5. Clean ODS/pilot (see Clean-
ing and Maintenance, page
17) or replace ODS/pilot
assembly
6. Replace gas regulator
7. Turn control knob to pilot
position
OBSERVED PROBLEM
When ignitor button is
pressed in, there is no spark
at ODS/pilot
When ignitor button is
pressed in, there is a spark
at ODS/Pilot but no ignition

www.desatech.com 19119342-01B
TROUBLESHOOTING
Continued
POSSIBLE CAUSE
1. Control knob not fully
pressed in
2. Control knob not pressed in
long enough
3. Equipment shutoff valve not
fully open
4. Thermocouple connection
loose at control valve
5. Pilot flame not touching
thermocouple, which allows
thermocouple to cool, caus-
ing pilot ame to go out. This
problem could be caused by
one or both of the following:
A) Low gas pressure
B) Dirty or partially clogged
ODS/pilot
6. Thermocouple damaged
7. Control valve damaged
8. Safety interlock system has
been triggered (thermostat
models only)
1. Burner orifice(s) is
clogged
2. Inlet gas pressure is too
low
1. Manifold pressure is too
low
2. Burner orifice(s) is
clogged
1. Burner orice(s) is clogged
or damaged
2. Burner damaged
3. Gas regulator defective
1. Plaque damaged
2. Inlet gas pressure is too
low
3. Control knob set between
locked positions
1. Residues from manufactur-
ing processes
REMEDY
1. Press in control knob fully
2. After ODS/pilot lights, keep
control knob pressed in 30
seconds
3. Fully open equipment shut-
off valve
4. Hand tighten until snug,
then tighten 1/4 turn more
5. A) Contact local natural or
propane/LP gas company
B) Clean ODS/pilot (see
Cleaning and Maintenance,
page 17) or replace ODS/
pilot assembly
6. Replace pilot assembly
7. Replace control valve
8. Wait one minute for safety
interlock system to reset.
Repeat ignition operation
1. Clean burner orice(s) (see
Cleaning and Maintenance,
page 17) or replace burner
orice(s)
2. Contact local natural or
propane/LP gas company
1. Contact local natural or
propane/LP gas company
2. Clean burner orice(s) (see
Cleaning and Maintenance,
page 17) or replace burner
orice(s)
1. Clean burner orice(s) (see
Cleaning and Maintenance,
page 17) or replace burner
orice(s)
2. Replace burner
3. Replace gas regulator
1. Replace burner
2. Contact local natural or
propane/LP gas company
3. Turn control knob until it
locks at desired setting
1. Problem will stop after a few
hours of operation
OBSERVED PROBLEM
ODS/pilot lights but ame
goes out when control knob
is released
Burner(s) does not light after
ODS/pilot is lit
Delayed ignition of
burner(s)
Burner backfiring during
combustion
Burner plaque(s) does not
glow
Slight smoke or odor during
initial operation

www.desatech.com 119342-01B20
TROUBLESHOOTING
Continued
POSSIBLE CAUSE
1. Metal expanding while
heating or contracting while
cooling
1. When heated, vapors from
furniture polish, wax, carpet
cleaner, etc., may turn into
white powder residue
1. Heater burning vapors from
paint, hair spray, glues, etc. See
IMPORTANT statement above
2. Low fuel supply (propane/
LP gas)
3. Gas leak. See Warning
statement at top of page
1. Not enough fresh air is
available
2. Low line pressure
3. O DS/pi l o t i s parti a l l y
clogged
1. Gas leak. See Warning
statement at top of page
2. Control valve defective
1. Foreign matter between
control valve and burner
2. Gas leak. See Warning
statement at top of page
1. Not enough combustion/
ventilation air
REMEDY
1. This is normal with most
heaters. If noise is exces-
sive, contact qualied ser-
vice person
1. Turn heater off when us-
ing furniture polish, wax,
carpet cleaners or similar
products
1. Ventilate room. Stop us-
ing odor causing products
while heater is running
2. Rell supply tank
3. Locate and correct all leaks
(see Checking Gas Con-
nections, page 12)
1. Open window and/or door
for ventilation
2. Contact local natural or
propane/LP gas company
3. Clean ODS/pilot (see
Cleaning and Maintenance,
page 17)
1. Locate and correct all leaks
(see Checking Gas Con-
nections, page 12)
2. Replace control valve
1. Take apart gas tubing and
remove foreign matter
2. Locate and correct all leaks
(see Checking Gas Con-
nections, page 12)
1. Refer to Air for Combustion
and Ventilation require-
ments (page 5)
OBSERVED PROBLEM
Heater produces a clicking/
ticking noise just after burner
is lit or shut off
White powder residue form-
ing within burner box or on
adjacent walls or furniture
Heater produces unwanted
odors
Heater shuts off in use (ODS
operates)
Gas odor even when control
knob is in OFF position
Gas odor during combus-
tion
Moisture/condensation no-
ticed on windows
WARNING: If you smell gas
• Shut off gas supply.
• Do not try to light any appliance.
• Do not touch any electrical switch; do not use any phone in your building.
• Immediately call your gas supplier from a neighbor’s phone. Fol-
low the gas supplier’s instructions.
• If you cannot reach your gas supplier, call the re department.
IMPORTANT: Operating heater where impurities in air exist may create odors. Cleaning sup-
plies, paint, paint remover, cigarette smoke, cements and glues, new carpet or textiles, etc.,
create fumes. These fumes may mix with combustion air and create odors.