Desa NY108 Original instructions

MODELS
NY108 AND NY109
UNVENTED (VENT-FREE) BLUE FLAME GAS HEATER
SAFETY INFORMATION AND INSTALLATION MANUAL
Actual heater may
vary from illustration
For more information, visit www.desatech.com
WARNING: If the information in this manual is not fol-
lowed exactly, a fire or explosion may result causing
property damage, personal injury or loss of life.
— Do not store or use gasoline or other flammable
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.
• Immediatelycallyourgassupplierfromaneighbor’s
phone. Follow the gas supplier’s instructions.
• If you cannot reach your gas supplier, call the fire
department.
— Installation and service must be performed by a quali-
fied 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,serviceormainte-
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 qualified
installer,serviceagencyor
the gas supplier.
WARNING: This is an
unvented gas-fired heat-
er. It uses air (oxygen)
from the room in which
it is installed. Provisions
for adequate combustion
and ventilation air must
be provided. Refer to Air
for Combustion and Ven-
tilation 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-
stalledinanaftermarket,*
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
contains and/or generates
chemicals known to the State
of California to cause cancer or
birth defects or other reproduc-
tive harm.
IMPORTANT: Read this owner’s
manualcarefullyandcompletely
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.
TABLE OF CONTENTS
Safety Information ............................................... 2
Local Codes......................................................... 4
Product Identification........................................... 4
Unpacking............................................................ 4
Product Features................................................. 4
Air For Combustion and Ventilation..................... 5
Installation ........................................................... 7
Operating Heater............................................... 15
Inspecting Heater .............................................. 17
Cleaning and Maintenance................................18
Troubleshooting................................................. 19
Specifications .................................................... 23
Service Hints ..................................................... 23
Replacement Parts............................................ 23
Technical Service............................................... 23
Service Publications.......................................... 23
Illustrated Parts Breakdown and Parts List........ 24
Wiring Diagrams................................................ 26
Accessories....................................................... 26
Parts Centrals.................................................... 27
Warranty Information...........................Back Cover

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119169-01E 3
DANGER:Carbonmonoxide
poisoning may lead to death!
Carbon MonoxidePoisoning: Earlysigns of car-
bonmonoxidepoisoning resemble the flu,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 influence
of alcohol and those at high altitudes.
Natural and Propane/LP Gas: Natural and pro-
pane/LPgases are fuel gases. Fuel gases are
odorless. An odor-making agent is added to
fuel gases. The odor helps you detect a fuel
gas leak. However, the odor added to fuel
gas can fade. Fuel 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
blower insert, heat exchanger
insertorotheraccessorynotap-
proved for use with this heater.
Due to high temperatures, the
applianceshouldbelocatedout
oftrafficandawayfromfurniture
and draperies.
Do not place clothing or other
flammable material on or near
the appliance. Never place any
objects on the heater.
Surfaceofheater becomesvery
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 flam-
mable vapors and liquids.
1. Thisapplianceisonlyforusewiththetype
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 touchany electrical switch; donot
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 fire department
5.
This heater needs fresh, outside air ventila-
tionto run properly.This heaterhasanOxy-
genDepletionSensing(ODS) safetyshutoff
system. The ODS shuts down the heater if
notenoughfreshair is available. See Air for
Combustion and Ventilation, page 5.
6. Keep all air openings in front and bottom
of heater clear and free of debris. This will
insure enough air for proper combustion.
7. If heater shuts off, do not relight until you
provide fresh, outside air. If heater keeps
shutting off, have it serviced.
SAFETY INFORMATION
Continued

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8. Do not run heater
• where flammable liquids or vapors are
used or stored
• under dusty conditions
9. Before using furniture polish, wax, carpet
cleanerorsimilarproducts,turnheateroff.If
heated,thevaporsfromtheseproductsmay
createawhitepowderresiduewithin burner
box or on adjacent walls or furniture.
10. Do not use heater if any part has been
under water. Immediately call a qualified
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.
11. Turnoffandletcoolbeforeservicing.Only
a qualified service person should service
and repair heater.
12. Operating heater above elevations of
4,500 feet could cause pilot outage.
13. Toprevent performance problems, do not
usepropane/LPfueltankof less than 100
lbs. capacity.
14. Provide adequate clearances around air
openings.
LOCAL CODES
Install and use heater with care. Follow all lo-
cal codes. In the absence of local codes, use
the latest edition of 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 fitter in the Commonwealth of Mas-
sachusetts.
Sellers of unvented propane or natural
gas-fired 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
Figure 1 - Vent-Free Gas Heater
Ignitor ButtonControl Knob
Heater
Cabinet
Front Panel Glass Panel Grill Guard
PRODUCT
IDENTIFICATION
UNPACKING
1. Remove heater from carton.
2. Remove all protective packaging applied
to heater for shipment.
3. Checkheater for any shippingdamage.If
heaterisdamaged, promptly informdealer
where you bought heater.
PRODUCT FEATURES
SAFETY DEVICE
Thisheaterhas a pilot with an OxygenDeple-
tionSensing(ODS) safety shutoffsystem.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.
PIEZO IGNITION SYSTEM
Thisheaterhas a piezo ignitor.Thissystemre-
quiresno matches, batteries or other sources
to light heater.
THERMOSTATIC HEAT CONTROL
Thermostat models have a thermostat sens-
ingbulbandacontrolvalve.This results in the
greatest heater comfort. This can also result
in lower gas bills.

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119169-01E 5
AIR FOR COMBUSTION
AND VENTILATION
WARNING: This heater shall
not be installed in a confined
space or unusually tight con-
struction unless provisions are
provided for adequate combus-
tionandventilationair.Readthe
following instructions to insure
proper fresh air for this and
other fuel-burning appliances
in your home.
Today’shomes are builtmore energy efficient
thanever. New materials, increasedinsulation
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.
During heating months, home owners want
their homes as airtight as possible.
While it is good to make your home energy
efficient, your home needs to breathe. Fresh
air must enter your home.All fuel-burning ap-
pliancesneed fresh air for proper combustion
and ventilation.
Exhaust fans, fireplaces, clothes dryers and
fuelburningappliancesdrawairfromthehouse
to operate. You must provide adequate fresh
airforthese appliances.Thiswillinsureproper
venting of vented fuel-burning appliances.
PROVIDING ADEQUATE
VENTILATION
The following are excerptsfrom 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 classifications:
1. Unusually Tight Construction
2. Unconfined Space
3. Confined Space
Theinformationonpages5through7will help
youclassifyyourspaceandprovideadequate
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 defined 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 floors,
between wall-ceiling joints, between wall
panels,atpenetrationsforplumbing,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
criteriaabove,proceedto Determining Fresh-
Air Flow For Heater Location, page 6.
Confined and Unconfined Space
The National Fuel Gas Code, ANSI Z223.1/
NFPA54definesaconfinedspaceasaspace
whose volume is less than 50 cubic feet per
1,000 Btu per hour (4.8 m3per kw) of the ag-
gregateinput rating of all appliancesinstalled
in that space and an unconfined space as a
spacewhosevolume is not less than 50 cubic
feet per 1,000 Btu per hour (4.8 m3per kw)
of the aggregate input rating of all appliances
installedinthatspace. Rooms communicating
directlywiththespaceinwhichtheappliances
areinstalled*,throughopenings not furnished
with doors, are considered a part of the un-
confined space.
* Adjoining rooms are communicating only if
therearedoorlesspassagewaysor ventilation
grills between them.

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AIR FOR COMBUSTION
AND VENTILATION
Continued
DETERMINING FRESH-AIR FLOW
FOR HEATER LOCATION
Determining if You Have a Confined or
Unconfined Space
Use this work sheet to determine if you have
a confined or unconfined space.
Space: Includesthe room in which youwill 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).
LengthxWidthx Height =__________cu. ft.
(volume of space)
Example: Space size 20 ft. (6.1 m) (length)
x 16 ft. (4.88 m) (width) x 8 ft. (2.44 m)
(ceiling height) = 2560 cu. ft. (72.49 m3)
(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. (72.49 m3) (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 fireplace 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
40,000
20,000
60,000
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)
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 confined
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
anunconfined space,removedoor toadjoin-
ing room or add ventilation grills between
rooms. See Ventilation Air From Inside
Building, page 7.
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 unconfined.
If the actual Btu/Hr used is less than the maxi-
mum Btu/Hr the space can support, the space is
anunconfined space.You will needno additional
fresh air ventilation.
WARNING:Iftheareainwhich
the heater may be operated is
smaller than that defined as
an unconfined space or if the
building is of unusually tight
construction, provide adequate
combustion and ventilation air
byoneofthemethodsdescribed
in the National Fuel Gas Code,
ANSIZ223.1/NFPA54Section5.3
or applicable local codes.

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119169-01E 7
Figure 3 - Ventilation Air from Outdoors
VENTILATION AIR
Ventilation Air From Inside Building
This fresh air would come from an adjoining
unconfined space. When ventilating to an
adjoiningunconfinedspace, you must provide
twopermanentopenings:onewithin12"(30.5
cm)oftheceilingandonewithin12"(30.5cm)
of the floor on the wall connecting the two
spaces (see options 1 and 2, Figure 2). You
canalsoremove door into adjoining room(see
option 3, Figure 2). 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.
Figure 2 - Ventilation Air from Inside
Building
Or
Remove
Door into
Adjoining
Room,
Option 3
Ventilation Grills
Into Adjoining Room,
Option 2
12"
12"
Ventilation
Grills into
Adjoining
Room,
Option 1
Outlet
Air
Ventilated
Attic
Outlet
A
ir
Inlet
Air
Inlet Air Ventilated
Crawl Space
To
Crawl
Space
To Attic
AIR FOR COMBUSTION
AND VENTILATION
Continued
INSTALLATION
NOTICE:Thisheaterisintended
for use as supplemental heat.
Use this heater along with your
primary heating system. Do not
install this heater as your pri-
mary heat source. If you have a
centralheatingsystem,youmay
run system’s circulating blower
whileusingheater.Thiswillhelp
circulatetheheatthroughoutthe
house. In the event of a power
outage, you can use this heater
as your primary heat source.
WARNING: A qualified 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.
WARNING:Thisapplianceis
equipped for either natural gas
or propane/LP gas but not both.
Gas type is indicated on the rat-
ingplate.Fieldconversionisnot
permitted.
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
andone within 12" of thefloor.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
inletoroutlet air into attic if attic has athermo-
stat-controlledpowervent. Heated air entering
the attic will activate the power vent.

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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*
• hardware packet
- wall anchor (4) 095112-02
- red key (1) 095116-01
- pan head screw, black (4) 097403-02
- nylon spacer (2) 099064-02
- clamp (1) 099123-01
- Phillips head screw, silver (4) 100159-02
* A CSA design-certified equipment shutoff
valvewith1/8"NPTtap is an acceptable alter-
native to test gauge connection. The optional
CSAdesign-certified equipment shutoff valve
can be purchased from your dealer. See Ac-
cessories, page 26.
LOCATING HEATER
This heater is designed to be mounted on a wall.
WARNING: Maintain the
minimum clearances shown
in Figure 4. If you can, provide
greater clearances from floor,
ceiling and joining wall.
You can locate heater on floor, away from
a wall. An optional floor mounting stand is
included.
WARNING: Never install the
heater
• in a bedroom or bathroom
• in a recreational vehicle
• wherecurtains,furniture,cloth-
ingorotherflammableobjects
arelessthan36"fromthefront,
top or sides of the heater
• as a fireplace insert
• in high traffic areas
• in windy or drafty areas Figure 4 - Mounting Clearances As
Viewed From Front of Heater
INSTALLATION
Continued 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 flu-
ids,oilorkerosenelamps,etc.)in
the air exist, may discolor walls
or cause odors.
IMPORTANT: Vent-freeheaters add moisture
tothe air.Although this isbeneficial, installing
heater in rooms without enough ventilation
air may cause mildew to form from too much
moisture.SeeAirforCombustionandVentila-
tion, page 5. If high humidity is experienced,
a dehumidifier may be used to help lower the
water vapor content in the air.
CAUTION: If you install the
heater in a home garage
• heater pilot and burner must
be at least 18" above floor
• locate heater where moving
vehicle will not hit it
For convenience and efficiency, install heater
• where there is easy access for operation,
inspection and service
• in coldest part of room
Anoptional fankitisavailable fromyourdealer.
See Accessories, page 26. If planning to use
fan, locate heater near an electrical outlet.
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
6"

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119169-01E 9
INSTALLATION
Continued
THERMOSTAT SENSING BULB
Locate thermostat sensing bulb.
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 thethermostat sensing
bulb is pointing up.
Figure 5 - Attaching Thermostat Sensing
Bulb
INSTALLING HEATER TO WALL
Mounting Bracket
Locatemountingbracketinheatercarton.Re-
move mounting bracket from heater carton.
Figure 7 - Removing Front Panel Of
Heater
Clamp
Thermostat
Sensing Bulb
Figure 6 - Mounting Bracket
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 ma-
terials.
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 pro-
vides the strongest hold. Insert mounting
screws through mounting bracket and into
wall studs.
Attaching to Wall Anchor: This method al-
lowsyouto attach mounting bracket to hollow
walls (wall areas between studs) or to solid
walls (concrete or masonry).
Decidewhichmethodbettersuitsyour needs.
Either method will provide a secure hold for
the mounting bracket.
Marking Screw Locations
1. Tape mounting bracket to wall where
heater will be located. Make sure mount-
ing bracket is level.
WARNING: Maintain mini-
mumclearancesshowninFigure
8, page 10. If you can, provide
greater clearances from floor
and joining wall.
Screw
Front Panel

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INSTALLATION
Continued
30,000 Btu/Hr Models
20,000 Btu/Hr Models
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.
Attaching To Wall Stud Method
For attaching mounting bracket to wall studs
1. Drillholesatmarkedlocations 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
firmly fastened to wall studs.
Figure 9 - Folding
Anchor
Figure 11 - Mounting Heater Onto
Mounting Bracket
Stand-
Out Tab
Adjoining Wall
Only Insert Mounting
Screws Through Last
Hole On Each End
Floor
14" (35.6 cm)
18
3
/ 4 "
(47.6 cm)
Min.
12"
(30.4
cm)
Min.
8"
(20.3
cm)
Min.
Adjoining Wall
Only Insert Mounting
Screws Through Last
Hole On Each End
Floor
14" (35.6 cm)
18
3
/ 4 "
(47.6 cm)
Min.
Figure 10 - Popping
Open Anchor Wings
For Thin Walls
Mounting Bracket
(attached to wall)
Horizontal Slots
Attaching To Wall Anchor Method
For attaching mounting bracket to hollow
walls(wallareasbetweenstuds)orsolidwalls
(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 first) into hole.
Tap anchor flush to wall.
4. For thin walls (1/2" or less), insert red key
intowallanchor.Pushred keyto“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. Placemountingbracketontowall.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
firmly fastened to wall.
Placing Heater On Mounting Bracket
1. Locatetwo horizontal slots onbackpanel
of heater.
2. Placeheaterontomountingbracket.Slide
horizontal slots onto stand-out tabs on
mounting bracket.
2. Mark screw locations on wall (see Figure 8).
Note: Only mark last hole on each end of
mountingbracket.Insertmountingscrews
through these holes only.
3. Remove tape and mounting bracket from
wall.

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119169-01E 11
Figure 12 - Installing Bottom Mounting
Screws
Side View
Front View
Wall
Spacer
Heater
Installing Bottom Mounting Screws
1. Locatetwobottommountingholes.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, page 10.
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
otherhand,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 firmly
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 pages 12 through 14).
INSTALLATION
Continued MOUNTING HEATER TO FLOOR
WITH OPTIONAL FLOOR KIT
Mounting Base Feet to Heater
Note: A 90° elbow is required for mounting
this unit and must be installed BEFORE base
feet to provide proper clearance (see Figure
15, page 13).
1.
Layheatercabinetonitsbackonatablewith
the heater bottom overhanging table edge.
2. Applypipejointsealantlightly to maleNPT
threadsof elbow.Hold pressure regulator
with a wrench when connecting elbow.
Do not overtighten elbow to regulator.
Regulator body could be damaged.
3. Alignholesinbasefoot withmountingholes
on bottom of cabinet (see Figure 13).
4. Secure base foot to heater using sheet
metal screws.
5. Repeat for other side.
Mounting Base Feet to Floor
Figure 13 - Installing Base Feet
Sheet Metal Screw
Wood
Screw
Base Foot
1. Removefront panel (see RemovingFront
Panel of Heater, page 9).
2. Position heater with base feet in desired
location. Mark holes for drilling. Remove
heater with base.
3. Forcarpetedfloors,make a small cut with
a sharp knife at marked locations prior to
drilling. If mounting base to a wood floor,
drill1/8"diameterhole, 3/4" deep. (Do not
use anchors in wood floors).
If mounting base to a concrete floor, drill
with 1/4" diameter concrete drill bit, 13/8"
into floor. Insert anchors completely into
holes.
4. Reposition heater with base feet over
holes. Secure base to floor with wood
screws. See Figure 13.

www.desatech.com 119169-01E12
Tee Joint
Reducer
Bushing to
1/8" NPT
1/8" NPT
Plug Tap
Test Gauge Connection*
3/8" NPT
Pipe Nipple
Heater
Cabinet
Equipment
Shutoff
Valve*
3"
Min.
Natural
Gas
From Gas
Meter (4" W.C.
to 10.5" W.C.
Pressure)
Propane/LP From External
Regulator (11" W.C. to 14"
W.C. Pressure)
Ground Joint
Union
Tee Joint
Pipe
Nipple
Cap
Sediment Trap
Figure 15 - Gas Connection
CONNECTING TO GAS SUPPLY
WARNING: This appliance
requires a 3/8" NPT (National
PipeThread)inletconnectionto
the pressure regulator.
WARNING:Aqualifiedservice
personmustconnectheatertogas
supply. Follow all local codes.
WARNING: For natural gas,
neverconnectheatertoprivate(non-
utility) gas wells. This gas is com-
monly known as wellhead gas.
IMPORTANT: For natural gas, check gas line
pressurebeforeconnectingheatertogasline.
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
theexternalregulatorbetweenthe
heater and propane/LP supply.
For propane/LP gas, the installer must supply
an external regulator. The external regulator will
reduceincominggaspressure.Youmustreduce
incoming gas pressure to between 11" and 14"
ofwater.Ifyoudonotreduceincominggaspres-
sure,heaterregulatordamagecouldoccur.Install
theexternalregulatorwiththeventpointingdown
as shown in Figure 14. Pointing the vent down
protects it from freezing rain or sleet.
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.
INSTALLATION
Continued
Figure 14 - External Regulator With Vent
Pointing Down
External
Regulator
Propane/LP
Supply Tank
Vent
Pointing
Down
Typical Inlet Pipe Diameters
20,000 Btu/Hr Models - 3/8" or greater
30,000 Btu/Hr Models - 1/2" or greater
Pressure
Regulator
* A CSA design-certified equipment shutoff
valve with 1/8" NPT tap is an acceptable al-
ternative to test gauge connection. Purchase
the optional CSA design-certified equipment
shutoff valve from your dealer. See Acces-
sories, page 26.
Connection Using Flexline
3/8" NPT/ 1/2"
Flare 90° Elbow
Flexline
See illustration
above for detail
Refer to
connector's
instructions

www.desatech.com
119169-01E 13
CHECKING GAS CONNECTIONS
WARNING:Testallgaspiping
and connections, internal and
external to unit, for leaks after
installing or servicing. Correct
all leaks at once.
WARNING: Never use an
open flame to check for a leak.
Applyanoncorrosiveleakdetec-
tion fluid to all joints. Bubbles
forming show a leak. Correct all
leaks at once.
Installation must include equipment shutoff
valve,unionand plugged 1/8"NPTtap. Locate
NPT tap within reach for test gauge hook up.
NPT tap must be upstream from heater (see
Figure 15, page 12).
IMPORTANT: Install an equipment shutoff
valve in an accessible location. The equip-
mentshutoffvalveisfor 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
sealantthatisresistanttoliquid
petroleum (LP) gas.
Install sediment trap in supply line as shown
in Figure 15, page 12. 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 mois-
tureand contaminants.Thiskeeps 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 fittings. Do not over tighten pipe
connection to regulator. The regulator body
could be damaged.
INSTALLATION
Continued 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 12.
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-
mentshutoffvalve fromgas supply piping
system. Pressures in excess of 1/2 psig
will damage heater regulator.
2. Capoffopen end of gaspipewhereequip-
ment shutoff valve was connected.
3. Pressurizesupplypipingsystem 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. Checkalljointsofgassupplypipingsystem.
Applya noncorrosive leak detectionfluidto
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
fittings 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. Pressurizesupplypipingsystem 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(seeFigure17,page14)orpropane/LP
supply tank for propane/LP gas, to equip-
mentshutoffvalve(seeFigure18,page14).
Applya noncorrosive leak detectionfluidto
all joints. Bubbles forming show a leak.
4. Correct all leaks at once.
Figure 16 - Equipment Shutoff Valve
Open
Closed
Equipment
Shutoff Valve

www.desatech.com 119169-01E14
PRESSURE TESTING HEATER GAS
CONNECTIONS
1. Openequipmentshutoffvalve (see Figure
16, page 13).
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 fluid to all joints. Bubbles forming
show a leak.
5. Correct all leaks at once.
6. Lightheater (see Operating Heater,page
15). Check all other internal joints for
leaks.
Figure 18 - Checking Gas Joints for
Propane/LP Gas
Equipment Shutoff Valve
Propane/LP
Supply Tank
Thermostat Gas Valve
Figure 17 - Checking Gas Joints for
Natural Gas
Equipment Shutoff Valve
Gas
Meter
Thermostat Gas Valve
INSTALLATION
Continued 7. Turn off heater (see To Turn Off Gas to
Appliance, page 16).
8. Replace front panel.
CONNECTING TO ELECTRICAL
SUPPLY)
WARNING: Fan accessory
must be grounded. Fan comes
with a three-prong, grounding
plug as shown in Figure 19. The
plug is your protection against
electrical shock. Plug it into a
standard,three-hole,grounded,
outlet. If cord needs replacing,
use only a cord with a three-
prong, grounding plug.
CAUTION: Label all wires
prior to disconnection when
servicingcontrols.Wiringerrors
cancauseimproperanddanger-
ous operation (see page 26).
Grounding Plug
Grounded Outlet
Figure 19 - Grounding Plug
EXTENSION CORD
Use extension cord if needed. The cord must
have a three-prong, grounding plug and a
three-hole receptacle. Make sure cord is in
goodshape.Itmustbeheavy enough to carry
the current needed. An undersized cord will
cause a drop in line voltage. This will result
in loss of power and overheating. Use a No.
16 AWG cord for lengths less than 50 feet
(15.24 m).
CAUTION: Verify proper op-
eration after servicing.

www.desatech.com
119169-01E 15
OPERATING HEATER
FOR YOUR SAFETY READ
BEFORE LIGHTING
WARNING: If you do not fol-
low these instructions exactly,
a fire 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 pilot, follow these instructions
exactly.
B. BEFORE LIGHTING smell all around
the appliance area for gas. Be sure to
smell next to the floor because some
gas is heavier than air and will settle
on the floor.
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 fire 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
qualified service technician. Force or
attempted repair may result in a fire or
explosion.
D. Do not use this appliance if any part
has been under water. Immediately call
aqualified service technicianto inspect
the appliance andto replace any partof
the control system and any gas control
which has been under water.
LIGHTING
INSTRUCTIONS
1. STOP! Read the safety information
above.
2. Makesureequipmentshutoffvalve 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.
O
F
F
P
I
L
O
T
Figure 20 - Control Knob In The OFF
Position
Ignitor Button Control Knob
5. Wait five minutes to clear out any gas.
Then smell for gas, including near the
floor. If you smell gas, STOP! Follow “B”
in the safety information, column 1. If you
don’t smell gas, go to the next step.
6. Turncontrolknobcounterclockwise
to the PILOT position. Press in control
knob for five (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
heaterforthe first time after hooking up to
gas supply. If so, you may need to press
in control knob 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
19 or contact a qualified service person
or gas supplier for repairs. Until repairs
are made, light pilot with match. To light
pilot with match, see Manual Lighting
Procedure, page 16.
8. Keep control knob pressed in for 30 sec-
ondsafter lighting pilot.After 30seconds,
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 havea safety inter-
lock system. Wait one (1) minute before
lighting pilot again.
9. Turncontrolknobcounterclockwise
to desired heating level. The main burner
should light.
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.

www.desatech.com 119169-01E16
OPERATING HEATER
Continued
CAUTION: Do not try to ad-
just heating levels by using the
equipment shutoff valve.
Figure 21 - Pilot (actual pilot may vary)
Ignitor Electrode
Pilot Burner
Thermocouple
MANUAL LIGHTING
PROCEDURE
1. Remove front panel (see Figure 7,
page 9).
2. Follow steps 1 through 7 under Lighting
Instructions, page 15.
3. Withcontrolknobpressedin, strike match.
Hold match to pilot until pilot lights.
4. Keep control knob pressed in for 30 sec-
ondsafter lighting pilot.After 30seconds,
release control knob. Now follow step 9,
under Lighting Instructions, page 15.
5. Replace front panel.
OPERATING
BLOWER
This heater has a thermostatic blower that will
automatically turn ON or OFF.
Note: Your heater and thermostat blower will
not turn on and off at the same time. The
heatermayrunfor several minutes before the
blowerturnson.After the heater modulatesto
the pilot position, the blower will continue to
run. The blower will shut off after the heater
cabinet temperature decreases.
Note: It is safe to operate heater with blower
turned off. However, the blower helps distrib-
ute heated air from the heater.
TO TURN OFF GAS
TO APPLIANCE
Shutting Off Heater
1. Turn control knob clockwise to the
OFF position.
2. Turn offallelectricpower to the appliance
if service is to be performed.
Shutting Off Burner Only (pilot stays lit)
Turn control knob clockwise to the
PILOT position.
THERMOSTAT CONTROL
OPERATION
The thermostatic control used on these
models differs from standard thermostats.
Standard thermostats simply turn on and off
theburner.Thethermostatused on this heater
sensestheroomtemperature.Thethermostat
adjusts the amount of gas flow to the burner.
Thisincreases or decreases the burner flame
height. At times the room may exceed the
set temperature. If so, the burner will shut
off. The burner will cycle back on when room
temperaturedropsbelowthesettemperature.
The control knob can be set to any heat level
between 1 and 5. Selecting the 5 setting will
cause the burner to remain fully on without
modulating down in most cases.
Note: The thermostat sensing bulb measures
the temperature of air near the heater cabinet.
This may not always agree with room tem-
perature (depending on housing construction,
installation location, room size, open air tem-
peratures,etc.).Frequentuseofyourheaterwill
let you determine your own comfort levels.

www.desatech.com
119169-01E 17
BURNER FLAME PATTERN
WARNING: If yellow tipping
occurs, your heater could pro-
duceincreasedlevelsofcarbon
monoxide.
NOTICE:Donotmistakeorange
flames with yellow tipping. Dirt
or other fine particles enter the
heater and burn causing brief
patches of orange flame.
Figure 24 shows a correct burner flame pat-
tern. Figure 25 shows an incorrect burner
flame pattern. The incorrect burner flame
pattern shows yellow tipping of the flame.
It also shows the flame higher than 1/2 the
glass panel height.
If burner flame pattern is incorrect, as shown
in Figure 25
• turn heater off (see To Turn Off Gas To
Appliance, page 16)
• see Troubleshooting, page 19
INSPECTING HEATER
Check pilot flame pattern and burner flame
pattern often.
PILOT FLAME PATTERN
Figure 22 shows a correct pilot flame pattern.
Figure 23 shows an incorrect pilot flame pat-
tern. The incorrect pilot flame is not touching
thethermocouple.This will causethe thermo-
coupletocool.Whenthethermocouple cools,
the heater will shut down.
If pilot flame pattern is incorrect, as shown
in Figure 23
• turn heater off (see To Turn Off Gas to Ap-
pliance, page 16)
• see Troubleshooting, page 19
Note: The pilot flame on natural gas units will
have a slight curve, but flame should be blue
and have no yellow or orange color.
Figure 23 - Incorrect Pilot Flame Pattern
Figure 22 - Correct Pilot Flame Pattern
Thermocouple
Pilot Burner
Pilot
Burner
Thermocouple
Blue Flame
Yellow Flame
Figure 24 - Correct Burner Flame Pattern
Yellow
Tipping
Figure 25 - Incorrect Burner Flame
Pattern
1/2Glass
Height
1/2Glass
Height
Blue
Flame

www.desatech.com 119169-01E18
Figure 26 - Pilot Inlet Air
(Propane/LP Pilot Shown)
Pilot Air Inlet
1. Shut off the unit, including the pilot.Allow
the unit to cool for at least thirty minutes.
2. Inspect burner, pilot for dust and dirt.
3. Blowair through the ports/slots and holes
in the burner.
4. Never insert objects into the pilot tube.
Clean the pilot assembly also.Ayellow tip on
the pilot flame indicates dust and dirt in the
pilot assembly. There is a small pilot air inlet
about two inches from where the pilot flame
comes out of the pilot assembly (see Figure
26). With the unit off, lightly blow air through
the air inlet. You may blow through a drinking
straw if compressed air is not available.
Pilot Assembly
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.
CLEANING AND
MAINTENANCE
WARNING: Turn off heater
and let cool before cleaning.
CAUTION: You must keep
control areas, burner and circu-
latingairpassagewaysofheater
clean. Inspect these areas of
heater before each use. Have
heater inspected yearly by a
qualifiedserviceperson.Heater
may need more frequent clean-
ing due to excessive lint from
carpeting,beddingmaterial,pet
hair, etc.
WARNING: Failure to keep
the primary air opening(s) of
theburner(s)cleanmayresultin
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-
videsacleanburningflame.Keep these holes
clearof dust, dirt and lint. Cleanthese airinlet
holes prior to each heating season. Blocked
airholeswill create soot. Werecommendthat
you clean the unit every three months during
operation and have heater inspected yearly
by a qualified service person.
Wealso recommend that you keep theburner
tubeandpilotassemblycleanandfreeofdust
and dirt. To clean these parts we recommend
usingcompressed air no greater than 30PSI.
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.

www.desatech.com
119169-01E 19
TROUBLESHOOTING
WARNING:Turnoffandunplugheaterandletcoolbeforeservicing.
Only a qualified 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. Ignitorelectrodepositioned
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 piezo ignitor
1. Gas supply turned off or
equipment shutoff valve
closed
2. Control knob not in PILOT
position
3. Control knob not pressed
in while in PILOT position
4. Air in gas lines when in-
stalled
5. Depleted gas supply (pro-
pane/LP gas only)
6. ODS/pilot is clogged
7. Gasregulatorsettingisnot
correct
OBSERVED PROBLEM
When ignitor button is
pressed, there is no spark at
ODS/pilot
Whenignitorbuttonispressed,
thereissparkatODS/pilotbut
no ignition
REMEDY
1. Replace pilot assembly
2. Replace pilot assembly
3. Reconnect ignitor cable
4. Freeignitorcableifpinched
by any metal or tubing.
Keep ignitor cable dry
5. Replace ignitor cable
6. Replace piezo ignitor
1. Turnongassupplyoropen
equipment shutoff valve
2. TurncontrolknobtoPILOT
position
3. Pressincontrolknobwhile
in PILOT position
4. Continue holding down
control knob. Repeat ig-
niting operation until air is
removed
5. Contact local propane/LP
gas company
6. Clean ODS/pilot (see
Cleaning and Mainte-
nance,page18)orreplace
ODS/pilot assembly
7. Replace gas regulator

www.desatech.com 119169-01E20
OBSERVED PROBLEM
ODS/pilot lights but flame
goes out when control knob
is released
Burner does not light after
ODS/pilot is lit
Delayed ignition of burner
Burnerbackfiringduring com-
bustion
REMEDY
1. Press in control knob fully
2. AfterODS/pilot lights, keep
control knob pressed in 30
seconds
3. Wait one minute for safety
interlock system to reset.
Repeat ignition operation
4. Fullyopenequipment shut-
off valve
5. Hand tighten until snug,
then tighten 1/4 turn more
6. A) Contact local natural or
propane/LP gas company
B) Clean ODS/pilot (see
CleaningandMaintenance,
page 18) or replace ODS/
pilot assembly
7. Replace pilot assembly
8. Replace control valve
1. Cleanburner(seeCleaning
andMaintenance,page18)
or replace burner orifice
2. Contact local natural or
propane/LP gas company
1. Contact local natural or
propane/LP gas company
2. Cleanburner(seeCleaning
andMaintenance,page18)
or replace burner orifice
1. Cleanburner(seeCleaning
andMaintenance,page18)
or replace burner orifice
2. Replace burner
3. Replace gas regulator
POSSIBLE CAUSE
1. Control knob not fully
pressed in
2. Controlknobnotpressedin
long enough
3. Safetyinterlocksystemhas
been triggered
4. Equipmentshutoffvalve not
fully open
5. Thermocouple connection
loose at control valve
6. Pilot flame not touching
thermocouple, which al-
lows thermocouple to cool,
causing pilot flame 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
7. Thermocouple damaged
8. Control valve damaged
1. Burner orifice is clogged
2. Inlet gas pressure is too
low
1. Manifold pressure is too
low
2. Burner orifice is clogged
1. Burner orifice is clogged or
damaged
2. Burner damaged
3. Gas regulator defective
TROUBLESHOOTING
Continued