Desa GCP10TGCN20T Original instructions

VENT-FREE BLUE FLAME
GAS HEATER
SAFETY INFORMATION AND
INSTALLATION MANUAL
Save this manual for future reference.
Save this manual for future reference.
For more information, visit www.desatech.com
For more information, visit www.desatech.com
WARNING: This is an unvented gas-fired
heater. It uses air (oxygen) from the room
in which it is installed. Provisions for ad-
equatecombustionandventilationairmust
be provided. Refer to Air For Combustion
and Ventilation on page 4 of this manual.
WARNING:Improperinstallation,adjust-
ment,alteration,service,ormaintenance
can cause injury or property damage.
Refer to this manual for correct installa-
tion and operational procedures. For as-
sistance or additional information con-
sult a qualified installer, service agency,
or the gas supplier.
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.
*Aftermarket: Completion of sale, not for purpose of resale, from the manufacturer
WARNING: If the information in this manual is
not followed exactly, a fire or explosion may
result causing property damage, personal in-
jury, 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.
• Immediately call your gas supplier from a
neighbor’s phone. Follow the gas
supplier’s instructions.
• Ifyou cannotreach yourgas supplier,call
the fire department.
— Installation and service must be performed
by a qualified installer, service agency, or
the gas supplier.
GCN6, GCP6
GCN10T, GCP10T
GCN20T, GCP20T
Unvented room heaters are for installa-
tion in SINGLE FAMILY TYPE RESI-
DENCES ONLY, and the installation is
limited to ONE (1) unit per residence.
CR94-001 UNVENTED
ROOM HEATER

112157-01A
2
For more information, visit www.desatech.com
For more information, visit www.desatech.com
SAFETY INFORMATION
WARNINGS
IMPORTANT: Read this owner’s manual carefully and
completely before trying to assemble, operate, or ser-
vicethisheater. Improperuseof this heatercancause
serious injury or death from burns, fire, explosion,
electrical shock, and carbon monoxide poisoning.
DANGER: Carbon monoxide poisoning may lead
to death!
Carbon Monoxide Poisoning: Early signs of carbon monoxide
poisoningresemble theflu, with headaches,dizziness, ornausea. If
you have these signs, the heater may not be working properly. Get
fresh air at once! Have heater serviced. Some people are more
affected by carbon monoxide than others. These include pregnant
women, persons with heart or lung disease or anemia, those under
the influence of alcohol, and those at high altitudes.
Natural and Propane/LP Gas: Natural and propane/LP gases 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 any accessory not ap-
proved for use with this heater.
TABLE OF CONTENTS
SAFETY INFORMATION
WARNING: Do not use a blower insert, heat
exchangerinsertorotheraccessorynotapprovedfor
use with this heater.
Childrenandadultsshouldbealertedtothehazardof
high surface temperature and should stay away to
avoid burns or clothing ignition.
Surface of heater becomes very hot when running
heater. Heater will remain hot for a time after shut-
down. Allow surface to cool before touching.
Any safety screen or guard removed for servicing the
appliancemustbereplacedpriortooperationtheheater.
Due to high temperatures, the appliance should be
located out of traffic and away from furniture and
draperies.
Do not place clothing or other flammable material on or
neartheappliance.Neverplaceanyobjectsontheheater.
Carefully supervise young children when they are in
the same room with heater.
Make sure grill guard is in place before running
heater.
Keeptheappliance areaclearand free fromcombus-
tiblematerials,gasoline,andotherflammablevapors
and liquids.
TABLE OF CONTENTS
SAFETY INFORMATION ............................................................ 2
UNPACKING ............................................................................... 3
PRODUCT IDENTIFICATION ..................................................... 3
PRODUCT FEATURES .............................................................. 3
LOCAL CODES........................................................................... 4
AIR FOR COMBUSTION AND VENTILATION ........................... 4
INSTALLATION ........................................................................... 6
OPERATING HEATER.............................................................. 14
INSPECTING BURNER ............................................................ 15
CLEANING AND MAINTENANCE ............................................ 16
TROUBLESHOOTING .............................................................. 17
ILLUSTRATED PARTS BREAKDOWNAND PARTS LIST ....... 20
SPECIFICATIONS..................................................................... 26
SERVICE CENTER/PARTS CENTRAL .................................... 26
OWNER’S REGISTRATION FORM .......................................... 27
REPLACEMENT PARTS .......................................................... 29
SERVICE HINTS....................................................................... 29
TECHNICAL SERVICE ............................................................. 29
SERVICE PUBLICATIONS ....................................................... 29
ACCESSORIES ........................................................................ 29
WARRANTY INFORMATION ...................................... Back Cover

112157-01A
3
3
For more information, visit www.desatech.com
For more information, visit www.desatech.com
SAFETY INFORMATION
UNPACKING
PRODUCT IDENTIFICATION
PRODUCT FEATURES
SAFETY INFORMATION
Continued
PRODUCT IDENTIFICATION
PRODUCT FEATURES
SAFETY DEVICE
This heater has a pilot with an Oxygen Depletion 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.
PIEZO IGNITION SYSTEM
This heater has a piezo ignitor. This system requires no matches,
batteries, or other sources to light heater.
THERMOSTATIC HEAT CONTROL
Thermostat models have a thermostat sensing bulb and a control
valve.Thisresultsinthegreatestheatercomfort.Thiscanalsoresult
in lower gas bills.
Figure 1 - Vent-Free Gas Heater
Control Knob
Piezo Ignitor
Button
Glass
Panel
Grill
Guard
Front
Panel
Heater
Cabinet
Installation and repair should be done by a qualified
service person. The appliance should be inspected
and serviced before use and at least annually by a
professional service person. More frequent cleaning
mayberequiredduetoexcessivelintfromcarpeting,
etc.Itis imperative that control compartments,burn-
ers and circulating air passageways of the appliance
be kept clean.
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. Do not install in a bedroom or a 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 fire department
5. This heater needs fresh, outside air ventilation 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,
pages 4 through 6.
6. Keep all air openings in the front and bottom of heater clear and
free of debris. This will insure enough air for proper combustion.
7. If heater and pilot shuts off unexpectedly, do not relight the
pilot until you provide fresh, outside air. If heater keeps shut-
ting off, have it serviced.
8. Do not run heater
• where flammable liquids or vapors are used or stored
• under dusty conditions
9. Before using furniture polish, wax, carpet cleaner, or similar
products, turn heater off. If heated, the vapors from these prod-
ucts may create a white powder residue within burner box or
on adjacent walls or furniture.
10. Do not use heater if any part has been under water. Immedi-
ately 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. Turn off heater and let cool before servicing. Only a qualified
service person should service and repair heater.
12. Operating heaterabove elevations of4,500 feet (1370 m)could
cause pilot outage due to lower levels of oxygen in the air.
13. To prevent performance problems, do not use propane/LPfuel
tank of less than 100 lbs. (45 kg) capacity.
Piezo Ignitor
Button
Control Knob
6,000/10,000 Btu/Hr 20,000 Btu/Hr
14. Provide adequate clearances around air openings.
15. Before using the heater, provide adequate ventilation.An area
of 10 square inches (65 cm2) of opening of a window or roof
vent is needed for adequate combustion and ventilation air.
UNPACKING
1. Remove heater from carton.
2. Removeall protective packagingapplied to heaterforshipment.
3. Check heater for any shipping damage. If heater is damaged,
promptly inform dealer where you bought heater.

112157-01A
4
For more information, visit www.desatech.com
For more information, visit www.desatech.com
AIR FOR COMBUSTION AND
VENTILATION
WARNING: This heater shall not be installed in a
confined space or unusually tight construction un-
less provisions are provided for adequate combus-
tion and ventilation air. Read the following instruc-
tionsto insureproperfreshairforthisand otherfuel-
burning appliances in your home.
Today’s homes are built more energy efficient than ever. New materi-
als, increased insulation, and new construction methods help reduce
heat loss in homes. Home owners weather strip and caulk around
windowsanddoorstokeepthecoldairoutandthewarmairin.During
heatingmonths,home owners wanttheirhomesas airtight aspossible.
While it is good to make your home energy efficient, your home
needs to breathe. Fresh air must enter your home. All fuel-burning
appliances need fresh air for proper combustion and ventilation.
Exhaustfans,fireplaces,clothesdryers,andfuelburningappliances
drawairfromthehousetooperate.Youmustprovideadequatefresh
air for these appliances. This will insure proper venting of vented
fuel-burning appliances.
PROVIDING ADEQUATE VENTILATION
The following are excerpts from CAN/CGA B149.1 Natural Gas
InstallationCode or CAN/CGA B149.2PropaneInstallation Code.
All spaces in homes fall into one of the three following ventilation
classifications:
1. Unusually Tight Construction
2. Unconfined Space
3. Confined Space
The information on pages 4 through 6 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
unusually 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 open-
ings gasketed or sealed
and
b. weather strippinghas been addedon openable windows
and doors
and
c. caulking or sealants are applied to areas such as joints
around window and door frames, between sole plates
andfloors,between wall-ceilingjoints,betweenwall pan-
els, at penetrations for plumbing, electrical, and gas
lines, and at other openings.
If your home meets all of the three criteria above, you must
provide additional fresh air. See
Ventilation Air From Out-
doors
, page 6 .
If your home does not meet all of the three criteria above,
proceedto
DeterminingFresh-AirFlowForHeaterLocation,
page 5.
Confined and Unconfined Space
The Canadian Gas Association Certification Requirement, CGA
CR94-001 REV. 2 states that when combustion air supply is for the
unvented room heater only, it shall be sized at the rate of one (1)
square inch per 5000 BTU/HR (1.5 KW) from outdoors or the
manufacturer’sspecification(whicheverisgreater).However,com-
bustion air is acceptable when available from the principal heat
source and sized to the current CAN/CGA-B149.1 or .2 require-
ments. Where unvented equipment is installed in an area separated
from a combustion air supply by a door, then permanent openings,
grillsorlouversshallbeprovided.Oneshallbewithin18inches(46
cm)fromthe ceilingandone18inches(46cm)from thefloor,sized
to one (1) square inch per 1000 BTU/HR (0.29 KW) to allow free
movement of air with the source of combustion air supply.
LOCAL CODES
AIR FOR COMBUSTION AND VENTILATION
Providing Adequate Ventilation
LOCAL CODES
Installand useheater with care.Follow alllocal codes. Inthe absenceof
local codes, use the latest edition of CAN/CGA B149.1 Natural Gas
InstallationCodeorCAN/CGAB149.2PropaneInstallationCode*.
*Available from www.csa.ca or 1-800-463-6727 (call your local
gas company for your local codes).

112157-01A
5
5
For more information, visit www.desatech.com
For more information, visit www.desatech.com
WARNING: If the area in which the heater may be
operatedissmallerthanthatdefinedasanunconfined
space or if the building is of unusually tight construc-
tion,provideadequate combustion andventilationair
by one of the methods described in CAN/CGA B149.1
Natural Gas Installation Code or CAN/CGA B149.2
Propane Installation Code or applicable local code.
AIR FOR COMBUSTION AND
VENTILATION
Continued
DETERMINING FRESH-AIR FLOW FOR
HEATER LOCATION
Determining if You Have a Confined or
Unconfined Space
Usethis worksheet todetermineif youhave aconfined orunconfinedspace.
Space:Includestheroominwhichyouwillinstallheaterplusanyadjoining
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. (m3) (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. (72.6m3) (volume of space)
Ifadditional ventilationto adjoiningroom issuppliedwith grillsor open-
ings, 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
(kW) the space can support.
__________ (volume of space) x 20 = [Maximum Btu/Hr (kW) the
space can support]
Example: 2560 cu. ft. (72.6m3) (volume of space) x 20 = 51,200
[maximum Btu/Hr (kW) the space can support]
3. Add the Btu/Hr of all fuel burning appliances in the space.
Vent-free heater _____________ Btu/Hr (kW)
Gas water heater* _____________ Btu/Hr (kW)
Gas furnace _____________ Btu/Hr (kW)
Vented gas heater _____________ Btu/Hr (kW)
Gas fireplace logs _____________ Btu/Hr (kW)
Other gas appliances* + _____________ Btu/Hr (kW)
Total = _____________ Btu/Hr (kW)
* Do not include direct-vent gas appliances. Direct-vent draws com-
bustion air from the outdoors and vents to the outdoors.
Example:
Gas water heater _____________ Btu/Hr (kW)
Vent-free heater + _____________ Btu/Hr (kW)
Total = _____________ Btu/Hr (kW)
4. Compare the maximum Btu/Hr the space can support with the actual
amount of Btu/Hr used.
__________________
Btu/Hr (kW)(maximum thespacecan support)
__________________ Btu/Hr (kW)(actual amount of Btu/Hrused)
Example: 51,200 Btu/Hr (15kW) (maximum the space can support)
60,000 Btu/Hr (17.6kW) [actual amount of Btu/Hr (kW)
used]
AIR FOR COMBUSTION AND VENTILATION
Determining Fresh-Air Flow For Heater Location
The space in the above example is a confined space because the actual Btu/Hr
(kW) used is more than the maximum Btu/Hr (kW) the space can support.
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 unconfined space, remove door to adjoining
roomoradd ventilation grills between rooms. SeeVentilationAir From
Inside Building, page 6.
B. Vent room directly to the outdoors. See Ventilation Air From Out-
doors, page 6.
C. Install a lower Btu/Hr (kW) heater, if lower Btu/Hr (kW) size makes
room unconfined.
If the actual Btu/Hr used is less than the maximum Btu/Hr (kW) the space
can support, the space is an unconfined space. You will need no additional
fresh air ventilation.
40,000 (11.7)
20,000 (5.9)
60,000 (17.6)

112157-01A
6
For more information, visit www.desatech.com
For more information, visit www.desatech.com
INSTALLATION
Installation must conform with local codes or, in the
absence of local codes, with the current standard
CAN/CGA B149.1 Natural Gas Installation Code or
CAN/CGA B149.2 Propane Installation Code
NOTICE: This heater is intended for use as supple-
mental 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
throughoutthehouse.Intheeventofapoweroutage,
you can use this heater as your primary heat source.
WARNING: A qualified service person must in-
stall heater. Follow all local codes.
CHECK GAS TYPE
Useonlythecorrect type ofgas (naturalorpropane/LP).Ifyourgas
supply is not the correct gas type, do not install heater. Call dealer
where you bought heater for proper type heater.
VENTILATION AIR
Ventilation Air From Inside Building
This fresh air would come from an adjoining unconfined space.
When ventilating to an adjoining unconfined space, you must
provide two permanent openings: one within 18" (45 cm) of the
ceiling and one within 18" (45 cm) of the floor on the wall
connecting the two spaces (see options 1 and 2, Figure 2). You can
also remove door into adjoining room (see option 3, Figure 2).
Follow CAN/CGA B149.1 Natural Gas Installation Code or CAN/
CGA B149.2 Propane Installation Code for required size of venti-
lation grills or ducts.
Ventilation Air From Outdoors
Provideextrafreshairbyusingventilationgrillsorducts.Youmust
provide two permanent openings: one within 18" (45 cm) of the
ceilingandonewithin18"(45 cm) of thefloor. Connect theseitems
directlytotheoutdoorsorspacesopentotheoutdoors.Thesespaces
include attics and crawl spaces. Follow CAN/CGA B149.1 Natural
Gas Installation Code or CAN/CGA B149.2 Propane Installation
Code for required size of ventilation grills or ducts.
IMPORTANT: Do not provide openings for inlet or outlet air into
attic if attic has a thermostat-controlled power vent. Heated air
entering the attic will activate the power vent.
Figure 2 - Ventilation Air from Inside Building
Outlet
Air Ventilated
Attic
Outlet
Air
Inlet
Air
Inlet Air Ventilated
Crawl Space
To
Crawl
Space
To Attic
AIR FOR COMBUSTION AND
VENTILATION
Continued
Figure 3 - Ventilation Air from Outdoors
Or
Remove
Door into
Adjoining
Room,
Option 3
Ventilation Grills
Into Adjoining Room,
Option 2
12"
12"
Ventilation
Grills
into Adjoining
Room,
Option 1
18"
(45 cm)
AIR FOR COMBUSTION AND VENTILATION
Ventilation Air
INSTALLATION
Check Gas Type
18"
(45 cm)

112157-01A
7
7
For more information, visit www.desatech.com
For more information, visit www.desatech.com
36" (91.5 cm
)
3" (7.7 cm)
CEILING
Minimum
6"
(15.3 cm)
Minimum
From
Sides Of
Heater
Right
Side
Left
Side
INSTALLATION
Installation Items
Locating Heater
INSTALLATION ITEMS
Beforeinstallingheater,makesureyouhave the items listedbelow.
• 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-certified equipment shutoff valve with 1/8" NPT
tap is an acceptable alternative to test gauge connection. Purchase
the optional CSA design-certified equipment shutoff valve from
your dealer. See Accessories, page 29.
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 clear-
ances from floor, ceiling, and joining wall.
Models GCN20T and GCP20T only: You can locate heater on
floor,awayfromawall.Anoptionalfloormountingstandisneeded.
Purchase the floor mounting stand from your dealer. See Accesso-
ries, page 29.
WARNING: Never install the heater
•in a bedroom or bathroom
•in a recreational vehicle
•where curtains, furniture, clothing, or other flam-
mableobjects arelessthan 36inches (92cm)from
the front, top, or sides of the heater
•as a fireplace insert
•in high traffic areas
•in windy or drafty areas Minimum To Top Surface
Of Carpeting, Tile Or Other
Combustible Material
6,000 Btu/Hr
(1.8 kW)
Model Shown
Figure4-MountingClearancesAsViewedFromFrontofHeater
INSTALLATION
Continued
CAUTION: This heater creates warm air currents.
These currents move heat to wall surfaces next to
heater. Installing heater next to vinyl or cloth wall
coveringsoroperatingheaterwhereimpurities(such
asbutnotlimitedto,tobaccosmoke,aromaticcandles,
cleaning fluids, oil or kerosene lamps, etc.) in the air
exist, may discolor walls or cause odors.
IMPORTANT: Vent-freeheaters add moisturetothe air.Although
this is beneficial, installing heater in rooms without enough venti-
lation air may cause mildew to form from too much moisture. See
Air for Combustion and Ventilation, pages 4 through 6. If high
humidity is experienced, a dehumidifier may be used to help lower
the water vapor content in the air.
CAUTION:Ifyouinstalltheheaterinahomegarage
•heater pilot and burner must be at least 18 inches
(46 cm) 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
For 20,000 Btu/hr (5.9 kW) models, an optional fan kit is available
from your dealer. See Accessories, page 29. If planning to use fan,
locate heater near a grounded electrical outlet. Outlet must be
groundedinaccordancewithlocalcodes,withthecurrentCanadian
Electrical Code Part 1 CSA C22.1.

112157-01A
8
For more information, visit www.desatech.com
For more information, visit www.desatech.com
INSTALLATION
Thermostat Sensing Bulb (Thermostat Models Only)
Installing Heater To Wall 6,000 and 10,000 Btu/Hr Models (1.8 and 2.9 kW)
INSTALLATION
Continued
THERMOSTAT SENSING BULB
(Thermostat Models Only)
Thethermostatsensingbulbhasbeenplacedinsidetheheaterfor
protection during shipping.
Locating Thermostat Sensing Bulb (for thermostat
applications)
1. Removefrontpanelofheater[for10,000 Btu/Hr (2.9 KW) heater,
see Figure 11 page 9 or for 20,000 Btu/Hr (5.9 KW) heater see
Figure 14, page 10].
2. Locate thermostat sensing bulb just under burner assembly.
IMPORTANT: Attachthermostatsensingbulbtobackofheaterfor
proper operation.
Attaching Thermostat Sensing Bulb
1. Remove thermostat sensing bulb from holders inside heater.
Route through slot opening in bottom of heater.
2. Place clamp on thermostat sensing bulb as shown in Figure 5.
Clamp is provided in hardware package.
3. 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.
Figure 5 - Attaching Thermostat Sensing Bulb
Figure 6 - Mounting Screw Locations
Mounting
Screw
Locations
8 7/8"
(22.5 cm)
Blue Flame
Minimum To
Maintain 6"
Clearance
From Wall
7 3/4"
(19.7 cm)
20 1/4" (51.4 cm)
Minimum To
Maintain 3" (7.6
cm) Clearance
From Floor
FLOOR
JOINING WALL
INSTALLING HEATER TO WALL 6,000 AND
10,000 BTU/HR MODELS (1.8 AND 2.9 KW)
Marking Screw Locations
1. Determine where you will locate heater.
WARNING:Maintain minimum clearancesshown
in Figure 6. If you can, provide greater clearances
from floor and joining wall.
2. Mark two mounting screw locations on wall (see Figure 6).
Figure 7 - Folding Anchor
Thin Walls (1/4" to 1/2" thick)
(1.6 to 1.2 cm)
Figure8-PoppingOpenAnchor
Wings For Thin Walls
Installing Two Mounting Screws
Note: Wall anchorsandmounting screwsarein hardwarepackage.
The hardware package is provided with heater.
Attaching to wall stud method
For attaching mounting screw to wall stud
1. Drill hole at marked location using 9/64" drill bit.
2. Insert mounting screw into wall stud.
3. Tighten screw until 1/16" (1.6 mm) space (thickness of penny)
is between screwhead and wall.
Attaching to wall anchor method
Followinstructionsbelowtoattach mounting screws tohollow 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 1/4" (3.2 cm) deep.
2. Fold wall anchor (see Figure 7).
3. Insert wall anchor (wings first) into hole. Tap anchor flush
to wall.
4. For thin walls [1/2" (1.27 cm) or less], insert red key into wall
anchor. Push red key to “pop” open anchor wings (see Figure 8).
IMPORTANT: Do not hammer key! For thick walls [over 1/2"
(1.27 cm) thick] or solid walls, do not pop open wings.
Clamp
Thermostat
Sensing Bulb

112157-01A
9
9
For more information, visit www.desatech.com
For more information, visit www.desatech.com
Figure 12 - Installing Bottom Mounting Screw
INSTALLATION
Installing Heater To Wall 6,000 and 10,000 Btu/Hr Models (1.8 and 2.9 kW) (Cont.)
Installing Heater To Wall 20,000 Btu/Hr Models (5.9 kW)
Installing Bottom Mounting Screw
1. Locate bottom mounting hole. This holeis nearbottom onback
panel of heater (see Figure 12).
2. Mark screw location on wall.
3. Remove heater from wall.
4. If installing bottom mounting screw into hollow or solid wall,
install wall anchor. Follow steps 1 through 5 under Attaching To
Wall Anchor Method, page 10. If installing bottom mounting
screw into wall stud, drill hole at marked location using 9/64"
drill bit.
5. Replace heater on wall.
6. Insert bottom anchor screw through back panel into bottom
anchor or drilled hole (see Figure 12).
7. Tighten screw 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 11 and 12).
INSTALLATION
Continued
Removing Front Panel Of Heater
1. Remove two screws near bottom corners of front panel.
2. Lift straight up on grill guard until it stops. Grill guard will slide
up about 1/4" (6 mm).
3. Pull bottom of front panel forward, then down.
Figure 11 - Removing Front Panel Of Heater
Figure 9 - Tightening Anchors
Thin or
Thick Wall
(thick wall
shown)
Solid
Wall
1/16"
Space
(1.6 mm)
Placing Heater On Mounting Screws
1. Locate two keyhole slots on back panel of heater (see Figure 10).
2. Place large openings of slots over screwheads. Slide heater
down until screws are in small portion of slots.
Figure 10 - Location Of Keyhole Slots On Back Panel Of Heater
Keyhole Slots
INSTALLING HEATER TO WALL
20,000 BTU/HR MODELS (5.9 KW)
Mounting Bracket
Locate mounting bracket in heater carton. Remove mounting bracket
from heater carton.
Figure 13 - Mounting Bracket
5. Tighten two screws until 1/16" (1.6 mm) space (thickness of
penny) is between screwheads and wall (see Figure 9).

112157-01A
10
For more information, visit www.desatech.com
For more information, visit www.desatech.com
INSTALLATION
Continued
Methods For Attaching Mounting Bracket To Wall
Onlyuselastholeoneachendofmountingbrackettoattachbracket
to wall. These two holes are 14 inches (35.5 cm) 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.
Insertmountingscrewsthroughmountingbracketandintowallstuds.
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.
Figure 14 - Removing Front Panel Of Heater
Removing Front Panel Of Heater (20,000 Btu/Hr
Models Only) (5.9 kW)
1. Removethe four paintedscrews,twoon eachsideoffront panel.
2. Pull bottom of front panel forward, then out.
3. Remove any remaining packaging materials.
WARNING:Maintain minimum clearancesshown
in Figure 15. If you can, provide greater clearances
from floor and joining wall.
Marking Screw Locations
1. Tape mounting bracket to wall where heater will be located.
Make sure mounting bracket is level.
2. Mark screw locations on wall (see Figure 15).
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.
Figure 15 - Mounting Bracket Clearances
14"
(35.6 cm)
18
3
/ 4 "
(47.7 cm)
Min.
8"
(20.3 cm)
Min.
Adjoining Wall
Only Insert Mounting
Screws Through Last
Hole On Each End
Floor
Attaching Mounting Bracket To Wall
Note: Wallanchors,mountingscrews,andspacersareinhardware
package. The hardware package is provided with heater.
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 firmly fastened to
wall studs.
Attaching To Wall Anchor Method
For attaching mounting bracket to hollow walls (wall areas be-
tween 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" (2.5 cm) deep.
2. Fold wall anchor as shown in Figure 16.
3. Insert wall anchor (wings first) into hole. Tap anchor flush
to wall.
4. For thin walls [1/2" (1.27 cm) orless], insert red key into wall
anchor. Push red key to “pop” open anchor wings.
IMPORTANT: Do not hammer key!
For thick walls [over 1/2" (1.27 cm) 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. Tightenscrews until mounting bracketisfirmlyfastenedtowall.
Figure 16 - Folding Anchor Figure 17- Popping Open
Anchor Wings For Thin Walls
INSTALLATION
Installing Heater To Wall 20,000 Btu/Hr Models (5.9 kW) (Cont.)

112157-01A
11
11
For more information, visit www.desatech.com
For more information, visit www.desatech.com
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.
Figure 18 - Mounting Heater Onto Mounting Bracket
Mounting Bracket
(attached to wall)
Horizontal Slots
Stand-Out Tab
INSTALLATION
Continued
Installing Bottom Mounting Screws
1. Locate two bottom mounting holes. These holes are near bot-
tom on back panel of heater (see Figure 19).
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 AttachingTo
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 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 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 11 and 12).
Figure 19 - Installing Bottom Mounting Screws
Side View
Wall
Spacer
Heater
Front View
MOUNTING HEATER TO FLOOR WITH OPTIONAL
FLOOR KIT [20,000 BTU/HR (5.9 KW) ONLY]
Mounting Base Feet to Heater
1. Lay heater cabinet on its back on a table with the heater bot-
tom overhanging the table edge.
2. Align holes in base foot with mounting holes on bottom of
cabinet (see Figure 20).
3. Secure base foot to heater using sheet metal screws.
4. Repeat for other side.
Mounting Base Feet to Floor (Where required by
local code)
Ifheateris being installed directlyoncarpeting, tile or
othercombustiblematerial(otherthanwoodflooring),
the heater shall be installed on a metal or wood panel
extending the full width and depth of the appliance.
1. Remove front cover (see Removing Front Panel of Heater,
page 10).
2. Position heater with base feet in desired location. Mark holes
for drilling. Remove heater with base.
3. If mounting base to a wood floor, drill 1/8 inch diameter hole,
3/4 inch (2 cm) deep. (Do not use anchors in wood floors).
If mounting base to a concrete floor, drill with 1/4 inch diam-
eter concrete drill bit, 13/8inches (3.5 cm) into floor. Insert
anchors completely into holes.
4. Reposition heater withbase feet overholes. Secure baseto floor
with wood screws. See Figure 20.
Figure20-InstallingBaseFeet(Heatermayvaryfromillustration)
Wood
Screw
Sheet Metal Screw Base Foot
INSTALLATION
Installing Heater To Wall 20,000 Btu/Hr Models (5.9 kW) (Cont.)
Mounting Heater To Floor With Optional Floor Kit [20,000 Btu/Hr (5.9 kW) Only]

112157-01A
12
For more information, visit www.desatech.com
For more information, visit www.desatech.com
INSTALLATION
Continued
INSTALLATION
Connecting To Gas Supply
Figure 22 - Gas Connection
* A CSA design-certified equipment shutoff valve with 1/8" NPT
tap is an acceptable alternative to test gauge connection. Purchase
the optional CSA design-certified equipment shutoff valve from
your dealer. See Accessories, page 29.
We recommend that you install sediment trap in supply line as
showninFigure22.Locatesedimenttrapwhereitiswithinreachfor
cleaning. Install in piping system between fuel supply and heater.
Locatesediment trapwhere trapped matter is notlikely tofreeze. 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 pressure regulator with wrench when con-
necting it to gas piping and/or fittings. Do not over tighten pipe
connection to regulator. The regulator body could be damaged.
Tee Joint
Reducer
Bushing to
1/8" NPT
1/8" NPT
Plug Tap
Test
Gauge
Connection*
Tee
Joint
Pipe
Nipple
Cap
Pressure
Regulator
Heater
Cabinet
3/8" NPT
Pipe Nipple
Ground
Joint Union
Sediment
Trap
3"
7.7 cm)
Minimum
Natural Gas
From Gas Meter
[ 6/10,000 Btu/Hr (1.8/2.9 kW)
4" (10 cm) W.C. to
10.5" (26.7 cm) W.C.
Pressure]
20,000 Btu/Hr (5.9 kW)
5" (12.7 cm) W.C. to 10.5"
(26.7 cm) W.C. Pressure]
Propane/LP
From External Regulator
(11" (27.9 cm) W.C. to
14" (35.6 cm) W.C. Pressure)
Equipment
Shutoff Valve*
Installationmustincludeequipmentshutoffvalve,union,andplugged
1/8" NPT tap. Locate NPT tap within reach for test gauge hook up.
NPT tap must be upstream from heater (see Figure 22).
IMPORTANT: Install an equipment shutoff valve in an accessible
location. The equipment 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:Usepipejoint sealant thatisresistant
to liquid petroleum (LP) gas.
CONNECTING TO GAS SUPPLY
WARNING: This appliance requires a 3/8" NPT
(National Pipe Thread) inlet connection to the pres-
sure regulator.
WARNING: A qualified service person must con-
nect heater to gas supply. Follow all local codes.
WARNING:Fornaturalgas,neverconnectheaterto
private (non-utility) gas wells. This gas is commonly
known as wellhead gas.
IMPORTANT :For natural gas, check gas line pressure before
connectingheatertogasline.Gaslinepressuremustbenogreaterthan
10.5 inches (26.6 cm) of water. If gas line pressure is higher, heater
regulator damage could occur.
CAUTION: For propane/LP gas, never connect
heater directly to the propane/LP supply. This heater
requires an external regulator (not supplied). Install
the external regulator between the heater and pro-
pane/LP supply.
Forpropane/LPgas,theinstallermustsupplyanexternalregulator.The
externalregulatorwillreduceincominggaspressure.Youmustreduce
incoming gas pressure to between 11 and 14 inches (28 and 35.5 cm)
of water. If you do not reduce incoming gas pressure, heater regulator
damage could occur. Install external regulator with the vent pointing
down as shown in Figure 21. Pointing the vent down protects it from
freezing rain or sleet.
CAUTION: Use only new, black iron or steel pipe.
Internally-tinned copper tubing may be used in cer-
tain areas. Check your local codes. Use pipe of large
enoughdiametertoallowpropergasvolumetoheater.
If pipe is too small, undue loss of volume will occur.
Propane/LP
Supply Tank
Figure 21 - External Regulator With Vent Pointing Down
(Propane/LP Systems Only)
External Regulator
Vent Pointing Down
Typical inlet pipe diameter for 20,000 btu/hr (5.9 kW) models - 3/8"
or greater.

112157-01A
13
13
For more information, visit www.desatech.com
For more information, visit www.desatech.com
ON
POSITIO
OF
POSI
Figure 23 - Equipment Shutoff Valve
Equipment
Shutoff Valve Open
Closed
Figure 25 - Checking Gas Joints for Propane/LP Gas [6,000
Btu/Hr Model (1.8 kW) Shown]
Figure 24- Checking Gas Joints for Natural Gas [6,000 Btu/Hr
Model (1.8 kW) Shown]
INSTALLATION
Continued
INSTALLATION
Checking Gas Connections
2. Open main gas valve located on or near gas meter for natural
gas or 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 control valve
(see Figures 24 and 25). Apply a noncorrosive leak detection
fluid to all joints. Bubbles forming show a leak.
5. Correct all leaks at once.
6. Light heater (see Operating Heater pages 14 and 15). Check
the rest of the internal joints for leaks.
7. Turn off heater (see To Turn Off Gas to Appliance, page 15).
8. Replace front panel.
CHECKING GAS CONNECTIONS
WARNING: Test all gas piping and connections
forleaksafterinstallingorservicing.Correctallleaks
at once.
WARNING: Never use an open flame to check for
aleak.Applyanoncorrosiveleakdetectionfluidtoall
joints.Bubblesformingshowaleak.Correctallleaks
at once.
CAUTION: For propane/LP gas, make sure exter-
nalregulator hasbeeninstalledbetweenpropane/LP
supply and heater. See guidelines under Connecting
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 (con-
trol valve) and equipment shutoff valve from gas supply pip-
ing system. Pressures in excess of 1/2 psig (3.5 kPa) will dam-
age heater regulator.
2. Cap off open end of gas pipe where equipment shutoff valve
was connected.
3. Pressurize supply piping system by either opening propane/LP
supplytank valve forpropane/LP gas oropening main gasvalve
located on or near gas meter for natural gas, or using com-
pressed air.
4. Check all joints of gas supply piping system.Apply a noncorrosive
leak detection fluid 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 fittings for leaks.
Test Pressures Equal To or Less Than 1/2 PSIG (3.5 kPa)
1. Close equipment shutoff valve (see Figure 23).
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 24)
or propane/LP supply tank for propane/LP gas, to equipment
shutoff valve (see Figure 25). Apply a noncorrosive leak de-
tection fluid 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 Figure 23).
Propane/LP
Supply Tank Control
Valve Location
Control Valve Location
Gas
Meter
Equipment
Shutoff Valve
Equipment
Shutoff Valve

112157-01A
14
For more information, visit www.desatech.com
For more information, visit www.desatech.com
O
F
F
P
I
L
O
T
Figure 27 - Control Knob In
TheOFFPosition (Thermostat
Controlled Models)
Ignitor Button
OPERATING HEATER
FOR YOUR SAFETY READ
BEFORE LIGHTING
WARNING:If youdonot followtheseinstructions
exactly, a fire or explosion may result causing prop-
erty damage, personal 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 IFYOU 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 de-
partment.
C. Useonlyyourhand topush in orturn thegas controlknob.
Never use tools. If the knob will not push in or turn by
hand, don’t try to repair it, call a qualified service techni-
cian or gas supplier. 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 a qualified 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 control knob clockwise
Clockwise
to the OFF position
(see Figure 26 or 27).
4. Wait five (5) minutes to clear out any gas. Then smell for
gas, including near the floor. If you smell gas, STOP! Fol-
low “B”in the safety information, above. If youdon’t smell
gas, go to the next step.
5. Press in control knob and turn counterclockwise C-clockwise
to the PILOT position. Keep control knob pressed in for
five (5) seconds (see Figure 26 or 27).
Note: You may be running this heater for the first 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 al-
low air to bleed from the gas system.
• If control knob does not pop up when released, contact a
qualified service person or gas supplier for repairs.
OPERATING HEATER
For Your Safety Read Before Lighting
Lighting Instructions
6. With control knob pressed in, push down and release igni-
tor button. This will light pilot. The pilot is attached to the
frontof burner.Thepilotcan beseenthroughtheglass panel.
If needed, keep pressing ignitor button until pilot lights.
Note: If pilot does not stay lit, refer to Troubleshooting,
pages 18 through 20. Also contact a qualified service per-
sonor gassupplier forrepairs.Until repairs aremade,light
pilot with a match. To light pilot with amatch, see Manual
Lighting Procedure, page 15.
7. Keep control knob pressed in for 30 seconds 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 3 through 7. Thermo-
stat model heaters have a safety interlock system.Wait one
(1) minute before lighting pilot again.
8. Manual Controlled Models Only Turncontrolknobcoun-
terclockwise C-clockwise to the HI position. The main burner
should light. Set control knob to HI or LO. To turn control
knobfromHItoLO,pressinthecontrolknobandturncoun-
terclockwise C-clockwise .
Note: Both HIand LOarelockedpositions.Youmustpress
in control knob before turning it from these positions.
9. Thermostat Controlled Models Only Turncontrolknob
counterclockwise
C-clockwise
to desired heating level. The
mainburnershouldlight. Setcontrolknob toany heatlevel
between 1 and 5.
CAUTION: Do not try to adjust heating levels by
using the equipment shutoff valve.
Figure 28 - Pilot
Figure 26 - Control Knob In
The OFF Position (Manual
Controlled Models)
Ignitor Electrode
Pilot Burner
Thermocouple
Ignitor Button Control Knob Control Knob

112157-01A
15
15
For more information, visit www.desatech.com
For more information, visit www.desatech.com
OPERATING HEATER
Continued
TO TURN OFF GAS
TO APPLIANCE
1. Remove front panel [for 6,000 (1.8 kW) and 10,000 (2.9 kW)
Btu/Hr heater see Figure 11, page 9, for 20,000 Btu/Hr (5.9
kW) heater, see Figure 14 page 10].
2. Follow steps 1 through 5 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 seconds after pilot is
lit. After 30 seconds, release control knob. Follow step 8
under Lighting Instructions, page 14.
5. Replace front panel.
Shutting Off Heater
1. Press inandturncontrolknobclockwise
Clockwise
totheOFF
position.
2. Turn off all electric power to the appliance if service is to
be performed.
Shutting Off Burner Only (pilot stays lit)
Turn control knob clockwise
Clockwise
to the PILOT position.
MANUAL LIGHTING
PROCEDURE
OPERATING HEATER
To Turn Off Gas To Appliance
Thermostat Control Operation (Thermostat Models Only)
Manual Lighting Procedure
INSPECTING BURNER
Pilot Flame Pattern
Burner Flame Pattern
The thermostatic control used on these models differs from
standardthermostats.Standard thermostatssimplyturn onand
off the burner. The thermostat used on this heater senses the
room temperature. The thermostat adjusts the amount of gas
flow to the burner. This increases or decreases the burner flame
height. At times the room may exceed the set temperature. If so,
theburnerwillshutoff.Theburnerwillcyclebackonwhenroom
temperature drops below the set temperature. The control knob
can be set to any heat level between 1 and 5.
Note: Thethermostatsensingbulb measuresthetemperatureof
airneartheheatercabinet.Thismaynotalwaysagreewithroom
temperature (depending on housing construction, installation
location,room size,open airtemperatures, etc.).Frequent useof
your heater will let you determine your own comfort levels.
THERMOSTAT CONTROL
OPERATION (THERMOSTAT
MODELS ONLY)
INSPECTING BURNER
Check pilot flame pattern and burner flame pattern often.
PILOT FLAME PATTERN
Figure 29 shows a correct pilot flame pattern. Figure 30 shows an
incorrect pilot flame pattern. The incorrect pilot flame is not
touching the thermocouple. This will cause the thermocouple to
cool. When the thermocouple cools, the heater will shut down.
If pilot flame pattern is incorrect, as shown in Figure 30
• turn heater off (see To Turn Off Gas to Appliance, column 1)
• see Troubleshooting, pages 18 through 20
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.
Figure30-IncorrectPilotFlame
Pattern
Figure 29 - Correct Pilot
Flame Pattern
Thermocouple
Pilot Burner Pilot
Burner
Thermocouple
Blue Flame Yellow Flame
BURNER FLAME PATTERN
WARNING: If yellow tipping occurs, your heater
could produce increased levels of carbon monoxide.
NOTICE: Do not mistake orange flames with yellow
tipping. Dust or other fine particles enter the heater
and burn causing brief patches of orange flame.
Figure31 showsa correct burnerflame pattern.Figure 32 showsan
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 32
• turn heater off (see To Turn Off Gas to Appliance, column 1)
• see Troubleshooting, pages 18 through 20
Figure 31 - Correct Burner
Flame Pattern Figure 32 - Incorrect Burner
Flame Pattern
(Models GCN6 and GCP6 will be
lower due to lower input rating)
1/2 GLASS HEIGHT
Yellow
Tipping

112157-01A
16
For more information, visit www.desatech.com
For more information, visit www.desatech.com
CLEANING AND
MAINTENANCE
WARNING: Turn off heater and let cool before
cleaning.
CAUTION: You must keep control areas, burner,
and circulating air passageways of heater clean. In-
spect these areas of heater before each use. Have
heater inspected yearly by a qualified service person.
Heatermayneedmorefrequentcleaningduetoexces-
sivelintfromcarpeting,beddingmaterial,pethair,etc.
CABINET
Air Passageways
• Use a vacuum cleaner or pressurized air to clean.
Exterior
• Use a soft cloth dampened with a mild soap and water mixture.
Wipe the cabinet to remove dust.
Figure 33 - Pilot Inlet Air Hole
CLEANING AND MAINTENANCE
ODS/Pilot and Burner Orifice
Burner Pilot Air Inlet Hole
Cabinet
ODS/PILOT AND BURNER ORIFICE
• Use a vacuum cleaner, pressurized air, or small, soft bristled
brush to clean.
BURNER PILOT AIR INLET HOLE
Theprimaryairinletholesallow the proper amount of airtomixwith
the gas. This provides a clean burning flame. Keep these holes clear
of dust, dirt, lint, and pet hair. 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
fireplace inspected yearly by a qualified 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
recommendusing compressed airnogreater than30PSI (207 kPa).
Your local computer store, hardware store, or home center may
carry compressed air in a can. You can use a vacuum cleaner in the
blow position. 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 damage the pilot assembly.
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. 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 flame
indicates dust and dirt in the pilot assembly. There is a small pilot
airinlet holeabouttwoinchesfromwherethepilotflamecomesout
ofthepilot assembly (seeFigure33).With the unitoff, lightlyblow
airthroughtheairinlethole.Youmayblowthroughadrinkingstraw
if compressed air is not available.
Pilot Assembly
Pilot Air Inlet
WARNING: Failure to keep the primary air
opening(s) of the burner(s) clean may result in soot-
ing and property damage.

112157-01A
17
17
For more information, visit www.desatech.com
For more information, visit www.desatech.com
TROUBLESHOOTING
TROUBLESHOOTING
WARNING: Turn off heater
andletcoolbeforeservicing.Only
aqualifiedservicepersonshould
service and repair heater.
POSSIBLE CAUSE
1. Ignitor electrode positioned wrong
2. Ignitor electrode broken
3. Ignitor electrode not connected to igni-
tor 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 installed
5. Depleted gas supply (propane/LP only)
6. ODS/pilot is clogged
7. Gas regulator setting is not correct
1. Control knob not fully pressed in
2. Control knob notpressed inlong enough
3. Safety interlock system has been
triggered
4. Equipment shutoff valve not fully open
5. Thermocouple connection loose at con-
trol valve
6. Pilot flame not touching thermocouple,
which allows thermocouple to cool,
causing pilot flame to go out. This prob-
lem 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
OBSERVED PROBLEM
When ignitor button is pressed, there is no
spark at ODS/pilot
When ignitor button is pressed, there is
spark at ODS/pilot but no ignition
ODS/pilot lights but flame goes out when
control knob is released
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 piezo ignitor
1. Turn on gas supply or open equipment
shutoff valve
2. Turn control knob to PILOT position
3. Press in control knob while in PILOT
position
4. Continue holding down control knob.
Repeat igniting operation until air is re-
moved
5. Contact local propane/LP gas company
6. Clean ODS/pilot (see Cleaning and
Maintenance, page 16) or replace ODS/
pilot assembly
7. Replace gas regulator
1. Press in control knob fully
2. After ODS/pilot lights, keep control
knob pressed in 30 seconds
3. Wait one minutefor safetyinterlock sys-
tem to reset. Repeat ignition operation
4. Fully open equipment shutoff 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 Cleaning and
Maintenance, page 16) or replace ODS/
pilot assembly
7. Replace pilot assembly
8. Replace control valve
CAUTION: Never use a wire,
needle, or similar object to clean
ODS/pilot.ThiscandamageODS/
pilot unit.
Note: For additional help, visit DESA’s
technical service web site at
www.desatech.com.
Note: Alltroubleshootingitemsarelistedin
order of operation.

112157-01A
18
For more information, visit www.desatech.com
For more information, visit www.desatech.com
TROUBLESHOOTING
OBSERVED PROBLEM
Burner does not light after ODS/pilot is lit
Delayed ignition of burner
Burner backfiring during combustion
Yellow flame during burner combustion
Slightsmokeor odor duringinitialoperation
Heater produces a whistling noise when
burner is lit
Heater produces a clicking/ticking noise
just after burner is lit or shut off
REMEDY
1. Clean burner orifice (see Cleaning and
Maintenance,page 16) orreplace burner
orifice
2. Contact local natural or propane/LP gas
company
1. Contact local natural or propane/LPgas
company
2. Clean burner orifice (see Cleaning and
Maintenance,page 16) orreplace burner
orifice
1. Clean burner orifice (see Cleaning and
Maintenance, page 16) or replace burner
orifice
2. Replace burner
3. Replace gas regulator
1. Check burner for dirt and debris. If
found, clean burner (see Cleaning and
Maintenance, page 16)
2. Replace gas regulator
3. Clean burner (see Cleaning and Main-
tenance, page 16)
1. Problem will stop after a few hours of
operation
1. Turn control knob to LO position and
let warm up for a minute
2. Operate burner until air is removed from
line. Have gas checked by local natural
or propane/LP gas company
3. Observe minimum installation clear-
ances (see Figure 4, page 7)
4. Clean burner (see Cleaning and Mainte-
nance, page 16) or replace burner orifice
1. This is common with most heaters. If
noise is excessive, contact qualified ser-
vice person
POSSIBLE CAUSE
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
1. Not enough air
2. Gas regulator defective
3. Clogged or dirty burner
1. Residues from manufacturing processes
1. Turning control knob to HI position
when burner is cold
2. Air in gas line
3. Air passageways on heater blocked
4. Dirty or partially clogged burner orifice
1. Metal expanding while heating or con-
tracting while cooling
TROUBLESHOOTING
Continued

112157-01A
19
19
For more information, visit www.desatech.com
For more information, visit www.desatech.com
TROUBLESHOOTING
Continued
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.
•Immediatelycallyourgassupplierfromaneighbor’sphone.Followthe
gas supplier’s instructions.
•If you cannot reach your gas supplier, call the fire department.
IMPORTANT: Operating heater where impurities in air exist may create odors. Cleaning
supplies, 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.
OBSERVED PROBLEM
Whitepowderresidueformingwithinburner
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 combustion
Moisture/condensationnoticedonwindows
POSSIBLE CAUSE
1. When heated, vapors from furniturepol-
ish, wax, carpet cleaners, 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 only)
3. Gas leak. SeeWarning statement at
top of page
1. Not enough fresh air is available
2. Low line pressure
3. ODS/pilot is partially clogged
1. Gas leak. SeeWarning statement at
top of page
2. Control valve defective
1. Foreign matter between control valve
and burner
2. Gas leak. SeeWarning statement at
top of page
1. Not enough combustion/ventilation air
REMEDY
1. Turn heater off when using furniture
polish, wax, carpet cleaners, or similar
products
1. Ventilate room. Stop using odor-causing
products while heater is running
2. Refill supply tank (propane/LP only)
3. Locate and correct all leaks (see Check-
ing Gas Connections, page 13)
1. Open window and/ordoorfor ventilation
2. Contact local natural or propane/LP gas
company
3. Clean ODS/pilot (see Cleaning and
Maintenance, page 16)
1. Locate and correct all leaks (see Check-
ing Gas Connections, page 13)
2. Replace control valve
1. Take apart gas tubing and remove for-
eign matter
2. Locate and correct all leaks (see Check-
ing Gas Connections, page 13)
1. Refer to Fresh Air for Combustion and
Ventilation requirements (page 4)
TROUBLESHOOTING

112157-01A
20
For more information, visit www.desatech.com
For more information, visit www.desatech.com
ILLUSTRATED PARTS
BREAKDOWN
MANUAL CONTROL MODELS
GCP6 AND GCN6
10
12
11
1
2
3
4
5
6
79
81
10
13 14
15
17
18
21 22
25
20
24
23
19
26
27
16
ILLUSTRATED PARTS BREAKDOWN
Models GCP6 and GCN6
PILOT