Desa MP10T Original instructions

VENT-FREE GAS HEATER
SAFETY INFORMATION AND INSTALLATION MANUAL
GWN6, GWP6, GWN10, GWP10, GWN10T, GWP10T, GWRN10,
GWRP10, MN10T, MP10T, VN1000BTA, VP1000BTA, VN10A,
VP10A, VN10TA, VP10TA, VN6D, VP5D, WMN10, WMP10
For more information, visit www.desatech.com
WARNING: If the information in this manual is not
followed exactly, a re or explosion may result causing
property damage, personal injury or loss of life.
— Do not store or use gasoline or other ammable
vapors and liquids in the vicinity of this or any other
appliance.
— WHAT TO DO IF YOU SMELL GAS
• Do not try to light any appliance.
• Do not touch any electrical switch; do not use any
phone in your building.
• Immediately call your gas supplier from a neighbor’s
phone. Follow the gas supplier’s instructions.
• If you cannot reach your gas supplier, call the re
department.
— Installation and service must be performed by a quali-
ed installer, service agency or the gas supplier.
INSTALLER: Leave this manual with the appliance.
CONSUMER: Retain this manual for future reference.

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SAFETY
This appliance may be in-
stalled in an aftermarket,*
permanently located,
manufactured (mobile)
home, where not prohib-
ited by local codes.
* Aftermarket: Completion of sale, not for
purpose of resale, from the manufacturer
WARNING: This product con-
tains and/or generates chemicals
known to the State of California
to cause cancer or birth defects
or other reproductive harm.
IMPORTANT: Read this owner’s
manual carefully and completely
before trying to assemble,
operate or service this heater.
Improper use of this heater can
cause serious injury or death
from burns, fire, explosion,
electrical shock and carbon
monoxide poisoning.
DANGER: Carbon monoxide
poisoning may lead to death!
Carbon Monoxide Poisoning: Early signs
of carbon monoxide poisoning resemble the
u, with headaches, dizziness or nausea. If
you have these signs, the heater may not be
working properly. Get fresh air at once! Have
heater serviced. Some people are more af-
fected by carbon monoxide than others. These
include pregnant women, people with heart or
lung disease or anemia, those under the inu-
ence of alcohol and those at high altitudes.
WARNING: Improper
installation, adjustment,
alteration, service or main-
tenance can cause injury
or property damage. Refer
to this manual for correct
installation and operation-
al procedures. For assis-
tance or additional infor-
mation consult a qualied
installer, service agency or
the gas supplier.
WARNING: This is an
unvented gas-red heater.
It uses air (oxygen) from the
room in which it is installed.
Provisions for adequate
combustion and ventila-
tion air must be provided.
Referto Air for Combustion
and Ventilation section on
page 5 of this manual.
This appliance is only for
use with the type of gas
indicated on the rating
plate. This appliance is
not convertible for use
with other gases.
TABLE OF CONTENTS
Safety .................................................................. 2
Local Codes......................................................... 4
Unpacking............................................................ 4
Product Identication ........................................... 4
Product Features ................................................. 5
Air for Ventilation and Combustion ...................... 5
Installation ........................................................... 7
Operation ........................................................... 13
Inspecting Burner .............................................. 15
Cleaning ............................................................ 17
Technical Service............................................... 17
Service Hints ..................................................... 17
Service Publications .......................................... 17
Troubleshooting ................................................. 18
Replacement Parts ............................................ 21
Parts .................................................................. 22
Specications .................................................... 26
Accessory .......................................................... 27
Parts Centrals .................................................... 27

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123995-01C 3
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 a
blower insert, heat exchanger
insert or other accessory not ap-
proved for use with this heater.
Due to high temperatures, the
appliance should be located out
of trafc and away from furniture
and draperies.
Do not place clothing or other
ammable material on or near
the appliance. Never place any
objects on the heater.
Surface of heater becomes very
hot when running heater. Keep
children and adults away from
hot surface to avoid burns or
clothing ignition. Heater will
remain hot for a time after shut-
down. Allow surface to cool
before touching.
Carefully supervise young chil-
dren when they are in the same
room with heater.
Make sure grill guard is in place
before running heater.
Keep the appliance area clear
and free from combustible ma-
terials, gasoline and other am-
mable vapors and liquids.
1. This appliance is only for use with the type
of gas indicated on the rating plate. This
appliance is not convertible for use with
other gases.
2. Do not place propane/LP supply tank(s)
inside any structure. Locate propane/LP
supply tank(s) outdoors.
3. Do not install 10,000 Btu/hr units in a bath-
room (6,000 Btu/hr heaters are allowed in
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 sup-
plier’s instructions
• If you cannot reach your gas supplier,
call the re department
5. This heater needs fresh, outside air ventila-
tion to run properly. This heater has an Oxy-
gen Depletion Sensing (ODS) safety shutoff
system. The ODS shuts down the heater if
not enough fresh air is available. See Air for
Combustion and Ventilation, page 5.
6. Always run heater with plaque control knob
at the locked positions or ON position.
Never set control knob between locked
positions. Poor combustion and higher
levels of carbon monoxide may result.
7. Keep all air openings in the front and
bottom of heater clear and free of debris.
This will insure enough air for proper
combustion.
8. If heater shuts off, do not relight until you
provide fresh, outside air. If heater keeps
shutting off, have it serviced.
9. Do not run heater
• where ammable liquids or vapors are
used or stored
• under dusty conditions
10. 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.
SAFETY
Continued

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11. Do not use heater if any part has been
under water. Immediately call a qualied
service technician to inspect the room
heater and to replace any part of the
control system and any gas control which
has been under water.
12. Turn off heater and let cool before servic-
ing. Only a qualied service person should
service and repair heater.
SAFETY
Continued
Figure 1 - Vent-Free Gas Heater
Blue Flame Heater Infrared Heater
Control Knob
Ignitor Button
Grill
Guard
Front
Panel
Burners
Heater
Cabinet
Control Knob
Ignitor Button
Glass
Panel
Front
Panel
Heater
Cabinet
Grill
Guard
PRODUCT IDENTIFICATION
13. Operating heater above elevations of
4,500 feet could cause pilot outage.
14. To prevent performance problems, do
not use propane/LP fuel tank of less
than 100 lbs. capacity.
15. 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 tter in the Commonwealth of Mas-
sachusetts.
Sellers of unvented propane or natural
gas-red supplemental room heaters shall
provide to each purchaser a copy of 527
CMR 30 upon sale of the unit.
Vent-free gas products are prohibited for
bedroom and bathroom installation in the
Commonwealth of Massachusetts.
UNPACkING
1. Remove heater from carton.
2. Remove all protective packaging applied
to heater for shipment.
3. Check heater for any shipping damage. If
heater is damaged call DESA Heating, LLC
at 1-866-672-6040 for replacement parts
before returning to dealer.

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123995-01C 5
WARNING: This heater shall not
be installed in a room or space un-
less the required volume of indoor
combustion air is provided by the
method described in the National
Fuel Gas Code, ANSI Z223.1/NFPA
54, the International Fuel Gas Code,
or applicable local codes. Read the
following instructions to insure
proper fresh air for this and other fuel-
burning appliances in your home.
Today’s homes are built more energy efcient
than ever. New materials, increased insulation
and new construction methods help reduce
heat loss in homes. Home owners weather
strip and caulk around windows and doors
to keep the cold air out and the warm air in.
During heating months, home owners want
their homes as airtight as possible.
While it is good to make your home energy
efcient, your home needs to breathe. Fresh
air must enter your home. All fuel-burning ap-
pliances need fresh air for proper combustion
and ventilation.
Exhaust fans, replaces, clothes dryers and
fuel burning appliances draw air from the house
to operate. You must provide adequate fresh
air for these appliances. This will insure proper
venting of vented fuel-burning appliances.
PROVIDING ADEQUATE VENTILATION
The following are excerpts from National Fuel
Gas Code, ANSI Z223.1/NFPA 54, Air for
Combustion and Ventilation.
All spaces in homes fall into one of the three
following ventilation classications:
1. Unusually Tight Construction
2. Unconned Space
3. Conned Space
The information on pages 5 through 7 will help
you classify your space and provide adequate
ventilation.
Unusually Tight Construction
The air that leaks around doors and windows
may provide enough fresh air for combustion
and ventilation. However, in buildings of un-
usually tight construction, you must provide
additional fresh air.
Unusually tight construction is dened as
construction where:
a. walls and ceilings exposed to the outside
atmosphere have a continuous water
vapor retarder with a rating of one perm
(6 x 10-11 kg per pa-sec-m2) or less with
openings gasketed or sealed and
b. weather stripping has been added on
openable windows and doors and
c. caulking or sealants are applied to areas
such as joints around window and door
frames, between sole plates and oors,
between wall-ceiling joints, between wall
panels, at penetrations for plumbing, electri-
cal and gas lines and at other openings.
If your home meets all of the three criteria
above, you must provide additional fresh air.
See Ventilation Air From Outdoors, page 7.
If your home does not meet all of the three
criteria above, proceed to Determining Fresh-
Air Flow For Heater Location, page 6.
Conned and Unconned Space
The National Fuel Gas Code, ANSI Z223.1/
NFPA 54 denes a conned space as a space
whose volume is less than 50 cubic feet per
1,000 Btu/hr (4.8 m3 per kw) of the aggregate
input rating of all appliances installed in that
space and an unconned space as a space
whose volume is not less than 50 cubic feet per
1,000 Btu/hr (4.8 m3 per kw) of the aggregate
input rating of all appliances installed in that
space. Rooms communicating directly with the
space in which the appliances are installed*,
through openings not furnished with doors, are
considered a part of the unconned space.
* Adjoining rooms are communicating only if
there are doorless passageways or ventilation
grills between them.
PRODUCT FEATURES
SAFETY DEVICE
This heater has a pilot with an Oxygen Deple-
tion Sensing (ODS) safety shutoff system. The
ODS/pilot is a required feature for vent-free
room heaters. The ODS/pilot shuts off the
heater if there is not enough fresh air.
PIEzO IGNITION SYSTEM
This heater has a piezo ignitor. This system re-
quires no matches, batteries or other sources
to light heater.
THERMOSTATIC HEAT CONTROL
(Thermostat Models Only)
Thermostat models have a thermostat sens-
ing bulb and a control valve. This results in the
greatest heater comfort. This can also result
in lower gas bills.
AIR FOR VENTILATION AND COMBUSTION

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AIR FOR COMBUSTION AND VENTILATION
Continued
DETERMINING FRESH-AIR FLOW
FOR FIREPLACE LOCATION
Determining if You Have a Conned or
Unconned Space
Use this work sheet to determine if you have
a conned or unconned space.
Space: Includes the room in which you will install
replace plus any adjoining rooms with door-
less passageways or ventilation grills between
the rooms.
1. Determine the volume of the space (length
x width x height).
Length x Width x Height =__________cu. ft.
(volume of space)
Example: Space size 20 ft. (length) x 16 ft.
(width) x 8 ft. (ceiling height) = 2,560 cu. ft.
(volume of space)
If additional ventilation to adjoining room
is supplied with grills or openings, add the
volume of these rooms to the total volume
of the space.
2. Multiply the space volume by 20 to determine
the maximum Btu/Hr the space can support.
________ (volume of space) x 20 = (Maxi-
mum Btu/Hr the space can support)
Example: 2,560 cu. ft. (volume of space) x
20 = 51,200 (maximum Btu/Hr the space can
support)
3. Add the Btu/Hr of all fuel burning appliances
in the space.
Vent-free heater __________Btu/Hr
Gas water heater* __________Btu/Hr
Gas furnace __________Btu/Hr
Vented gas heater __________Btu/Hr
Gas replace logs __________Btu/Hr
Other gas appliances* + _________Btu/Hr
Total = _________Btu/Hr
* Do not include direct-vent gas appliances.
Direct-vent draws combustion air from the
outdoors and vents to the outdoors.
Example:
Gas water heater __________Btu/Hr
Vent-free heater + _________Btu/Hr
Total = _________Btu/Hr
4. Compare the maximum Btu/Hr the space
can support with the actual amount of Btu/Hr
used.
_______ Btu/Hr (maximum can support)
_______ Btu/Hr (actual amount used)
Example: 51,200 Btu/Hr (maximum the
space can support)
60,000 Btu/Hr (actual amount of
Btu/Hr used)
The space in the example is a conned space
because the actual Btu/Hr used is more than the
maximum Btu/Hr 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 unconned space, remove door to adjoin-
ing room or add ventilation grills between
rooms. See Ventilation Air From Inside
Building.
B. Vent room directly to the outdoors. See
Ventilation Air From Outdoors, page 7.
C. Install a lower Btu/Hr heater, if lower Btu/Hr
size makes room unconned.
If the actual Btu/Hr used is less than the maxi-
mum Btu/Hr the space can support, the space
is an unconned space. You will need no ad-
ditional fresh air ventilation.
WARNING:Iftheareainwhich
the heater may be operated does
not meet the required volume for
indoor combustion air, combus-
tion and ventilation air shall be
provided by one of the methods
described in the National Fuel
Gas Code,ANSI Z223.1/NFPA54,
theInternational Fuel Gas Code,
or applicable local codes.
VENTILATION AIR
Ventilation Air From Inside Building
This fresh air would come from an adjoining
unconned space. When ventilating to an
adjoining unconned space, you must provide
two permanent openings: one within 12" of
the ceiling and one within 12" of the oor on
the wall connecting the two spaces (see op-
tions 1 and 2, Figure 2, page 7). You can also
remove door into adjoining room (see option
3, Figure 2, page 7). Follow the National Fuel
Gas Code, ANSI Z223.1/NFPA 54, Air for
Combustion and Ventilation for required size
of ventilation grills or ducts.
50,000
10,000
60,000

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123995-01C 7
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
Or
Remove
Door into
Adjoining
Room,
Option 3
V e ntilation Grills
Into Adjoining Room,
Option 2
12"
12"
V e ntilation
Grills into
Adjoining
Room,
Option 1
Figure 2 - Ventilation Air from Inside
Building
Outlet
Air
Ve ntilated
Attic
Outlet
Air
Inlet
Air
Inlet Air Ve ntilated
Crawl Space
T o
Crawl
Space
T o Attic
Figure 3 - Ventilation Air from Outdoors
AIR FOR COMBUSTION AND VENTILATION
Continued
INSTALLATION
and one within 12" of the oor. Connect these
items directly to the outdoors or spaces open
to the outdoors. These spaces include attics
and crawl spaces. Follow the National Fuel
Gas Code, ANSI Z223.1/NFPA 54, Air for
Combustion and Ventilation for required size
of ventilation grills or ducts.
IMPORTANT: Do not provide openings for
inlet or outlet air into attic if attic has a thermo-
stat-controlled power vent. Heated air entering
the attic will activate the power vent.
NOTICE: This heater is intended
for use as supplemental heat.
Use this heater along with your
primary heating system. Do not
install this heater as your pri-
mary heat source. If you have a
central heating system, you may
run system’s circulating blower
while using heater. This will help
circulate the heat throughout the
house. In the event of a power
outage, you can use this heater
as your primary heat source.
WARNING: A qualied ser-
vice person must install heater.
Follow all local codes.
CHECK GAS TYPE
Use only the correct type of gas (natural or
propane/LP). If your gas supply is not the
correct gas type, do not install heater. Call
dealer where you bought heater for proper
type heater.
WARNING: This appliance is
equipped for either natural gas
or propane/LP gas but not both.
Gas type is indicated on the rat-
ing plate. Field conversion is not
permitted.
INSTALLATION ITEMS
Before installing heater, make sure you have
the items listed below.
• for propane/LP gas, external regulator
(supplied by installer)
• piping (check local codes)
• sealant (resistant to propane/LP gas)
• equipment shutoff valve *
• ground joint union
• sediment trap
• tee joint
• pipe wrench
• for natural gas, test gauge connection*
* A CSA design-certied equipment shutoff
valve with 1/8" NPT tap is an acceptable al-
ternative to test gauge connection. Purchase
the optional CSA design-certied equipment
shutoff valve from your dealer.

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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 oor,
ceiling and joining wall.
WARNING: Never install the
heater
• in a bathroom (10,000 Btu/hr
only. 6,000 Btu/hr models are
allowed in a bathroom. Check
local codes.)
• in a recreational vehicle
• where curtains, furniture,
clothing or other ammable
objects are less than 36" from
the front, top or sides of the
heater
• as a replace insert
• in high trafc areas
• in windy or drafty areas
INSTALLATION
Continued
CAUTION: If you install the
heater in a home garage
• heater pilot and burner must
be at least 18" above oor
• locate heater where moving
vehicle will not hit it
CAUTION: This heater cre-
ates warm air currents. These
currents move heat to wall sur-
faces next to heater. Installing
heater next to vinyl or cloth wall
coverings or operating heater
where impurities (such as, but
not limited to, tobacco smoke,
aromatic candles, cleaning u-
ids, oil or kerosene lamps, etc.) in
the air exist, may discolor walls
or cause odors.
IMPORTANT: Vent-free heaters add moisture
to the air. Although this is benecial, installing
heater in rooms without enough ventilation
air may cause mildew to form from too much
moisture. See Air for Combustion and Ventila-
tion, page 5.. If high humidity is experienced,
a dehumidier may be used to help lower the
water vapor content in the air.
For convenience and efficiency, install
heater
• where there is easy access for operation,
inspection and service
• in coldest part of room
THERMOSTAT SENSING BULB
(Thermostat Models Only)
The thermostat sensing bulb is located below
the heater. Do not move this bulb during instal-
lation or operation of the heater.
36" (91.5 cm)
3" (7.7 cm)
FLOOR
CEILING
Minimum
8"
(20.3 cm)
Minimum
From
Sides Of
Heater
Right
Side
Left
Side
36"
(91.5 cm)
Figure 4 - Mounting Clearances As
Viewed From Front of Heater
Minimum To Top
Surface Of Carpeting,
Tile Or Other
Combustible Material

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123995-01C 9
INSTALLING HEATER TO WALL
Marking Screw Locations
1. Determine where you will locate heater.
WARNING: Maintain mini-
mum clearances shown in Figure
5. If you can, provide greater
clearances from oor and join-
ing wall.
2. Mark two mounting screw locations on
wall (see Figure 5).
INSTALLATION
Continued
Figure 5 - Mounting Screw Locations
Mounting
Screw
Locations
10 7/8"
Minimum 7 3/4"
20 1/4"
Minimum To
Maintain 3"
Clearance
From Floor
FLOOR
JOINING WALL
Installing Two Mounting Screws
Note: Wall anchors and mounting screws are
in hardware package. 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" space (thickness
of penny) is between screw head and
wall.
Attaching to Wall Anchor Method
Follow instructions below to attach mounting
screws to hollow walls (wall areas between
studs) or solid walls (concrete or masonry).
1. Drill holes at marked locations using
5/16" drill bit. For solid walls (concrete or
masonry), drill at least 1 1/4" deep.
2. Fold wall anchor (see Figure 6).
3. Insert wall anchor (wings rst) into hole.
Tap anchor ush to wall.
4. For thin walls (1/2" or less), insert red key
into wall anchor. Push red key to “pop”
open anchor wings (see Figure 7).
IMPORTANT: Do not hammer key! For
thick walls (over 1/2" thick) or solid walls,
do not pop open wings.
5. Tighten two screws until 1/16" space
(thickness of penny) is between screw
heads and wall (see Figure 8).
Figure 6 - Folding Anchor
Figure 7 - Popping Open Anchor Wings
For Thin Walls
Figure 8 - Tightening Anchors
Thin or
Thick Wall
(thick wall
shown)
Solid
Wall
1/16"
Space
Placing Heater On Mounting Screws
1. Locate two keyhole slots on back panel
of heater (see Figure 9).
2. Place large openings of slots over screw
heads. Slide heater down until screws are
in small portion of slots.
Figure 9 - Location Of Keyhole Slots On
Back Panel Of Heater
Keyhole Slots

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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".
3. Pull bottom of front panel forward, then
down.
Figure 10 - Removing Front Panel Of
Heater
Installing Bottom Mounting Screw
1. Locate bottom mounting hole. This hole is
near bottom on back panel of heater (see
Figure 11).
2. Mark screw location on wall.
3. Remove heater from wall.
4. If installing bottom mounting screw into hol-
low or solid wall, install wall anchor. Follow
steps 1 through 5 under Attaching To Wall
Anchor Method, page 9. 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 11).
7. Tighten screw until heater is rmly se-
cured 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 10 through 13).
Figure 11 - Installing Bottom Mounting
Screw
CONNECTING TO GAS SUPPLY
WARNING: This appliance
requires a 3/8" NPT (National
Pipe Thread) inlet connection to
the pressure regulator.
WARNING: A qualied service
person must connect heater to gas
supply. Follow all local codes.
WARNING: For natural
gas, never connect heater to
private (non-utility) gas wells.
This gas is commonly known
as wellhead gas.
IMPORTANT: For natural gas, check gas line
pressure before connecting heater to gas line.
Gas line pressure must be no greater than
10.5" of water. If gas line pressure is higher,
heater regulator damage could occur.
CAUTION: For propane/LP
gas, never connect heater di-
rectly to the propane/LP supply.
This heater requires an external
regulator (not supplied). Install
the external regulator between the
heater and propane/LP supply.
For propane/LP gas, the installer must supply
an external regulator. The external regulator
will reduce incoming gas pressure. You must
reduce incoming gas pressure to between 11"
and 14" of water. If you do not reduce incom-
ing gas pressure, heater regulator damage
could occur. Install external regulator with
the vent pointing down as shown in Figure
12, page 11. 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.

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123995-01C 11
Installation must include equipment shutoff
valve, union and plugged 1/8" NPT tap. Locate
NPT tap within reach for test gauge hook up.
NPT tap must be upstream from heater (see
Figure 13).
IMPORTANT: Install an equipment shutoff
valve in an accessible location. The equip-
ment shutoff valve is for turning on or shutting
off the gas to the appliance.
Check your building codes for any special
requirements for locating equipment shutoff
valve to heaters.
Apply pipe joint sealant lightly to male NPT
threads. This will prevent excess sealant from
going into pipe. Excess sealant in pipe could
result in clogged heater valves.
WARNING: Use pipe joint
sealant that is resistant to liquid
petroleum (LP) gas.
Install sediment trap in supply line as shown
in Figure 13. Locate sediment trap where it is
within reach for cleaning. Locate sediment trap
where trapped matter is not likely to freeze.
A sediment trap traps moisture and contami-
nants. 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 connecting it to gas piping
and/or ttings. Do not over tighten pipe con-
nection to regulator. The regulator body could
be damaged.
INSTALLATION
Continued
Propane/LP
Supply Tank
Figure 12 - External Regulator With Vent
Pointing Down (propane/LP only)
Figure 13 - Gas Connection
* A CSA design-certied equipment shutoff
valve with 1/8" NPT tap is an acceptable al-
ternative to test gauge connection. Purchase
the optional CSA design-certied equipment
shutoff valve from your dealer.
Tee Joint
Reducer
Bushing to
1/8" NPT
1/8" NPT
Plug Tap
Tee
Joint
Pipe
Nipple
Cap
3/8"
NPT
Pipe
Nipple
Ground
Joint
Union
3"
Min
Natural Gas
From Gas Meter
(4" W.C. to 10.5" W.C.
Pressure [See
Specications, page 26])
Propane/LP
From External Regulator
(11" W.C. to 14" W.C.
Pressure)
Equipment
Shutoff
Valve*
Test Gauge Connection*
Pressure
Regulator
Heater
Cabinet
Sediment
Trap
External
Regulator
with Vent
Pointing
Down

www.desatech.com 123995-01C12
Test Pressures Equal To or Less Than
1/2 PSIG (3.5 kPa)
1. Close equipment shutoff valve (see Fig-
ure 14).
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 natu-
ral or propane/LP supply to equipment
shutoff valve (see Figure 15 or 16). Apply
a noncorrosive leak detection uid to all
joints. Bubbles forming show a leak.
4. Correct all leaks at once.
INSTALLATION
Continued
Figure 14 - Equipment Shutoff Valve
Equipment
Shutoff Valve
Open
Closed
Propane/LP
Supply Tank
Control Valve Location
Figure 16 - Checking Gas Joints for
Propane/LP Gas
Figure 15 - Checking Gas Joints for
Natural Gas
Control
Valve
Location
Gas Meter
Equipment
Shutoff
Valve
Equipment Shutoff Valve
CHECKING GAS CONNECTIONS
WARNING: Test all gas piping
and connections, internal and
external to unit, for leaks after
installing or servicing. Correct
all leaks at once.
WARNING: Never use an
open ame to check for a leak.
Apply a noncorrosive leak detec-
tion uid to all joints. Bubbles
forming show a leak. Correct all
leaks at once.
CAUTION: For propane/LP
gas, make sure external regula-
tor has been installed between
propane/LP supply and heater.
See guidelines under Connect-
ing to Gas Supply, page 10.
PRESSURE TESTING GAS SUPPLY
PIPING SYSTEM
Test Pressures In Excess Of 1/2 PSIG
(3.5 kPa)
1. Disconnect appliance with its appliance
main gas valve (control valve) and equip-
ment shutoff valve from gas supply piping
system. Pressures in excess of 1/2 psig
will damage heater regulator.
2. Cap off open end of gas pipe where equip-
ment shutoff valve was connected.
3. Pressurize supply piping system by either
opening propane/LP supply tank valve
for propane/LP gas or opening main gas
valve located on or near gas meter for
natural gas, or using compressed air.
4. Check all joints of gas supply piping sys-
tem. Apply a noncorrosive leak detection
uid to all joints. Bubbles forming show a
leak.
5. Correct all leaks at once.
6. Reconnect heater and equipment shutoff
valve to gas supply. Check reconnected
ttings for leaks.

www.desatech.com
123995-01C 13
INSTALLATION
Continued
OPERATION
PRESSURE TESTING HEATER GAS
CONNECTIONS
1. Open equipment shutoff valve (see Figure
14, page 12).
2. For natural gas open main gas valve locat-
ed on or near gas meter. For propane/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 control valve (see Figures 15 or
LIGHTING
INSTRUCTIONS
1. STOP! Read the safety information start-
ing in column 1.
2. Make sure equipment shutoff valve is fully
open.
3. Turn off any electric power to the appli-
ance if service is to be performed.
4. Turn control knob clockwise to the
OFF position.
5. Wait ve (5) minutes to clear out any gas.
Then smell for gas, including near the oor.
If you smell gas, STOP! Follow “B” in the
safety information starting in column 1. If
you don’t smell gas, go to the next step.
6. Thermostat Models: Turn control knob
counterclockwise to the PILOT
position. Press in control knob for ve (5)
seconds.
Manual Models: Press in and turn control
knob counterclockwise to the PI-
LOT position. Keep control knob pressed
in for ve (5) seconds.
7. With control knob pressed in, push down and
release ignitor button. This will light pilot. The
pilot is attached to the front of burner.
Note: You may be running this heater for
the rst time after hooking up to gas sup-
ply. If so, the control knob may need to be
pressed in for 30 seconds or more. This will
allow air to bleed from the gas system.
If needed, keep pressing ignitor button
until pilot lights. If ignitor does not light
pilot, refer to Troubleshooting, page 18
or contact a qualied service person or
gas supplier for repairs. Until repairs are
made, light pilot with match. See Manual
Lighting Procedure, page 14.
16, page 12). Apply a noncorrosive leak
detection uid to all joints. Bubbles form-
ing show a leak.
5. Correct all leaks at once.
6. Light heater (see Operation). Check all
other internal joints for leaks.
7. Turn off heater (see To Turn Off Gas to
Appliance, page 14).
8. Replace front panel.
FOR YOUR SAFETY
READ BEFORE LIGHTING
WARNING: If you do not fol-
low these instructions exactly,
a re or explosion may result
causing property damage, per-
sonal injury or loss of life.
A. This appliance has a pilot which must
be lighted by hand. When lighting the pi-
lot, follow these instructions exactly.
B. BEFORE LIGHTING smell all around
the appliance area for gas. Be sure to
smell next to the oor because some
gas is heavier than air and will settle
on the oor.
WHAT TO DO IF YOU SMELL GAS
• Do not try to light any appliance.
• Do not touch any electric switch; do
not use any phone in your building.
• Immediately call your gas supplier
from a neighbor’s phone. Follow the
gas supplier’s instructions.
• If you cannot reach your gas supplier,
call the re department.
C. Use only your hand to push in or turn
the gas control knob. Never use tools.
If the knob will not push in or turn by
hand, don’t try to repair it, call a qualied
service technician. Force or attempted
repair may result in a re or explosion.
D. Do not use this appliance if any part
has been under water. Immediately call
a qualied service technician to inspect
the appliance and to replace any part of
the control system and any gas control
which has been under water.

www.desatech.com 123995-01C14
8. Keep control knob pressed in for 30 sec-
onds after lighting pilot. After 30 seconds,
release control knob.
• If control knob does not pop up when
released, contact a qualified service
person or gas supplier for repairs.
Note: If pilot goes out, repeat steps 4 thru
7. Wait one (1) minute before lighting pilot
again.
9. Turn control knob counterclockwise
to desired heating level. The main
burner should light. Manual control heat-
ers should be used in locked positions.
10. To leave pilot lit and shut off burners only,
turn control knob clockwise to the
PILOT position.
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.
OPERATION
Continued
OFF
Figure 17 - Control Knob In The OFF
Position (Manual Control Models)
Ignitor Button Control Knob
Figure 19 - Pilot (pilot may vary from
illustration)
Figure 18 - Control Knob In The OFF
Position (Thermostat Models)
Ignitor Button Control Knob
O
O
T
CAUTION: Do not try to ad-
just heating levels by using the
equipment shutoff valve.
TO TURN OFF GAS
TO APPLIANCE
1. Turn control knob clockwise to the
OFF position.
2. Turn off any electric power to the appli-
ance if service is to be performed.
3. Close equipment shutoff valve (see Figure
14, page 12.
MANUAL LIGHTING
PROCEDURE
1. Remove front panel (see page 10).
2. Follow steps 1 through 7 under Lighting
Instructions, page 13.
3. With control knob pressed in, strike match.
Hold match to pilot until pilot lights.
4. Keep control knob pressed in for 30 sec-
onds after lighting pilot. After 30 seconds,
release control knob. Now follow step 9,
under Lighting Instructions, column 2.
5. Replace front panel.
THERMOSTAT
CONTROL OPERATION
Thermostat models only
The thermostatic control used on these models
differs from standard thermostats. Standard
thermostats simply turn on and off the burner.
The thermostat used on this heater senses
the room temperature. At times the room may
exceed the set temperature. If so, the burner
will shut off. The burner will cycle back on when
room temperature drops below the set temper-
ature. The control knob can be set to any heat
level between 1 and 5. This adjusts the amount
of gas ow to the burner. This increases or
decreases the burner ame height.
Note: The thermostat sensing bulb mea-
sures the temperature of air near the heater
cabinet. This may not always agree with
room temperature (depending on housing
construction, installation location, room size,
open air temperatures, etc.). Frequent use of
your heater will let you determine your own
comfort levels.
Thermocouple Ignitor Electrode
Pilot Burner

www.desatech.com
123995-01C 15
OPERATION
Continued
MANUAL CONTROL INFRARED
MODELS ONLY
TO SELECT
HEATING LEVEL
WARNING: When running
heater, set control knob at LOW
or HIGH locked positions for
double burner heater or ON po-
sition for single burner heater.
Never set control knob between
locked positions. Poor combus-
tion and higher levels of carbon
monoxide may result.
CAUTION: Do not try to ad-
just heating levels by using the
equipment shutoff valve.
Control Double
Knobs Burners
ON
OFF
PILOT
IGN
OFF
Control Single
Knob Burner
Figure 20 - Burner Patterns
INSPECTING BURNER
Thermocouple
Pilot Burner
Pilot Burner
Thermocouple
Figure 21 - Correct Pilot Flame Pattern
Figure 22 - Incorrect Pilot Flame Pattern
Slightly press in control knob and turn counter-
clockwise to the LOW or HIGH positions
for double burner heater or ON position for
single burner heater.
IMPORTANT: Release downward pressure
while turning control knob. Control knob will
lock at the desired position.
Check pilot ame pattern and burner ame
pattern often.
PILOT FLAME PATTERN
Figure 21 shows a correct pilot ame pattern.
Figure 22 shows an incorrect pilot ame pat-
tern. The incorrect pilot ame is not touching
the thermocouple. This will cause the thermo-
couple to cool. When the thermocouple cools,
the heater will shut down.
If pilot ame pattern is incorrect, as shown
in Figure 22
• turn heater off (see To Turn Off Gas to Ap-
pliance, page 14)
• see Cleaning, page 17
Note: The pilot ame on natural gas units will
have a slight curve, but ame should be blue
and have no yellow or orange color.

www.desatech.com 123995-01C16
1/2 GLASS HEIGHT
CORRECT FLAME PATTERN
AT HIGH POSITION
INCORRECT FLAME PATTERN
AT HIGH POSITION
1/2 GLASS HEIGHT
1/2 GLASS HEIGHT
CORRECT FLAME PATTERN
AT HIGH POSITION
INCORRECT FLAME PATTERN
AT HIGH POSITION
1/2 GLASS HEIGHT
Figure 23 - Correct Burner Flame Pattern
Yellow
Tipping
Figure 24 - Incorrect Burner Flame
Pattern
BURNER FLAME PATTERN
INFRARED MODELS
Figure 25 shows a correct burner ame pat-
tern. Figure 26 shows an incorrect burner
ame pattern.
If burner ame pattern is incorrect, as shown
in Figure 26
• turn heater off (see To Turn Off Gas to Ap-
pliance, page 14)
• see Cleaning, page 17
Figure 26 - Incorrect Burner Flame
Pattern (Dual Burner Shown)
Figure 25 - Correct Burner Flame Pattern
(Dual Burner Shown)
INSPECTING BURNER
Continued
WARNING: If yellow tipping
occurs, your heater could pro-
duce increased levels of carbon
monoxide. If burner ame pattern
shows yellow tipping, proceed
with the following instructions.
NOTICE: Do not mistake orange
ames with yellow tipping. Dust
or other ne particles enter the
heater and burn causing brief
patches of orange ame.
BURNER FLAME PATTERN BLUE
FLAME MODELS
Figure 23 shows a correct burner ame pat-
tern. Figure 24 shows an incorrect burner
ame pattern. The incorrect burner ame
pattern shows yellow tipping of the ame.
It also shows the ame higher than 1/2 the
glass panel height.
If burner ame pattern is incorrect, as shown
in Figure 24
• turn heater off (see To Turn Off Gas to Ap-
pliance, page 14)
• see Cleaning, page 17
(Models GWN6 and GWP6 will be lower due to
lower input rating)

www.desatech.com
123995-01C 17
CLEANING
dirt, lint and pet hair. To clean these parts we
recommend using compressed air no greater
than 30 PSI. Your local computer store,
hardware store or home center may carry
compressed air in a can. If using compressed
air in a can, please follow the directions on the
can. If you don’t follow directions on the can,
you could 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 ame indicates dust and dirt in the
pilot assembly. There is a small pilot air inlet
hole about 2" from where the pilot ame comes
out of the pilot assembly (see Figure 27). With
the unit off, lightly blow air through the air inlet
hole. You may blow through a drinking straw
if compressed air is not available.
Figure 27 - Pilot Inlet Air (Propane/LP
Pilot Shown)
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.
Pilot Assembly
Pilot Air Inlet
WARNING: Turn off heater
and let cool before cleaning.
CAUTION: You must keep con-
trol areas, burner and circulating
air passageways of heater clean.
Inspect these areas of heater
before each use. Have heater
inspected yearly by a qualied
service person. Heater may need
more frequent cleaning due to
excessive lint from carpeting,
bedding material, pet hair, etc.
WARNING: Failure to keep
the primary air opening(s) of
the burner(s) clean may result in
sooting and property damage.
ODS/PILOT AND BURNER ORIFICE
Use a vacuum cleaner, pressurized air or
small, soft bristled brush to clean.
BURNER PILOT AIR INLET HOLE
The primary air inlet holes allow the proper
amount of air to mix with the gas. This pro-
vides a clean burning ame. Keep these holes
clear of dust, dirt and lint. Clean these air inlet
holes prior to each heating season. Blocked
air holes will create soot. We recommend that
you clean the unit every three months during
operation and have heater inspected yearly
by a qualied service person.
We also recommend that you keep the burner
tube and pilot assembly clean and free of dust,
TECHNICAL SERVICE
You may have further questions about installa-
tion, operation, or troubleshooting. If so, con-
tact DESA Heating, LLC at 1-866-672-6040.
When calling please have your model and
serial numbers of your heater ready.
You can also visit DESA Heating, LLC’s web
site at www.desatech.com.
SERVICE HINTS
When Gas Pressure Is Too Low
• pilot will not stay lit
• burner will have delayed ignition
• heater will not produce specied heat
• for propane/LP unit, propane/LP gas supply
may be low
You may feel your gas pressure is too low. If
so, contact your local gas supplier.
SERVICE PUBLICATIONS
A service manual is available at www.desat-
ech.com. At any time while viewing heaters,
click on “tech tips”.

www.desatech.com 123995-01C18
TROUBLESHOOTING
WARNING: Turn off heater and let cool before servicing. Only a
qualied service person should service and repair heater.
CAUTION: Never use a wire, needle or similar object to clean
ODS/pilot. This can damage ODS/pilot unit.
Note: All troubleshooting items are listed in order of operation.
POSSIBLE CAUSE
1. Ignitor electrode positioned
wrong
2. Ignitor electrode broken
3. Ignitor electrode not con-
nected to ignitor cable
4. Ignitor cable pinched or
wet
5. Piezo ignitor nut is loose
6. Broken ignitor cable
7. 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 only)
6. ODS/pilot is clogged
7. Gas regulator setting is not
correct
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
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. Tighten nut holding piezo
ignitor to heater cabinet.
Nut is located inside heater
cabinet at top
6. Replace ignitor cable
7. 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 ignit-
ing operation until air is
removed
5. Contact local propane/LP
gas company
6. Clean ODS/pilot (see Clean-
ing, page 17) or replace
ODS/pilot assembly
7. Replace gas regulator

www.desatech.com
123995-01C 19
OBSERVED PROBLEM
ODS/pilot lights but ame
goes out when control knob
is released
Burner does not light after
ODS/pilot is lit
Delayed ignition of burner
Burner backfiring during
combustion
Burner plaque(s) does not
glow (Infrared models only)
Yellow ame during burner
combustion
TROUBLESHOOTING
Continued
REMEDY
1. Press in control knob fully
2. After ODS/pilot lights, keep
control knob pressed in 30
seconds
3. Fully open equipment shut-
off valve
4. Hand tighten until snug,
then tighten 1/4 turn more
5. A) Contact local natural or
propane/LP gas company
B) Clean ODS/pilot (see
Cleaning, page 17) or re-
place ODS/pilot assembly
6. Replace pilot assembly
7. Replace control valve
1. Clean burner orifice (see
Cleaning, page 17) or re-
place burner orice
2. Contact local natural or
propane/LP gas company
1. Contact local natural or
propane/LP gas company
2. Clean burner orifice (see
Cleaning, page 17) or re-
place burner orice
1. Clean burner orifice (see
Cleaning, page 17) or re-
place burner orice
2. Replace burner
3. Replace gas regulator
1. Turn control knob until it
locks at desired setting
2. Contact local natural or
propane/LP gas company
3. Replace burner
1. Check burner for dirt and
debris. If found, clean burn-
er (see Cleaning, page 17)
2. Contact local natural or
propane/LP gas company
3. Replace gas regulator
POSSIBLE CAUSE
1. Control knob not fully
pressed in
2. Control knob not pressed in
long enough
3. Equipment shutoff valve not
fully open
4. Thermocouple connection
loose at control valve
5. Pilot flame not touching
thermocouple, which allows
thermocouple to cool, caus-
ing pilot ame to go out. This
problem could be caused by
one or both of the following:
A) Low gas pressure
B) Dirty or partially clogged
ODS/pilot
6. Thermocouple damaged
7. Control valve damaged
1. Burner orice is clogged
2. Inlet gas pressure is too
low
1. Manifold pressure is too
low
2. Burner orice is clogged
1. Burner orice is clogged or
damaged
2. Burner damaged
3. Gas regulator defective
1. Control knob set between
locked positions
2. Inlet gas pressure is too
low
3. Plaque damaged
1. Not enough air
2. Inlet gas pressure is too
low
3. Gas regulator defective

www.desatech.com 123995-01C20
TROUBLESHOOTING
Continued
OBSERVED PROBLEM
Heater shuts off in use (ODS
operates)
Slight smoke or odor during
initial operation
Heater produces a whistling
noise when burner is lit
Heater produces a clicking/
ticking noise just after burner
is lit or shut off
White powder residue forming
within burner box or on adja-
cent walls or furniture
Moisture/condensation no-
ticed on windows
REMEDY
1. Open window and/or door
for ventilation
2. Contact local natural or
propane/LP gas company
3. Clean ODS/pilot (see Clean-
ing, page 17)
1. Problem will stop after a few
hours of operation
1. Turn control knob to LOW
or position 1 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 installa-
tion clearances (see Figure
4, page 8)
4. Clean burner (see Cleaning,
page 17) or replace burner
orice
1. This is normal with most
heaters. If noise is exces-
sive, contact qualied ser-
vice person
1. Turn heater off when us-
ing furniture polish, wax,
carpet cleaners or similar
products
1. Refer to Air for Combustion
and Ventilation require-
ments (page 5)
POSSIBLE CAUSE
1. Not enough fresh air is
available
2. Low line pressure
3. ODS/pilot is partially
clogged
1. Residues from manufactur-
ing processes
1. Turning control knob to
HIGH or position 5 when
burner is cold
2. Air in gas line
3. Air passageways on heater
blocked
4. Dirty or partially clogged
burner orice
1. Metal expanding while heat-
ing or contracting while
cooling
1. When heated, vapors from
furniture polish, wax, carpet
cleaners, etc. may turn into
white powder residue
1. Not enough combustion/
ventilation air