Desa VUL18NR Quick start guide

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.
UNVENTED (VENT-FREE) GAS LOG HEATER
OWNER’S OPERATION AND INSTALLATION MANUAL
Remote-Ready Models VUL18/24/30/36(N,P)R
Thermostatically-Controlled Models VUL18/24/30/36(N,P)T
Remote-Ready Models Also Design-Certied As Vented Decorative Appliances

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SAFETy
TAbLE OF CONTENTS
Safety .................................................................. 2
Unpacking............................................................ 5
Product Identication........................................... 5
Local Codes......................................................... 5
Optional Remote Control Accessories................. 5
Air For Combustion and Ventilation ..................... 6
Product Features................................................. 6
Installation ........................................................... 9
Operation........................................................... 20
Inspecting Burners............................................. 26
Cleaning and Maintenance................................ 27
Wiring Diagram.................................................. 28
Troubleshooting................................................. 29
Optional Positioning of
Thermostat Sensing Bulb ............................. 33
Specications .................................................... 33
Parts .................................................................. 34
Service Hints ..................................................... 40
Technical Service............................................... 40
Replacement Parts............................................ 40
Accessories ....................................................... 40
Warranty ..............................................Back Cover
WARNING: Improper
installation, adjustment,
alteration, service or
maintenance can cause
injury or property dam-
age. Refer to this manual
for correct installation
and operational proce-
dures. For assistance or
additional information
consult a qualified in-
staller, service agency or
the gas supplier.
WARNING: This ap-
pliance is for installation
only in a solid-fuel burning
masonry or UL127 fac-
tory-built replace or in a
listed ventless rebox en-
closure. It is design-certi-
ed for these installations
in accordance with ANSI
Z21.11.2. Exception: Do
not install this appliance
in a factory-built replace
that includes instructions
stating it has not been test-
ed or should not be used
with unvented gas logs.
WARNING: This is an
unvented gas-red heat-
er. It uses air (oxygen)
from the room in which
it is installed. Provisions
for adequate combustion
and ventilation air must
be provided. Refer to Air
for Combustion and Ven-
tilation section on page 6
of this manual.
This appliance may be in-
stalled in an aftermarket,*
permanently located,
manufactured (mobile)
home, where not prohib-
ited by local codes.
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

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122001-01C 3
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, op-
erate or service this replace.
Improper use of this replace
can cause serious injury or
death from burns, re, explo-
sion, 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 replace may not be
working properly. Get fresh air at once! Have
replace 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.
Natural and Propane/LP gases are odorless.
An odor-making agent is added to these gases.
The odor helps you detect a gas leak. However,
the odor added to the gas can fade. Gas may
be present even though no odor exists.
Make certain you read and understand all
warnings. Keep this manual for reference. It
is your guide to safe and proper operation of
this replace.
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.
SAFETy
Continued
WARNING: Do not allow fans
to blow directly into the replace.
Avoid any drafts that alter burner
ame patterns. Ceiling fans can
create drafts that alter burner
ame patterns. Altered burner
patterns can cause sooting.
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.
Heater base assembly 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
shutdown. Allow surface to cool
before touching.
Carefully supervise young chil-
dren when they are in the room
with heater. When using the hand-
held remote accessory (Remote-
Ready Models Only), keep selec-
tor switch in the OFF position to
prevent children from turning on
burners with remote.
You must operate this heater
with the replace screen and
hood in place. Make sure re-
place screen and hood are in
place before running heater.
Keep the appliance area clear
and free from combustible ma-
terials, gasoline and other am-
mable vapors and liquids.

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SAFETy
Continued
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 (propane/LP
units only).
3. If you smell gas
• shut off gas supply
• do not try to light any appliance
• do not touch any electrical switch; do not
use any phone in your building
• immediately call your gas supplier from
a neighbor’s phone. Follow the gas
supplier’s instructions
• if you cannot reach your gas supplier,
call the re department
4. This heater shall not be installed in a bed-
room or bathroom, unless installed as a
vented appliance. See Installing Damper
Clamp Accessory for Vented Operation,
page 12 (Remote-Ready Models Only).
This gas log set may not be installed as a
vented appliance in a bedroom or bathroom
in the Commonwealth of Massachusetts.
5. Before installing in a solid fuel burning re-
place, the chimney ue and rebox must
be cleaned of soot, creosote, ashes and
loose paint by a qualied chimney cleaner.
Creosote will ignite if highly heated. A dirty
chimney ue may create and distribute
soot within the house. Inspect chimney
ue for damage. If damaged, repair ue
and rebox before operating heater.
6. Do not burn solid-fuel in a masonry or
UL127 factory-built replace in which a
vent-free room heater is installed.
7. If replace has glass doors, never operate
this heater with glass doors closed. If you
operate heater with doors closed, heat
buildup inside replace will cause glass to
burst. Make sure there are no obstructions
across openings of replace.
8. To prevent the creation of soot, follow the
instructions in Cleaning and Maintenance,
page 27.
9. Before using furniture polish, wax, carpet
cleaner or similar products, turn heater off. If
heated, the vapors from these products may
create a white powder residue within burner
box or on adjacent walls and furniture.
10. This heater needs fresh, outside air ven-
tilation to run properly. This heater has an
Oxygen Depletion Sensing (ODS) safety
shutoff system. The ODS shuts down the
heater if enough fresh air is not available.
See Air for Combustion and Ventilation,
page 6. If heater keeps shutting off, see
Troubleshooting, page 29.
11. Do not run heater
• where ammable liquids or vapors are
used or stored
• under dusty conditions
12. Do not use this heater to cook food or burn
paper or other objects.
13. Do not use heater if any part has been ex-
posed to or 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.
14. Do not operate heater if any log is broken.
Do not operate heater if a log is chipped
(dime-sized or larger).
15. Turn heater off and let cool before ser-
vicing, installing or repairing. Make sure
the selector switch is in the OFF position
(Remote-Ready Models Only). Only a
qualied service person should install,
service or repair heater.
16. Make sure the selector switch is in the
OFF position when you are away from
home for long periods of time (Remote-
Ready Models Only).
17. Remote-ready heaters must not be con-
nected to any external electrical source.
18. Operating heater above elevations of
4,500 feet may cause pilot outage.
19. To prevent performance problems, do not
use propane/LP fuel tank of less than 100
lb. capacity (propane/LP units only).
20. Provide adequate clearances around air
openings.

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122001-01C 5
PRODUCT IDENTIFICATION
Figure 1 - Product Identication
Log Set
Control
Knob
Base Assembly
Ignitor
Rear Burner
Flame Adjustment Knob
Remote Control
(Optional)
OPTIONAL REMOTE CONTROL ACCESSORIES
LOCAL CODES
State of Massachusetts: The installa-
tion must be made by a licensed plumber
or gas fitter in the Commonwealth of
Massachusetts.
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
CAUTION: Do not remove the
data plates from the grate as-
sembly. The data plates contain
important warranty and safety
information.
1. Remove logs and heater base assembly
from carton.
Note: Do not pick up heater base assem-
bly by burners. This could damage heater.
Always handle base assembly by grate.
2. Remove all protective packaging applied
to logs and 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.
Install and use heater with care. Follow all
local codes. In the absence of local codes,
use the latest edition of The National Fuel
Gas Code, ANSI Z223.1/NFPA 54*.
*Available from:
American National Standards Institute, Inc.
1430 Broadway
New York, NY 10018
National Fire Protection Association, Inc.
Batterymarch Park
Quincy, MA 02269
There are four optional remote controls that
can be purchased separately for Remote-
Ready Models Only:
• wall switch
• hand-held ON/OFF remote
• wall thermostat
• hand-held thermostat remote
See Accessories, page 40.
The wall thermostat or hand-held thermostat
may not be used where vented decorative
listing is required.

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AIR FOR COMbUSTION AND VENTILATION
PRODUCT FEATURES
OPERATION
This heater is clean burning. It requires no
outside venting. There is no heat loss out a
vent or up a chimney. Heat is generated by
both realistic ames and glowing coals. This
heater is designed for vent-free operation with
ue damper closed. It has been tested and ap-
proved to ANSI Z21.11.2 standard for unvented
heaters. State and local codes in some areas
prohibit the use of vent-free heaters. This heater
may also be operated as a vented decorative
(ANSI Z21.60) product by opening the ue
damper (Non-Thermostat Models Only).
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.
ELECTRONIC IGNITION SYSTEM
This heater has an electronic ignitor to light
heater fuel supply.
WARNING: This heater shall
not be installed in a room or
space unless the required vol-
ume of indoor combustion air
is provided by the method de-
scribed 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 6 through 8 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 out-
side 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, electrical and gas lines
and at other openings.

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122001-01C 7
AIR FOR COMbUSTION AND VENTILATION
Continued
If your home meets all of the three criteria
above, you must provide additional fresh
air. See Ventilation Air From Outdoors,
page 8.
If your home does not meet all of the
three criteria above, proceed to Determin-
ing Fresh-Air Flow For Heater Location,
below.
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 m3per 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 m3per kw) of the ag-
gregate input rating of all appliances installed
in that space. Rooms communicating directly
with the space in which the appliances are
installed*, through openings not furnished
with doors, are considered a part of the un-
conned space.
* Adjoining rooms are communicating only if
there are doorless passageways or ventilation
grills between them.
DETERMINING FRESH-AIR FLOW
FOR HEATER LOCATION
Determining if You Have a Conned or
Unconned Space
Use this work sheet to determine if you have
a conned or unconned space.
Space: Includes the room in which you will install
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) = 2560 cu. ft.
(volume of space)
If additional ventilation to adjoining room
is supplied with grills or openings, add the
volume of these rooms to the total volume
of the space.
2. Multiply the space volume by 20 to determine
the maximum Btu/Hr the space can support.
________ (volume of space) x 20 = (Maxi-
mum Btu/Hr the space can support)
Example: 2560 cu. ft. (volume of space) x 20
= 51,200 (maximum Btu/Hr the space can
support)
3. Add the Btu/Hr of all fuel burning appliances
in the space.
Vent-free replace __________ 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 replace + _________ 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)
73,000 Btu/Hr (actual amount of
Btu/Hr used)
The space in the above example is a conned
space because the actual Btu/Hr used is more
than the maximum Btu/Hr the space can sup-
port. You must provide additional fresh air. Your
options are as follows:
A. Rework worksheet, adding the space of an
adjoining room. If the extra space provides
an unconned space, remove door to adjoin-
ing room or add ventilation grills between
rooms. See Ventilation Air From Inside
Building, page 8.
B. Vent room directly to the outdoors. See
Ventilation Air From Outdoors, page 8.
C. Install a lower Btu/Hr replace, if lower Btu/Hr
size makes room unconned.
If the actual Btu/Hr used is less than the maxi-
mum Btu/Hr the space can support, the space is
an unconned space. You will need no additional
fresh air ventilation.
40,000
33,000
73,000

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AIR FOR COMbUSTION AND VENTILATION
Continued
Figure 3 - Ventilation Air from Outdoors
Outlet
Air
V e ntilated
Attic
Outlet
A
ir
Inlet
Air
Inlet Air V e ntilated
Crawl Space
T o
Crawl
Space
T o Attic
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/NFPA 54,
the International 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 options
1 and 2, Figure 2). You can also remove door
into adjoining room (see option 3, Figure 2).
Follow the National Fuel Gas Code, ANSI
Z223.1/NFPA 54, Air for Combustion and
Ventilation for required size of ventilation
grills or ducts.
Figure 2 - Ventilation Air from Inside Building
Or
Remove
Door into
Adjoining
Room,
Option
3
Ve ntilation Grills
Into Adjoining Room,
Option 2
Ve ntilation
Grills Into
Adjoining
Room,
Option 1
12"
12"
Ventilation Air From Outdoors
Provide extra fresh air by using ventilation
grills or ducts. You must provide two perma-
nent openings: one within 12" of the ceiling
and one within 12" of the oor. Connect these
items directly to the outdoors or spaces open
to the outdoors. These spaces include attics
and crawl spaces. Follow the National Fuel
Gas Code, ANSI Z223.1/NFPA 54, 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.

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122001-01C 9
INSTALLATION
WARNING: Seal any fresh
air vents or ash clean-out doors
located on oor or wall of re-
place. If not, drafting may cause
pilot outage or sooting. Use a
heat-resistant sealant. Do not
seal chimney ue damper.
WARNING: Never install the
heater
• in a bedroom or bathroom
unless installed as a vented
appliance, see page 12 (Re-
mote-Ready Models Only)
• in a recreational vehicle
• where curtains, furniture,
clothing or other ammable
objects are less than 36" from
the front and 42" from top
heater, For side clearances
see Figure 4 page 10
• in high trafc areas
• in windy or drafty areas
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 6.
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.
NOTICE:Stateorlocalcodesmay
only allow operation of this appli-
ance in a vented conguration.
Check your state or local codes.
WARNING: Make sure the
selector switch is in the OFF
position before installing heater
(Remote-Ready Models Only).
WARNING: Before installing
in a solid fuel burning replace,
the chimney ue and rebox
must be cleaned of soot, creo-
sote, ashes and loose paint by
a qualified chimney cleaner.
Creosote will ignite if highly
heated. A dirty chimney ue may
create and distribute soot within
the house. Inspect chimney and
rebox ue for damage. If dam-
aged, repair ue and rebox
before operating heater.

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LOG SIZING REQUIREMENTS
Minimum Firebox Size
Log
Size Height Depth Front Width
Rear
Width*
18" 17" 14" 20" 14"
24" 17" 14" 26" 18"
30" 21" 14" 32" 22"
36" 21" 14" 38" 27 1/2"
*Measured at 14" depth
CHECK GAS TYPE
Use 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 AND CLEARANCES
FOR VENT-FREE OPERATION
WARNING: Maintain the
minimum clearances. If you
can, provide greater clearances
from oor, ceiling and adjoining
wall.
Minimum Fireplace Clearance to
Combustible Materials
Side Wall 16", Ceiling 42", Floor 5",
Front 36"
INSTALLATION
Continued
Carefully follow these instructions. This will
ensure safe installation into a masonry,
UL127-listed manufactured replace or listed
vent-free rebox.
Minimum Clearances For Side
Combustible Material, Side Wall and
Ceiling
A. Clearances from the side of the replace
cabinet to any combustible material and
wall should follow diagram in Figure 4.
Figure 4 - Minimum Clearance for
Combustible to Wall
*Minimum 16" from Side Wall
*
Example
Example: The face of a mantel, bookshelf,
etc. is made of combustible material and
protrudes 3 1/2" from the wall. This com-
bustible material must be 4" from the side
of the replace cabinet (see Figure 4).
Note: When installing your gas logs into
a manufactured rebox, follow rebox
manufacturer’s instructions for minimum
clearances to combustible materials.
B. Clearances from the top of the replace
opening to the ceiling should not be less
than 42".
NOTICE: Manual control heaters
may be used as a vented product.
If so, you must always run heater
with chimney ue damper open.
If running heater with damper
open, noncombustible material
above replace opening is not
needed. Go to Installing Damper
Clamp Accessory for Vented
Operation, page 12.

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122001-01C 11
INSTALLATION
Continued
Heat Resistant
Material
(A)
Figure 5 - Heat Resistant Material (Slate,
Marble, Tile, etc.) Above Fireplace
Noncombustible
Material
Distance (A)
Requirements for Safe
Installation
1 2" or more Noncombustible mate-
rial OK.
Between 8" and 12" 24", 30" or 36" Models:
Install replace hood
accessory (GA6050,
GA6052 or GA6053 see
Accessories, page 40).
18" Model: Noncom-
bustible material OK.
Less than 8" Noncombustible mate-
rial must be extended
to at least 8". See
Between 8" and 12",
above. If you cannot ex-
tend material, you must
operate heater with ue
damper open.
MINIMUM NONCOMbUSTIbLE
MATERIAL CLEARANCES
If Not Using Mantel
Note: If using a mantel proceed to If Using
Mantel. If not using a mantel, follow the infor-
mation on this page.
You must have noncombustible material(s)
above the replace opening. Noncombus-
tible materials (such as slate, marble, tile,
etc.) must be at least 1/2" thick. With sheet
metal, you must have noncombustible ma-
terial behind it. Noncombustible material
must extend at least 8" up (for all models).
If noncombustible material is less than 12",
you must install the replace hood accessory
(24" and 30" Models Only). See Figure 5 for
minimum clearances.
If Using Mantel
You must have noncombustible material(s)
above the replace opening. Noncombustible
materials (such as slate, marble, tile, etc.)
must be at least 1/2" thick. With sheet metal,
you must have noncombustible material be-
hind it. Noncombustible material must extend
at least 8" up (for all models). If noncombus-
tible material is less than 12", you must install
the replace hood accessory (24" and 30"
Models Only). Even if noncombustible mate-
rial is more than 12", you may need the hood
accessory to deect heat away from your
mantel shelf. See Figures 5 and 6 and Figure
7, page 9, for minimum clearances.
IMPORTANT: If you cannot meet these mini-
mum clearances, you must operate heater
with chimney ue damper open. Go to Install-
ing Damper Clamp Accessory for Vented
Operation, page 12.
MANTEL CLEARANCES
In addition to meeting noncombustible mate-
rial clearances, you must also meet required
clearances between replace opening and
mantel shelf. If you do not meet the clearances
listed below, you will need a hood.
Determining Minimum Mantel Clearance
If you meet minimum clearance between
mantel shelf and top of replace opening, a
hood is not required (see Figure 6).
Figure 6 - Minimum Mantel Clearances
Without Using Hood
Minimum
Noncombustible
Material
Minimum
Noncombustible
Material Height
Distances to
Underside of
Mantel
Top of
Fireplace
Opening
Underside of
Mantel Shelf
12"
8"
(A)
18"
14"
20"
17"
22"
19"
24"
20"
All minimum
distances are
in inches
Log Set
24"/30"/36"
Models
18" Model
2 1/2"
6"
8"
10"
Mantel Shelf

www.desatech.com 122001-01C12
INSTALLATION
Continued
Determining Minimum Mantel Clearance
When Using a Hood
If minimum clearances in Figure 6, page 11, are
not met, you must have a hood. When using
a hood there are still certain minimum mantel
clearances required. Follow minimum clear-
ances shown in Figure 7, when using hood.
NOTICE: Surface temperatures
of adjacent walls and mantels
become hot during operation.
Walls and mantels above the
firebox may become hot to
the touch. If installed properly,
these temperatures meet the
requirement of the national
product standard. Follow all
minimum clearances shown in
this manual.
NOTICE: If your installation does
not meet the minimum clear-
ances shown, you must do one
of the following:
• operate the logs only with the
ue damper open
• raise the mantel to an accept-
able height
• remove the mantel
14"
Min.
Combustible
Material
Noncombustible Material
Figure 8 - Minimum Fireplace Clearances
If Installed at Floor Level
Figure 7 - Minimum Mantel Clearances
When Using Hood
FLOOR CLEARANCES
A. If installing appliance on the oor level,
you must maintain the minimum distance
of 14" to combustibles (see Figure 8).
B. If combustible materials are less than 14"
to the replace, you must install appliance
at least 5" above the combustible ooring
(see Figure 9).
Hearth
5"
Min.
Combustible
Material
Figure 9 - Minimum Fireplace Clearances
Above Combustible Flooring
Minimum
Noncombustible
Material
8"
Min.
12" 15" 18"
All minimum
distances are
in inches
Log Sets
18", 24",
30" & 36"
Models
20"
2
1/2
"
6"
8"
10"
12"
Distances to
Underside of
Mantel
Hood
(GA6050,
GA6052,
or GA6053)
Top of
Fireplace
Opening
Underside of
Mantel Shelf
Mantel Shelf
INSTALLING DAMPER CLAMP
ACCESSORY FOR VENTED
OPERATION
Note: When used as a vented heater, ap-
pliance must be installed only in a solid-fuel
burning fireplace with a working flue and
constructed of noncombustible material.
For Massachusetts Residents Only: Instal-
lation of this gas log set as a vented appliance
in the Commonwealth of Massachusetts re-
quires the damper be permanently removed
or welded in the fully open position.
If your heater is a manually-controlled model,
you may use this heater as a vented product.
There are three reasons for operating your
heater in the vented mode.
1. The replace does not meet the clearance
to combustibles requirements for vent-
free operation.

www.desatech.com
122001-01C 13
INSTALLATION
Continued
Area of Various Standard Round Flues
Diameter Area
5" 20 sq. inches
6" 29 sq. inches
7" 39 sq. inches
8" 51 sq. inches
Chimney Height
Minimum Permanent
Flue Opening
6' to 15' 39 sq. inches
15' to 30' 29 sq. inches
Damper
Damper
Clamp
Damper
Damper
Clamp
Damper
Figure 10 - Attaching Damper Clamp
Manufactured Fireplace
Masonry Fireplace
INSTALLING HEATER bASE
ASSEMbLY
WARNING: You must secure
this heater to replace oor. If
not, heater will move when you
adjust controls. Moving heater
may cause a gas leak.
WARNING: If installing in a
sunken replace, special care
is needed. You must raise the
replace oor to allow access
to heater control panel. This
will insure adequate air ow
and guard against sooting and
controls being damaged. Raise
replace oor with noncombus-
tible material. Make sure material
is secure.
CAUTION: Do not pick up
heater base assembly by burn-
ers. This could damage heater.
Only handle base assembly by
grates.
IMPORTANT: Make sure the heater burners
are level. If heater is not level, heater will not
work properly. For thermostat models, avoid
damage to thermostat bulb. Avoid nicks or
sharp bends in thermostat bulb wire. Keep
thermostat bulb in mounting bracket until
ready to mount base to oor. See Optional
Positioning Of Thermostat Sensing Bulb,
page 33.
Installation Items Needed
• hardware package (provided with heater)
• approved exible gas hose and ttings (not
provided) (if allowed by local codes)
• sealant (resistant to propane/LP gas, not
provided)
• electric drill with 3/16” masonry drill bit
Note: Install optional Receiver and Hand-Held
Remote Control Kit (see Accessories, page
40) before installing gas log heater (Remote-
Ready Models Only). See installation instruc-
tions included with the kit.
2. State or local codes do not permit vent-
free operation.
3. You prefer vented operation.
If reasons number 1 or 2 apply to you, you
must permanently open chimney ue damper.
You must install the damper clamp accessory
(to order, see Accessories, page 40). This
will insure vented operation (see Figure 10).
The damper clamp will keep damper open.
Installation instructions are included with
clamp accessory.
See chart below for minimum permanent ue
opening you must provide. Attach damper
clamp so the minimum permanent ue open-
ing will be maintained at all times.

www.desatech.com 122001-01C14
INSTALLATION
Continued
1. Apply pipe joint sealant lightly to male
threads of gas fitting (provided). For
Thermostatically-Controlled Models con-
nect approved exible gas hose to gas
regulator of heater (see Figure 11). For
Remote-Ready models connect approved
exible gas hose to inlet side of gas con-
trol (see Figure 12).
IMPORTANT: Hold gas regulator with
wrench when connecting flexible gas
hose (Thermostatically-Controlled Models
Only).
2. Position heater base assembly in
fireplace.
3. Mark screw locations through holes in
front panel of base (see Figure 13). If
installing in a brick-bottom replace, mark
screw locations in mortar joint of bricks.
4. Remove heater base from replace.
5. Drill holes at marked locations using 3/16"
drill bit.
6. Attach base, through holes in front panel
of base, to replace oor using masonry
screws provided in hardware package
(see Figure 13).
7. Connect to gas supply. See Connecting
To Gas Supply.
Heater Gas
Regulator
Flexible Gas Hose (if
allowed by local codes)
Figure 11 - Attaching Flexible Gas Hose to
Heater Gas Regulator (Thermostatically-
Controlled Models Only)
Figure 12 - Attaching Flexible Gas Hose
to Heater Gas Regulator
(Remote-Ready Models Only)
Gas Control
Flexible Gas Hose
(if allowed by local
codes)
Figure 13 - Attaching Base to Fireplace
Floor (Remote-Ready Models Only)
Masonry
Screw
CONNECTING TO GAS SUPPLY
WARNING: This appliance
requires a 1/2" NPT (National
Pipe Thread) inlet connection to
the pressure regulator.
WARNING: A qualied ser-
vice person must connect heater
to gas supply. Follow all local
codes.
CAUTION: Never connect
propane/LP replace directly
to the propane/LP supply. This
heater requires an external regu-
lator (not supplied). Install the
external regulator between the
heater and propane/LP supply.
WARNING: Never connect
natural gas replace to private
(non-utility) gas wells. This
gas is commonly known as
wellhead gas.

www.desatech.com
122001-01C 15
Installation Items Needed
Before installing heater, make sure you have
the items listed below.
• external regulator (supplied by installer)
• piping (check local codes)
• sealant (resistant to propane/LP gas)
• equipment shutoff valve *
• test gauge connection *
• sediment trap
• tee joint
• pipe wrench
• approved exible gas line with gas con-
nector (if allowed by local codes) (not
provided)
* 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.
For propane/LP units, 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 re-
duce incoming gas pressure, heater regulator
damage could occur. Install external regulator
with the vent pointing down as shown in Figure
14. Pointing the vent down protects it from
freezing rain or sleet.
CAUTION: Use only new,
black iron or steel pipe. Inter-
nally-tinned copper tubing may
be used in certain areas. Check
your local codes. Use pipe of
1/2" diameter or greater to allow
proper gas volume to heater. If
pipe is too small, undue loss of
volume will occur.
Installation must include an equipment shutoff
valve, union and plugged 1/8" NPT tap. Locate
NPT tap within reach for test gauge hook up.
NPT tap must be upstream from heater (see
Figure 15 or Figure 16 on page 16, depending
on your model).
Propane/LP
Supply Tank External
Regulator
with Vent
Pointing
Down
Figure 14 - External Regulator With Vent
Pointing Down
INSTALLATION
Continued
IMPORTANT: Install equipment shutoff valve
in an accessible location. The equipment
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 replaces.
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.
Figure 15 - Gas Connection
(Thermostatically-Controlled Models Only)
Tee Cap Pipe
Joint Nipple
3" Minimum
Gas
Regulator
PROPANE/LP From
External Regulator
(11" W.C.** to 14"
W.C. Pressure)
NATURAL From
Gas Meter (5" W.C.**
to 10.5" W.C.
Pressure)
CSA Design-Certied
Equipment Shutoff Valve
With 1/8" NPT Tap*
Approved
Flexible Gas
Hose (if allowed
by local codes)
Sediment Trap

www.desatech.com 122001-01C16
Pipe Cap Tee
Nipple Joint
INSTALLATION
Continued
* Purchase the optional CSA design-certied
equipment shutoff valve from your dealer.
**Minimum inlet pressure for purpose of input
adjustment.
Figure 16 - Gas Connection (Remote-
Ready Models Only)
Gas
Control
3" Minimum
Sediment Trap
CSA Design-Certied
Equipment Shutoff Valve
With 1/8" NPT Tap*
Approved Flexible
Gas Hose (if
allowed by local
codes)
PROPANE/LP
From External
Regulator
(11" W.C.**
to 14" W.C.
Pressure)
NATURAL
From Gas
Meter
(5" W.C.**
to 10.5"
W.C.
Pressure)
We recommend that you install a sediment
trap in supply line as shown in Figure 15,
page 15, or Figure 16, depending on your
model. Locate sediment trap where it is within
reach for cleaning. Install in piping system
between fuel supply and heater. Locate sedi-
ment trap where trapped matter is not likely
to freeze. A sediment trap traps moisture and
contaminants. This keeps them from going
into heater controls. If sediment trap is not
installed or is installed wrong, heater may
not run properly.
CAUTION: Avoid damage to
regulator. Hold gas regulator
with wrench when connecting
it to gas piping and/or ttings
(Thermostatically-Controlled
Models Only).
CAUTION: Avoid damage to
gas control. Hold gas control
with wrench when connecting
it to gas piping and/or ttings
(Remote-Ready Models Only).
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: Make sure exter-
nal regulator has been installed
between propane/LP supply
and heater. See guidelines un-
der Connecting to Gas Supply,
page 14.
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 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
122001-01C 17
Test Pressures Equal To or Less Than
1/2 PSIG (3.5 kPa)
1. Close equipment shutoff valve (see Fig-
ure 17).
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 to equip-
ment shutoff valve for natural gas or
propane/LP supply to equipment shutoff
valve for propane/LP (see Figure 18 or 19).
Apply noncorrosive leak detection uid to
all joints. Bubbles forming show a leak.
4. Correct all leaks at once.
Figure 17 - Equipment Shutoff Valve
Figure 18 - Checking Gas Joints
(Propane/LP Only)
Thermostat Gas
Valve or Control
Valve Location
Propane/LP
Supply Tank
Equipment
Shutoff Valve
Open
Closed
Equipment
Shutoff
Valve
Gas Meter
Figure 19 - Checking Gas Joints (Natural
Gas Only)
Thermostat Gas Valve or
Control Valve Location
Equipment Shutoff Valve
INSTALLATION
Continued
PRESSURE TESTING HEATER GAS
CONNECTIONS
1. Open equipment shutoff valve (see Fig-
ure 17).
2. Open main gas valve located on or near
gas meter for natural gas or open pro-
pane/LP supply tank valve.
3. Make sure control knob of heater is in the
OFF position.
4. Check all joints from equipment shutoff
valve to thermostat gas valve (Thermo-
stat-Controlled Models) or to gas control
(Remote-Ready Models) (see Figure 18 or
19). Apply noncorrosive leak detection uid
to all joints. Bubbles forming show a leak.
5. Correct all leaks at once.
6. Light heater (see Operation, page 21 or
23, depending on your model). Check all
other internal joints for leaks.
7. Turn off heater (see To Turn Off Gas to
Appliance, page 21 or page 24, depending
on your model).
INSTALLING OPTIONAL REMOTE
ACCESSORIES
Installing Remote Receiver
Remote control accessories are available
separately (see Accessories, page 40).
1. If unit is already installed in replace, con-
tinue with these instructions. If unit has not
been installed in replace, go to step 6 and
continue installation of remote accessory.
WARNING: Turn off heater
and let cool before handling any
part of heater. Make sure gas is
turned of to unit.
2. Carefully remove logs and set aside.
3. Locate mounting screws on sides of heat-
er base assembly and remove screws. Set
screws aside for reinstallation.
4. Disconnect gas line from heater base as
shown in Figure 11 or 12, page 14.
WARNING: A qualied ser-
vice person must connect and
disconnect gas to heater. Follow
all local codes.

www.desatech.com 122001-01C18
INSTALLATION
Continued
5. Remove heater base from replace.
6. Install receiver bracket to base with Phil-
lips screws provided in hardware kit as
shown in Figure 20.
7. Disconnect jumper wire from control valve at
TPTH and TH locations (see Figure 21).
8. Install remote receiver into receiver
bracket using pads and push button clips
provided with receiver (see Figure 22).
9. Connect wires to control valve at the
TPTH and TH locations as shown in
Figure 23.
Note: Make sure excess wire does not
interfere with burner or pilot.
10. If heater was removed from replace be-
fore installation of remote accessory, see
Installing Heater Base Assembly on page
13 to reinstall heater into replace. Test
gas connection for leaks (see Checking
Gas Connections, page 16).
Figure 22 - Installing Remote Receiver
Push Button
Clips Bracket
Battery
Clip
9-Volt
Battery
Terminal
Wires
Pad
Figure 21 - Disconnecting Jumper Wire
From Control Valve
Jumper
Wire
Control Valve
Figure 20 - Installing Remote Receiver
Bracket
Remote Receiver Bracket
Phillips
Screws
Figure 23 - Connecting Wires
Control Valve
White Wire
From Receiver
Red Wire From
Receiver
Figure 24 - Installing Battery in Hand-Held
Remote Control Unit
Installing Batteries for Remote Receiver
and Hand Held Remote Control
Two 9-volt alkaline batteries (not included)
are required to operate this heater with the
wireless hand-held remote control set. One
battery must be installed in the receiver and
one in the hand-held remote control unit.
Note: Only use alkaline batteries.
Installing 9-Volt Battery in Receiver
1. Locate back of receiver behind receiver
bracket mounted on base assembly.
2. Locate the battery clip mounted on the
back of the receiver (see Figure 22).
3. Slide a 9-volt battery through the clip.
4. Attach the terminal wires to the battery.
Installing 9-Volt Battery (Not Included) in
Hand-Held Remote Control Unit
1. Remove battery cover on back of remote
control unit.
2. Attach terminal wires to the battery. Place
battery into the battery housing.
3. Replace battery cover onto remote con-
trol unit.
9-Volt
Battery
Battery
Housing
Battery Cover
Terminal
Wires
Remote Control
Unit
11. If logs were removed from heater for in-
stall remote accessory, replace logs (see
Installing Logs, page 19).

www.desatech.com
122001-01C 19
INSTALLING LOGS
WARNING: Failure to posi-
tion the parts in accordance
with these diagrams or failure
to use only parts specically
approved with this heater may
result in property damage or
personal injury.
Each log is marked with a number. These
numbers will help you identify the log when
installing. It is very important to install these
logs exactly as instructed. Do not modify logs.
Only use logs supplied with heater.
Note: Your appliance may vary from model
shown but log placement will be the same.
VUL36 Model brackets
If installing a VUL36 model, attach log support
brackets before installing logs.
1. Install left bracket to left side of chassis us-
ing 2 screws provided (see Figure 25).
2. Install right bracket to right front of chassis
using 2 screws provided (see Figure 25).
This bracket will also be used as remote
control bracket if remote is installed.
INSTALLATION
Continued
Installing Logs (All Models)
1. Place bottom log in center of the base as-
sembly as shown in Figure 26.
2. Rest rear log in back corner sections of
base assembly as shown in Figure 26.
Make sure log is completely vertical and
not leaning in toward burner where ame
will touch the log.
3. Position front right log against right side
of grate prongs (see Figure 26).
4. Position front left log against left side of
grate prongs (see Figure 26).
5. Place middle right log over front right and
bottom logs as shown in Figure 27, page
20. Be sure hole in middle right log seats
over pin in bottom log.
6. Place middle left log over front left and
bottom logs as show in Figure 27, page
20. Be sure hole in middle left log seats
over pin in front left log.
7. For VUL36 models, the front right and
left logs are longer and are supported
with brackets on each end (see Figure
28 , page 20 ). Place left and right small
front logs under left bracket and beside
right bracket.
Figure 25 - Installing Log Support
Brackets
Left Log
Support
Bracket
Chassis
Right Log
Support
Bracket
Right Front of Chassis
Rear Log
Grate
Prongs
Figure 26 - Installing Log Set
Bottom Log
Base Assembly Front
Right Log
Front Left
Log

www.desatech.com 122001-01C20
INSTALLATION
Continued
Figure 27 - Installing Log Sets
Middle Right Log
Middle
Left Log
Bottom
Log
Pin on Front
Left Log
Figure 28 - Installing VUL36 Model
Control Cover Logs
Left Control
Cover Log
Right Control
Cover Log Right Small Front Log
Left Small
Front Log
Bracket
Bracket
OPERATION
THERMOSTAT-CONTROLLED MODELS
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 pilot, 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.
VUL18/24/30 MODELS
VUL36 MODELS
Figure 29 - Correct Log Placement
8. For VUL36 models, position left and right
control cover logs as shown in Figure 28 ,
page 20 . These may be placed as desired
to hide controls.