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.