Vanguard VN1800ITB Quick start guide

®
VN1800ITB
and
VN2550ITB
Save this manual for future reference.
INFRARED VENT-FREE NATURAL GAS HEATER
OWNER’S OPERATION AND INSTALLATION MANUAL
WARNING: If the information in this manual is
not followed exactly, a fire or explosion may
result causing property damage, personal in-
jury, or loss of life.
— Do not store or use gasoline or other
flammable vapors and liquids in the vicinity
of this or any other appliance.
— WHAT TO DO IF YOU SMELL GAS
• Do not try to light any appliance.
• Do not touch any electrical switch; do not
use any phone in your building.
• Immediately call your gas supplier from a
neighbor’sphone.Followthegassupplier’s
instructions.
• If you cannot reach your gas supplier, call
the fire department.
— Installationandservicemustbeperformedby
a qualified installer, service agency, or the
gas supplier.
WARNING:Thisisanunvented
gas-firedheater.Itusesair(oxy-
gen) from the room in which it
is installed. Provisions for ad-
equate combustion and venti-
lation air must be provided.
Refer to Air For Combustion
and Ventilation on page 4 of
this manual.
WARNING: Improper installa-
tion, adjustment, alteration,
service, or maintenance can
cause injury or property dam-
age. Refer to this manual for
correctinstallationandopera-
tional procedures. For assis-
tance or additional informa-
tion consult a qualified in-
staller, service agency, or the
gas supplier.
This appliance may be installed in an aftermarket*, permanently located, manufac-
tured (mobile) home, where not prohibited 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

2
104246
VENT-FREE NATURAL GAS HEATER
®
1. This appliance is only for use with the
typeof gas indicated onthe rating plate.
Thisappliance is not convertiblefor use
with other gases.
2. If you smell gas
• Shut off gas supply.
• Do not try to light any appliance.
• Donot touchanyelectrical switch;do
not use any phone in your building.
• Immediately call your gas supplier
from a neighbor’s phone. Follow the
gas supplier’s instructions.
• Ifyou cannot reach yourgas supplier,
call the fire department
SAFETY
INFORMATION
Carbon Monoxide Poisoning: Early signs
ofcarbonmonoxidepoisoningresemblethe
flu, with headaches, dizziness, or nausea. If
you have these signs, the heater may not be
working properly. Get fresh air at once!
Haveheaterserviced.Somepeoplearemore
affected by carbon monoxide than others.
These include pregnant women, persons
with heart or lung disease or anemia, those
under the influence of alcohol, and those at
high altitudes.
Natural Gas: Natural gas is odorless. An
odor-making agent is added to natural gas.
Theodorhelpsyoudetectanaturalgasleak.
However, the odor added to natural gas can
fade.Naturalgasmaybepresenteventhough
no odor exists.
Make certain you read and understand all
warnings.Keepthismanualforreference.It
isyourguidetosafeandproperoperationof
this heater.
IMPORTANT: Read this owner’s
manual carefully and completely
before trying to assemble, oper-
ate, or service this heater. Im-
proper use of this heater can
causeseriousinjuryordeathfrom
burns, fire, explosion, electrical
shock, and carbon monoxide
poisoning.
WARNINGS
DANGER: Carbon monoxide
poisoning may lead to death!
WARNING: Any change to
this heater or its controls can be
dangerous.
3. This heater shall not be installed in a
bedroom or bathroom.
4. Always run heater with plaque control
knob at the 1, 2, 3, or 4 locked posi-
tions. Never set control knob between
locked positions. Poor combustion and
higher levels of carbon monoxide may
result.
5. This heater needsfresh, 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 not enough fresh air
isavailable. SeeAir forCombustion and
Ventilation, pages 4 through 6.
6. Keep all air openings in front and bot-
tom of heater clear and free of debris.
This will insure enough air for proper
combustion.
7. If heater shuts off, do not relight until
you provide fresh, outside air. If heater
keeps shutting off, have it serviced.
8. Before using furniture polish,wax, car-
pet cleaner or similar products, turn
heater off. If heated, the vapors from
theseproductsmay create a white pow-
der residue within burner box or on
adjacent walls or furniture.
9. Do not run heater
• where flammable liquids or vapors
are used or stored
• under dusty conditions
10. Do not use heater if any part has been
under water. Immediately call a quali-
fied service technician to inspect the
room heater and to replace any part of
the control system and any gas control
which has been under water.
11. Turn off and unplug heater and let cool
before servicing. Only a qualified ser-
vice person should service and repair
heater.
12. Operating heater above elevations of
4,500 feet could cause pilot outage.
Do not place clothing or other
flammable 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 re-
main hot for a time after shut-
down. Allow surface to cool be-
fore 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.
Keeptheapplianceareaclearand
free from combustible materials,
gasoline, and other flammable
vapors and liquids.
Due to high temperatures, the
appliance should be located out
oftrafficandawayfromfurniture
and draperies.
WARNING: Do not use any
accessory not approved for use
with this heater.

3
104246
OWNER’S MANUAL
PRODUCT
IDENTIFICATION
LOCAL CODES
Install and use heater with care. Follow all
localcodes.Intheabsenceoflocalcodes,use
the latest edition of National Fuel Gas Code
ANS Z223.1, also known as 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
Figure 1 - Vent-Free Natural Gas Heater (Model VN2550ITB Shown)
Control Knob
PRODUCT
FEATURES
SAFETY DEVICE
This heater has a pilot with an Oxygen
Depletion Sensing (ODS) safety shutoff
system. The ODS/pilot is a required feature
for vent-free room heaters. The ODS/pilot
shuts off the heater if there is not enough
fresh air.
PIEZO IGNITION SYSTEM
This heater has a piezo ignitor. This system
requires no matches, batteries, or other
sources to light heater.
THERMOSTATIC HEAT
CONTROL
This heater has a thermostat sensing bulb
and thermostat control. This results in the
greatest heater comfort. This can also result
in lower gas bills.
UNPACKING
1. Remove heater from carton.
2. Remove all protective packaging ap-
plied to heater for shipment.
3. Check heater for any shipping damage.
If heater is damaged, promptly inform
dealer where you bought heater.
Grill
Guard
Burners
Thermostat Control KnobPiezo Ignitor
Heater
Cabinet
Front
Panel

4
104246
VENT-FREE NATURAL GAS HEATER
®
AIR FOR
COMBUSTION AND
VENTILATION
Today’s homes are built more energy effi-
cient than ever. New materials, increased
insulation, and new construction methods
helpreduceheatlossinhomes.Homeowners
weatherstripand caulkaround windowsand
doorstokeepthecoldairoutandthewarmair
in. During heating months, home owners
want their homes as airtight as possible.
While it is good to make your home energy
efficient,yourhomeneedstobreathe.Fresh
air must enter your home. All fuel-burning
appliances need fresh air for proper com-
bustion and ventilation.
Exhaustfans,fireplaces,clothesdryers,and
fuel burning appliances draw air from the
house to operate. You must provide ad-
equate fresh air for these appliances. This
will insure proper venting of vented fuel-
burning appliances.
WARNING: This heater shall
notbeinstalledinaconfinedspace
or unusually tight construction
unless provisions are provided
foradequatecombustionandven-
tilation air. Read the following in-
structions to insure proper fresh
air for this and other fuel-burning
appliances in your home.
PROVIDING ADEQUATE
VENTILATION
The following are excerpts from National
Fuel Gas Code. NFPA 54/ANS Z223.1, Sec-
tion5.3,AirforCombustionandVentilation.
Allspacesinhomesfallintooneofthethree
following ventilation classifications:
1. Unusually Tight Construction
2. Unconfined Space
3. Confined Space
The information on pages 4 through 6 will
help you classify your space and provide
adequate ventilation.
Unusually Tight Construction
The air that leaks around doors and win-
dows may provide enough fresh air for
combustion and ventilation. However, in
buildings of unusually tight construction,
you must provide additional fresh air.
Unusually tight construction is de-
fined as construction where:
a. walls and ceilings exposed to the
outside atmosphere have a con-
tinuous water vapor retarder with
a rating of one perm (6 x 10-11kg
per pa-sec-m2) or less with open-
ings 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, be-
tween sole plates and floors,be-
tween wall-ceiling joints, be-
tween wall panels, at penetra-
tionsforplumbing,electrical,and
gas lines, and at other openings.
If your home meets all of the three
criteria above, you must provide ad-
ditional fresh air. See Ventilation Air
From Outdoors , page 6 .
If your home does not meet all of the
threecriteriaabove,proceedto Deter-
mining Fresh-Air Flow for Heater
Location, page 5.
Confined and Unconfined Space
The National Fuel Gas Code ANS Z223.1
defines a confined space as a space whose
volume is less than 50 cubic feet per 1,000
Btu per hour (4.8 m3per kw) of the aggre-
gate input rating of all appliances installed
in that space and an unconfined space as a
space whose volume is not less than 50
cubicfeetper1,000Btuperhour(4.8m3per
kw) of the aggregate input rating of all
appliances installed in that space. Rooms
communicating directly with the space in
whichtheappliancesareinstalled*,through
openings not furnished with doors, are con-
sidered a part of the unconfined space.
This heater shall not be installed in a con-
fined space or unusually tight construction
unlessprovisions are providedfor adequate
combustion and ventilation air.
*Adjoiningroomsarecommunicatingonly
iftherearedoorlesspassagewaysorventila-
tion grills between them.

5
104246
OWNER’S MANUAL
AIR FOR
COMBUSTION AND
VENTILATION
Continued
DETERMINING FRESH-AIR FLOW FOR HEATER LOCATION
Determining if You Have a Confined or Unconfined Space
Use this worksheet to determine if you have a confined or unconfined space.
Space:Includestheroominwhichyouwillinstallheaterplusanyadjoiningroomswithdoorlesspassagewaysorventilationgrillsbetween
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. Divide the space volume by 50 cubic feet to determine the maximum Btu/Hr the space can support.
_____________ (volume of space) ÷50 cu. ft. = (Maximum Btu/Hr the space can support)
Example: 2560 cu. ft. (volume of space) ÷50 cu. ft. = 51.2 or 51,200 (maximum Btu/Hr the space can support)
3. Add the Btu/Hr of all fuel burning appliances in the space.
Vent-free heater _______________ Btu/Hr
Gas water heater* _______________ Btu/Hr
Gas furnace _______________ Btu/Hr
Vented gas heater _______________ Btu/Hr
Gas fireplace logs _______________ Btu/Hr
Other gas appliances* +_______________ Btu/Hr
Total =_______________ Btu/Hr
* Do not include direct-vent gas appliances. Direct-vent draws combustion air from the outdoors and vents to the outdoors.
4. Compare the maximum Btu/Hr the space can support with the actual amount of Btu/Hr used.
_________________ Btu/Hr (maximum the space can support)
_________________ Btu/Hr (actual amount of Btu/Hr used)
Example: 51,200 Btu/Hr (maximum the space can support)
58,000 Btu/Hr (actual amount of Btu/Hr used)
ThespaceintheaboveexampleisaconfinedspacebecausetheactualBtu/HrusedismorethanthemaximumBtu/Hrthespacecansupport.
You must provide additional fresh air. Your options are as follows:
A. Rework worksheet, adding the space of an adjoining room. If the extra space provides an unconfined space, remove door to adjoin-
ing room or add ventilation grills between rooms. See Ventilation Air From Inside Building, page 6.
B. Vent room directly to the outdoors. See Ventilation Air From Outdoors, page 6.
C. Install a lower Btu/Hr heater, if lower Btu/Hr size makes room unconfined.
If the actual Btu/Hr used is less than the maximum Btu/Hr the space can support, the space is an unconfined space. You will need no
additional fresh air ventilation.
Continued
Example:
Gas water heater 40,000 Btu/Hr
Vent-free heater +18,000 Btu/Hr
Total =58,000 Btu/Hr
WARNING:Iftheareainwhichtheheatermaybeoperatedissmallerthanthatdefinedasanunconfinedspace
or if the building is of unusually tight construction, provide adequate combustion and ventilation air by one of
the methods described in the National Fuel Gas Code, ANS Z223.1, Section 5.3 or applicable local codes .

6
104246
VENT-FREE NATURAL GAS HEATER
®
Figure 3 - Ventilation Air from Outdoors
Ventilation Air From Outdoors
Provide extra fresh air by using ventilation
grills or ducts. You must provide two per-
manent openings: one within 12" of the
ceiling and one within 12" of the floor.
Connecttheseitemsdirectlytotheoutdoors
orspacesopentotheoutdoors.Thesespaces
include attics and crawl spaces. Follow the
National Fuel Gas Code NFPA 54/ANS
Z223.1,Section5.3,AirforCombustionand
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
thermostat-controlled power vent. Heated
air entering the attic will activate the power
vent.
AIR FOR
COMBUSTION AND
VENTILATION
Continued
VENTILATION AIR
Ventilation Air From Inside
Building
Thisfreshairwouldcomefromanadjoining
unconfined space. When ventilating to an
adjoining unconfined space, you must pro-
vide two permanent openings: one within
12" of the ceiling and one within 12" of the
floor on the wall connecting the two spaces
(seeoptions1and2,Figure2).Youcanalso
remove door into adjoining room (see op-
tion 3, Figure 2). Follow the National Fuel
Gas Code NFPA 54/ANS Z223.1, Section
5.3, Air for Combustion and Ventilation for
required size of ventilation grills or ducts.
Figure 2 - Ventilation Air from Inside Building
WARNING: Rework work-
sheet, adding the space of the
adjoiningunconfinedspace.The
combined spaces must have
enough fresh air to supply all
appliances in both spaces.
Or
Remove
Door into
Adjoining
Room,
Option 3
Ventilation Grills
Into Adjoining Room,
Option 2
12"
12"
Ventilation
Grills
into Adjoining
Room,
Option 1
Outlet
Air Ventilated
Attic
Outlet
Air
Inlet
Air
Inlet Air Ventilated
Crawl Space
To
Crawl
Space
To Attic

7
104246
OWNER’S MANUAL
36"
3"
FLOOR
CEILING
Minimum
Minimu
m
Of Carpe
t
Combus
t
8"
Minimum
From
Sides Of
Heater
Left
Side Right Side
INSTALLATION
WARNING: A qualified ser-
vice person must install heater.
Follow all local codes.
CHECK GAS TYPE
Use only natural gas. If your gas supply is
notnatural, donot install heater.Call dealer
where you bought heater for proper type
heater.
INSTALLATION ITEMS
Beforeinstallingheater,makesureyouhave
the items listed below.
• piping (check local codes)
• sealant (resistant to propane/LP gas)
• equipment shutoff valve *
• ground joint union
• test gauge connection *
• sediment trap
• tee joint
• pipe wrench
* A CSA/AGA design-certified equipment
shutoff valve with 1/8" NPT tap is an ac-
ceptable alternative to test gauge connec-
tion. Purchase the optional CSA/AGA de-
sign-certifiedequipmentshutoffvalvefrom
your dealer. See Accessories, page 23.
LOCATING HEATER
Thisheaterisdesignedtobemountedonawall.
WARNING:Maintainthemini-
mumclearancesshowninFigure
4.Ifyoucan,providegreaterclear-
ances from floor, ceiling, and
joining wall.
Youcan locate heateron floor, awayfrom a
wall. An optional floor mounting stand is
needed. Purchase the floor mounting stand
fromyour dealer.SeeAccessories,page 23.
WARNING: Never install the
heater
• in a bedroom or bathroom
• in a recreational vehicle
• where curtains, furniture,
clothing, or other flammable
objectsarelessthan36inches
from the front, top, or sides of
the heater
• as a fireplace insert
• in high traffic areas
• in windy or drafty areas
IMPORTANT: Vent-free heaters add mois-
ture to the air. Although this is beneficial,
installing heater in rooms without enough
ventilationairmaycausemildewtoformfrom
too much moisture. See Air for Combustion
and Ventilation, pages 4 through 6.
CAUTION: If you install the
heater in a home garage
• heater pilot and burner must
be at least 18 inches above
floor
• locateheaterwheremovingve-
hicle 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 to-
bacco smoke, aromatic candles,
cleaning fluids, oil or kerosene
lamps, etc.) in the air exist, may
discolor walls.
NOTICE: This heater is intended
foruseassupplementalheat.Use
this heater along with your pri-
mary heating system. Do not in-
stall this heater as your primary
heatsource.Ifyouhave a central
heating system, you may run
system’scirculatingblowerwhile
usingheater.Thiswillhelpcircu-
late the heat throughout the
house. In the event of a power
outage, you can use this heater
as your primary heat source.
Forconvenienceandefficiency,installheater
• there there is easy access for operation,
inspection, and service
• in coldest part of room
An optional fan kit is available from your
dealer. See Accessories, page 23. If plan-
ningtousefan,locate heaternearanelectri-
cal outlet.
Figure4-MountingClearancesAsViewed
From Front of Heater
Continued
Minimum
To Top
Surface
Of Carpeting, Tile or
Other Combustible
Material

8
104246
VENT-FREE NATURAL GAS HEATER
®
Marking Screw Locations
1. Tape mounting bracket to wall where
heater will be located. Make sure
mounting bracket is level.
Model VN2550ITB
Model VN1800ITB
Figure 8 - Mounting Bracket Clearances
2. Mark screw locations on wall (see Fig-
ure 8).
Note: Only mark last hole on each end
of mounting bracket. Insert mounting
screws through these holes only.
3. Remove tape and mounting bracket
from wall.
18 3/4"
Min.
13"
Min. 16"
Adjoining Wall
Only Insert Mounting
Screws Through Last
Hole On Each End
Floor
WARNING:Maintainminimum
clearances shown in Figure 8. If
you can, provide greater clear-
ancesfromfloorandjoiningwall.
Methods For Attaching
Mounting Bracket To Wall
Only use last hole on each end of mounting
bracket to attach bracket to wall. These two
holes are 16 inches apart from their centers.
Attach mounting bracket to wall in one of
two ways.
1. Attaching to wall stud
2. Attaching to wall anchor
Attaching To Wall Stud: This method pro-
vides the strongest hold. Insert mounting
screws through mounting bracket and into
wall studs.
INSTALLING HEATER TO
WALL
Mounting Bracket
Locate mounting bracket in heater carton.
Removemountingbracketfromheatercarton.
Figure7-RemovingFrontPanelOfHeater
Removing Front Panel Of Heater
1. Remove two screws near bottom cor-
ners of front panel.
2. Liftstraightupongrillguarduntilitstops.
Grill guard will slide up about 1/4".
3. Pull bottomof front panel forward,then
down.
Figure 6 - Mounting Bracket
INSTALLATION
Continued
Figure5- Attaching Thermostat Sensing
Bulb
Thermostat
Sensing
Bulb
THERMOSTAT SENSING
BULB
The thermostat sensing bulb has been placed
insidetheheaterforprotectionduringshipping.
Locating Thermostat Sensing
Bulb
1. Remove front panel of heater (see Fig-
ure 7).
2. Locate thermostat sensing bulb just
under the burner assembly.
IMPORTANT: Attachthermostatsensingbulb
to the back of heater for proper operation.
Attaching Thermostat Sensing
Bulb
1. Remove thermostat sensing bulb from
holders inside heater. Route through
slot opening in bottom of heater.
2. Place clamponthermostat sensing bulb
as shown in Figure 5. Clamp is pro-
vided in hardware package.
3. Snap clamp into upper mounting hole
as shown in Figure 5. Mounting hole is
located on lower left edge on back of
heater. Make sure the thermostat sens-
ing bulb is pointing up.
Attaching To Wall Anchor: This method
allows you to attach mounting bracket to
hollow walls (wall areas between studs) or
to solid walls (concrete or masonry).
Decidewhichmethodbettersuitsyourneeds.
Eithermethodwillprovideasecureholdfor
the mounting bracket.
Clamp
16"
18 3/4"
Min.
9 1/4"
Min.
Adjoining Wall
Only Insert Mounting
Screws Through Last
Hole On Each End
Floor

9
104246
OWNER’S MANUAL
Attaching Mounting Bracket To
Wall
Note: Wall anchors, mounting screws, and
spacers are in hardware package. The hard-
ware package is provided with heater.
Attaching To Wall Stud Method
Forattachingmountingbrackettowallstuds
1. Drill holes at marked locations using
9/64" drill bit.
2. Place mounting bracket ontowall. Line
uplasthole on each end of bracket with
holes drilled in wall.
3. Insert mountingscrews through bracket
and into wall studs.
4. Tighten screws until mounting bracket
is firmly fastened to wall studs.
Attaching To Wall Anchor Method
For attaching mounting bracket to hollow
walls (wall areas between studs) or solid
walls (concrete or masonry)
1. Drill holes at marked locations using
5/16"drillbit. For solid walls (concrete
or masonry), drill at least 1" deep.
2. Fold wall anchor as shown in Figure 9.
3. Insert wall anchor (wings first) into
hole. Tap anchor flush to wall.
4. For thin walls (1/2" or less), insert red
key into wall anchor. Push red key to
“pop” open anchor wings.
IMPORTANT: Do not hammer key!
Forthick walls (over1/2" thick) orsolid
walls, do not pop open wings.
5. Place mounting bracket ontowall. Line
uplasthole on each end of bracket with
wall anchors.
6. Insert mountingscrews through bracket
and into wall anchors.
7. Tighten screws until mounting bracket
is firmly fastened to wall.
Placing Heater On Mounting
Bracket
1. Locate two horizontal slots on back
panel of heater.
2. Place heater onto mounting bracket.
Slide horizontal slots onto stand-out
tabs on mounting bracket.
Figure 9 - Folding Anchor
INSTALLATION
Continued
Figure 10 - Popping Open Anchor Wings
For Thin Walls
Figure 11 - Mounting Heater Onto
Mounting Bracket
Stand-Out Tab
Mounting Bracket
(attached to wall)
Installing Bottom Mounting
Screws
1. Locate two bottom mounting holes.
These holes are near bottom on back
panel of heater (see Figure 14).
2. Mark screw locations on wall.
3. Remove heater frommounting bracket.
4. If installing bottom mounting screws
into hollow or solid wall, install wall
anchors. Follow steps 1 through 4 un-
der Attaching To Wall Anchor Method.
If installing bottom mounting screw
into wall stud, drill holes at marked lo-
cations using 9/64" drill bit.
5. Replace heater onto mounting bracket.
6. Place spacers between bottom mount-
ingholesandwallanchor ordrilled hole.
7. Hold spacer in place with one hand.
With otherhand, insert mounting screw
through bottom mounting hole and
spacer. Place tip of screw in opening
of wall anchor or drilled hole.
8. Tighten both screws until heater is
firmly secured to wall. Do not over
tighten.
Note: Do not replace front panel at this
time. Replace front panel after making
gas connections and checking for leaks
(see pages 10 and 11).
Figure 12 - Installing Bottom Mounting
Screws
Horizontal Slots
Continued

10
104246
VENT-FREE NATURAL GAS HEATER
®
Tee Joint
Reducer
Bushing to
1/8" NPT
1/8" NPT
Plug Tap
Test
Gauge
Connection *
Sediment
Trap
Tee Joint
Pipe Nipple
Cap
Equipment
Shutoff
Valve *
3/8" NPT
Pipe Nipple
Heater
Cabinet
Figure 13 - Gas Connection
* ACSA/AGAdesign-certifiedequipmentshutoffvalvewith1/8"NPTtapisanacceptable
alternative to test gauge connection. Purchase the optional CSA/AGA design-certified
equipment shutoff valve from your dealer. See Accessories, page 23.
3" Minimum
Ground Joint
Union
Pressure
Regulator
Regulator
Bracket
From Gas
Meter
(7" W.C. to
10.5" W.C.
Pressure)
CONNECTING TO GAS
SUPPLY
WARNING: A qualified service
personmustconnectheatertogas
supply. Follow all local codes.
Typical Inlet Pipe Diameters
VN1800ITB 3/8" or greater
VN2550ITB 1/2" or greater
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).
Installsedimenttrapinsupplylineasshown
in Figure 13. Locate sediment trap where it
is within reach for cleaning. Locate sedi-
menttrapwhere 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.
IMPORTANT: Hold pressure regulator
with wrench when connecting it to gas pip-
ing and/or fittings.
CAUTION:Usepipejointseal-
ant that is resistant to liquid pe-
troleum (LP) gas.
IMPORTANT: Check gasline pressure be-
fore connecting heater to gas line. Gas line
pressure must be no greater than 14 inches
of water. If gas line pressure is higher,
heater regulator damage could occur.
WARNING : Never connect
heater to private (non-utility) gas
wells. This gas is commonly
known as well-head gas.
CAUTION: Use only new,
black iron or steel pipe. Inter-
nally-tinned copper tubing may
be used in certain areas. Check
yourlocalcodes.Usepipeoflarge
enough diameter to allow proper
gas volume to heater. If pipe is
too small, undue loss of pres-
sure will occur.
Typical
Inlet Pipe
INSTALLATION
Continued
IMPORTANT: Installanequipmentshutoff
valve in an accessible location. The equip-
ment shutoff valve is for turning on or
shutting off the gas to the appliance.Apply
pipe joint sealant lightly to male threads.
This will prevent excess sealant from going
intopipe.Excesssealantinpipecouldresult
in clogged heater valves.
WARNING:Thisappliancere-
quires a 3/8" NPT (National Pipe
Thread) inlet connection to the
pressure regulator.

11
104246
OWNER’S MANUAL
O
POS
P
O
CHECKING GAS
CONNECTIONS
Pressure Testing Gas Supply
Piping System
Test Pressures In Excess Of 1/2 PSIG
(3.5 kPa)
1. Disconnect appliance with its appliance
maingasvalve(controlvalve)and equip-
ment shutoff valve from gas supply pip-
ingsystem.Pressuresinexcessof1/2psig
will damage heater regulator.
2. Cap off open end of gas pipe where
equipmentshutoffvalve wasconnected.
3. Pressurize supply piping system by ei-
ther using compressed air or opening
main gas valve located on or near gas
meter.
4. Check all joints of gas supply piping
system. Apply mixture of liquid soap
and water to gas joints. Bubbles form-
ing show a leak.
5. Correct all leaks at once.
6. Reconnect heater and equipment
shutoff valve to gas supply. Check re-
connected fittings for leaks.
WARNING:Neveruseanopen
flame to check for a leak. Apply a
mixture of liquid soap and water
to all joints. Bubbles forming
show a leak. Correct all leaks at
once.
WARNING: Test all gas pip-
ing and connections for leaks
after installing or servicing. Cor-
rect all leaks at once.
Figure 14 - Equipment Shutoff Valve
Equipment
Shutoff
Valve
Open
Closed
Figure 15 - Checking Gas Joints
Gas Meter
Control Valve Location
TestPressures Equal Toor Less Than1/2
PSIG (3.5 kPa)
1. Close equipmentshutoff valve(see Fig-
ure 14).
2. Pressurize supply piping system by ei-
ther using compressed air or opening
main gas valve located on or near gas
meter.
3. Check all joints from gas meter to
equipment shutoff valve (see Figure
15). Apply mixture of liquid soap and
water to gas joints. Bubbles forming
show a leak.
4. Correct all leaks at once.
Pressure Testing Heater Gas
Connections
1. Open equipmentshutoff valve(see Fig-
ure 14).
2. Open main gas valve located on or near
gas meter.
3. Make sure control knob of heater is in
the OFF position.
4. Check alljoints from equipmentshutoff
valve to control valve (see Figure 15).
Apply mixture of liquid soap and wa-
ter to gas joints. Bubbles forming show
a leak.
5. Correct all leaks at once.
6. Light heater (see Operating Heater,
pages 12 and 13). Check the rest of the
internal joints for leaks.
7. Turn off heater (see To Turn Off Gas to
Appliance, page 13).
8. Replace front panel.
Equipment
Shutoff
Valve
INSTALLATION
Continued

12
104246
VENT-FREE NATURAL GAS HEATER
®
IGNITOR
PILOT
LO
OFF
HI
1
2
3
4
Figure 17 - Pilot
Pilot Burner
Thermocouple Ignitor Electrode
LIGHTING
INSTRUCTIONS
1. STOP! Read the safety information
at the top column 1.
2. Make sure equipment shutoff valve
is fully open.
3. Turnthermostat controlknob on left
side of heater clockwise
Clockwise
to
the OFF position.
4. Waitfive minutestoclearoutanygas.
Thensmell forgas,includingnearthe
floor. If you smell gas, STOP! Follow
“B” in the safety information at the
topofcolumn1.Ifyoudon’tsmellgas,
go to the next step.
5. Turnthermostatcontrolknobonleftside
of heater counterclockwise
C-clockwise
to
thePILOTposition.Pressinthermostat
control knob for 5 seconds.
Note: You may be running this
heater for the first time after hook-
ing up to gas supply. If so, you may
need to press in thermostat control
knob for 30 seconds. This will allow
air to bleed from the gas system.
• If thermostat control knob does
not pop up when released, contact
a qualified service person or gas
supplier for repairs.
Plaque Control Knob
Thermostat Control Knob Ignitor Button
Figure 16 - Thermostat Control Knob In The OFF Position
6. Keep thermostat control knob
pressed in while pushing down and
releasingtheignitorbutton.Thiswill
light pilot. If necessary, continue to
pressignitorbuttonuntil pilot lights.
If pilot does not light
• turn thermostat control knob
clockwise
Clockwise
to the OFF po-
sition
• repeat steps 5 and 6
If pilot does not stay lit after several
tries
• refer to Troubleshooting, pages 15
through 17
• contact a qualified service person
or gas supplier
Untilrepairsaremade, lightpilotwith
match. To light pilot with match, see
Manual Lighting Procedure, page 13
7. Keep thermostat control knob
pressed in for 30 seconds after light-
ing pilot. After 30 seconds, release
control knob.
Note: If pilot goes out, repeat steps
3 through 7.This heater has a safety
interlock system. Wait one minute
before lighting pilot again.
8. Turn thermostat control knob coun-
terclockwise
C-clockwise
to the desired
heating level. The plaque directly
above the pilot should light.
OPERATING
HEATER
FOR YOUR SAFETY
READ BEFORE
LIGHTING
WARNING: If you do not fol-
low these instructions exactly, a
fireorexplosionmayresultcaus-
ing property damage, personal
injury or loss of life.
A. Thisappliancehas apilotwhich must
belighted byhand.Whenlightingthe
pilot,followtheseinstructionsexactly.
B. BEFORE LIGHTING smell all
aroundtheapplianceareafor gas. Be
suretosmellnextto the floorbecause
some gas is heavier than air and will
settle on the floor.
WHAT TO DO IF YOU SMELL
GAS
• Do not try to light any appliance.
• Donottouchanyelectricswitch; do
notuseany phone in yourbuilding.
• Immediatelycall yourgassupplier
from a neighbor’s phone. Follow
the gas supplier’s instructions.
• If you cannot reach your gas sup-
plier, call the fire department.
C. Useonlyyourhand to pushinorturn
thegascontrol knob. Neveruse tools.
If the knob will not push in or turn
by hand, don’t try to repair it, call a
qualified service technician or gas
supplier. Force or attempted repair
may result in a fire or explosion.
D. Do not use this appliance if any part
has been under water. Immediately
call a qualified service technician to
inspect the appliance and to replace
any part of the control system and
any gas control which has been un-
der water.

13
104246
OWNER’S MANUAL
3
4
21
3
4
21
3
4
21
3
4
21
1. Slightlypressin plaque controlknob
onright sideofheaterandturncoun-
terclockwise
C-clockwise
to the desired
position.
IMPORTANT: Release downward
pressure while turning controlknob.
Control knob will lock at the desired
position.
2. Turnthermostat controlknob on left
side of heater to any setting between
LO and HI. Note: When burners
cycle on, or from LO to HI, a “click”
will be heard. When the burners
light,a “whoosh” noise willbeheard.
TO SELECT HEATING
LEVEL
WARNING: When running
heater, set control knob at the 1,
2, 3, or 4 locked positions. Never
set control knob between locked
positions. Poor combustion and
higher levels of carbon monox-
ide may result.
CAUTION:Donottrytoadjust
heatinglevelsbyusingtheequip-
ment shutoff valve.
Control
Knob VN1800ITB VN2550ITB
OPERATING
HEATER
Continued
Figure 18 - Burner Patterns
TO TURN OFF GAS
TO APPLIANCE
1. Followsteps1through5underLight-
ing Instructions, page 12.
2. With thermostat control knob
pressedin,strikematch. Hold match
to pilot until pilot lights.
3. Keep thermostat control knob
pressed in for 30 seconds after light-
ing pilot. After 30 seconds, release
control knob. Follow step 8 under
Lighting Instructions, page 12.
Shutting Off Heater
1. Turnthermostat controlknob clock-
wise
Clockwise
to the OFF position.
2. Turn off all electric power to the ap-
pliance if service is to be performed.
Shutting Off Burner Only (pilot
stays lit)
Turn thermostat control knob clockwise
Clockwise
to the PILOT position.
THERMOSTAT
OPERATION
Since the thermostat measures the tem-
perature of air near the heater cabinet,
this may not always agree with room
temperature(depending onhousingcon-
struction,installationlocation,roomsize,
open air temperatures, etc.). Frequent
operation of your heater will enable you
to determine your own comfort levels.
MANUAL LIGHTING
PROCEDURE

14
104246
VENT-FREE NATURAL GAS HEATER
®
GRH/OV 009A
CLEANING AND
MAINTENANCE
CAUTION: You must keep
control areas, burner, and circu-
lating air passageways of heater
clean. Inspect these areas of
heater before each use. Have
heaterinspectedyearlybyaquali-
fied service person. Heater may
needmorefrequentcleaningdue
to excessive lint from carpeting,
bedding material, pet hair, etc.
WARNING: Turn off heater
and let cool before cleaning.
BURNER FLAME PATTERN
Figure 21 shows a correct burner flame
pattern.Figure22showsanincorrectburner
flame pattern.
Ifburnerflamepatternisincorrect,asshown
in Figure 22
• turn heater off (see To Turn Off Gas to
Appliance, page 13)
• seeTroubleshooting,pages 15 through 17
Figure 21 - Correct Burner Flame Pattern
Figure22-IncorrectBurnerFlamePattern
INSPECTING
BURNER
Check pilot flame pattern and burner flame
pattern often.
PILOT FLAME PATTERN
Figure 19 shows a correct pilot flame pat-
tern. Figure 20 shows an incorrect pilot
flame pattern. The incorrect pilot flame is
not touching the thermocouple. This will
cause the thermocouple to cool. When the
thermocouple cools, the heater will shut
down.
If pilot flame pattern is incorrect, as shown
in Figure 20
• turn heater off (see To Turn Off Gas to
Appliance, page 13)
• seeTroubleshooting,pages 15 through 17
Figure 19 - Correct Pilot Flame Pattern
Thermocouple
Pilot Burner
Pilot Burner
Thermocouple
Figure 20 - Incorrect Pilot Flame Pattern
CABINET
Air Passageways
• Use a vacuum cleaner or pressurized air
to clean.
Exterior
• Use a soft cloth dampened with a mild
soap and water mixture. Wipe the cabi-
net to remove dust.
ODS/PILOT AND BURNER
ORIFICE
• Use a vacuum cleaner, pressurized air,
or small, soft bristled brush to clean.
CLEANING BURNER
PILOT AIR INLET HOLE
We recommend that you clean the unit ev-
ery 2,500 hours of operation or every three
months.
Figure 23 - Pilot Inlet Air Hole
Pilot Assembly
Wealsorecommendthatyoukeeptheburner
tube and pilot assembly clean and free of
dustanddirt.Tocleanthesepartswerecom-
mend using compressed air no greater than
30 PSI. Your local computer store, hard-
ware store, or home center may carry com-
pressed air in a can. You can use a vacuum
cleaner in the blow position. If using com-
pressed air in a can, please follow the direc-
tions on the can. If you don't follow direc-
tionsonthecan, youcoulddamagethepilot
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.
Clean the pilot assembly also. A yellow tip
on the pilot flame indicates dust and dirt in
the pilot assembly. There is a small pilot air
inlet hole about two inches from where the
pilot flame comes out of the pilot assembly
(see Figure 23). With the unit off, lightly
blowair through theair inlet hole.You may
blowthroughadrinkingstrawifcompressed
air is not available.
Pilot Air Inlet
Hole

15
104246
OWNER’S MANUAL
TROUBLESHOOTING
OBSERVED PROBLEM
Whenignitorbuttonispressedin,thereisno
spark at ODS/pilot
When ignitor button is pressed in, there is a
spark at ODS/pilot but no ignition
ODS/pilot lights but flame goes out when
control knob is released
POSSIBLE CAUSE
1. Ignitor electrode positioned wrong
2. Ignitor electrode broken
3. Ignitor electrode not connected to igni-
tor cable
4. Ignitor cable pinched or wet
5. Broken ignitor cable
6. Bad piezo ignitor
7. Piezo ignitor nut is loose
1. Gas supply turned off or equipment
shutoff valve closed
2. Control knob not fully pressed in while
pressing ignitor button (non-thermostat
models only)
Thermostat control knob not fully
pressed in while pressing ignitor button
(thermostat models only)
3. Air in gas lines when installed
4. ODS/pilot is clogged
5. Gas regulator setting is not correct
6. Thermostat control knob not in pilot
position
1. Control knob not fully pressed in
2. Control knob notpressed in long enough
3. Equipment shutoff valve not fully open
4. Thermocouple connection loose at con-
trol valve
5. Pilot flame not touching thermocouple,
which allows thermocouple to cool,
causing pilot flame to go out. This prob-
lem could be caused by one or both of
the following:
A) Low gas pressure
B) Dirty or partially clogged ODS/pilot
6. Thermocouple damaged
7. Control valve damaged
8. Safety interlock system has been trig-
gered (thermostat models only)
REMEDY
1. Replace ignitor
2. Replace ignitor
3. Reconnect ignitor cable
4. Free ignitor cable if pinched by any
metal or tubing. Keep ignitor cable dry
5. Replace ignitor cable
6. Replace control valve (piezo is part of
control valve)
7. Tighten nut holding piezo ignitor. Nut
is located inside heater cabinet at top
1. Turn on gas supply or open equipment
shutoff valve
2. Fully press in control knob while press-
ing ignitor button (non-thermostat mod-
els only)
Fully press in thermostat control knob
while pressing ignitor button (thermo-
stat models only)
3. Continue holding downcontrol knob. Re-
peatignitingoperationuntil airisremoved
4. Clean ODS/pilot (see Cleaning and
Maintenance, page 14) or replace ODS/
pilot assembly
5. Replace gas regulator
6. Turn thermostat control knob to pilot
position
1. Press in control knob fully
2. After ODS/pilot lights, keep control
knob pressed in 30 seconds
3. Fully open equipment shutoff valve
4. Hand tighten until snug, then tighten 1/4
turn more
5. A) Contact local natural gas company
B) Clean ODS/pilot (see Cleaning and
Maintenance, page 14) or replace ODS/
pilot assembly
6. Replace thermocouple
7. Replace control valve
8. Wait one minute for safetyinterlocksys-
tem to reset. Repeat ignition operation
WARNING: Turn off and un-
plug heater and let cool before
servicing. Only a qualified ser-
vice person should service and
repair heater.
CAUTION: Never use a wire,
needle, or similar object to clean
ODS/pilot.ThiscandamageODS/
pilot unit.
Continued
Note: For additional help, visit DESA
International’stechnicalservicewebsite
at www.desatech.com.
Note: Alltroubleshootingitemsarelistedin
order of operation.
www.desatech.com

16
104246
VENT-FREE NATURAL GAS HEATER
®
OBSERVED PROBLEM
Burner(s)does notlight after ODS/pilotis lit
Delayed ignition of burner(s)
Burner backfiring during combustion
Burner plaque(s) does not glow
Slightsmoke orodor duringinitial operation
Heater produces a clicking/ticking noise
just after burner is lit or shut off
Whitepowderresidueformingwithinburner
box or on adjacent walls or furniture
REMEDY
1. Clean burner orifice(s) (see Cleaning
and Maintenance, page 14) or replace
burner orifice(s)
2. Replace burner orifice(s)
3. Contact local natural gas company
1. Contact local natural gas company
2. Clean burner orifice(s) (see Cleaning
and Maintenance, page 14) or replace
burner orifice(s)
1. Clean burner orifice(s) (see Cleaning
and Maintenance, page 14) or replace
burner orifice(s)
2. Replace burner
3. Replace gas regulator
1. Replace burner
2. Contact local natural gas company
3. Turn control knob until it locks at de-
sired setting
1. Problem will stop after a few hours of
operation
1. This is common with most heaters. If
noise is excessive, contact qualified ser-
vice person
1. Turn heater off when using furniture
polish, wax, carpet cleaners, or similar
products
POSSIBLE CAUSE
1. Burner orifice(s) is clogged
2. Burner orifice(s) diameter is too small
3. Inlet gas pressure is too low
1. Manifold pressure is too low
2. Burner orifice(s) is clogged
1. Burner orifice(s) is clogged or damaged
2. Burner damaged
3. Gas regulator defective
1. Plaque damaged
2. Inlet gas pressure is too low
3. Control knob set between locked
positions
1. Residues from manufacturing processes
1. Metal expanding while heating or con-
tracting while cooling
1. When heated, vapors fromfurniture pol-
ish, wax, carpet cleaners, etc. turn into
white powder residue
TROUBLESHOOTING
Continued
www.desatech.com

17
104246
OWNER’S MANUAL
WARNING: If you smell gas
• Shut off gas supply.
• Do not try to light any appliance.
• Do not touch any electrical switch; do not use any phone in your
building.
• Immediatelycallyourgassupplierfromaneighbor’sphone.Followthe
gas supplier’s instructions.
• If you cannot reach your gas supplier, call the fire department.
POSSIBLE CAUSE
1. Heater burning vapors from paint, hair
spray, glues, etc. See IMPORTANT
statement above
2. Gas leak. SeeWarning statement at
top of page
1. Not enough fresh air is available
2. Low line pressure
3. ODS/pilot is partially clogged
1. Gas leak. SeeWarning statement at
top of page
2. Control valve defective
1. Foreign matter between control valve
and burner
2. Gas leak. SeeWarning statement at
top of page
1. Not enough combustion/ventilation air
OBSERVED PROBLEM
Heater produces unwanted odors
Heater shuts off in use (ODS operates)
Gas odor even when control knob is in OFF
position
Gas odor during combustion
Moisture/condensationnoticedonwindows
REMEDY
1. Ventilate room. Stop using odor caus-
ing products while heater is running
2. Locate and correct all leaks (see Check-
ing Gas Connections, page 11)
1. Open windowand/or door forventilation
2. Contact local natural gas company
3. Clean ODS/pilot (see Cleaning and
Maintenance, page 14)
1. Locate and correct all leaks (see Check-
ing Gas Connections, page 11)
2. Replace control valve
1. Take apart gas tubing and remove for-
eign matter
2. Locate and correct all leaks (see Check-
ing Gas Connections, page 11)
1. Refer to Fresh Air for Combustion and
Ventilation requirements (page 4)
IMPORTANT: Operating heater where impurities in air exist may create odors. Cleaning
supplies, paint, paint remover, cigarette smoke, cements and glues, new carpet or textiles,
etc., create fumes. These fumes may mix with combustion air and create odors.
TROUBLESHOOTING
Continued
www.desatech.com

18
104246
VENT-FREE NATURAL GAS HEATER
®
ILLUSTRATED
PARTS
BREAKDOWN
VN1800ITB
21-15
21-14
A
B
C
21-1
21-2
21-3
21-4
21-5 21-6
21-7
21-8
21-12
21-10
21-1121-9
21-13
1
2
3
11
6
48
5
6
7
12
21
910
22
14
16
19
20
18
17
15
13

19
104246
OWNER’S MANUAL
PARTS LIST
VN1800ITB
This list contains replaceable parts used in your heater. When ordering parts, follow the instructions
listed under Replacement Parts on page 22 of this manual.
KEY PART
NO. NUMBER DESCRIPTION QTY.
1 098304-01 Screw, #10 x 3/8" 2
2 098742-13 Front Panel 1
3 098238-06 Grill Guard 1
4 101108-01 Clip-Grill Guard 2
5 098198-03 Apron 1
6 M11084-26 Screw, #10 x 3/8" 9
7 098462-01 Control Rod Assembly 1
8 098457-01 Reflector Assembly 1
9 099415-08 Regulator 1
10 M11084-38 Screw, #8 x 3/8" 2
11 104617-01 Cabinet Assembly 1
12 098324-01 Control Knob 1
13 098325-01 Roll Pin 1
14 097159-04 Piezo Ignitor 1
15 100537-02 Regulator Bracket 1
16 098522-16 Thermostat Gas Valve 1
17 098271-03 Ignitor Cable 1
18 104224-01 SIT Tube 1
19 104197-01 Inlet Tube 1
20 099211-01 Hex-Head Screw 2
21 See Detail Burner Assembly 1
21-1 099218-01 Burner 1
21-2 098508-01 Valve Retainer Nut 1
21-3 099056-03 Injector 3
21-4 099048-01 Tubing-Valve to Plaque A 1
21-5 099049-02 Tubing-Valve to Plaque B 1
21-6 099050-01 Tubing-Valve to Plaque C 1
21-7 100605-01 Control Valve 1
21-8 099387-06 Pilot Tubing 1
21-9 100616-01 Control Valve Tube 1
21-10 103594-06 ODS/Pilot 1
21-11 100615-01 Male Connector 2
21-12 M11084-26 Screw, #10 x 3/8" 2
21-13 M11084-37 Screw, #8 x 1/4" 3
21-14 098514-01 Thermocouple 1
21-15 106842-01 Ignitor Electrode 1
22 099066-01 Mounting Bracket 1
PARTS AVAILABLE - NOT SHOWN
100619-01 Thermostat Control Position Label 1
100619-03 Control Position Label 1
100642-01 Hardware Assembly 1

20
104246
VENT-FREE NATURAL GAS HEATER
®
1
2
3
11
6
48
5
6
7
12
21
910
22
14
16
19
20 17
15
13
18
ILLUSTRATED
PARTS
BREAKDOWN
VN2550ITB
D
C
21-1
21-2
21-3
21-7
21-13
21-14
21-10
B
A
21-5
21-4
21-8
21-6
21-9
21-11
21-12
21-16
21-15