Desa Comfort Glow CGN12 Quick start guide

OWNER’S OPERATION AND INSTALLATION MANUAL
®
VENT-FREE NATURAL GAS HEATER
Model: CGN12
Save this manual for future reference
WARNING: If the information in this manual
is not followed exactly, a fire or explosion
may result causing property damage, per-
sonal injury, 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.
• Immediatelycallyourgassupplierfrom
a neighbor’s phone. Follow the gas
supplier’s instructions.
• If you cannot reach your gas supplier,
call the fire department.
— Installation and service must be per-
formed by a qualified installer, service
agency, or the gas supplier.
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WARNING:Improperinstallation,
adjustment, alteration, service, or
maintenance can cause injury or
property damage. Refer to this
manual for correct installation and
operationalprocedures.Forassis-
tance or additional information
consult a qualified installer, ser-
vice agency, or the gas supplier.

2
CONTENTS SECTION PAGE
Safety Information......................................................................... 2
Product Identification .................................................................... 4
Local Codes ...................................................................................4
Unpacking......................................................................................4
Product Features ............................................................................ 4
Installing To Wall.......................................................................... 5
Connecting To Gas Supply............................................................9
Checking Gas Connections............................................................10
Operating Heater ........................................................................... 12
For Your Safety Read Before Lighting...................................12
Lighting Instructions ............................................................... 12
To Select Heating Level.......................................................... 14
To Turn Off Gas To Appliance...............................................15
Manual Lighting Procedure ....................................................15
Inspecting Burner ..........................................................................15
Pilot Flame Pattern..................................................................15
Burner Flame Pattern .............................................................. 16
Cleaning And Maintenance ...........................................................17
Troubleshooting.............................................................................17
Technical Service ..........................................................................20
Specifications ................................................................................ 21
Service Hints ................................................................................. 21
Replacement Parts .........................................................................21
Parts Centrals................................................................................. 22
Service Publications ......................................................................22
Accessory ......................................................................................22
Parts List ........................................................................................ 23
Illustrated Parts Breakdown .......................................................... 23
Warranty Information .................................................................... Back Cover
!
WARNING ICON G001
WARNINGS
IMPORTANT:Readthisowner’smanualcarefullyandcompletelybefore
trying to assemble, operate, or service this heater. Improper use of this
heatercancauseseriousinjuryordeathfromburns,fire,explosion,and
carbon monoxide poisoning.
!
WARNING ICON G001
DANGER
Carbon monoxide poisoning may lead to death!
Carbon Monoxide Poisoning: Early signs of carbon monoxide poisoning
resemble the flu, with headaches, dizziness, or nausea. If you have these signs, the
heater may not be working properly. Get fresh air at once! Have heater serviced.
Some people are more affected by carbon monoxide than others. These include
pregnant women, people with heart or lung disease or anemia, those under the
influence of alcohol, and those at high altitudes.
NaturalGas:Naturalgasisodorless.Anodor-makingagentisaddedtonaturalgas.
The odor helps you detect a natural gas leak. However, the odor added to natural gas
can fade. Natural gas may be present even though no odor exists.
Make certain you read and understand all warnings. Keep this manual for reference.
It is your guide to safe and proper operation of this heater.
SAFETY
INFORMATION
Continued

3
SAFETY
INFORMATION
Continued
!
WARNINGICON G 001
WARNINGS Continued
1. Use only natural gas. Do not convert heater to use different fuel type.
2. If you smell gas
• shut off gas supply
• do not try to light any appliance
• do not touch any electrical switch; do not use any phone in your building
• immediately call your gas supplier from a neighbor’s phone. Follow the
gas supplier’s instructions
• if you cannot reach your gas supplier, call the fire department
3. Never install the heater
• in sleeping quarters, a mobile home, or a recreational vehicle
• where curtains, furniture, clothing, or other flammable objects are less than
36 inches from the front, top, or sides of the heater
• as a fireplace insert
• in high traffic areas
• in windy or drafty areas
4. Always run heater with control knob at LOW or HIGH locked positions.
Never set control knob between locked positions. Poor combustion and higher
levels of carbon monoxide may result.
5. Open window to admit fresh, outside air when using heater. Open window one
or two inches. When used without fresh, outside air, heater may give off
carbon monoxide gas.
6. Never run heater in small, closed room. Open door into next room to help
ventilate.
7. Keep all air openings in front and bottom of heater clear and free of debris.
This will insure enough air for proper combustion.
8. If heater shuts off, do not relight until you provide fresh, outside air. If heater
keeps shutting off, have it serviced.
9. Do not run heater
• where flammable liquids or vapors are used or stored
• under dusty conditions
10.Never place any objects on the heater.
11.Surface of heater becomes very hot when running heater. Keep children and
adults away from hot surface to avoid burns or clothing ignition. Heater will
remain hot for a time after shut-down. Allow surface to cool before touching.
12.Make sure grill guard is in place before running heater.
13.Do not alter heater or its controls. Any change may create a safety hazard.
14. Do not use heater if any part of heater has been under water.
15.Turn off heater and let cool before servicing. Only a qualified service person
should service and repair heater.
16. Do not operate heater in elevations above 4,500 feet.

4
PRODUCT
IDENTIFICATION
LOCAL CODES 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, 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
Control Knob
Heater
Cabinet
Grill
Guard
Burners
Front
Panel
Figure 1 - Vent-Free Natural Gas Heater
UNPACKING 1. Remove heater from carton.
2. Remove all protective packaging applied to heater for shipment.
3. Check heater for any shipping damage. If heater is damaged, promptly inform
dealer where you bought heater.
PRODUCT
FEATURES
Safety Device
This heater has a pilot with an Oxygen Depletion Sensor Shutoff System (ODS).
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.

5
INSTALLING
TO WALL NOTICE
A qualified service person must install heater. Follow all local
codes.
Continued
CHECK GAS TYPE
Use only natural gas. If your gas supply is not natural, do not install heater. Call
dealer where you bought heater for proper type heater.
INSTALLATION ITEMS
Before installing heater, make sure you have the items listed below.
• piping (check local codes)
• sealant (resistant to propane gas)
• manual shutoff valve *
• ground joint union
• test gauge connection * (see
Figure 10, page 10)
• sediment trap
• tee joint
• pipe wrench
*AnA.G.A. design-certified manual shutoffvalvewith 1/8" NPTtapis an acceptable
alternative to test gauge connection. Purchase the optional A.G.A. design-certified
manual shutoff valve from your dealer. See ACCESSORY, page 22.
LOCATING HEATER
This heater is designed to be mounted on a wall.
!
WARNING ICON G 001
WARNING
Maintain the minimum clearances shown in Figure 2 (page 6). If
you can, provide greater clearances from floor, ceiling, and
joining wall.
!
WARNING ICON G 001
WARNING
Never install the heater
• in sleeping quarters, a mobile home, or a recreational vehicle
• where curtains, furniture, clothing, or other flammable objects
are less than 36 inches from the front, top, or sides of the
heater
• as a fireplace insert
• in high traffic areas
• in windy or drafty areas
!
WARNING ICON G001
CAUTION
Operating heater where impurities in the air (such as tobacco
smoke) exist may discolor walls.
!
WARNING ICON G 001
CAUTION
If you install the heater in a home garage
• heater pilot and burner must be at least 18 inches above floor
• locate heater where moving vehicle will not hit it
For convenience and efficiency, install heater
• where there is easy access for operation, inspection, and service
• in coldest part of room

6
!
WARNING ICON G001
WARNING
Maintain minimum clearances shown in Figure 3. If you can,
provide greater clearances from floor and joining wall.
2. Mark two mounting screw locations on wall (see Figure 3).
INSTALLING HEATER TO WALL
Marking Screw Locations
1. Determine where you will locate heater.
Figure 3 - Mounting Screw Locations
Mounting
Screw
Locations
10 7/8"
Minimum To
Maintain 6"
Clearance
From Wall
7 3/4"
20 1/4"
Minimum To
Maintain 3"
Clearance
From Floor
36"
3"
FLOOR
CEILING
Minimum
Minimum To Top Surface
Of Carpeting, Tile Or Other
Combustible Material
8"
Minimum
From
Sides Of
Heater
Right
Side
Left
Side
Figure 2 - Mounting Clearances As Viewed From Front of Heater
FLOOR
JOINING WALL
INSTALLING
TO WALL
Continued

7
Installing Two Mounting Screws
Note: Wall anchors and mounting screws are in hardware package. The hardware
package is provided with heater.
Attaching to wall stud method
For attaching mounting screw to wall stud
1. Drill hole at marked location using 9/64" drill bit.
2. Insert mounting screw into wall stud.
3. Tighten screw until 1/16" space (thickness of penny) is between screwhead and
wall.
Attaching to wall anchor method
Follow instructions below to attach mounting screws to hollow walls (wall areas
between studs) or solid walls (concrete or masonry).
1. Drill holes at marked locations using 5/16" drill bit. For solid walls (concrete or
masonry), drill at least 1 1/4" deep.
2. Fold wall anchor (see Figure 4).
3. Insert wall anchor (wings first) into hole. Tap anchor flush to wall.
Figure 4 - Folding Anchor
4. For thin walls (1/2" or less), insert red key into wall anchor. Push red key to
“pop” open anchor wings (see Figure 5). IMPORTANT: Do not hammer key!
For thick walls (over 1/2" thick) or solid walls, do not pop open wings.
5. Tighten two screws until 1/16" space (thickness of penny) is between
screwheads and wall (see Figure 6).
Thin Walls
(1/4" to 1/2" thick)
Figure 5 - Popping Open Anchor Wings For Thin Walls
ANCHOR
Thin or Thick Wall
(thick wall shown)
Solid Wall
1/16" Space
Figure 6 - Tightening Anchors

8
Placing Heater On Mounting Screws
1. Locate two keyhole slots on back panel of heater (see Figure 7).
2. Place large openings of slots over screwheads. Slide heater down until screws
are in small portion of slots.
Figure 9 - Installing Bottom Mounting Screw
Removing Front Panel Of Heater
1. Remove two screws near bottom corners of front panel.
2. Lift straight up on grill guard until it stops. Grill guard will slide up about 1/4".
3. Pull bottom of front panel forward, then down.
Figure 8 - Removing Front Panel Of Heater
Installing Bottom Mounting Screw
1. Locate bottom mounting hole. This hole is near bottom on back panel of heater
(see Figure 9).
2. Mark screw location on wall.
3. Remove heater from wall.
4. If installing bottom mounting screw into hollow or solid wall, install wall anchor.
Follow steps 1 through 5 under Attaching To Wall Anchor Method, page 7.
If installing bottom mounting screw into wall stud, drill hole at marked location
using 9/64" drill bit.
5. Replace heater on wall.
6. Insert bottom anchor screw through back panel into bottom anchor or drilled
hole (see Figure 9).
7. Tighten screw until heater is firmly secured to wall. Do not over tighten.
Note: Do not replace front panel at this time. Replace front panel after making
gas connections and checking for leaks (see pages 9-11).
Figure 7 - Location Of Keyhole Slots On Back Panel Of Heater
Keyhole
Slots

9
!
WARNING ICON G 001
WARNING
Never connect heater to private (non-utility) gas wells. This gas is
commonly known as well-head gas.
NOTICE
A qualified service person must connect heater to gas supply.
Follow all local codes.
CONNECTING
TO GAS
SUPPLY
IMPORTANT: Check gas line pressure before 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.
Installation must include a manual shutoff valve, ground joint 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 10, page 10).
Apply pipe joint sealant lightly to male threads. This will prevent excess sealant
from going into pipe. Excess sealant in pipe could result in clogged heater valves.
Continued
Install sediment trap in supply line as shown in Figure 10. Locate sediment trap
where it is within reach for cleaning. Locate sediment trap where trapped matter is
not likely to freeze. A sediment trap traps moisture and contaminants. This keeps
them from going into heater controls. If sediment trap is not installed or is installed
wrong, heater may not run properly.
!
WARNING ICON G001
CAUTION
Use pipe joint sealant that is resistant to liquid petroleum (LP) gas.
!
WARNING ICON G 001
CAUTION
Use only new, black iron or steel pipe. Copper tubing may be used
in certain areas. Check your local codes. Use pipe 3/8" diameter or
greater to allow proper gas volume to heater. If pipe is too small,
undue loss of pressure will occur.

10
!
WARNING ICON G 001
WARNING
Test all gas piping and connections for leaks after installing or
servicing. Correct all leaks at once.
Manual
Shutoff Valve *
IMPORTANT: Holdpressure regulatorwithwrench whenconnectingit togas piping
and/or fittings.
Figure 10 - Gas Connection
* AnA.G.A. design-certifiedmanualshutoffvalvewith 1/8"NPTtapisan acceptable
alternative to test gauge connection. Purchase the optional A.G.A. design-certified
manual shutoff valve from your dealer. See ACCESSORY, page 22.
Tee Joint
Reducer
Bushing to
1/8" NPT
1/8" NPT
Plug Tap
Test
Gauge
Connection *
Tee
Joint
Pipe
Nipple
Cap
Sediment
Trap
PRESSURE TESTING GAS SUPPLY PIPING SYSTEM
Test Pressures In Excess Of 1/2 PSIG
1. Disconnect heater and its individual manual 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 manual shutoff valve was connected.
3. Pressurize supply piping system by either using compressed air or
opening main gas valve located on or near gas meter.
CHECKING
GAS
CONNECTIONS
Continued
Pressure
Regulator
Heater
Cabinet
3/8" NPT
Pipe Nipple
Ground Joint Union
From Gas Meter
(4" W.C. to
10.5" W.C. Pressure)
!
WARNING ICON G 001
WARNING
Never use an open 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.
3" Minimum