Desa CGN20TA User Manual

OWNER’S MANUAL

BLUE FLAME VENT-FREE NATURAL GAS HEATER

OWNER’S OPERATION AND INSTALLATION MANUAL

CGN20TA

®

Heater Size: 20,000 Btu/Hr Thermostat

WARNING: If the information in this manual is not
followed exactly, a fire or explosion may result
causing property damage, personal 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.

• 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.

— Installation and service must be performed by

a qualified installer, service agency, or the gas
supplier.

This appliance may be installed in an aftermarket* manufactured (mobile) home, where not prohibited by
state or local codes.

* Aftermarket: Completion of sale, not for purpose of resale, from the manufacturer.

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.

WARNING: This is an
unvented gas-fired heater. It
uses air (oxygen) from the
room in which it is installed.
Provisions for adequate
combustion must be pro­vided. Refer to page 4 of this
manual

104190

Save this manual for future reference.

1

CGN20TA

Blue Flame Vent-Free Natural Gas Heater

SAFETY
INFORMATION

WARNINGS

IMPORTANT: Read this owner’s
manual carefully and completely
before trying to assemble, oper­ate, or service this heater. Im­proper use of this heater can
cause serious injury or death from
burns, fire, explosion, electrical
shock, and carbon monoxide
poisoning.

DANGER: Carbon monoxide

poisoning may lead to death!

Carbon Monoxide Poisoning: Early

signs of carbon monoxide poisoning re­semble the 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.

Natural Gas: Natural gas is odorless. An
odor-making agent is added to natural gas.
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.

WARNING: Any change to this
heater or its controls can be dan­gerous.

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. 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. F ollow the
gas supplier’s instructions

• if you cannot reach your gas supplier,

call the fire department

3. This heater shall not be installed in a
bedroom or bathroom.

4. Never install the heater

• in 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

5. This heater needs fresh, outside air ven­tilation to run properly. This heater has
an oxygen depletion sensor (ODS) pi­lot light safety system. The ODS shuts
down the heater if not enough fresh air
is available. See F r esh Air for Comb us-
tion and Ventilation, pages 4 through 6.

6. Keep air openings in front and bottom
of heater clear and free of debris. This
will ensure 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. Do not run heater

• where flammable liquids or vapors

are used or stored

• under dusty conditions

9. Never place any objects on the heater.

10. Surface of heater becomes very hot
when running heater. K eep 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.

11. Carefully supervise young children
when they are in the same room with
heater.

12. Make sure grill guard is in place be­fore running heater.

13. Do not use heater if any part has been
under water. Immediately call a quali­fied 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. Turn of f and unplug heater and let cool
before servicing. Only a qualified ser­vice person should service and repair
heater.

15. Operating heater above elevations of
4,500 feet could cause pilot outage.

2

104190

PRODUCT

OWNER’S MANUAL

IDENTIFICATION

Front
Panel

Ignitor Button

Control Knob

Grill Guard

Glass Panel

Heater Cabinet

Figure 1 - Vent-Free Natural Gas Heater

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, 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

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 vent­free 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

Thermostat models have a thermostat sens­ing bulb and a control valve. 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 ap­plied to heater for shipment.

3. Check heater for any shipping damage.
If heater is damaged, promptly inform
dealer where you bought heater.

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3

CGN20TA

Blue Flame Vent-Free Natural Gas Heater

FRESH AIR FOR
COMBUSTION AND
VENTILATION

WARNING: This heater shall
not be installed in a confined
space unless provisions are pro­vided for adequate combustion
and ventilation air. 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 effi­cient 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
efficient, your home needs to breathe. Fresh
air must enter your home. All fuel-burning
appliances need fresh air for proper com­bustion and ventilation.

Exhaust fans, fireplaces, 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 fuel­burning appliances.

PROVIDING ADEQUATE
VENTILATION

The following is exerpts from National Fuel
Gas Code. NFPA 54/ANSI Z223.1, Section

5.3, Air for Combustion and Ventilation.

All spaces in homes fall into one of the three
following ventilation classifications:

1. Unusually Tight Contruction

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 win­dows 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 de­fined as construction where:

a. walls and ceilings exposed to the

outside atmosphere have a con­tinuous water vapor retarder with
a rating of one perm (6x10
per pa-sec-m2) or less with open­ings gasketed or sealed

b. weather stripping has been

added on openable windows and
doors

c. caulking or sealants are applied

to areas such as joints around
window and door frames, be­tween sole plates and floors, be­tween wall-ceiling joints, be­tween wall panels, at penetra­tions for plumbing, electrical, and
gas lines, and at other openings.

If your home meets all of the three
criteria above, you must provide ad­ditional fresh air. See

From Outdoors

If your home does not meet all of the
three criteria above, proceed to page 5.

and

, page 6

Ventilation Air

.

and

-11

kg

Confined and Unconfined Space

The National Fuel Gas Code (ANSIZ2123.1,
1992 Section 5.3) defines a confined space

as a space whose volume is less than 50
cubic feet** per 1,000 Btu per hour (4.8 m
per kw) of the aggregate input rating of all
appliances installed in that space and an
unconfined space as a space whose volume
is not less than 50 cubic feet per 1,000 Btu
per hour (4.8 m3 per kw) of the aggregate
input rating of all appliances installed in that
space. Rooms communicating directly with
the space in which the appliances are in­stalled*, through openings not furnished
with doors, are considered a part of the
unconfined space.

* Adjoining rooms are communicating only
if there are doorless passageways or ventila­tion grills between them.

** Cubic feet equals length x width x height
of room.

3

4

104190

OWNER’S MANUAL

FRESH 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: Includes the room in which you
will install heater plus any adjoining rooms
with doorless 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:

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.

Space size 20 ft. (length) x

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:

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

Example:

Gas water heater 40,000 Btu/Hr
Vent-free heater + 20,000 Btu/Hr
Total = 60,000 Btu/Hr

* Do not include direct-vent gas appli­ances. Direct-vent draws combustion
air from the outdoors and vents to the
outdoors.

2560 cu. ft. (volume of

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:

the space can support)60,000 Btu/Hr
(actual amount of Btu/Hr used)

The space in the above example is a con­fined space because the actual Btu/Hr used
is more than the maximum Btu/Hr the space
can support. You must provide additional
fresh air. Your options are as follows:

A. Rework worksheet, adding the space of

an adjoining room. If the extra space
provides an unconfined space, remove
door to adjoining room or add ventila­tion grills between rooms. See Ventila-
tion Air From Inside Building, page 6.

B. V ent room directly to the outdoors. See

V entilation Air Fr om 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.

51,200 Btu/Hr (maximum

104190

Continued

5

CGN20TA

Blue Flame Vent-Free Natural Gas Heater

FRESH AIR FOR
COMBUSTION AND
VENTILATION

Continued

WARNING: If the area in which
the heater may be operated is
smaller than that defined as an
unconfined space, provide ad­equate combustion and ventila­tion air by one of the methods
described in the

Gas Code, ANSI Z223.1, 1992,
Section 5.3

codes

.

VENTILATION AIR

Ventilation Air From Inside
Building

This fresh air would come from an adjoining
unconfined space. When ventilating to an
adjoining unconfined space, you must pro­vide two permanent openings: one within
12" of the ceiling and one within 12" of the
floor 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 NFPA 54/ANSI Z223.1, Section

5.3, Air for Combustion and Ventilation for

required size of ventilation grills or ducts.

WARNING: Rework work­sheet, adding the space of the
adjoining unconfined space. The
combined spaces must have
enough fresh air to supply all
appliances in both spaces.

National Fuel

or applicable local

Ventilation

Grills

into Adjoining

Room,

Option 1

Figure 2 - Ventilation Air from Inside Building

Or

Remove
Door into
Adjoining

Room,

Option 3

Outlet
Air

12"

Ventilated
Attic

Outlet
Air

12"

Ventilation Grills

Into Adjoining Room,

Option 2

To Attic

Ventilation Air From Outdoors

Provide extra fresh air by using ventilation
grills or ducts. You must provide two per­manent openings: one within 12" of the
ceiling and one within 12" of the floor.
Connect these items directly to the outdoors
or spaces open to the outdoors. These spaces
include attics and crawl spaces.

IMPORTANT:

inlet or outlet air into attic if attic has a
thermostat-controlled power vent. Heated air
entering the attic will activate the power vent.

Do not provide openings for

Inlet
Air

Inlet Air

Figure 3 - Ventilation Air from Outdoors

6

To

Crawl

Space

Ventilated

Crawl Space

104190

OWNER’S MANUAL

INSTALLATION

NOTICE: A qualified service per­son must install heater. Follow
all local codes.

CHECK GAS TYPE

Use only natural gas. If your gas supply is
not natural gas, 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/LP gas)

• manual shutoff valve *

• ground joint union

• test gauge connection * (see Figure 13,
page 10)

• sediment trap

• tee joint

• pipe wrench

* An A.G.A. design-certified manual shutoff
valve with 1/8" NPT tap is an acceptable
alternative to test gauge connection. Pur­chase the optional A.G.A. design-certified
manual shutoff valve from your dealer. See
Accessories, page 19.

LOCATING HEATER

This heater is designed to be mounted on a
wall.

WARNING: Never install the

heater

• in a bedroom or a bathroom

• in 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

CAUTION: This heater cre­ates warm air currents. These
currents move heat to wall sur­faces next to heater. Installing
heater next to vinyl or cloth wall
coverings or operating heater
where impurities in the air (such
as tobacco smoke) exist, may
discolor walls.

CEILING

6"
Minimum
From
Sides Of
Heater

IMPORTANT:

Vent-free heaters add mois­ture to the air. Although this is beneficial,
installing heater in rooms without enough
ventilation air may cause mildew to form from
too much moisture. See Fresh Air for Com-
bustion 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

• 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

An optional fan kit is available from your
dealer. See Accessories, page 19. If plan­ning to use fan, locate heater near an electri­cal outlet.

36"
Minimum

WARNING: Maintain the mini-

mum clearances shown in Figure

4. If you can, provide greater clear­ances from floor, ceiling, and join­ing wall.

You can locate heater on floor, away from a
wall. An optional floor mounting stand is
needed. Purchase the floor mounting stand
from your dealer. See Accessories, page 19.

104190

Left
Side

FLOOR

Figure 4 - Mounting Clearances As Viewed From Front of Heater

7

Right
Side

3"

Minimum To Top Surface
Of Carpeting, Tile Or Other
Combustible Material

Continued

CGN20TA

Blue Flame Vent-Free Natural Gas Heater

INSTALLATION

Continued

THERMOSTAT SENSING
BULB

The thermostat sensing bulb has been placed
inside the heater for protection during ship­ping.

Locating Thermostat Sensing
Bulb

1. Remove front panel of heater (see Fig­ure 7, page 8).

2. Locate thermostat sensing bulb just
under burner assembly.

IMPORTANT:

bulb to 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 clamp on thermostat sensing bulb
as shown in Figure 5. Clamp is pro­vided 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. Mak e sure the thermostat sens­ing bulb is pointing up.

Attach thermostat sensing

INSTALLING HEATER TO
WALL

Mounting Bracket

The mounting bracket is located on back
panel of heater. It has been taped there for
shipping. Remove mounting bracket from
back panel.

Mounting
Bracket

Figure 6 - Bracket Location

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
downward.

4. Remove cardboard packing from grill
and glass.

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 provides the strongest hold.
Insert mounting screws through mounting
bracket and into wall studs.

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).

Decide which method better suits your needs.
Either method will provide a secure hold for
the mounting bracket.

Marking Screw Locations

1. Tape mounting bracket to wall where
heater will be located. Make sure
mounting bracket is level.

WARNING: Maintain minimum
clearances shown in Figure 8. If
you can, provide greater clear­ances from floor and joining wall.

Thermostat
Sensing Bulb

Clamp

Figure 5 - Attaching Thermostat Sensing
Bulb

Figure 7 - Removing Front Panel Of Heater

8

2. Mark screw locations on wall (see Fig­ure 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.

7 1/4"

Min.

Only Insert Mounting

Screws Through Last

Hole On Each End

Adjoining Wall

Figure 8 - Mounting Bracket Clearances

16"

18 3/4"

Min.

Floor

104190