Unitary products group DLAS User manual

INSTALLATION
INSTRUCTIONS
SEALED COMBUSTION
DOWNFLOW GAS FURNACES
1973--106/F Rev.2 (599)
Supersedes: 1973--106/F Rev.1 (1098)
(Forced Draft with Direct HSI)
MODELS DLAS, DGAT AND DGAM
DLAS MODELS
(No Coil Cabinet) DGAT & DGAM MODELS (With Built--in Coil Cabinet)
For Installation In:
1. Manufactured (Mobile) Homes
2. Recreational Vehicles & Park Models
3. Modular Homes & Buildings
IMPORTANT: Only individuals having proven experi-
ence with this type of equipment should attempt to per-
form set--up.
Properfurnaceset--upandadjustmentistheresponsibil-
ity of the retailer/homeowner and is not covered under
warranty.
FURNACE SET--UP CHECK LIST
-Has roof jack crown been correctly installed?
-Has furnace gas valve and burner orifice been cor-
rectly converted for L.P. gas where applicable?
-Has furnace gas valve been de--rated for altitudes
above 2000 feet where applicable?
-Is gas line outlet pressure properly set for fuel type?
(natural gas is 3.5” W.C.; L.P. is 10” W.C.)
-Is primary air properly adjusted per installation in-
structions?
-Is cross--over duct installed per home builder and
UPG installation instructions?
-Has furnace been operated through a complete
heating cycle?
Improper installation, adjustment, service or
maintenancecancauseinjuryor propertydam-
age. Please refer to all the instructions of this
manual for proper installation procedures. Im-
proper installation will void the warranty.
The furnace shall be installed so the electrical
components are protected from water.
The furnace is not to be used for temporary
heating of buildings or structures under
constructions.
Do not testthefuel systemat morethan 14 inch-
es water column after furnace has been con-
nected to the fuel line. Such testing may void
the warranty. Any test run above 14 inches wa-
ter column may damage the furnace control
valve which could cause an explosion, fire, or
asphyxiation.
Improper installation may damage equipment, can
create a shock hazard, and will void the warranty.
NOTE: The words “Shall” or “Must” indicate a
requirement which is essential to satisfactory
and safe product performance.
The words “Should” or “May” indicate a
recommendation or advice which is not
essential and not required but which may be
useful or helpful.
IMPORTANT: These instructions are primarily in-
tended to assist qualified individuals experienced in the
proper installation of heating and/ or air conditioning ap-
pliances. Some local codes require licensed installation
service personnel for this type of equipment. Read all in-
structions carefully before starting the installation.

2Unitary Products Group
TABLE OF CONTENTS
FURNACE SPECIFICATIONS 3...................
INSTALLATION STANDARDS 4...................
Code Compliance 4...........................
High Altitude Installation 4.....................
Minimum Furnace Clearance 4.................
RETURN AIR REQUIREMENTS 5.................
Closet Installations 5..........................
Air Distribution Systems 5.....................
ROOF JACKS 7.................................
Existing Furnace Replacement 7...............
New Home Installation 7.......................
Installation in Snow Regions 7..................
Locating and Cutting Roof Jack Opening 7.......
Installing Roof Jack in Roof 7..................
DUCT CONNECTORS 10........................
Installation of Screw Attachment
Duct Connector 11............................
Installation of Tab Attachment
Duct Connector 11............................
Installation of Furnace 12.....................
CONNECTING ROOF JACK TO FURNACE 12.....
Ceiling Rings 13.............................
ELECTRICAL WIRING 13........................
Connect Power Supply Wires 13..............
Connect Thermostat Wires 13.................
Wall Thermostat 14..........................
WIRING DIAGRAMS 15 &16.....................
GAS PIPING 17................................
Installation and Checking of Gas Line 17........
FINAL PROCEDURE 19.........................
Install Furnace Doors 19......................
Finish and Trim 19...........................
Furnace and Air Conditioner Installations 19.....
HIGH ALTITUDE DERATION CHART 20...........
Natural Gas 20..............................
Propane Gas 20.............................
REPAIR PARTS 21--22..........................
LIST OF FIGURES
FIGURE 1 — Furnace Dimensions 3............
TABLE 1 — Minimum Clearances 4.............
FIGURE 2 — Air Distribution Systems 5.........
FIGURE 3 — Closet to Door Clearance — 6” or
greater 6....................................
FIGURE 4 — Furnace to Closet Door Clearance
—1”to6” 6..................................
FIGURE 5 — Furnace to Closet Door Clearance
— Less than 1” 6............................
FIGURE 6 — Standard Roof Jack 8.............
FIGURE 7 — Roof Jack with Removable
Crowns 9....................................
FIGURE 8 — Duct Connector Dimensions 10...
FIGURE 9 — Duct Connector Screw
Attachment 11...............................
FIGURE 10 — Duct Connector Tab
Attachment 11...............................
FIGURE 11 — Installation of Furnace 12........
FIGURE 12 — Connecting Roof Jack to
Furnace 12.................................
FIGURE 13 — Ceiling Rings 13...............
FIGURE 14 — Field Wiring 13................
FIGURE 15 — Thermostat Wiring for DGAT and
DGAM 14..................................
FIGURE 16 — Thermostat Wiring for DLAS 14..
FIGURE 17 — Wiring Diagram for DGAT 15....
FIGURE 18 — Wiring Diagram for DGAM 16...
FIGURE 19 — Natural Gas Flame 18..........
FIGURE 20 — Propane Gas Flame 18.........
FIGURE 21 — Anti--Backflow Damper 19.......

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Unitary Products Group
FURNACE SPECIFICATIONS
DGAM — Automatic ignition — with Built--in Coil Cabinet — 4 Ton -- A/C Ready
Model No. Factory Equipped for use with: Input/BTUH Output/BTUH
DGAM056BDF NATURAL GAS 56,000 46,000
DGAM075BDF NATURAL GAS 75,000 61,000
DGAT — Automatic Ignition — with Built--in Coil Cabinet — 3 Ton -- A/C Ready
Model No. Factory Equipped for use with: Input/BTUH Output/BTUH
DGAT056BDF NATURAL GAS 56,000 46,000
DGAT070BDF NATURAL GAS 70,000 57,000
DGAT075BDF NATURAL GAS 75,000 61,000
DGAT090BDF NATURAL GAS 90,000 72,000
DLAS — Automatic Ignition — Heating Only — No Coil Cabinet
Model No. Factory Equipped for use with: Input/BTUH Output/BTUH
DLAS056BDF PROPANE 56,000 47,000
DLAS075BDF PROPANE 75,000 62,000
Electrical Specifications
Electrical Power Supply 120Volts—60Hz—1Phase
Breaker or Fuse 15 Amp
Thermostat Circuit 24Volt—60Hz—40VA
Nominal Anticipator Setting .50
Gas Valve Inlet 1/2”NFPT
DGAT & DGAM SeriesDLAS Series
59--1/2” 76”
19--1/2”
9--3/4”
23”
24”
10--5/8”
19--1/2”
9--3/4”
23”
24”
10--5/8”
FIGURE 1 -- DLAS, DGAT AND DGAM SERIES FURNACE DIMENSIONS

4Unitary Products Group
INSTALLATION STANDARDS
CODE COMPLIANCE
The installer shall familiarize himself with and comply
with all local codes and regulations which govern the in-
stallation of this appliance. Local codes and regulations
shall take precedent over these regulations where appli-
cable. In lieu of local codes, the appliance shall be in-
stalled in accordance with one or more of the following
standards.
Manufactured homes in the U.S.A.:
1. Federal Manufactured Home Construction & Safety
Standard (H.U.D. Title 24, Part 3280)
2. American National Standard (ANSI--Z223.1,
NFPA--54) for gas fired furnaces.
3. Unitelectricalwiringandgroundingshallcomplywith
current CSA standard C22.2 No.148/CAN/CSA--
Z240.6.2 -- Electrical Requirements for recreational
vehicles.
Manufactured homes in Canada:
1. CAN/CGA B149 for gas fired furnaces.
2. CSA 22.1 Canadian Electrical Code part 1 for all
electrical field wiring.
Recreational Vehicles in U.S.A.:
1. American National Standard (ANSI--119--2/NFPA--
501C) for recreation vehicle installations.
2. Unitelectricalwiringandgroundingshallcomplywith
current CSA standard C22.2 No.148/CAN/CSA--
Z240.6.2 -- Electrical Requirements for recreational
vehicles.
Recreational Vehicles in Canada:
1. Unit installation shall comply with current CSA stan-
dard CAN/CGA--Z240.4.2 -- Installation Require-
ments for Propane Appliances and Equipment in
Recreational Vehicles.
2. Unitelectricalwiringandgroundingshallcomplywith
current CSA standard C22.2 No.148/CAN/CSA--
Z240.6.2 -- Electrical Requirements for recreational
vehicles.
HIGH ALTITUDE INSTALLATION
Forelevationabove2,000feet,deratefurnaceorifice4%
foreach1,000feetofelevationabovesealevel.Derating
is accomplished by reducing the orifice size. See Derat-
ing Chart for orifice size.
CAUTION:
DNever attempt to alter or modify this furnace or any
of its components.
DNeverattempttorepairdamagedorinoperablecom-
ponents. Such action could cause unsafe operation,
explosion, fire and/or asphyxiation.
DIf a malfunction has occurred, or if you feel that the
furnace is not operating as it should, contact aquali-
fied service agency or gas utility for assistance.
MINIMUM FURNACE CLEARANCES
Access for servicingis animportant factor inthe location
of any furnace. A minimum of 24 inches should be pro-
vided infront of the furnace for access to the heating ele-
ments and controls. This access may be provided by a
closet door or by locating the furnace 24 inches from a
facing wall or partition.
These furnaces are design certified for the following
minimum clearances from combustible material in al-
cove or closet installation:
TABLE 1 — Minimum Clearances
CLOSET ALCOVE
BACK 0” 0”
SIDES 0” 0”
FRONT 6” 24”
TOP 2” 2”
ROOF JACK 0” 0”
DUCT 0” 0”

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Unitary Products Group
RETURN AIR REQUIREMENTS
CLOSET INSTALLATIONS
Additional Requirements
Additional requirements for floor and ceiling return sys-
tem for closet installed sealed combustion heating
appliance are given in the next paragraph.
Floor or Ceiling Return Air System
Floororceilingreturnairsystemforclosetinstalleddirect
vent forced air heating appliance.
Listed in the next paragraph are the conditions to be met
byMobileHome ManufacturerstohaveU.L.acceptance
of in--floor or ceiling return air systems of closet installed
direct vent forced air heating appliances for Mobile
Homes to be sold in the United States.
1. The return--air opening into the closet, regardless of
location, is to be sized not less than specified on the
appliance’s rating plate.
2. If the return--air opening is located in the floor of the
closet (versus the vertical front or side wall), the
opening is to be provided with means to prevent its
inadvertent closure by a flat object placed over the
opening.
3. The cross--sectional area of the return duct system
(when located in the floor or ceiling of the mobile
home) leading into the closet is to be not less than
that of the opening specified on the appliance’s rat-
ing plate.
4. The total free area of openings in the floor or ceiling
registers serving the return--air duct system is to be
not less than 150% of the size of the opening speci-
fiedontheappliance’sratingplate. Atleastonesuch
register is to be located where likelihood of its being
covered by carpeting, boxes, and other objects is
minimized.
5. Materials located in the return duct system have a
flame spread classification of 200 or less.
6. Non--combustible pans having one--inch upturned
flanges are located beneath openings in the floor re-
turn duct system.
7. Wiring materials located in the return duct system
conformtoArticle300--22(b&c) oftheNationalElec-
tric Code (ANSI C1 / NFPA--70).
8. Gas piping is not run in or through the return duct
system.
9. The negative pressure in the closet as determined
by test with the air--circulating fan operating at high
heating speed andthe closet door closedis to benot
more negative than minus 0.05--inch water column.
10. For floor return systems, the mobile homemanufac-
turer orinstallershall affixaprominentmarkingonor
near the appliance where it is easily read when the
closet door is open. The marking shall read:
HAZARD OF ASPHYXIATION
DO NOT COVER OR RESTRICT FLOOR
OPENING, or equivalent.
AIR DISTRIBUTION SYSTEMS
For proper air distribution, the supply duct system shall
be designed so that the static pressure does not exceed
the listed static pressure rating on the furnace rating
plate.
Three typical distribution systems are illustrated in Fig-
ure 2.
Location, size and number of registers should be se-
lected on the basis of best air distribution and floor plan
of the home.
The Air Temperature Rise is to be adjusted to obtain a
temperaturerisewithinthe range(s) specifiedonthefur-
nace rating plate.
A
Single trunk duct
Dual trunk duct
Transition duct
*B
D1Crossover Duct must be centered directly under furnace.
D2Use 12” Diameter Round or equivalent insulated Flex--duct only.
D3Terminate Flex--duct (opposite furnace) in the center of the trunk duct.
D4Flex--duct material must be pulled tight — No Loops or unnecessary dips — Air Flow may be impeded.
1
2
3
4
B*
Dual trunk duct with crossover connector
Crossover
C
Transition Duct with Branches
Branches
FIGURE 2
—
A
IR DISTRIBUTION SYSTEMS

6Unitary Products Group
As an option to the lower grill,
an undercut of 2 1/2” will provide
50 Sq. In. of free area.
FIGURE 3 — CLOSET TO DOOR CLEARANCE — 6” OR GREATER
DOOR
6” or greater — Closet
to Door Clearance
Furnace to Closet Door Clearance —
Greater than 6 Inches
TheclosetdoorMUSThaveaminimumof250Square Inchesoffreearea
in the upper half of the door.
Ifopeningforreturnairis locatedinthefloororsidewalls andbelowthetop
of the furnace casing:
1. 6 inches minimum clearance must be provided on side where return
is located, and
2. 6 inches minimum clearance must be maintained from the front of
furnace.
Return Air Grille Part No.
7900--286P/A — Almond
7900--287P/A — White
Return Air Closet Door Part No.
7900--7771/C — White
CLOSET
250 SQ. IN.
MINIMUM
FREE AREA
50 SQ. IN.
MINIMUM
FREE AREA 250 SQ. IN.
MINIMUM
FREE AREA
FURNACE
A
B
FIGURE 4 — FURNACE TO CLOSET DOOR CLEARANCE — 1” to 6”
As an option to the lower grill,
an undercut of 2 1/2” will provide
50 Sq. In. of free area.
1. The closet door MUST have a minimum of 250 Square In-
ches of free area in the upper half of the door and a mini-
mum of 50 Square Inches of free area in the lower area of
the door.
The lower closet door grille may be omitted if an undercut
of 2 1/2 Inches is provided in the door.
2. A fully louvered closet door MUST have a minimum of 250
Square Inches of free area in the upper half of the door.
Furnace to Closet Door Clearance — Greater
than 1 Inch and Less than 6 Inches
A
250 SQ. IN.
MINIMUM
FREE AREA
B
250 SQ. IN.
MINIMUM
FREE AREA
50 SQ. IN.
MINIMUM
FREE AREA
FIGURE 5 — FURNACE TO CLOSET DOOR CLEARANCE — LESS THAN 1”
Theclosetdoor MUST havethreereturnairgrilles.The totalfree
area of the two upper grilles must be a minimum of 250 Square
Inches. The total free area of the lower grille MUST be a mini-
mum of 50 Sq. In.
Each grille MUST BE ALIGNED directly opposite the corre-
sponding return air grille of the furnace door.
Furnace to Closet Door
Clearance — Less than 1 Inch
250 SQ. IN.
MINIMUM
FREE AREA
50 SQ. IN.
MINIMUM
FREE AREA

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Unitary Products Group
ROOF JACKS
FAILURE TO FOLLOW ALL VENTING IN-
STRUCTION CAN RESULT IN FIRE ASPHYXI-
ATION, OR EXPLOSION.
CAUTION: Only use the appropriate roof jack.
See Figures 6 & 7 for correct application.
Do not exceed the maximum height as determined
from Figures 2 & 3. Installer should allow an addi-
tional 1-1/2” travel before the flue pipe assembly is
fully extended against the built-in stop. This pro-
vides an additional safeguard against the flue as-
semblybeingpulledfromtheroofjackduringtrans-
portation or other stress conditions.
EXISTING FURNACE REPLACEMENT
If this furnace replaces an exciting furnace,dothefol-
lowing:
1. If a 2nd roof, roof cap or addition has been made to
the existing roof of the home, remove the old roof
jack completely!... to avoid the possibility of an
improperly installed pipe orgaps in the old roof
jack, INSTALL A NEW ROOF JACK. Your ceiling
and roof height will determine the correct roof
jack to use. Refer to the vent selection table, of
the furnace installation instructions.
2. After unpacking the roof jack, check the rain caps.
Insure they are not damaged, tilted or crooked. Do
not twist, crush or sit on the roof caps during
installation. Damaged roof caps will cause improp-
er furnace operation. The furnace will not heat prop-
erly and could result in explosion.
3. Before inserting the roof jack into the furnace top, in-
spect the furnace flue and combustion air opening
for debris or insulation which might have fallen in
during pre--installation steps. Donot proceedunless
all debris have been cleaned out or removed.
4. After installing roof jack on furnace top collar, check
to make sure there isnogapin back or sidebetween
the pipe collar and the furnace casing top.
5. Use only the pipes provided with the roof jack as-
sembly. Do not add to or adapt other sheet metal
pipes.Donotcut,insertoraddotherpipestothis
assembly.
6. In no case should there be a gap between sections
of the flue pipe or the combustion air pipe. If neces-
sary to prevent excessive air leakage, the installer
shouldsealjointsinthe combustionairtubewithalu-
minum type or other suitable sealant.
NEW HOME INSTALLATION
Ifthisfurnaceisinstalledonanewhomedothefollowing:
1. Inspect the furnace top collars for signs of insulation
or ceiling debris which might have fallen in during
cutting of the ceiling and roof holes. Remove all de-
bris before continuing.
2. After unpacking the roof jack, check the rain caps.
Insure they are not damaged, tilted or crooked. Do
not twist, crush or sit on the roof caps during
installation. Damaged roof caps will cause improp-
er furnace operation. The furnace will not heat prop-
erly and could result in explosion.
3. Before inserting the vent pipe into the furnace top,
inspect the furnace flue and combustion air opening
for debris or insulation which have fallen in during
pre--installation steps. Do not proceed unless all de-
bris have been cleaned out or removed.
4. After installing roof jack on furnace top collar, check
to make sure there isnogapin back or sidebetween
the pipe collar and the furnace casing top. If neces-
sary to prevent excessive air leakage, the installer
shouldsealjointsinthe combustionairtubewithalu-
minum type or other suitable sealant.
INSTALLATION IN SNOW REGIONS
Whenthecombustionairpipeinletiscovered orblocked
with snow, the furnace will not operate properly due to
the depleted combustion air supply.
Therefore, if the furnace will be located in regionswhere
snow accumulation on the roof exceeds 7” or in H.U.D.
Snow Load Zones, a roof jack extension (Part No.
7680B6541) is recommended.
LOCATING AND CUTTING ROOF JACK
OPENING
To facilitate the proper installation of the roof jack, it is
very important that the roof jack opening in the ceiling
and roof be on the same vertical center line as the fur-
nacefluecollar.SeeFigure8.
Mark this location on ceiling and scribe a circle with a 5”
radius (10” diameter) around this mark. Cut opening for
roof jack through ceiling and roof. (If furnace was in-
stalled during construction, cover furnace and flue
opening to prevent debris from entering flue when
hole is cut for roof jack.)
INSTALLING ROOF JACK IN ROOF
(See Figure 6 & 7 for Dimensional requirements.)
Insert roof jack into opening in the roof.
The roof jack should be secured to the furnace be-
foreroof flange(flashing) is secured to the roof. This
will insure a better alignment of the flue pipe andfurnace
fluecollar.Caulkaroundandunderroofflangetoprovide
a water tight seal, before securing roof jack flashing to
roof.

8Unitary Products Group
WARM AIR DUCT
DUCT CONNECTOR
ROOF
76”
59--1/2”
WARM AIR DUCT DUCT CONNECTOR
FLOOR
FLUE
GASES
COMBUSTION
AIR
CAULK
UNDER
FLASHING
DLAS & COAS Models
19 1/2”
CAULK
UNDER
FLASHING
DGAT, DGAM, COAT & CGAT Models
FLUE
GASES
COMBUSTION
AIR
19 1/2”
CAULK CAREFULLY ALL AROUND SWIVEL JOINT WITH
SEALANT SUPPLIED BY FURNACE MANUFACTURER.
SWIVEL FLASHING
ADJUSTS FROM
0/12 TO 5/12 PITCH
SLANT
FLASHING
3/12 PITCH
DLAS & COAS Furnaces DGAT, DGAM, COAT, CGAT Furnace
Installation Dimensions Installation Dimensions
A
Adjustable Height B
Adjustable Height
4000--7101/C
4000--7121/C
4000--7141/C
4000--7151/C
4000--7171/C
4000--6101/A
4000--6121/A
4000--6141/A
4000--6151/A
4000--6171/A
70” to 79”
75” to 86”
83” to 104”
90” to 116”
127” to 157”
86” to 95”
91” to 102”
99” to 120”
106” to 132”
143” to 173”
FIGURE 6 -- STANDARD ROOF JACK
IMPORTANT
SEALROOFJACKFLASHINGTOTHE ROOFJACK
AND ROOF.
THIS IS THE INSTALLER’S RESPONSIBILITY.
The End of Upper Portion of Roof Jack need
Not extend below the ceiling.
A B

9
Unitary Products Group
WARM AIR DUCTDUCT CONNECTOR
ROOF
76”
59--1/2”
WARM AIR DUCT DUCT CONNECTOR
FLOOR
CAULK
UNDER
FLASHING
CAULK
UNDER
FLASHING
CAULK CAREFULLY ALL AROUND SWIVEL
JOINT WITH SEALANT SUPPLIED BY FURNACE
MANUFACTURER.
DLAS & COAS Models DGAT, DGAM, COAT & CGAT Models
DLAS & COAS Furnaces DGAT, DGAM, COAT, CGAT Furnace
Installation Dimensions Installation Dimensions
A
Adjustable Height B
Adjustable Height
4000--8101/C
4000--8181/C 4000--9161/A
4000--9181/A 85” to 101” 99” to 129” 101” to 117” 115” to 145”
FIGURE 7 -- ROOF JACK WITH REMOVABLE CROWNS
A B
SWIVEL FLASHING
ADJUSTS FROM 0/12
TO 5/12 PITCH
SLANT
FLASHING
3/12 PITCH
IMPORTANT
SEAL ROOF JACK FLASHING TO THEROOF
JACK AND ROOF.
THISISTHEINSTALLER’SRESPONSIBILITY.
The End of Upper Portion of Roof Jack
need Not extend below the ceiling.

10 Unitary Products Group
DUCT CONNECTORS
FIGURE 8 — DUCT CONNECTOR DIMENSIONS
DUCT CONNECTOR
PART NUMBER DUCT CONNECTOR
DEPTH
7990--6011
7990--6021
7990--6041
7990--6061
7990--6071
7990--6081
7990--6101
7990--6121
1”
2”
4--1/2”
6--1/2”
7--1/2”
8--1/2”
10--1/4”
12--1/4”
DUCT CONNECTOR
PART NUMBER DUCT CONNECTOR DEPTH
7990--6211
7990--6221
7990--6241
7990--6261
7990--6271
7990--6281
7990--6301
7990--6321
1”
2”
4--1/2”
6--1/2”
7--1/2”
8--1/2”
10--1/4”
12--1/4”
These duct connectors are for connecting the furnace to an under the floor supply ductsystem.
The furnace may be installed on combustible flooring without a separate sub base.
DUCT CONNECTOR DIMENSIONS DUCT CONNECTOR DIMENSIONS
DUCT CONNECTORS FOR
SCREW ATTACHMENT DUCT CONNECTORS FOR TAB ATTACHMENT
23
8
23
8
183
4
14
183
4
14 23
8
23
8
183
4
12
43
8
23
8
SEE
CHART
SEE
CHART
11 183
4
43
8
23
8
12
13
DUCT CUTOUT
DIMENSIONS
11
13
DUCT CUTOUT
DIMENSIONS
SUPPLY DUCT
FLOOR
FLOOR
JOIST
DUCT
CONNECTOR
DEPTH
23--1/4
9--7/8
20--1/2
1
15
15
2--1/8
1--3/8
9--3/4 20
6--3/8 1--1/8
3--1/4
2--3/4 MIN.
C
L
REAR WALL
OF ENCLOSURE CEILING CUT--OUT
FOR ROOF JACK
FLOOR CUT--OUT
FOR DUCT
CONNECTOR
SUPPLY
DUCT
FURNACE
OUTLINE
FLOOR
OPTIONAL
GAS OR
ELECTRIC
ENTRANCE
FRONT PANEL
OF FURNACE
FUTURE REFRIGERANT
LINE ENTRANCE

11
Unitary Products Group
FIGURE 9 -- DUCT CONNECTOR SCREW
ATTACHMENT
SUPPLY DUCT
LOCATOR BRACKET
NAILS, FLAT HEAD SCREWS
OR STAPLES
SCREWS FLOOR
FIGURE 10 -- DUCT CONNECTOR TAB
ATTACHMENT
SUPPLY DUCT
LOCATOR BRACKET
NAILS, FLAT HEAD SCREWS
OR STAPLES
FLOOR
BEND TABS UNDER
DUCT OPENING TO
SECURE TO THE
SUPPLY DUCT.
INSTALLATION OF SCREW ATTACHMENT
DUCT CONNECTOR
1. Make floor cut out as shown in Figure 8.
2. Determine the depth of the floor cavity from the sur-
face of the floor to the top of the supply air duct and
selectthe appropriateduct connectorfromthechart.
3. Place locating bracket (supplied with the duct con-
nector) to the back edge of the floor opening. See
Figure 9.
4. Apply a water based duct sealant to the 1/2” supply
duct attachment flange of the duct connector.
5. Determine which of the four positions the duct con-
nector best centers over the supply duct and insert
it through the floor cutout.
6. When properly aligned with the supply duct, secure
the duct connector to the floor with nails, flat head
screws or staples.
7. Usescrewsasrequiredtosecuretheductconnector
to the supply duct.
8. Cut out the opening to the supply duct. If sealant
was not used, the installer should tape the mat-
ing flanges to provide a good air seal.
NOTE: Duct sealant andtapemustbeU.L. classifiedas
meeting HUD standard 3280.715 and U.L.
standard 181.
INSTALLATION OF TAB ATTACHMENT
DUCT CONNECTORS
1. Make floor cut out as shown in figure 8.
2. Determine the depth of the floor cavity from the sur-
face of the floor to the top of the supply air duct and
selectthe appropriateduct connectorfromthechart.
3. Place locating bracket (supplied with the duct con-
nector) to the rear of the floor area for the furnace.
See Figure 10.
4. Determine which of the four positions the duct con-
nector best centers over the supply duct and insert
it through the floor cutout.
5. Mark cut--out location on the supply duct and re-
move the duct connector.
6. Cut out the opening to the supply duct.
7. Bend tabsdownthrough andback upunder the sup-
ply duct.
8. Secure the duct connector to the floor with nails, flat
head screws or staples.
The duct connector is designed for use on ducts down to
12” in width. When using the connector on smaller width
ducts, there will not be sufficient clearance to bend the
tabs on two sides of the duct connector.
In such cases the tabs may be attached to the sides of
the duct by using sheet metal screws or other suitable
fasteners. Holes for sheet metal screws are provided in
three (3)tabs on each side of the duct connector. If more
than3tabsneedtobeusedtoprovideamoresecureand
air tight connection, the remaining tabs can also be fas-
tened to the duct with screws after drilling the required
screw holes.
If tape is used to provide a better air seal, it should be a
type approved by the applicable national or local codes.

12 Unitary Products Group
SECURE
FURNACE
TO FLOOR
WITH TWO
NAILS OR
SCREWS
FURNACE
SEATED
AGAINST
THE LOCATOR
BRACKET
FIGURE 11 -- INSTALLATION OF FURNACE
INSTALLATION OF THE FURNACE
1. Remove the front panels and set the furnace onto
the duct connector. Slide it back until the rear of the
unit engages the locator bracket.
2. Securethefrontofthefurnacewithtwoscrewsatthe
mounting holes provided.
3. Secure thetop of the furnace to a structural member
using screw through the strap at the back of the fur-
nace. Strap may be moved to any of the holes lo-
catedalongthetopbackofthefurnace.Installermay
provide an equivalent method, such as screws
through the casing side.
CONNECTING ROOF JACK TO FURNACE
CAUTION: The inner flue pipe must be present.
Itismandatorythatthecombustionairpipeandflue
pipeassemblybefullyengaged.Thecombustion air
pipe MUST be securely fastened to the furnace with
a sheet metal screw in the hole provided.
Use a 1/2” blunt or sharp end sheet metal screw to
fasten roofjack combustion air pipe to furnacecom-
bustionair collar.Screw holeisprovided in thepipe
and collar. Excessively long screws may extend to
fluepipeandpunctureit.Screwsarenot toexceed 1
1/2” in length.
NOTE: Combustion air tubeand flue pipe arepart of the
same assembly. Only the combustion air tube
need be fastened to the furnace.
1. Check to be certain that the flue pipe and combus-
tion air tube are present.
2. Pull the telescoping flue tube and combustion air
tubeassemblydownfromtheroofjack.Slidetheflue
tube/combustion air tube assembly down firmly over
the furnace flue outlet and combustion air collar. In-
sure that the back, side and front of combustion air
tubecollarisfullyengagedandis incontactwithgas-
ket. Fasten the combustion air tube to the furnace
combustion air collar using a 1/2inch sheet metal
screw. (Screw hole provided in combustion air tube
and furnace combustion air collar. (See Figure 12.)
Itismandatorythatthecombustionairandfluetubeassembly
be fully engaged at back sides and front, and combustion air
tubesecurelyfastenedtothefurnacewithasheetmetalscrew
in the screw hole provided.
COMBUSTION
AIR TUBE
FLUE
PIPE COMBUSTION
AIR TUBE COLLAR
#8 OR #10 SCREW RECOMMENDED
FURNACE
FLUE OUTLET
SECURE
STRAP
TO WALL
FRONT OF
FURNACE
FIGURE 12 — CONNECTING ROOF JACK TO FURNACE
GASKET

13
Unitary Products Group
CEILING RINGS
The ceiling ring is to meet fire stop requirements. Acces-
sory Ceiling Ring (P/N 7660--2841) may be used, (See
Figure6)orthemobilehome manufacturerortheinstall-
er may use other approved methods to stop fire.
If required, three (3) sections of Accessory Ring may be
used as shown in Figure 13 to provide closer clearance
around roof jack. FIGURE 13 — CEILING RINGS
AB
ELECTRICAL WIRING
CAUTION:
TO INSTALLER: Incoming power must be polarized.
Observe color coding.
SHOCK HAZARD - DISCONNECT ELECTRICAL
POWER SUPPLY TO THE UNIT BEFORE SERV-
ICING TO AVOID THE POSSIBILITY OF SHOCK
INJURY OR DAMAGE TO THE EQUIPMENT.
CONNECT POWER SUPPLY WIRES
1. Remove the field wiring cover.
2. Insert 115 volt wires through the large plastic bush-
ing on the left side of the furnace ( See Figure 14).
If conduit is used it should be secured to the control
box.
3. Connectthe“hot”wiretotheBLACKpigtail lead,and
the “neutral” wire to the WHITE pigtail lead. Secure
all connections with suitable wire nuts and wrapwith
electrical tape.
4. Connect the “ground” wire to the grounding screw.
5. Reinstall the control panel cover and secure mount-
ing screw.
CONNECT THERMOSTAT WIRES
1. Insert 24volt wires through the small plastic bushing
just above the control panel.
2. Connectthethermostatwirestothefurnacelowvolt-
age pigtails (See Figure14).
3. Connect low--voltage circuit to the wall thermostat
pigtails.
Aseparate120V.A.C.supply circuitmustbeusedforthe
furnace. The circuit should be protected by a 15 amp
fuse or circuit breaker.
This screw does not need to
be removed in order to re-
move the field wiring cover.
(just loosen).
NOTE:
Cover should
not be removed
except when
servicing the
controls.
FIGURE 14 -- FIELD WIRING

14 Unitary Products Group
WALL THERMOSTAT
Avoidlocations where the thermostat could be subject to
draftsfromoutside,orexposedtodirectlightfromlamps,
sun, fireplaces, etc., or affected by air from a duct regis-
ter blowing directly on the thermostat.
The wall thermostat should be located 52 to 66 inches
above the floor. The preferred location is on an inside
wall situated in an area with good air circulation, and
wherethe temperaturewillbereasonablyrepresentative
of other living areas the thermostat is controlling.
WHITE GREEN BLACK RED
Blend Air
Control Box
Condensing
Unit
Wall Thermostat
Not Factory Installed
WHITE
GREEN
BLACK
RED
YELLOW
WHITE
GREEN
RED
YELLOW
FIGURE 15 -- THERMOSTAT WIRING FOR DGAT AND DGAM SERIES
R
W
WHITE
GREEN
BLACK
RED
YELLOW
WHITE
RED
FIGURE 16 -- THERMOSTAT WIRING FOR DLAS SERIES

15
Unitary Products Group
WIRING DIAGRAMS
FIGURE 17 -- WIRING DIAGRAM FOR DGAT SERIES
W
G
RH
Y
Wall
Thermostat
Upper
Limit Switch
Lower
Limit
Switch
Combustion Air
Switch
Combustion
Blower
Motor
Hot Surface
Ignitor
Gas
Valve
Blower
Motor
System
Switch
To Earth Ground
Neutral
L1
115
VAC
To A/ C
Condensing
Unit (If equipped)
Incoming Power Must
Be Polarized. Observe
Color Coding
NEUTRALS
Ground
Screw
HEAT COOL L1 XFMR
COM
24
VAC
RED
BLK
BRN
WHT
WHT
BLK
BLU
RED
LOAD
LINE
WHT
WHT
BLK
Sensor Rod
BLK
BRN
BRN
BLK
BLU
BLU
GRN
ORG
BLU
GRY
W
G
R
Y
C
BLK
BLK
BLK GRN
WHT
RED
YEL
BLK
GRN
WHT
Transformer
YEL
RED
WHT
Blend Air
Control Box
(If equipped)
134567
89 2
1
2
3
4
5
6
7
8
91
2
3
4
5
6
1
2

16 Unitary Products Group
FIGURE 18 -- WIRING DIAGRAM FOR DGAM SERIES
Blend Air
Control Box
(If equipped)
G
RH
Y
Upper
Limit
Switch
Lower
Limit
Switch
Combustion
Blower
Motor
Hot Surface
Ignitor
Gas
Valve
Blower
Motor
System
Switch
To Earth Ground
Neutral
L1
115
VAC
To A/C
Condensing
Unit (If
equipped)
Incoming Power Must
Be Polarized. Observe
Color Coding
NEUTRALS
Ground
Screw
HEAT COOL L1 XFMR
COM
24
VAC
RED
BLK
WHT
WHT
BLK
BLU
RED
LOAD
LINE
WHT
WHT
BLK
Sensor Rod
BLK
BRN
BRN
BLU
BLU
GRN
ORG
BLU
GRY
W
G
R
Y
C
BLK
BLK
BLK
GRN
WHT
RED
YEL
BLK
GRN
WHT
Transformer
YEL
RED
WHT
WHT
BLK
RED
W
Combustion Air
Switch
13567
89 24
1
2
1
2
3
4
5
6
7
8
92
1
3
4
5
6

17
Unitary Products Group
GAS PIPING
INSTALLATION AND CHECKING OF GAS
LINE
Gas Supply piping must be sized in accordance with the
recommendations contained in “American National
StandardInstituteInstallationofGasPiping” ANSI223.1
unless local codes or regulations state otherwise.
Materials used and pipe sizing for U.S. mobile homes
must comply with requirements contained in Mobile
Homes A119.1, Recreational Vehicles A119.2 and
H.U.D. Title 24, Section 3280.705 and any local or state
codes.
NOTE: The gas line inlet on the gas valve is 1/2-- 14
N.P.T. The gas line may be installed through the
furnace floor or furnace side to the gas valve.
CAUTION: To install gas line and to connect it
to the gas valve, care must be taken to hold gas
valve firmly to prevent misalignment of the burner
orifice, orto damagegasvalve whichcould resultin
improper heating, explosion, fire or asphyxiation.
DO NOT USE EXCESSIVE PIPE SEALANT ON PIPE
JOINTS. Pipe sealant, metal chips or other foreign
material that could be deposited in the inlet of the
gas valve, when gas pipe is installed or carried
through the gas piping into the gas valve inlet after
installation, may cause the gas valve to malfunction
and could result in possible improper heating, ex-
plosion, fire or asphyxiation. Also, pipe sealant
must be resistant to Propane gas.
Where regulations require, a main shut-off valve
shall be installed externally of furnace casing. After
piping has been installed, turn gas on and check all
connections with a leak detector or soap solution.
NEVER USE OPEN FLAME TO TEST FOR GAS
LEAKS AS FIRE OR EXPLOSION COULD OCCUR.
Do not test the fuel system at more than 14” W.C. af-
ter furnace has been connected to fuel line. Such
testing could void the warranty. Any test run above
14” W.C. may damage furnace control valve which
could cause an explosion, fire or asphyxiation
A dirt leg may be required by some local codes to trap
moisture and contaminations.
For NAT. gas operation, the furnace is designed for 7”
W.C. inlet gas pressure. Pressure to main burner is then
reduced to 3 1/2”W.C.
For Propane gas operation, the furnace is designed for
11” W.C. inlet gas pressure. Pressure to main burner is
then reduced to 10” W.C.
IMPORTANT: When converting valve from or to Pro-
pane gas, it will be necessary to change main burner ori-
fice to prevent an underfired or overfired condition. See
labelinsidelowerfurnacedoor forcompleteinstructions.
CAUTION: Ifthegasinputtothefurnaceistoo
great because of excessive gas pressure, wrong
size orifice, high altitude, etc., the burner flame will
be sooty and may produce carbon monoxide,
which could result in unsafe operation, explosion,
and/or fire or asphyxiation.
Observing Burner Operation
1. Observeburner tomakesureit ignites.Observecol-
or of flame. On natural gas the flame will burn blue
with appreciably yellow tips. On Propane gas a yel-
lowflame maybeexpected. Ifflameisnottheproper
color call a qualified serviceman for service.
2. Let furnace heat until blower cycles on.
3. Turn thermostat down.
4. Observe burner to make sure it shuts off.
5. Let the furnace cool and blower cycle off.
Should overheating occur, or the gas supply
failtoshut off,shut offthe manualgas valve to
the furnace and allow burner to run until fur-
nace cools down and blower shuts off before
shutting off the electrical supply.
If anyabnormalities areobservedwhencheckingforcor-
rect operation, such as burner failing to ignite or to turn
off, sooty flame, etc., call your nearest authorized ser-
vice technician as shown in the Service Center List in-
cluded in the home owner envelope with the furnace.
Combustion Air
In orderfor theburnerflameto burnefficiently,it must re-
ceive adequate combustion air.
The amount of combustion air can be changed by oper-
ating the combustion air adjustment rod located beneath
the gas valve.
The adjustment rod is set at an “average” position at the
factory and may be properly set for many applications.
However,theamount ofcombustionairrequiredwillvary
dependingonaltitude,actualBTU.contentofthegasbe-
ing used, gas pressure, conversion to another gas, and
other variable factors.
Therefore, it is essential that the burner flame be ob-
servedandanynecessaryadjustments aremadebefore
the furnace is put into service at the final home site. Ad-
justing the burner air is considered part of the normal
homeset--up procedureandistheresponsibilityofeither
the home seller or buyer, depending on their agreement.
Adjustmentsofthistypearenotcoveredbythewarranty.

18 Unitary Products Group
CAUTION: Combustion air adjustments
must be made only by a qualified technician.
Improper air adjustment may cause unsafe op-
eration, explosion or asphyxiation.
To adjust the combustion air:
1. To light and operate furnace see label inside lower
furnace door.
2. Allow the burner to burn for about 1 MINUTE.
3. Look through the observation window and observe
the appearance of the flame.
4. On natural gas, the base of the flame should beblue
but the tips of the flame will be yellow. (See Figure
19.)
5. OnPropanegas,almostalloftheflamewillbeyellow
although some blue should still be present at the
base of the flame next to the end of the burner. (See
Figure 20.)
6. If the flame is too yellow, the combustion air should
beincreased. Iftheflameis excessivelyblue(noyel-
low) the combustion air should be decreased.
7. To adjust the combustion air, loosen the lock screw
holding the combustion air rod in place. Push in on
therodtoincreasethecombustionair.Pulloutonthe
combustion air rod to decrease the combustion air.
Tighten lock screw after adjustment is made. Do not
completely close air damper at any time. Complete
closureofairdamperto burnerwillresultinimproper
operation. See caution above.
View of Burner Through the Observation Window
LIGHT BLUE
WITH YELLOW TIPS
DARK BLUE
BLUE TIPS JUST STARTING
TO BECOME PRONOUNCED.
YELLOW WITH
ORANGE TIPS
LIGHT BLUE
NO BLUE TIPS
EXTENDING
FROM THE END
OF THE BURNER
DARK BLUE
DARK BLUE
LONG AND EXTREMELY
PRONOUNCED BLUE TIPS
EXTENDING FROM THE
END OF THE BURNER
WHTISH YELLOW TO
LIGHT YELLOW
LIGHT BLUE
BLUE TIPS JUST STARTING
TO BECOME PRONOUNCED
DARK YELLOW TO
ORANGISH YELLOW
MAINFLAMEISA
WHITISH YELLOW
REFLECTIVE COLOR.
VERYLITTLEBLUE
EXTENDING FROM
THE END OF THE
BURNER.
WHITISH YELLOW
LIGHT BLUE
LONG AND EXTREMELY
PRONOUNCED BLUE TIPS
EXTENDING FROM THE
END OF THE BURNER
CORRECT AMOUNT OF
PRIMARY AIR TOO LITTLE PRIMARY AIR
PUSH SHUTTER ROD IN TOO MUCH PRIMARY AIR
PULL SHUTTER ROD OUT
CORRECT AMOUNT OF
PRIMARY AIR TOO LITTLE PRIMARY AIR
PUSH SHUTTER ROD IN TOO MUCH PRIMARY AIR
PULL SHUTTER ROD OUT
FIGURE 20 -- PROPANE GAS FLAME APPEARANCE
FIGURE 19 -- NATURAL GAS FLAME APPEARANCE
View of Burner Through the Observation Window
If Furnace Fails to Operate Properly
1. Check setting of thermostat -- and position of HEAT/
COOL switch if air conditioning is installed. If a set--
back type thermostat is employed be sure that the
thermostat is in the correct operating mode.
2. Check to see that electrical power is ON.
3. Check to see that the knob on the gas control valve
is in the full ON position.
4. Make sure filters are clean, return grilles are not ob-
structed, and supply registers are open.
5. Be sure that furnace flue piping is open and unob-
structed.
If the cause for the failure to operate is not obvious, do
not attempt to service the furnace yourself. Call a quali-
fied service agency or your gas supplier.

19
Unitary Products Group
FINAL PROCEDURE
INSTALL FURNACE DOORS
Install the bottom door first by holding the door flush
against the casing and sliding the door down until the
door top and bottom flanges rest in the casing channels.
Then install the upper door in the same manner.
FINISH AND TRIM
Alcove and Closet Installations may now be fin-
ished and trimmed as necessary.
Leave enough gap above upper furnace door to allow it
to be lifted and removed.
SUPPLY DUCT
OPENING
Furnace
Base
Duct Connector
Automatic
Damper
Note:For best air delivery install damper with blades
parallel to supply duct.
FIGURE 21 -- ANTI--BACKFLOW DAMPER
FURNACE AND AIR CONDITIONER
INSTALLATIONS
In an air conditioner is installed which does not use the
blower for air distribution and operates completely inde-
pendent of the furnace, the thermostat system must
have an interlock to prevent the furnace and air condi-
tioner form operating at the same time. This interlock
system usually contains a heat--cool switch which must
be turned to either HEAT or COOL to activate either
heating or cooling operation, or a positive OFF switch on
the cooling thermostat.
When used in connection with a cooling unit the furnace
shall be installed parallel with or on the upstream side of
the cooling unit to avoid condensation in the heat
exchanger.
For installationswithaparallelflowarrangement, thefur-
nace must beequipped withadamper toprevent coldair
from being discharged up around the heat exchanger.
Cold air causes condensation inside the exchanger and
can cause it to rust out which can allow products of com-
bustiontobecirculatedintothelivingareabythefurnace
blower resulting in possible asphyxiation. An air flow
activated automatic damper, P/N 7900--6771, is avail-
able from furnace manufacturer. See Figure 21.
NOTE: See label inside lower front door for conversion
and lighting instructions. Obtain a temperature
rise within the ranges specified on the name
plate.

20 Unitary Products Group
HIGH ALTITUDE DERATION CHART
DGAM, DGAT, DLAS Series
NATURAL GAS
56,000 — Input 70,000 — Input 75,000 — Input 90,000 — Input
Elevation Orifice
Dia. Drill Size Part # Orifice Dia. Drill Size Part # Orifice Dia. Drill Size Part # Orifice Dia. Drill Size Part #
Sea Level 0.136 29 9951--1361 0.154 23 9951--1541 0.161 20 9951--1611 0.18 15 9951--1801
2,000 0.136 29 9951--1361 0.149 25 9951--1491 0.157 22 9951--1571 0.177 16 9951--1771
3,000 0.128 30 9951--1281 0.149 25 9951--1491 0.157 22 9951--1571 0.173 17 9951--1731
4,000 0.128 30 9951--1281 0.147 26 9951--1471 0.154 23 9951--1541 0.173 17 9951--1731
5,000 0.128 30 9951--1281 0.144 27 9951--1441 0.152 24 9951--1521 0.169 18 9951--1691
6,000 0.128 30 9951--1281 0.144 27 9951--1441 0.149 25 9951--1491 0.166 19 9951--1661
7,000 0.12 31 9951--1201 0.14 28 9951--1401 0.147 26 9951--1471 0.161 20 9951--1611
8,000 0.12 31 9951--1201 0.136 29 9951--1361 0.144 27 9951--1441 0.161 20 9951--1611
9,000 0.12 31 9951--1201 0.136 29 9951--1361 0.14 28 9951--1401 0.157 22 9951--1571
10,000 0.116 32 9951--1161 0.128 30 9951--1281 0.136 29 9951--1361 0.152 24 9951--1521
PROPANE GAS
56,000 — Input 70,000 — Input 75,000 — Input 90,000 — Input
Elevation Orifice
Dia. Drill Size Part # Orifice Dia. Drill Size Part # Orifice Dia. Drill Size Part # Orifice Dia. Drill Size Part #
Sea Level 0.082 45 9951--0821 0.093 42 9951--0931 0.098 40 9951--0981 0.106 36 9951--1061
2,000 0.081 46 9951--0821 0.093 42 9951--0931 0.096 41 9951--0961 0.104 37 9951--1041
3,000 0.078 47 9951--0781 0.089 43 9951--0891 0.093 42 9951--0931 0.101 38 9951--1011
4,000 0.078 47 9951--0781 0.089 43 9951--0891 0.093 42 9951--0931 0.101 38 9951--1011
5,000 0.078 47 9951--0781 0.089 43 9951--0891 0.093 42 9951--0931 0.099 39 9951--0991
6,000 0.076 48 9951--0761 0.086 44 9951--0861 0.089 43 9951--0891 0.098 40 9951--0981
7,000 0.076 48 9951--0761 0.086 44 9951--0861 0.089 43 9951--0891 0.096 41 9951--0961
8,000 0.073 49 9951--0731 0.082 45 9951--0821 0.086 44 9951--0861 0.096 41 9951--0961
9,000 0.073 49 9951--0731 0.081 46 9951--0811 0.086 44 9951--0861 0.093 42 9951--0931
10,000 0.073 50 9951--0731 0.078 47 9951--0781 0.082 45 9951--0821 0.089 43 9951--0891
Adjust air shutter for correct flame appearance.
Table shows 4% Input Reduction per 1,000 feet Elevation.
Reference Source: NFPA No. 54, ANSI Z 223.1 1996 Edition.