Yukon SUPER JACK SJ125 User manual

OWNER’S
MANUAL
ASSEMBLY
INSTALLATION
OPERATION
REPAIR PARTS
MODEL NUMBERS
BJ90 AND SJ125
CANADIAN MODELS
BJ90-C AND SJ125-C
CAUTION:
Read Rules and Instructions
Carefully for Safe Operation
IMPORTANT:
Installation must be made in
accordance with State and
Local Ordinances which may
differ from this Installation
Manual.
SUPER JACK
MODEL SJ125
BIG JACK
MODEL BJ90
SUPER JACK & BIG JACK
WOOD BURNING FURNACES
ALPHA AMERICAN CO., 10 INDUSTRIAL BLVD., PALISADE, MN 56469
www.yukon-eagle.com

DANGER
RISK OF FIRE OR EXPLOSION
Do not burn garbage, gasoline, drain oil, kerosene, thinners, etc.
WARNING
RISK OF FIRE
Tightly close the firing door and ash door during operation.
Do not operate with flue draft exceeding .03" W.C.
Do not store flammable materials within marked installation clearance.
Frequently inspect and clean soot and/or creosote from the heat exchanger,
smoke pipe, and chimney.
Do not connect this unit to a chimney flue serving another appliance.
CAUTION
BLACK SURFACES ARE HOT
Keep children away. Do not touch.
Questions?
Visit www.yukon-eagle.com
or call
1-800-358-0060
For repair or replacement parts,
See back cover for details.
Before installing this
furnace, read and follow all
instructions in this manual.
It is recommended that a
heating professional installs
or supervises the entire
installation of the furnace,
ducts, chimney and
electrical connections.
FOR YOUR SAFETY:
If you smell gas:
1. Open windows
2. Do not touch electrical switches
3. Extinguish any open flame
4. Immediately call your gas supplier
FOR YOUR SAFETY:
Do not store or use gasoline or
other flammable vapors and
liquids in the vicinity of this or
any other appliance.
2

3
TABLE OF CONTENTS
INTRODUCTION
Safety Statements.......................................................................................................................2, 4-6
Unpacking and Inspection.................................................................................................................7
Features and Benefits of SJ125.....................................................................................................8, 9
Features and Benefits of BJ90.................................................................................................. 10, 11
BJ90 Specifications .......................................................................................................................12
SJ125 Specifications ......................................................................................................................13
PLAN YOUR INSTALLATION
Plan your Installation .....................................................................................................................14
Locating the Furnace .....................................................................................................................15
Clearances to Combustibles ..........................................................................................................15
Typical Installations ......................................................................................................................16
Proper Chimneys ...........................................................................................................................17
Furnace Located in Confined Space .............................................................................................18
Combustion Air (Make Up Air) ....................................................................................................19
INSTALLATION
Place Furnace ...............................................................................................................................20
Furnace Casing .........................................................................................................................20-21
Combustion Blower .......................................................................................................................22
Junction Box .................................................................................................................................22
Fan and Limit Control ..................................................................................................................23
Mounting Thermostat .....................................................................................................................24
Electrical Wiring ............................................................................................................................25
Wiring Diagram ......................................................................................................................26, 27
Connecting Smoke Pipe ...............................................................................................................28
Barometric Draft Regulator .....................................................................................................29-31
OPERATING FURNACE
Best Wood to Burn ......................................................................................................................32
Helpful Hints ................................................................................................................................33
Wood Firing the Furnace ...............................................................................................................34
Burning Coal ..........................................................................................................................35, 36
Ash Removal ................................................................................................................................37
MAINTENANCE
Faulty Chimney and Draft Problems ......................................................................................38, 39
Cleaning Chimney, Smoke Pipe and Heat Exchanger ................................................................40
EXPLODED VIEWS AND PARTS LISTS
Super Jack (SJ125) .................................................................................................................42, 43
Big Jack (BJ90) ......................................................................................................................44, 45
SERVICE HINTS & TROUBLESHOOTING.....................................................................46, 47
YOUR NOTES..........................................................................................................................48-51

STOP FOR SAFETY!
Safe assembly, operating and maintenance practices should always be
followed whenever using any equipment. Wherever you see the caution sign,
extra safety precautions should be taken.
You must stop, read, and carefully follow the safety instructions before proceeding.
READ THROUGH THE ENTIRE MANUAL
It is recommended to read through the entire manual before beginning your
installation and/or operating your furnace. Follow all steps exactly.
NFPA PRACTICES
Areas of this manual refer to the National Fire Protection
Association (NFPA). NFPA is a non-profit organization.
This furnace must be installed according to NFPA codes.
NFPA Codes, Standards, recommended practices, and guides referred to in this document are approved by
the American National Standards Institute. State and local codes are adopted from these standards.
DANGERS-CAUTION - FIRE HAZARDS
(BURN WOOD LOGS OR COAL ONLY)
Ducts and Plenums shall be constructed entirely of sheet metal
Do Not use flammable liquids to start a fire.
Do Not attempt to light a wood fire when gas or oil vapors are present.
Do Not install on a combustible floor.
In the event of an electrical power failure, be sure ash door and fire door remain closed.
Do Not install a power humidifier on warm air plenum.
Store all ashes in a metal container with a tight fitting lid. Allow ashes to cool before disposing of them.
Be sure there is a sufficient supply of outside combustion air to the area where the furnace is located.
Keep smoke pipe connection as short as possible with a minimum of 1-inch rise per linear foot from the
furnace to the chimney opening. Smoke pipe shall be 24 gauge galvanized or black pipe.
Before servicing, allow furnace to cool. Shut off electricity.
Familiarize yourself with this wood burning furnace before leaving it unattended.
Follow a regular service and maintenance schedule of furnace and chimney.
IN THE EVENT OF A CHIMNEY FIRE, CALL FIRE DEPARTMENT, AND THEN BE SURE ALL FURNACE
DOORS ARE CLOSED TIGHTLY. TURN OFF ELECTRIC POWER TO FURNACE.
Safety Statements
4
SAVE THESE INSTRUCTIONS

Safety Statements
CAUTION
INSPECT FLUE PIPES, FLUE PIPE JOINTS, AND FLUE PIPE SEALS REGULARLY TO ENSURE
THAT SMOKE AND FLUE GASES ARE NOT DRAWN INTO, AND CIRCULATED BY, THE AIR-
CIRCULATION SYSTEM.
ADD-ON to GAS FURNACE INSTALLATIONS
Installation shall comply with CAN/CSA-B365 and if changes are made to the central fur-
nace, changes are to comply with CSA-B139 (add-on to oil furnaces), CSA C22.1 (add-on
to electric furnaces), or CAN/CGA-B149.1 or B149.2 (add-on to gas furnaces).
When adding on to a gas furnace, the operation of the gas furnace must be verified
for acceptable operation before and after installation of the Jack add-on furnace by a
gas fitter who is recognized by the regulatory authority.
DO NOT connect, under any circumstances, to the chimney or vent serving a gas
furnace or gas appliance.
Operate the gas-fired unit periodically to ensure that it will operate satisfactorily
when needed.
DO NOT relocate or bypass any of the safety controls in the original furnace installation.
DO NOT use duct elbows having an inside radius of less than 150 mm (6 in)
Unit shall only be installed on a furnace duct system and chimney that are in good
operating condition.
External static pressure of the central furnace shall be measured before any chang-
es are made for the Jack add-on installation. These values shall be maintained fol-
lowing the add-on installation.
CAUTION
THE WARM-AIR SUPPLY OF THE SUPPLEMENTARY FURNACE SHALL NOT BE CONNECTED
TO THE COLD-AIR RETURN DUCTING OF THE CENTRAL FURNACE.
Questions? Visit www.yukon-eagle.com or call 1-800-358-0060
5

Safety Statements
6
TO THE INSTALLER
It is necessary to ensure that there is sufficient air flow through each furnace after the add-
on installation has been completed. It is suggested that the temperature rise method be
used since most installers are likely to have the necessary equipment. The temperature
measurements may be made using a potentiometer and thermocouples, mercury thermome-
ters. If thermometers are used, sufficient time must be allowed for the thermometer to reach
actual temperature. As much as twenty minutes may be required.
PROCEDURE
To check the existing system, drill a hole 1/4” in the side of the return plenum on the primary
furnace and a similar 1/4” hole in the side of the main supply air duct, 24” from the supply air
plenum. Insert a temperature measuring device in each of these holes and start the primary
furnace. Allow the furnace to operate until all temperatures have stabilized. This will take at
least 1/2 an hour. Read the two temperatures thus obtained and not the difference, TS - TR.
(see diagram 1, page 16). This difference should not exceed 85 degrees F. (29° C)
Complete the installation of the Jack as an add-on furnace and drill a third 1/4” hole in the
TA (See TA, page 16). Insert a temperature measuring device.
Operate the primary furnace until the temperature rise TA - TR across the primary furnace is
equal to or less than 85 degrees F (29° C). Should this temperature difference exceed 85
degrees (29° C), increase the blower speed until the temperature rise TA - TR is equal or
less than 85 degrees F (29° C).
Shut off the primary furnace and build a fire in the Jack unit. When the fire is established, fill
the fire box to the top of the firebrick (maximum level). Open the combustion blower air
damper. Allow the temperature to stabilize and measure the temperature difference TS - TR.
Should it exceed 85 degree F (29° C), a further increase in blower speed will be necessary.
Once the proper air temperature rise has been obtained, an ammeter should be connected
to the blower motor to measure current draw. If it exceeds the name plate rating, change the
motor to a higher rating (if the old motor was a two stage, ensure that the new motor is as
well). It is permissible to change the blower motor and blower drive pulleys in the primary
furnace but not the blower unit.
This equipment must be installed according to the manufacturer’s instructions and in a man-
ner acceptable to the regulatory authority having jurisdiction by mechanics experienced in
such a service. When required by regulatory authority, such mechanics shall be licensed to
perform this service.

Unpack and Check your Cartons
INSPECT SHIPMENT
Note any damage to the shipping cartons. Remove all
items from your shipping cartons. Check all items
against the packing list below. Note any items lost or
damaged in shipment. Refer to the exploded view and
parts list in the back of the manual for the part names
and numbers of missing or damaged items.Keep the
small parts in the parts bag until you are ready to
install them.
Inspect the furnace for visible damage.
The furnace is shipped strapped to a pallet.
Inside the wood loading door is another carton.
This carton contains:
·Barometric Draft Regulator
·Gasket
·Conduit Clip
·Wiring Harness
·Fan and Limit control
·Combustion Blower
·Transformer-Relay
·Interlock Relay
·Thermostat
·Owner’s Manual
·Warranty Sheet
Note:
If ordered, the Circulating Blower and Motor and
Cabinet are shipped in separate cartons.
Plenum Packages are also shipped in a separate
carton.
Super Jack - SJ125
Big Jack - BJ90
7

Furnace Features - SJ125
1FAN AND LIMIT CONTROL
The fan limit control turns the fan on
and off. It works off of temperature
and also provides a high temperature
safety limit.
2
3
4
5
6
7
8
9
SECONDARY HEAT EXCHANGER
More heat exchanger surface means
less heat up the Chimney. Made of 10
gauge steel rectangular tubes, which
the heat produced by the furnace,
passes through, before entering the
chimney.
EASY ACCESS CLEAN OUTS
The two clean out plates on the front of
the furnace allow easy access to clean
the Secondary Heat Exchanger tubes.
Keeping the inside of your furnace
clean insures high efficiency and helps
prevent creosote fires.
PICTURE FRAME FRONT
The front and back of the furnace is
built of 10 gauge steel and painted
with high temperature black paint. The
22 gauge painted side panels are de-
signed to slide onto the flanged steel
for easy installation.
LARGE LOADING FIRE DOOR
WITH POSITIVE DOOR LOCK
This 13” x 13” opening allows for easy
loading and larger diameter split logs.
The positive door lock ensures that
smoke and heat will not escape from
the furnace.
The round cast iron disc allows sec-
ondary air over the flame. It helps burn
smoke and unburned gases that leave
the flame, thereby increasing efficien-
cy.
FORCED DRAFT COMBUSTION
BLOWER
This furnace operates on a forced draft
principle. When the thermostat is call-
ing for heat, the draft blower will turn
on to get the fire burning. Draft blower
air disc must be open.
HONEYWELL TRANSFORMER /
RELAY
These Honeywell Transformers are the
industry standard and made for heating
systems. This 24V control circuit step-
down transformer is designed to power
any 24V control system, including ther-
mostats and relays.
EASY ACCESS ASH PAN
Designed to allow for easy removal of
ashes. Pulls out of furnace, equipped
with additional cross bar handle for
easy ash disposal.
HIGH TEMPERATURE FIREBRICK
1-1/4 thick Hi-Temperature firebrick
surrounds the wood/coal fire. The
Super Jack features 90 pounds of
firebrick. This firebrick not only pro-
tects the steel from the extreme com-
bustion temperature in the firebox, but
it also retains a substantial amount of
heat after the wood/coal fire burns
down.
HEAVY CAST IRON GRATE
It is imperative that 80 percent of the
air for combustion enter the firebox
from below a wood/coal grate to in-
sure an efficient and clean burning fire.
This grate is made of heavy cast iron
that can endure the temperatures of
wood and coal fires.
8

Furnace Features - SJ125
3
1
2
4
5
6
7
8
9

Furnace Features - BJ90
1FAN AND LIMIT CONTROL
The fan limit control turns the fan on
and off in furnace applications. It
works off of temperature and also pro-
vides a high temperature safety limit.
2
3
4
5
6
7
PICTURE FRAME FRONT
The front and back of the furnace is
built of 10 gauge steel and painted
with high temperature black paint. The
22 gauge painted side panels are de-
signed to slide onto the flanged steel
for easy installation.
LARGE LOADING FIRE DOOR
WITH POSITIVE DOOR LOCK
This 13” x 13” opening allows for easy
loading and larger diameter split logs.
The positive door lock ensures that
smoke and heat will not escape from
the furnace.
The round cast iron disc allows sec-
ondary air over the flame. It helps burn
smoke and unburned gases that leave
the flame, thereby increasing efficien-
cy.
FORCED DRAFT COMBUSTION
BLOWER
This furnace operates on a forced draft
principle. When the thermostat is call-
ing for heat, the Draft Blower will turn
on to get the fire burning. Draft blower
disc must be open.
HONEYWELL TRANSFORMER /
RELAY
These Honeywell Transformers are the
industry standard and made for heating
systems. This 24V control circuit step-
down transformer is designed to power
any 24V control system, including ther-
mostats and relays.
EASY ACCESS ASH PAN
Designed to allow for easy removal of
ashes. Pulls out of furnace, equipped
with additional cross bar handle for
easy ash disposal.
HIGH TEMPERATURE FIREBRICK
1-1/4 thick Hi-Temperature firebrick
surrounds the wood/coal fire. The
Big Jack features 90 pounds of fire-
brick. This firebrick not only protects
the steel from the extreme combustion
temperature in the firebox, but it also
retains a substantial amount of heat
after the wood/coal fire burns down.
HEAVY CAST IRON GRATE
It is imperative that 80 percent of the
air for combustion enter the firebox
from below a wood/coal grate to in-
sure an efficient and clean burning fire.
This grate is made of heavy cast iron
that can endure the temperatures of
wood and coal fires.
10

Furnace Features - BJ90
1
2
3
4
5
6
7
11

Specifications
BIG JACK 90
MODEL BJ90
BTU Capacity...........................................................................................................90,000
Wood Capacity...................................................................................................5.25 Cu. Ft
Heat Exchanger (Total Area)......................................................................... ......19 Sq. Ft
Maximum Wood Length.................................................................................................24”
Fire Box Dimensions.............................................. ............16” wide x 24” long x 23” high
Smoke Collar........................................................................... .......................................6”
Weight................................................................................................ .....................595 lbs
Height...................................................................................................... ...................39.5”
Width.............................................................................................................. ..........24.25”
Depth......................................................................................................... .................34.5”
Warm Air Plenum Opening....................................................................................22” x 16”
Fire Door Opening................................................................................................13” x 13”
Secondary Heat Exchanger (Area)............................................................. ..............None
Blower (Optional).................................................................... ...........................1460 CFM
12
29-1/2”

Specifications
BTU Capacity..............................................................................................................125,000
Wood Capacity........................................................................................................5.25 Cu. Ft.
Heat Exchanger (Total Area)...................................................................................24.5 Sq. Ft.
Maximum Wood Length.......................................................................................................24”
Fire Box Dimensions....................................................................16” wide x 24” long x 23” high
Smoke Collar.........................................................................................................................7”
Weight...........................................................................................................................645 lbs
Height..................................................................................................................................47”
Width...............................................................................................................................26.25”
Depth................................................................................................................................34.5”
Warm Air Plenum Opening...........................................................................................22” x 20”
Fire Door Opening......................................................................................................13” x 13”
Secondary Heat Exchanger (Area).......................................................................15.56 Sq. Ft
Blower (Optional).....................................................................................................1460 CFM
SUPER JACK 125
MODEL SJ125
13
37”

Plan Your Installation
PLAN YOUR INSTALLATION
It is recommended to read through the entire manual
before beginning your installation. Follow all steps exactly.
Reading this manual will also help you get all the benefits
from your furnace.
CAUTION: Read these rules and the
instructions carefully. Failure to follow these
rules and instructions could cause a
malfunction of the furnace. This could
result in death, serious bodily injury and/or
property damage.
IMPORTANT!
CHECKING THE FURNACE INSTALLATION AND
MAKING ADJUSTMENTS
It is imperative that a heating professional, before startup
and at the beginning of each heating season, inspects the
entire installation and make any necessary adjustments.
RULES FOR SAFE INSTALLATION AND OPERATION
1. Check your local codes. The installation must comply
with them.
2. USE ONLY WOOD LOGS OR COAL in this furnace.
Over firing will result in failure of heat exchanger and
cause dangerous operation.
3. You must have a sufficient supply of outside
combustion air to the area in which the furnace is
located. (See page 19).
4. Factory Built Chimneys: Connect this furnace to a
chimney that complies with NFPA 211. Factory built
chimneys for use with wood-burning appliances shall
comply with the HT requirements of UL 103 or
CAN/ULC-S629-M87. This means you must install what
is referred to as type HT All Fuel chimney.
Masonry Chimneys: Connect this furnace to a
chimney that complies with NFPA 211. A field
constructed chimney of solid masonry units, bricks,
stones, listed masonry chimney units, or reinforced
portland cement concrete that is lined with suitable
chimney flue liners and built in accordance with the
provisions of Chapter 4 of this standard.
5. Follow a regular service and maintenance schedule for
efficient and safe operation.
6. Before servicing, allow furnace to cool. Always shut off
electricity to furnace.
14
DUCTS SHOULD BE LARGE
ENOUGH TO HANDLE GRAVITY AIR
FLOW IN THE EVENT OF ELECTRIC
POWER OR FURNACE FAN FAILURE
AIR CONDITIONING COIL MUST BE
INSTALLED WITH A METAL
CONDENSATE PAN.
DO NOT USE PLASTIC
CONDENSATE PAN

Plan Your Installation
LOCATING THE FURNACE
Locate the furnace as close to the chimney or
flue as possible. The furnace should be located
no more than 10 feet away from the chimney.
You will need 1” rise per linear foot of pipe as a
minimum.
The furnace should be located with respect to
building construction and the placement of other
equipment. Consideration should be given to
sufficient clearance. Sufficient clearance
provides adequate access for the cleaning of
surfaces; the replacement of blowers, motors,
controls and the chimney connector; and for the
lubrication and servicing of moving parts.
Making sure that sufficient air supply for
ventilation and proper combustion are piped into
the room where the furnace is located.
REDUCED CLEARANCES
Up to 50% less clearance between combustible
walls and chimney connector to furnace and
ducts is allowed if insulated according to NFPA
Standard 90B or your local building code. This
copyrighted book is available from the National
Fire Protection Association, Inc., PO Box 9101,
Quincy, MA 02269-9101.
It is a mistake to assume that sheet metal,
masonry, or asbestos-like board placed directly
against a wall protects it. Materials installed in
this manner give very little protection. These
materials are good conductors, so they will be
almost as hot on their back-side as well as on
their exposed side. Therefore, the combustible
wall behind it is still a fire hazard.
NOTE:
It is recommended that a 2” non-combustible
raised pad be used for the furnace. This will
prevent moisture from getting under the furnace
and causing corrosion.
15
1” CLEARANCE TO COMBUSTIBLES
BEYOND 6’ TO A POINT WHERE
THERE IS A CHANGE IN DIRECTION OF
90 DEGREES OR MORE.
48”

Plan Your Installation
TYPICAL INSTALLATIONS
•
SERIES ADD-ON
‚
PARALLEL ADD-ON
ƒ
INDEPENDENT INSTALLATION
•‚
ƒ
DUCTS AND PLENUMS SHALL BE
CONSTRUCTED ENTIRELY OF
SHEET METAL.
IMPORTANT
! !
16

PROPER CHIMNEYS
The National Fire Protection Association (NFPA) requires that all factory built chimneys be Listed and
installed in accordance with conditions of the Listing in the manufacturers instructions. NFPA also
requires that your chimney extend at least three (3) feet above the highest point when it passes through
the roof and at least two (2) feet higher than any portion of the building within ten (10) feet of the
chimney.
Factory built chimneys must be what NFPA refers to in NFPA 211 1-5.217.4 as Type HT. HT is an
abbreviation meaning High Temperature.
Masonry Chimneys as referred to in NFPA 211 1-5.2.17.6, a field constructed chimney of solid masonry
units, bricks, stones, listed masonry chimney units, or reinforced concrete that is lined with suitable chim-
ney flue liners and built with the provisions of Chapter 4 of this standard.
RIDGE
More than 10 ft.
(3.1m)
10 ft. (3.1m)
2 ft. (0.61m)
minimum
Chimney 3ft. (0.92m)
minimum
RIDGE
Less than 10 feet
(3.1m)
2 ft. (0.61m)
minimum
Chimney 3 ft. (0.92m)
minimum
CHIMNEY TERMINATION (LESS THAN 10 FEET)
CHIMNEY TERMINATION (MORE THAN 10 FEET)
Plan Your Installation
IMPORTANT:
DO NOT CONNECT THIS
FURNACE TO A CHIMNEY
SERVING ANOTHER APPLIANCE
17

Plan Your Installation
FURNACE LOCATED IN CONFINED SPACE
When the furnace is in utility room, install two open grilles.
Place them in a wall or door opening to the rest of the
house. One grille will supply combustion air.
Locate it near the floor. The other grille is for ventilation.
Locate it close to the ceiling. Each grille must have a free
area. It should be not less than one square inch for each
1000 BTU/hr. of the total input rating of appliances in
confined space.
FOR EXAMPLE: Your furnace is rated at 150,000 BTU
per hour. The water heater is rated 30,000 BTU per hour.
The total is 180,000 BTU per hour. You need two grilles,
each with 180 square inches of free opening. Metal grilles
have about 60% free (open) area. Therefore, you need
two metal grilles with 300 square inches each of louvered
area. The height should be about half the width.
SIZE
1/4” MESH
SCREEN
BTU
WOOD
LOUVERS
BTU
METAL
LOUVERS
BTU
3-1/4 X 12 INCH
8 INCH ROUND
8 X 12 INCH
8 X 16 INCH
144,000
200,000
382,000
512,000
36,000
50,000
96,000
128,000
108,000
150,000
288,000
384,000
BTU Per Hour Input*
* Based on opening covered by 1/4 inch mesh screen, wood or metal louvers.
FRESH AIR DUCT CAPACITIES
Fresh air duct capacities for duct supplying fresh air
18

Plan Your Installation
COMBUSTION AIR
Make-up outside air must be provided to furnace for
proper fuel combustion. This is provided by openings
to outside of building. These openings shall have
unobstructed areas not less than the areas of the flue
pipe.
IMPORTANT:
Outside air is needed to replace air used by the
burner and wood combustion process. Outside air
is required to replace air used for taking the by-
products of combustion out the chimney. Outside
air is needed to replace air expelled by kitchen or
bathroom fans. It is also needed to replace air
expelled by water heater chimneys or fans.
Failure to provide outside air to the furnace area will
result in negative pressure, or vacuum, in the home.
Smoke from the wood fire may not be drawn up the
chimney. This causes creosote buildup and sometimes
causes smoke to enter furnace room.
WARNING: You must provide for
enough fresh air to assure proper
combustion. The fire in the furnace uses
oxygen and must have a continuous
supply. The air in a house contains only enough
oxygen to supply the furnace for a short time.
Outside air must enter the house to replace that
used by the furnace.
19

Installation
PLACE FURNACE
Review all instructions in the Planning Your
Installation section. Place the furnace in the
pre-selected location.
Refer to Page 15 in the Plan Your Installation
section. Make sure the furnace is level.
Furnace Casing
The furnace casing is shipped unassembled in a
carton attached to the furnace.
Slide side panels down over angled edges of the
black steel on the front and back of the furnace.
See Fig. 1
Place top panel over the front edge of the furnace
and set down over the side panels.
See Fig. 2
20
FIG. 1
FIG. 2