Monessen Hearth LO-Rider Designer Vent Free Fireboxes LSTF36 User manual

READ AND SAVE THESE INSTRUCTIONS
WARNINGS
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 yourgas supplierfrom aneighbor'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.
WARNING: Improperinstallation, adjustment,alteration, service
or maintenance can cause injury or property damage. Refer to
this manual. For assistance or additional information consult
a qualified installer, service agency, or the gas supplier.
Carefully review the instructions
supplied with the decorative
type unvented room heater
for the minimum fireplace size
requirement.
DO NOT INSTALLANAPPLIANCE
IN THIS FIREBOX UNLESS THIS
FIREBOX MEETS THE MINIMUM
DIMENSIONS REQUIRED FOR
THE INSTALLATION.
Foruseonlywithalistedgas-fired
unventeddecorativeroom heater
not to exceed 40,000 BTU/hr. DO
NOT BUILD A WOOD FIRE.
MODELS: LSTF36, LPF36, LRCF36, LLCF36
LO-RIDER
DESIGNER VENT-
FREE FIREBOXES
INSTALLATION AND OPERATING
INSTRUCTIONS

2 79D0004
IMPORTANT SAFETY INFORMATION................................................................................................. 3
PLANNING the INSTALLATION............................................................................................................ 4
LOCATION of FIREBOX........................................................................................................................ 5
CLEARANCES and HEIGHT REQUIREMENTS................................................................................... 7
FIREPLACE FRAMING ........................................................................................................................ 9
FIREPLACE INSTALLATION ..............................................................................................................11
GAS LINE INSTALLATION.................................................................................................................. 14
CANOPY INSTALLATION ................................................................................................................... 15
WIRING to JUNCTION BOX ............................................................................................................... 16
GLASS CLEANING........................................................................................................................... 16
ILLUSTRATED PARTS LIST............................................................................................................... 17
USING OPTIONAL OUTSIDE AIR KIT................................................................................................ 18
WARRANTY.....................................................................................................................BACK COVER
CONTENTS

79D0004 3
INSTALLER
Please leave this manual with the appliance.
OWNER
Please retain this manual for future reference .
IMPORTANT
Read these instructions carefully before installing this vent-free firebox.
WARNING
• Improper installation or use of the firebox can cause serious injury or death from
fire, burns, explosion or carbon monoxide poisoning.
• Do not allow fans to blow directly into the fireplace. Avoid drafts that alter burner
flame patterns.
• Do not use a blower insert, heat exchanger insert or other accessory, not approved
for use with this firebox where applicable.
IMPORTANT SAFETY INFORMATION
1. Due to high temperatures, the firebox should be
located out of traffic and away from furniture
and draperies.
2. Children and adults should be alerted to the hazard
of high surface temperature and should stay away
to avoid burns or clothing ignition.
3. Young children should be carefully supervised
when they are in the same room with the firebox.
4. Do not place clothing or other flammable material
near the fireplace when the firebox is in use.
5. Any safety screen or guard removed for servicing,
must be replaced prior to operating a heater within
the firebox.
6. Installation and repair should be done by a qualified
service person.
7. To prevent malfunction and/or sooting, an unvented
gas heater/firebox should be cleaned at least
annually by a professional service person. More
frequent cleaning may be required due to excessive
lint from carpeting, etc. It is imperative that
control compartments, burners and circulating air
passageways be kept clean.
8. The installation must conform with local codes or, in
the absence of local codes, with the National Fuel Gas
Code, ANSI Z223.l/NFPA 54.
9. This unit complies with Z21-91 Ventless Firebox
Enclosures for gas-fired unvented decorative room
heaters.
10. Do not install the firebox in a bathroom or bedroom.
11. Avoid any drafts that alter burner flame patterns. Do not
allow fans to blow directly into fireplace. Do not place
a blower inside burn area of firebox. Ceiling fans may
create drafts that alter burner flame patterns. Sooting
and improper burning will occur.
12. Caution: Candles, incense, oil lamps, etc. produce
combustion byproducts including soot. Vent-free appli-
ances will not filter or clean soot produced by these types
of products. In addition, the smoke and/or aromatics
(scents) may be reburnt in the vent-free appliance which
can produce odors. It is recommended to minimize the
use of candles, incense, etc. while the vent-free appliance
is in operation.
13. Keep room area clear and free from combustible
materials, gasoline and other flammable vapors and
liquids.
14. During manufacturing, fabricating and shipping, various
components of this appliance are treated with certain
oils, films or bonding agents. These chemicals are not
harmful but may produce annoying smoke and smells
as they are burned off during the initial operation
of the appliance; possibly causing headaches or eye
or lung irritation. This is a normal and temporary
occurrence.
The initial break-in operation should last 2-3 hours with
the burner at the highest setting. Provide maximum
ventilation by opening windows or doors to allow odors
to dissipate. Any odors remaining after this initial
break-in period will be slight and will disappear with
continued use.
15. Always have a fireplace screen in place when the
appliance is in operation and, unless other provisions
for combustion air are provided, the screen shall have an
opening(s) for induction of combustion air.

4 79D0004
NOTICE
Illustrations shown in this manual reflect “typical” installations with nominal
dimensions and are for design and framing reference only. Actual installations may
vary due to individual design preferences. However, always maintain minimum
clearances to combustible materials and do not violate any specific installation
requirements.
GENERAL INSTALLATION INFORMATION
DO NOT ATTEMPT TO BURN SOLID WOOD FUELS, VENTED GAS LOG SETS, OR ANY OTHER COM-
BUSTIBLE IN THIS UNVENTED FIREBOX. ALSO, DO NOT INSTALL A VENT-FREE GAS LOG SET IN THIS
FIREBOX IF THE MINIMUM CLEARANCE AND HEIGHT REQUIREMENTS OF THE LOG SET ARE TOO
LARGE FOR THE FIREBOX.
The LSTF36, LPF36, LRCF36, and LLCF36 Series are vent-free fireboxes. They feature a self-contained heat-circulating
system. These units also feature a 2-in-1 flexible-face system (except for corner unit) that converts the circulating system
into a radiant system in seconds.
This installation manual will enable you to obtain a safe, efficient, and dependable installation of your vent-free
fireplace system.
Do not alter or modify the firebox or its components under any circumstances. Any modification or alteration of the firebox
system, including but not limited to the firebox and accessories, may void the warranty, listings and approvals of this system
and could result in an unsafe and potentially dangerous installation.
BEFORE YOU START:
CHECK YOUR PACKING LIST TO VERIFY THAT ALL LISTED PARTS HAVE BEEN RECEIVED.
ALSO INSPECT THE CONTENTS FOR SHIPPING DAMAGEAND IMMEDIATELY INFORMYOUR DEALER
IF ANY DAMAGE IS FOUND.
You should have the following:
1. Vent-Free Gas Firebox
2. One (1) - 36" Canopy (LRCF36/LLCF36)
One (1) - 20" Canopy (LRCF36/LLCF36)
Two (2) - 36" Canopys (LSTF36/LPF36)
3. Installation and Operating Instructions
4. Five (5) drywall spacers
ITEMS REQUIRED FOR INSTALLATION
TOOLS: BUILDING SUPPLIES:
Phillips screwdriver Square Framing materials
Hammer Piping complying with local codes Wall finishing materials
Saw and/or saber saw Tee joint Caulking material (noncombustible)
Level Pipe wrench Fireplace surround materials (noncombustible)
Measuring tape Pliers
Electric drill and bits Pipe sealant approved for use
with propane/LPG (resistant to sulfur compounds)
Refer to the installation instructions provided with the log sets for items required for log set installation.

79D0004 5
1 13/16
"
1 13/16
"
20 3/16
"
TOP
FRONTREAR OPEN
SIDE
23 13/16"
22 5/16"
42 3/16"
39 9/16"
12 3/8" 11 3/8"
3 3/16"
5 5/8"
11 7/8"11 7/8"
2 5/8" 1 3/4"
1 13/16"
35 15/16"
5 5/8"
15/16
"
28 1/16"
39 9/16"
27 3/4"
35 9/16"
27 3/4"
23 13/16"
Figure 1 - Firebox Dimensions
PLANNING THE INSTALLATION
In planning the installation for the appliance it is necessary to determine where the unit is to be installed and whether optional
accessories are desired. Gas supply piping should also be planned. The following steps represent the normal sequence of
installation. Each installation is unique, however, and might require a different sequence.
1. Position firebox prior to framing or into prepared framing.
2. Field wire main power supply to circulating models with fan kit. (Electrical connections should only be performed
by an experienced, licensed/certified tradesman).
3. Plumb gas line. (Gas connections should only be performed by an experienced, licensed/certified tradesman).
4. Install vent-free gas log heater per the instructions provided with the vent-free gas log heater.
5. Complete finish wall material and surround to your individual taste.

6 79D0004
CORNER LEFT
CORNER LEFT
PENINSULA
SEE-THROUGH
CORNER RIGHT
CORNER RIGHT
LOCATION OF FIREBOX
Carefully select the best location for installation of your vent-free firebox. The following factors should be taken into con-
sideration.
• Clearance to side wall, ceiling, woodwork, and windows. Refer to “CLEARANCES and HEIGHT REQUIREMENTS”
section below and on pages 8 and 9. Minimum clearances to combustibles must be maintained.
• Location must not be affected by drafts caused by kitchen exhaust fans, ceiling fans, return air registers for forced air
furnaces/air conditioners, windows, or doors.
• Installation must provide adequate ventilation and combustion air.
• DO NOT INSTALL THIS FIREBOX IN A BATHROOM.
• This firebox enclosure is approved for bedrooms on the condition that the unvented room heater does not exceed 10,000
BTUs input and the room is properly sized for combustion air.
• Location should be out of high traffic or windy or drafty areas.
• DO NOT INSTALL WHERE CURTAINS, FURNITURE, CLOTHING OR OTHER FLAMMABLE OBJECTS
ARE LESS THAN 36" FROM FRONT OF HEATER.
• Never obstruct the front opening of the vent-free firebox or restrict the flow of combustion and ventilation air.
• Minimize modifications to existing construction. Refer to Figure 2 for location suggestions.
• Do not install in the vicinity where gasoline or other flammable liquids may be stored. The vent-free firebox must be
kept clear and free from these combustible materials.
Figure 2 - Suggested Firebox Locations

79D0004 7
CLEARANCES and HEIGHT REQUIREMENTS
CLEARANCES and HEIGHT REQUIREMENTS
Ensure that minimum clearances shown in Figures 3 through 7 are maintained. Left and right clearances are determined
when facing the front of the firebox.
Follow these instructions carefully to ensure safe installation. Failure to follow these requirements may create a
fire hazard.
1. Sidewall Clearances — The clearance from the inside of the appliance to any combustible adjacent wall should not
be less than 27/8". Refer to Figure 3.
2. Ceiling Clearance — The ceiling must be at least 42" from the top of the firebox opening (bottom of hood). Refer
to Figure 3.
3. Back Wall Clearance — The appliance may be placed against a combustible back wall.
4. Parallel Wall Clearance — The clearance from the opening of the firebox to any wall that is parallel to the opening
should not be less than 36" (LSTF36 and LPF36 models only). Refer to Figure 4.
Figure 3 - Sidewall and Ceiling Clearances Figure 4 - Parallel Wall Clearance
(LSTF36 and LPF36 Models Only)
Figure 5 - Minimum Hearth Dimensions
AB C
See-Thru 33 3/16" 27 3/4" 21 15/16"
Corner 35 5/16" 27 3/4" 21 15/16"
Peninsula 35 5/16" 27 3/4" 21 15/16"
Minimum Hearth Dimensions
55/8"
42" 36"
C
A
B

8 79D0004
13"
17"20" 22" 24"
2.5"
6"
8"
10"
12"
TOP VIEW
FIREPLACE
HOOD
COMBUSTIBLE
MATERIAL
WALL
AREA
45°
5.63
4.50
3.50
1.50
5.00
1.00
2.50
3.00
1/2"
MIN. 0"
14"
MIN.
8"
14"
8"
12"
CLEARANCES and HEIGHT REQUIREMENTS
5. Mantel clearances — The canopy supplied with
the unit must be installed. If a combustible mantel
is installed, it must meet the clearance requirements
detailed in Figure 6.
6. Floor clearance — This firebox hearth opening
(inter-chamber floor) must be installed
at least 1/2" above any combustible
flooringmaterial or, the firebox hearth
may be installed flush with the floor
if noncombustible material such as
slate or marble is installed between
the base of the firebox and the com-
bustible flooring. The firebox may be
installed directly on a combustible
floor or raised on a platform of an
appropriate height. Do not place fire-
box on carpeting, vinyl, or other soft
floor coverings. It may, however, be
placed on a flat wood, plywood, par-
ticle board, or other hard surfaces. Be
sure firebox rests on a solid continuous floor or platform with
appropriate framing for support so that no cold air can enter room
from under the firebox. Refer to Figure 8.
NOTE: The combustible area above the facing must
not protrude more than 3/4" from the facing. If it does,
it is considered a mantel and must meet the mantel
requirements listed in this manual.
Figure 6c - Minimum Mantel Clearances
Figure 6 a&b - Minimum Mantel Clearances for Canopy
and Wide Profile Canopy
Figure 7 - Floor Clearance above Combustible
Flooring Material Figure 8 - Floor Clearance above Noncombustible Flooring Material
Canopy Wide Profile
Canopy
Combustible Material Noncombustible
Material

79D0004 9
11 9/16"
GAS
CONNECTION
10 9/16"
41 9/16"
22 3/16"
GAS
CONNECTION
23 1/4"
41 9/16"
10 9/16" 12 5/8"
419/16"
231/4"
3413/16"
419/16"
223/16"
3413/16"
Firebox framing can be built before or after the appliance is set in place. Construct firebox framing following Figures 9
through 14 on pages 9 and 10 for your specific installation requirements. Refer to Figure 1 on Page 5 for firebox dimensions.
The framing headers may rest on the top of the firebox standoffs.
The firebox may be installed directly on a combustible floor or raised on a platform of an appropriate height. Do not place
firebox on carpeting, vinyl, or other soft floor coverings. It may, however, be placed on a flat wood, plywood, particle board,
or other hard surfaces. Be sure firebox rests on a solid continuous floor or platform with appropriate framing for support so
that no cold air can enter room from under the firebox.
The classification “noncombustible material” includes, but is not limited to: stone, brick, and mortar. Noncombustibles are
safe to overlay the black-painted metal face, including radiant plates, and
do not pose a fire hazard. Any noncombustible finish material must not
extend past or interfere with the fireplace opening.
The classification “combustible material” includes, but is not limited to:
plywood, drywall, and particle board. Combustible materials may contact
the sides, bottom, or back of the firebox. Do not overlay the black painted
face with combustible materials.
FIREPLACE FRAMING
Figure 9 - Top View of Framing Specifications for
Peninsula Units (Model LPF36) Figure 10 - Top View of Framing Specifications for
Corner Units (Model LRCF36/LLCF36)
Figure 11 - Framing Specifications for
Peninsula Units (Model LPF36) Figure 12 - Framing Specifications
for Corner Units (Model LRCF36/LLCF36)
Two by Four
Do not fill spaces around
firebox with insulation or
other materials. This could
cause a fire.
WARNING
NOTE:
All dimensions are based on
1/2" drywall. If 5/8" drywall
is used, dimensions must be
changed accordingly.

10 79D0004
GAS
CONNECTION
10 9/16" 11 9/16"
22 3/16"
42 9/16"
The fireplace must be installed giving
full consideration to the clearance and
height requirements identified in this
manual.
WARNING
Figure 13 - Top View of Framing Specifications for
See-Through Unit (Model LSTF36)
FIREPLACE FRAMING
Figure 14 - Framing Specifications for
See-Through Unit (Model LSTF36)
Two by Four
Two by (2x)
filler to be
installed after
fireplace is set
in place
425/8"
223/16"
3413/16"

79D0004 11
PENINSULA UNIT (LPF36)
INSTALLATION
1. Attach nailing flanges in desired position. See Figure
16.
2. Slide firebox into prepared framing or position firebox
in its final position and frame later.
3. Level and plumb firebox by checking edges of firebox.
Shim if necessary.
4. Attach nailing flanges to studs. See Figure 15.
5. Install canopy. Refer to page 15 for canopy installation.
FIREPLACE INSTALLATION
Figure 15 - Location of Nailing Flanges and
Floor Screws
Nailing Flange
Figure 16a - 1/2 drywall position Figure 16b - 5/8 drywall position

12 79D0004
FIREPLACE INSTALLATION
SEE-THROUGH UNIT (LSTF36) INSTALLATION
1. Attach nailing flanges in desired position. See Figure 16.
3. Slide firebox into prepared framing or position firebox in its final position and frame later.
4. Level and plumb firebox by checking edges of firebox. Shim if necessary.
5. Attach nailing flanges to studs. See Figure 17.
6. Install canopy. Refer to page 15 for canopy installation.
Figure 17 - Location of Nailing Flanges and Floor Screws
Nailing Flange

79D0004 13
FIREPLACE INSTALLATION
RIGHT (LRCF36) AND LEFT (LLCF36) CORNER INSTALLATION
1. Attach nailing flanges in desired position. See Figure 16.
2. Slide firebox into prepared framing or position firebox in its final position and frame later.
3. Level and plumb firebox by checking edges of firebox. Shim if necessary.
4. Attach nailing flanges to studs. See Figure 18.
5. Install canopy. Refer to page 15 for canopy installation.
Figure 18 - Location of Nailing Flanges and
Floor Screws

14 79D0004
CAUTION
Plumbing connections should only be performed by a
qualified, licensed plumber. Main gas supply must be
off when plumbing gas line to fireplace or performing
service.
WARNING
Connecting directlyto an unregulated
propane/LPG tank can cause an
explosion.
Consult all local codes. All gas piping must be installed to comply with local codes, or in the absence of local codes, with
the latest edition of the National Fuel Gas Code, ANSI Z223.1/NFPA54.
The gas supply line must have an ANSI approved manual shutoff valve, upstream of the appliance. Either a recessed valve
with a key should be mounted to the wall or floor outside the firebox, or an on/off appliance-style valve with union can be
placed inside the firebox. A plugged 1/8" NPT pressure taping point is recommended for service and may be incorporated
to the valve assembly. Bring a minimum 1/2" gas supply line through the knockout hole provided in the firebox.
A sediment trap may be upstream of the heater to prevent moisture and contaminants from passing through trap to
the heater controls and burners. Failure to do so could prevent the heater from operating reliably. Consult applicable
codes.
In addition to the regulator fitted to the heater, an external regulator must be used on all propane/LPG heaters to reduce
the supply tank pressure to 13" w.c. (maximum). Any copper tubing used to supply propane/LPG from the tank must be
internally tinned. Note: When connecting propane/LPG vent-free room heaters, you must use pipe sealant
resistant to propane/LPG.
Check gas type: The gas supply must be the same as stated on the heater’s rating plate. If the gas supply is different,
DO NOT INSTALL THE HEATER. Contact your dealer for the correct model.
After completing connection, test all gas joints from the gas meter to the gas heater regulator for leaks. Using soap and
water solution or a gas sniffer. DO NOT USE AN OPEN FLAME
GAS LINE INSTALLATION
WARNING
Do not connect directly to natural
gas 1/2 PSI or 2 PSI systems. Always
make sure natural gas pressure is
regulated 10.5 w.c. (maximum before
operating the unit).

79D0004 15
WARNING WARNING
A canopy is furnished with each firebox and MUST be installed for safe operation. Refer to Figure 19.
The firebox canopy must not be
modified or replaced with a canopy
that may be provided with the
unvented decorative room heater.
1. Align the canopy with the holes in the top frame.
2. Secure canopy with five (5) screws provided.
3 Repeat on other side for See-Through Unit (LSTF36) and
Peninsula Unit (LPF36). Install the 20" canopy on the
shorter end with two (2) screws (LRCF36/LLCF36).
Close fireplace screen panel before
operating decorative type unvented
room heater.
CANOPY INSTALLATION
Figure 19 - Canopy Installation

16 79D0004
120VAC
Receptacle
Junction Box
BLACK
GREEN
TANTANWHITEBLACKBLACK
Speed Control Optional Thermostatic Switch
WIRING TO JUNCTION BOX & GLASS CLEANING
CAUTION
FORCED AIR KIT
If you are installing the forced air kit Model BLOTDL on the LSTF36, LPF36, GCRF36 or GCLF36 units, see the installa-
tion instructions below supplied with kit.
Electrical connections should only be performed by a qualified, licensed electrician,
main power must be off when connecting to main electrical power supply or
performing service.
The blower when installed, must be electrically grounded in accordance with local
codes or in the absence of local codes, with the National Electrical CodeANSI/NFPA
70.
WIRING TO JUNCTION BOX
NOTE: The wire must be run to the junction box before framing the firebox.
1. Wire the receptacle into an electrical circuit. Use minimum 60°C wire in accordance to prevailing codes.
2. The junction box is preinstalled at the factory. Remove junction box cover by removing the screw from the out
side firebox wall.
3. The junction box cover has a factory-installed “romex” style strain relief connector. Connect the wires according
to the wiring diagram below. Route the connected wire leads through the strain relief connector. See Figure 20.
Figure 20a - Wiring Diagram for Junction
GLASS CLEANING
NOTE: Glass should not be removed for cleaning
When Cleaning Glass
• Allow glass to cool before cleaning.
• Never use abrasive cleaning materials on glass.
• Keep children and pets at safe distance away.
• Never operate fireplace if glass is broken. Replace any glass that is chipped, cracked or broken. Replacement
glass frame assemblies MUST be supplied by the fireplace manufacturer. Do not substitute other materials.
• Handle glass frame with care. Avoid striking or scratching glass on hard objects.
Figure 20b - Wiring Diagram for Blower
NOTE: For see thru and peninsula
models, two blower kits may be used
and will be controlled independently.

79D0004 17
ILLUSTRATED PARTS LIST
STANDARD FEATURES
ITEM DESCRIPTION LST LPF LRCF/LLCF
1 36” Canopy 71D0500 71D0500 71D0500
2 20” Canopy - - 79D0082(1)
3 Screen Panel 79D0001(4) 79D0001(4) 79D0001(3)
4 Screen Rod Side 26D0138(4) 26D0138(4) 26D0138(2)
5 Screen Rod End - - 43D0116(1)
6 Brick Panel Common 79D0093(1) 79D0093(1) 79D0093(1)
6 Brick Panel Corner - - 79D0094(1)
6 Brick Panel Hearth 79D0095(1) 79D0095(1) 79D0095(1)
6 Brick Panel See Thru 79D0096(1) - -
7 Door Assembly - 79D0034(1) -
8 Nailing Flange 79D0091(5) 79D0091(5) 79D0091(5)
ACCESSORIES
9 Outside Air Kit* AK-4(1) AK-4(1) AK-4(1)
10 Blower Kit BLOTDL BLOTDL BLOTDL
*Not shown
1
8
6
7
2
10
4
3
3
5
Figure 21 - Exploded View

18 79D0004
8'max.
USE OF OPTIONAL AK-4 OUTSIDE AIR KIT
COMBUSTION AIR
1. Locate combustion air assembly at an exterior location which is not likely to be accidentally blocked in any manner.
Locate assembly amin. of 12" above the snow line to prevent blockage by snow accumulation.
2. Never mount the combustion air inlet assembly in a garage or storage area where combustible fumes such as gasoline
might be drawn into the fireplace.
3. Combustion air can be drawn from the crawl space under a house when an adequate supply of air is provided by open
ventilation.
4. CAUTION: Do not take combustion air from attic space or garage space.
5. locate air supply at least 3' away from any appliance vent terminal.
6. Avoid extremely long runs and numerous turns in the duct leading from the fireplace to the combustion air assembly.
These conditions increase the resistance to the free flow of air through the duct. See Figures 22 through 25 for methods
of installing the outside air for combustion assemblies.
Figure 22 - Basement Installation Figure 23 - Concrete Slab Installation
(Optional Outside Air Runs)
Above
Snow
Level
Ground
Level
Basement
Wall
Inlet Grill in
Soffit
(Overhang)
Figure 25 - 45° Corner Installation on
Slab Floor
Figure 24 - Installation Above Basement or
Crawl Space
Inside Wall
Outside
Wall
Duct Extended
to Miss Joist
To Outside Wall
Note: Fireplace model in illustrations may not be representative of your appliance.

79D0004 19
USE OF OPTIONAL AK-4 OUTSIDE AIR KIT
The use of outside air for combustion is optional unless required by building codes. It is only necessary to supply outside
combustion air to one side of the fireplace. Use the model AK4 combustion air kit.
MODEL AK-4 COMBUSTION AIR ASSEMBLY
1. Remove the cover plate from the 4" outlet opening location on the left or
right outside of the fireplace.
2. Place the insulation ring between the AK-4 starting collar and fire-
place wall.
3. Place the starting collar (4") into the hole on the side of fireplace. Fasten it in place with the four sheet metal screws
provided. See Figures 26 and 28.
Note: The air starting collar extends through the fireplace outer wrap. When the air starting collar is
securely attached, it will form a seal against the fireplace wall.
4. Attach outside duct to starting collar with duct clamp or screws. See Figure 27.
DO NOT remove the
cover if the outside air
will not be connected.
WARNING
Figure 26 - Attaching Outside Air Starting Collar
and Insulation Ring to Left Side of Fireplace
Figure 27 - Attaching Outside Duct
to Starting Collar
Insulation Ring
AK-4 Starting
Collar
Sheet
Meal
Screws
Left Side of
Fireplace
Shorter End
of Air Starting
Collar
Air Starting
Collar
Duct
Screws
Left Side of
Fireplace
5. Cut a 6-inch diameter opening for modelAK-4 in the outside
wall covering where the outside vent is to be located. See
Figure 28.
6. Select and cut a piece of duct long enough to attach to the
fireplace and stick out at least 3" beyond the face of the wall
to which theAK-4 inlet air vent will be attached. See Figure
27.
Figure 28 - Combustion Air Assembly for
Model No. AK-4
Nail
Holes
UseFP-4Uductformaximumefficiency
and safety. Do not use a combustible
duct. Always use UL Listed Class 0 or
1 duct material.
WARNING
6" Diameter
Hole
Duct
Extending
3"min.
AK-4 Inlet
Air Vent
Screw
Screws
Continued

20 79D0004
MODEL AK-4 COMBUSTION AIR ASSEMBLY (CONTINUED)
7. If the duct is the insulated type, push the insulation back from one end of
the duct approximately 2". See Figure 29.
8. Slip the exposed end of the duct over the starting collar on the fireplace.
9. Using the sheet metal screws provided, secure the duct end to the collar
attached to the fireplace.
10. Nail or screw the combustion air assembly to the surface of the wall.
Note: If the wall covering is brick or stone, use appropriate
masonry fasteners. If necessary, splice the duct. Use a model
403-duct connector to splice duct sections.
INSTALLING MODEL 403 DUCT CONNECTOR
1. Push insulation back approximately 2" from the end of each duct.
2. Slip each duct over duct connector until an equal length of connector extends into each duct.
3. Place duck clamp over the end of each duct. Tighten duct clamp down snuggly.
4. Push insulation back into place and over duct clamp.
Figure 29 - Installing Duct
Connector 403
Approximately
2"
Insulation
Duct
Connector
Duct Clamp
USE OF OPTIONAL AK-4 OUTSIDE AIR KIT