Monessen Hearth SWB400I User Manual

SWB400I DELUXE

RADIANT WOOD BURNING FIREPLACE

INSTALLATION, OPERATION AND MAINTENANCE MANUAL

The SWB400I fireplace is an insulated radiant wood burning fireplace with a 36-inch wide
front opening. It comes complete with an interior damper to prevent heat loss when not in
use, and it has fire screens for safe use. The SWB400I fireplace may be installed in residential
and manufactured type homes as explained by this instruction manual. The SWB400I installs
with S-series chimney system components and is designed to utilize the MGD36-series of
glass doors. The SWB400I can be converted to a louvered circulating unit by utilizing the
MLK36 louver kit, and can utilize the FA2 fan once the fireplace has been converted to a
louvered circulating unit. Natural gas or LP gas log sets may be installed in the SWB400I
fireplace if desired, as allowed by local code authorities.

53D9033. Rev 1 03/03

CONGRATULATIONS!

You have chosen a fine woodburning fireplace. Your fireplace has been designed and built for years
of heating and viewing enjoyment. Please take time to read this entire manual before installing or
operating your fireplace.

TABLE OF CONTENTS

LISTING AND CODE APPROVALS ............................................................................................................... 2

AUTIONARY INFORMATION ...................................................................................................................... 3

C
O

PERATION GUIDELINES ......................................................................................................................... 4

CLEARANCES ........................................................................................................................................ 5

IREPLACE LOCATION............................................................................................................................. 7

F
I

NSTALLATION PREPARATION .................................................................................................................... 8

LOOR PROTECTION ............................................................................................................................ 10

F
F

IREPLACE COMPONENTS ..................................................................................................................... 12

FIREPLACE INSTALLATION ...................................................................................................................... 14

HIMNEY INSTALLATION ........................................................................................................................ 15

C
C

HIMNEY OFFSET INSTALLATION ............................................................................................................. 17

CHIMNEY OFFSET AND CAP INSTALLATION ............................................................................................... 18

CHIMNEY CAP INSTALLATION ................................................................................................................. 19

CHIMNEY HEIGHT AND OFFSET CHARTS .................................................................................................. 20

CHIMNEY CAP CHASE INSTALLATION ....................................................................................................... 21

OUTSIDE COMBUSTION AIR PRECAUTIONS & RECOMMENDATIONS ................................................................ 22

COMBUSTION AIR ASSEMBLY ................................................................................................................. 24

GAS APPLIANCE INSTALLATION .............................................................................................................. 24

TRIM INSTALLATION .............................................................................................................................. 26

GLASS DOOR INSTALLATION AND FAN ACCESSORY ................................................................................... 28

FIREPLACE OPERATION......................................................................................................................... 29

MAINTENANCE AND SAFETY ................................................................................................................... 31

PARTS DIAGRAM AND LIST .................................................................................................................... 34

LIMITED WARRANTY ............................................................................................................................. 36

LISTING AND CODE APPROVALS

The instructions contained in this manual provide the information necessary to install this fireplace in accordance with
Underwriter’s Laboratories requirements and in compliance with the National Fire Protection Association Standard No.

211. Some codes may require the fireplace and chimney be electrically grounded. Before beginning the installation, you
should check with local building officials to obtain required permits and assure compliance with local regulations and
coded. If you encounter problems with code requirements, contact your dealer for assistance.

This fireplace is listed by OMNI-Test Laboratories, Inc. to U.L. 127-standard for factory-built fireplaces. The design of this
fireplace and these instructions complied with applicable safety standard for a factory built fireplace in effect at the time
the fireplace was manufactured. You should be aware, however, that failure to install, operate, and maintain this or any
other factory built fireplace properly can result in a house fire or other occurences that could cause deaths, injuries, and
property damages. It is very important that the persons installing and/or supervising the installation of this fireplace have
appropriate skills in using the tools and techniques required: and reading and comprehension skills sufficient to read and
follow these instructions. These instructions contain warnings, cautions, and notes to emphasize important safety
information. To assure that safe and satisfactory service is received from this fireplace, please read the following special
notices and all the contents of this manual.

2

53D9033. Rev 1 03/03

CAUTIONARY INFORMATION

1. Read these instructions entirely before beginning any part of the installation. Save these instructions for
any future repairs.

2. Use these instructions as a guide during the installation of the fireplace.

3. Be sure these instructions become the property of and are reviewed by all future users of this fireplace to
encourage proper operation and maintenance.

4. All the parts used with this fireplace system must be installed in accordance with these installation instructions.
Failure to do so may be hazardous and will void the warranty.

5. This fireplace and accessories should not be altered in any way that is not specifically recommended in
this manual.

6. Refer to your local building code for local requirements pertaining to installation of factory-built fireplaces.
Monessen Hearth Systems fireplaces are intended for installation and use according to standard NFPA
211 of the National Fire Protection Association.

7. This fireplace must not be installed with a masonry flue.

8. This fireplace and chimney should not be used for venting a wood or coal burning heater or fireplace insert.

WARNING:

SYSTEM

9. Do not pack required air spaces with combustible material or insulation not specifically recommended for
use in such areas.

WITHOUT WRITTEN AUTHORIZATION FROM MONESSEN HEARTH SYSTEMS.

DO NOT INSTALL A SEPARATE SOLID FUEL INSERT OR GAS FIREPLACE INSERT IN THIS FIREPLACE AND CHIMNEY

2

INTENDED PRODUCT USAGE

This fireplace is intended for supplemental heating only and is not intended for use as a primary heating
system.

This fireplace is designed to sit directly on a combustible floor. The fireplace must be installed with clearances
to combustible building materials as specified by this manual. Only parts manufactured by Monessen Hearth
Systems and labeled for use with this fireplace should be used in the installation of the fireplace except for
special roof flashings that may be fabricated locally. The use of improper parts in the installation can be
hazardous and voids the warranty offered by Monessen Hearth Systems.

This fireplace is designed to burn solid wood fuel (wood), UL- classified processed solid fuel fire logs, or a
certified decorative gas appliance may be installed in the fireplace as described later by this instruction manual.

This fireplace is not designed to burn coal, unplumbed liquid fuels, unplumbed gaseous fuels or household
refuse. Any attempt to burn these fuels in the fireplace can be hazardous.

NOTICE:

FIREPLACE

MGD36B OR MGD36PB GLASS DOORS, AN AK6 OUTSIDE COMBUSTION AIR KIT (INSTEAD OF THE AK4 OUTSIDE COMBUSTION

KIT OFFERED FOR RESIDENTIAL TYPE HOMES AS DESCRIBED LATER BY THIS INSTRUCTION MANUAL), A SVTR FIRESTOP

AIR

THIMBLE

CAUTION:

WARNING:

1. Damage to the fireplace from overheating.

2. Hazardous temperatures to develop on combustible materials adjacent to the fireplace or chimney.

3. The emission of smoke, sparks or hazardous gases into the dwelling.

4. Leakage of rain water into the dwelling.

THIS FIREPLACE IS NOT DESIGNED FOR INSTALLATION IN MANUFACTURED HOMES WITHOUT A VENTED ATTIC SPACE. THE

MAY BE INSTALLED IN MANUFACTURED HOMES WHICH HAVE A VENTED ATTIC SPACE IF THE FIREPLACE IS EQUIPPED WITH

, AND THE MINIMUM INSTALLED HEIGHT FROM FLOOR TO FLUE OUTLET IS 16 FEET. SEE FIGURE 1.

DO NOT USE A FIREPLACE INSERT OR OTHER PRODUCT NOT SPECIFIED FOR USE WITH THIS FIREPLACE.

IMPROPER INSTALLATION OR USE OF THIS FIREPLACE WILL VOID ITS WARRANTY AND CAN CAUSE:

53D9033. Rev 1 03/03

3

OPERATION GUIDELINES

As wood is burned in the fireplace, room air entering the fireplace through vents is circulated around the firebox of
the fireplace. This air circulation protects the firebox from overheating. Fireplace vents must not be blocked or
restricted in any manner. Blocking or restricting air circulation through the fireplace can cause a fire hazard.

In residential type installation, an AK4 outside combustion air kit may be connected to either the left or right side of
the fireplace to allow outside air to enter the firebox through a dampered opening in that side of the fireplace. This
“outside combustion air” feature reduces the room air used for combustion and prevents excessive heat loss from
the room. When the fireplace is in use, the fireplace’s “outside combustion air” damper connected to an AK4 may be
opened to allow air from outside to enter the fireplace firebox. When the fireplace is not in use, the “outside combustion
air” damper should be closed to prevent cold air from entering the firebox. An “outside combustion air” damper is
open when its control lever is up, and closed when its control lever is down. A control lever for each “outside
combustion air” damper is located inside the firebox near the top of the side firebrick on each side of the fireplace.
The design of the fireplace allows the routing of the combustion air duct downward or horizontally to obtain the
outside combustion air; this permits flexibility in planning your installation. See Figures 24 thru 27 and their instructions
for typical installation of outside combustion air kits. Review the precautions and recommendations in this manual
pertaining to outside combustion air. Outside air for combustion is optional in residential type installations

unless required by local codes; it is mandatory in manufactured home installations. Use an AK6 outside
combustion air kit in manufactured home installations, instead of the AK4 offered for residential type
installations.

Glass doors (model MGD36B or MGD36PB by Monessen Hearth Systems) may be installed to receive the maximum
benefit from your fireplace. For large fires, the maximum heating benefit from the fireplace will be obtained with the
doors open due to the high amount of radiant heat being emitted out of the front opening of the fireplace. With a
small fire, or before retiring in the evenings, it is best to operate the fireplace with the doors closed to prevent
excessive room air from being drawn up the chimney. When the doors are open, the mesh screens should be closed
to help keep burning embers from popping out of the firebox.

Glass doors are mandatory on fireplaces installed in manufactured homes.
WARNING: Fireplaces equipped with glass doors should be operated only with the glass doors fully open or fully

closed. If doors are left partly open, gas and flame may be drawn out of the fireplace opening, creating risks of both
fire and smoke.

5

The fireplace also is equipped with a flue damper, which must be open when the fireplace is in use. The flue damper
control lever is located inside the fireplace. The counterweighted damper is operated by simply pushing up to open
or pulling down to close the damper. When the fireplace is not in use, the damper should be closed to prevent cold
air form entering the chimney as well as preventing warm air in the room from escaping up the chimney. NOTE: It
is normal for a small amount of smoke to be released from the upper portion of the fireplace the first few times you
use your new Monessen Hearth Systems fireplace. This results from an oil residue on the metal. Open a door or
window to allow the smoke to escape.

The grate included with this fireplace helps to appropriately locate and contain the burning wood. Failure to use this
grate may cause overheating of parts of the fireplace and allow large pieces of burning wood to roll forward out of the
firebox. If the grate becomes warped or damaged, it must only be replaced by a Monessen Hearth Systems 078355
grate.

All fireplace chimneys are in direct contact with cold air on the exterior of the structure. Consequently, when the
fireplace is not in use, cold air can fall down the chimney of the fireplace to cool off the fireplace chase. Therefore,
the fireplace chase must be insulated to minimize the risk of cold air infiltration to the home. Even if the fireplace
chase is adequately insulated, this cannot completely ensure that cold air infiltration into the structure will be eliminated.
Cold air infiltration is a possibility with any fireplace or device that freely communicates with the air on the outside of
the structure. Today’s homes are more energy-efficient and, therefore, better insulated and tightly constructed.
Unfortunately, when air is removed from the house, as by a bathroom fan, or consumed by a furnace, additional air
is needed to replace the air consumed. Unless the additional air is

4

53D9033. Rev 1 03/03

OPERATION GUIDELINES

6

supplied, this can cause a negative pressure in the home. When this happens, the house will draw in outside
air from the cracks in the windows, down the fireplace flue or other locations of air leakage in the home.
Because cold air infiltration may be unavoidable in some structures, Monessen Hearth Systems is not
responsible for heat loss or air infiltration through or around the fireplace.

CLEARANCES

FIGURE 1

ROUND CHIMNEY
CAP MODEL SC

612 ROOF
FLASHING

SF FIRESTOP SPACER
REQUIRES A 14-1/2" X
14-1/2" FRAMED OPENING.
(1-3/4" MINIMUM AIR SPACE
TO COMBUSTIBLES.)

CHIMNEY PIPE (2" MINIMUM
AIR SPACE TO COMBUSTIBLES)

MAY USE:
S12 (12 IN. LONG) PIPE,
S18 (18 IN. LONG) PIPE,
S36 (36 IN. LONG) PIPE,
S48 (48 IN. LONG) PIPE.

TOP SPACER

FP4U AIR DUCT
FOR AK4 KIT.

AK4 OUTSIDE
COMBUSTION
AIR KIT
(OPTIONAL)

TYPICAL FRAMING FOR

RESIDENTIAL HOME

INSTALLATION

38 1/2"

FRAMING

DIMENSION

NAIL TO FRAMING MEMBER.

25 3/4"
FRONT TO BACK
FRAMING DIMENSION

(TYPICAL FOR RIGHT SIDE.)

TLET

U

H

FLUE O

HEIG

STORM

COLLAR

16 FT. = MIN. HEIGHT (NO OFFSETS)

METAL SAFETY
STRIP

T

ROUND CHIMNEY
CAP MODEL SC

VENTED ATTIC SPACE

SVTR FIRESTOP THIMBLE.
REQUIRES A 14-1/2" X 14-1/2"
FRAMED OPENING.
(1-3/4" MINIMUM AIR SPACE
TO COMBUSTIBLES.)

16 FT. = MIN. HEIGHT (2-30∞ ELBOWS)

21 FT. = MIN. HEIGHT (4-30∞ ELBOWS)

CHIMNEY PIPE (2" MINIMUM

SUPPORT EVERY 30 FT.)

86 FT. = MAX. HEIGHT (SCS CHIMNEY

AIR SPACE TO COMBUSTIBLES)

MAY USE:
S12 (12 IN. LONG) PIPE,
S18 (18 IN. LONG) PIPE,
S36 (36 IN. LONG) PIPE,
S48 (48 IN. LONG) PIPE.

TOP SPACER

FP6U AIR DUCT
FOR AK6 KIT.

AK6 OUTSIDE
COMBUSTION
AIR KIT

TYPICAL FRAMING FOR

MANUFACTURED HOME

INSTALLATION

STORM COLLAR

612 ROOF
FLASHING

38 1/2"

FRAMING

DIMENSION

NAIL TO FRAMING MEMBER.

25 3/4"
FRONT TO BACK
FRAMING DIMENSION

(TYPICAL FOR RIGHT SIDE.)

TLE

U

H

G

I

FLUE O

HE

16 FT. = MIN. HEIGHT (NO OFFSETS)

METAL SAFETY
STRIP

MGD36B/MGD36PB
GLASS DOORS

T

T

16 FT. = MIN. HEIGHT (2-30∞ ELBOWS)

NOTICE:

COMBUSTIBLE MATERIALS SHOULD NOT BE INSTALLED BELOW TOP SPACERS OF
THE FIREPLACE. NONCOMBUSTIBLE MATERIALS SUCH AS BRICK OR TILE MAY BE
USED TO TRIM FACE OF THE FIREPLACE BUT SHOULD NOT COVER ANY AIR INLETS.
COMBUSTIBLES MUST NOT OVERLAP BLACK PAINTED SURFACES OF THE FIREPLACE.

53D9033. Rev 1 03/03

5

CLEARANCES

NOTE: DIMENSIONS MAY VARY SLIGHTLY DUE TO MANUFACTURING TOLERENCES.

S18

S36

S36

S36

S48

S18

S36

FIGURE 2 (ALL DIMENSIONS IN INCHES.)

1" AIR SPACE

25 3/4

FRAMING
DIMENSION

38 1/4

38 3/4

NAILING FLANGE

(EACH SIDE)

23 1/8

TOP

10 1/4

(REF)

9 1/2

25 1/4

1/2

FRONT FACE LINE

44

21 7/8

8

44 1/4

FRAMING
DIMENSION

FRONT

OUTSIDE AIR

GAS LINE

11 1/2

15 7/8

LEFT SIDE

JUNCTION BOX

GAS LINE

FRONT

8 3/4

FLOOR
LINE

OUTSIDE AIR

4 3/4

9 1/4

8 3/4

9 1/4

36

3/4

38

38 1/2

FRAMING DIMENSIONS

FLOOR
LINE

FRONT

FIGURE 3 (ALL DIMENSIONS IN INCHES.)

SE30
ELBOW

16 1/16

4 5/16

NOTE: DIMENSIONS MAY VARY SLIGHTLY DUE TO MANUFACTURING TOLERENCES.

9 13/16

S12

25 9/16

12 3/16

S18

30 3/4

21 13/16

46 3/8

6

3

S

27 13/16

S48

56 3/4

9 1/2

11 1/2

30 5/16

15 7/8

RIGHT SIDE

6

3

S

S18

3/4

61 1/16

39 5/16

FLOOR

LINE

6

3

S

S

6

3

76 11/16

6

53D9033. Rev 1 03/03

FIREPLACE LOCATION

CAUTION: Do not install fireplace over carpeting.

This fireplace does not weigh more than large pieces of furniture and can normally be located near a load
bearing wall without requiring additional foundations or supports. If however, the fireplace is to be trimmed
with a heavy stone or brick facing and hearth extension, be sure the supporting structure is adequate.

Figures 4 and 5 provide dimensional details of the fireplace, required spacing to combustible walls, and some
suggested fireplace locations. When selecting a location, choose one that is away from frequently opened
doors, central heat outlets or returns, or other places where air movements may disturb the airflow around the
fireplace. Air turbulence near the fireplace may cause smoke to spill out of the fireplace opening.

FIGURE 4 (ALL DIMENSIONS IN INCHES.)

INCH

51 3/8

(MIN)

17 5/16

(MIN)

1
AIR SPACE
CLEARANCE

25 3/4 (MIN)
FRAMING

DIMENSION

FIGURE 5

17 5/16

(MIN)

72 5/8

(MIN)

CORNER INSTALLATION

CORNER

20 3/4 (MIN)

22 (MIN)

SCREENED

OPENING

FULL PROJECTION

FLUSH

NAIL FLANGE
(EACH SIDE)

58 3/4

SIDE WALL INSTALLATION

53D9033. Rev 1 03/03

7

INSTALLATION PREPARATION

Survey the planned location for the fireplace for overhead plumbing or electrical wires, etc., that might complicate
the installation or endanger persons installing or cleaning the chimney. Avoid a location where the chimney
cap will be near abrupt changes in the roof shape, nearby wall or embankments, under or near trees or above
the roof of a single story wing of a two story building as shown by Figure 8. All these conditions can cause
turbulence or pressure conditions that can cause poor chimney draft and smoke spillage from the fireplace
opening. Elbows may be used to offset the chimney to avoid obstructions or to locate the chimney cap in a
preferred location. Refer to the sections of this manual pertaining to chimney offsets for instructions on proper
elbow use. Poor installation or location of the chimney cap and/or components can cause wind blown rain to
enter the chimney.

Be sure the selected location will allow a 14-1/2" square combustible material-free space for the chimney to
pass through. If the chimney is to pass through living or storage spaces, be sure there is adequate space to
enclose the chimney to avoid personal contact with, or damage to, the chimney. If the fireplace is to be
installed on an outside wall, the surrounding walls (chase) should be constructed and insulated as shown by
Figure 6. Failure to insulate the fireplace form outside temperatures will cause heat loss through and around
the fireplace.

JOIST INSULATE SAME AS CEILING

FIGURE 6

SCL TELESCOPING

CHIMNEY CAP

FLAT CHASE FLASHING
R3672 (36" x 72")

OR

R4884 (48" x 84")

SEE NOTES

SF FIRESTOP SPACER

NOTES:

1. MODEL SF FIRESTOP
SPACER MUST BE USED.

2. LOCAL CODES MAY NOT REQUIRE
FIRESTOPPING AT THE CEILING LEVEL
FOR CHASE INSTALLATIONS, BUT IT IS
RECOMMENDED FOR SAFETY AND
REDUCING HEAT LOSS.

3. DO NOT INSULATE THE CHASE WITH
BLOWN OR FILL TYPE INSULATION.
INSULATION SHOULD ONLY CONTACT
THE FIREPLACE AT POINTS WHERE
THE FIREPLACE WOULD NORMALLY BE

CONTACTED BY FRAMING MATERIALS .

8

53D9033. Rev 1 03/03

SOLID
SURFACE

8' 0"

LEVEL

CHIMNEY SECTIONS

"S" SERIES

INSULATE OUTSIDE
WALLS OF CHASE

SOLID CONTINUOUS

SURFACE

INSULATION

(THERMAL BARRIERS)

OUTSIDE BASE

INSTALLATION PREPARATION

FIGURE 7

SINGLE STORY INSTALLATION WITH ATTIC SPACE

SC CHIMNEY CAP

FLUE OUTLET HEIGHT

STORM COLLAR
(INCLUDED WITH CAP)

FLASHING

(612 OR 1212)

ATTIC SPACE

SEE TABLE 1 FOR
ROOF OPENING
SIZE

3 FT. MIN. HEIGHT,
AND 2 FT. MIN. ABOVE
ANY POINT WITHIN 10
FEET OF CHIMNEY.

NOTICE:

Chimney must be correct height above the roof
or other obstruction for safety and for proper draft
operation. The chimney must be at least 3 feet
higher than the highest point where it passes
through the roof and at least 2 feet higher than
the highest part of the roof or structure that is
within 10 feet of the chimney, measured
horizontally. See Figures 7, 9, and 14.

16 FT.

MIN.

FIGURE 8

SF FIRESTOP SPACER
(1 3/4" AIR SPACE
CLEARENCE TO
COMBUSTIBLES)

14 1/2" SQUARE
OPENING IN JOIST

2" MIN. CLEARENCE
TO COMBUSTIBLES

PREFERRED LOCATION

POOR LOCATION

INSTALLATION HEIGHT

SC CHIMNEY CAP

STORM COLLAR
(INCLUDED WITH CAP)

(612 OR 1212)

ATTIC SPACE

14 1/2" SQUARE HOLE

IN JOIST (1 3/4" AIR
SPACE CLEARANCE
TO COMBUSTIBLES)

86 FT. MAX.

*

2" MIN. CLEARANCE
TO COMBUSTIBLES
(TYPICAL ALL AROUND.)

FIGURE 9

MULTIPLE STORY INSTALLATION

FLUE OUTLET HEIGHT

3 FT. MIN. HEIGHT,
AND 2 FT. MIN. ABOVE

FLASHING

SEE TABLE
1 FOR ROOF
OPENING SIZE

ANY POINT WITHIN 10
FEET OF CHIMNEY.

SF FIRESTOP
SPACER

THIRD FLOOR AREA

SF FIRESTOP
SPACER

SECOND FLOOR AREA

14 1/2" SQUARE HOLE
IN JOIST (1 3/4" AIR
SPACE CLEARANCE

TO COMBUSTIBLES)

SF FIRESTOP
SPACER

FIRST FLOOR AREA

: SCS CHIMNEY SUPPORT REQUIRED EVERY 30 FEET OF INSTALLATION HEIGHT.

*

9

53D9033. Rev 1 03/03

FLOOR PROTECTION

If this fireplace is installed on a combustible floor, the floor area 16 inches in front of, and 8 inches either side
of the fireplace opening must be protected by an insulating noncombustible hearth extension. This hearth
extension may be either minimum 6-inch thick stone or brick as shown by Figure 10, a H1652 Hearth Extension
Kit or a locally constructed hearth equivalent to the H1652.

The insulation used in the H1652 hearth extension has a thermal conductivity (K Factor) of .43. If you do
construct a hearth extension equivalent to the H1652, be sure the insulation you use has enough compressive
strength to support the weight of the covering materials and persons standing on it, and insulating qualities
equal to or better than the ˚" covering provided by the H1652.

8"

MIN.

FIREPLACE

FIGURE 10

16"

MIN.

6"

MIN.

HEARTH

PLATFORM (PLATFORM MAY
EXTEND UNDER HEARTH
EXTENSION IF DESIRED.)

8"

MIN.

16"

MIN.

6"

MIN.

BRICK OR STONE
HEARTH EXTENSION

(52" LONG MIN.)

6"

MIN.

8"

MIN.

BRICK OR STONE
HEARTH EXTENSION

(52" LONG MIN.)

FIREPLACE

16"

MIN.

FIREPLACE

ALTERNATE BRICK OR STONE

HEARTH

DO NOT PLACE HEARTH MATERIAL
ABOVE OPENING OF FIREPLACE.

METAL SAFETY STRIP

HEARTH

PLATFORM (PLATFORM MAY
EXTEND UNDER HEARTH
EXTENSION IF DESIRED.)

HEARTH EXTENSION SHOWN WITHOUT
THE OPTIONAL MLK36 LOUVER KIT
INSTALLED ON THE FIREPLACE.

ALTERNATE BRICK OR STONE
HEARTH EXTENSION SHOWN WITH
THE OPTIONAL MLK36 LOUVER KIT
INSTALLED ON THE FIREPLACE.

DO NOT PLACE HEARTH
MATERIALS ABOVE OPENING

OF FIREPLACE.

METAL SAFETY STRIP

BRICK OR STONE
HEARTH EXTENSION

(52" LONG MIN.)

10

53D9033. Rev 1 03/03

METAL SAFETY STRIP

DO NOT BLOCK ANY LOUVERED OPENINGS

FLOOR PROTECTION

The ability of insulating material to retard the transfer of heat may be expressed as either Thermal Conduc­tance (C), Thermal Conductivity (K), or Thermal Resistance (R). The mathematical relationship of these
values and the formulas for converting one value to another is as follows:

C = K divided by the material thickness
(Example C = .43 divided by 1/2 (.50)
C = .86)
K = C multiplies by the material thickness
(Example K = .86 multiplied by 1/2 (.50)
K = .43)
R = The material thickness divided by K
(Example R = 1/2 (.50) divided by .43
R = 1.16)

FIGURE 12

FIREPLACE

HEARTH EXTENSION

16"

(MIN)

FIGURE 11

(MIN)

52"

METAL
SAFETY
STRIP

8" MIN. 8" MIN.

FLOOR LINE WITH
RAISED HEARTH.

WARNING: THE HEARTH EXTENSION AND THE METAL SAFETY STRIP
SHOULD BE INSTALLED ONLY IN A HORIZONTAL RELATIONSHIP TO
THE FIREPLACE, AS ILLUSTRATED.

16"
MIN.

METAL SAFETY STRIP

With either type hearth extension minor shifting of the supporting floor or expansion and contraction may
eventually cause a crack to develop between the hearth extension and the face of the fireplace. To help
prevent the crack from developing, the hearth extension materials must be firmly fastened in place. Wall ties
should be screwed to the face of the fireplace and imbedded in the mortar joints of brick, stone, or other non­combustible materials. The metal safety strip packed with the fireplace must be placed beneath the fireplace
and extended under the hearth extension or into a mortar joint of the hearth extension as shown by Figures 10,
11, and 12. In the event a crack does eventually develop, the metal safety strip will serve as a barrier to
prevent sparks or embers from falling from the fireplace onto combustible flooring materials.

The hearth extension must not block the side air vents, or air inlet louvers on the lower front of the fireplace.
These openings must be unobstructed to assure an adequate flow of cooling air around the firebox. If the
fireplace is equipped with a blower, or may be equipped with one at a later date, the hearth extension must not
prevent the removal of the lower louver panel for servicing the blower. Plan adequately by determining the
finished height of the hearth extension to be used and elevate the fireplace on a platform, if necessary, to
prevent obstructing the air openings or lower louvered panel.

53D9033. Rev 1 03/03

11

FIREPLACE COMPONENTS

FIGURE 13

MLK36 LOUVER KIT

612 OR 1212

FLASHING

AK4 OR AK6

COMBUSTION

AIR ASSEMBLY

MGD36B OR MGD36PB

GLASS DOOR KIT

SF FIRESTOP

SPACER

FP4U OR FP6U
UNINSULATED

FLEX PIPE

SCS
CHIMNEY
SUPPORT

SVTR FIRESTOP

THIMBLE

403 OR 603

DUCT CONNECTOR

SE30 30∞

ELBOW

SC ROUND

CHIMNEY CAP

H1652 HEARTH

EXTENSION KIT

FA2 FAN

ASSEMBLY

CF8

CHIMNEY CAP

12

53D9033. Rev 1 03/03

S48

S36

S18

S12