TOA Electronics CST38MH User Manual

INSTALLATION INSTRUCTIONS MANUAL

36" Wood Burning Fireplaces

P/N 700,033M, REV. C, 12/2006

Retain These Instructions

For Future Reference

Model CST38MH

This installation manual will enable you to obtain a safe, efcient and dependable installation of

Report No. 116-F-20-4

your replace system. Please read and understand these instructions before beginning your

installation.

Do not alter or modify the replace or its components under any circumstances. Any

modication or alteration of the replace system, including but not limited to the

replace, chimney components and accessories, may void the warranty, listings

and approvals of this system and could result in an unsafe and potentially

dangerous installation.

IMPORTANT! TO ASSURE PROPER ALIGNMENT OF

GLASS DOORS: INSTALL THIS FIREPLACE IN A

SQUARE AND PLUMB CONDITION, USING

SHIMS AS NECESSARY AT SIDES AND/OR

BOTTOM.

TABLE OF CONTENTS

Safety Rules ......................................Page 2

Tools and Building Supplies ..............Page 2

Precautions .......................................Page 2

Introduction ......................................Page 3

Clearances/Height Requirements ......Page 3

Chimney System ...............................Page 3

Assembly Outline ..............................Page 4

Location of Fireplace .........................Page 4

Assembly Steps ................................Page 5

Preinstallation Notes .........................Page 5

Clearances ........................................Page 5

Installing the Fireplace ......................Page 5

Fireplace and Framing Specifications Page 7

Framing Wall Variations ....................Page 8

Combustion Air Kits ..........................Page 8

Installing the Chimney System ..........Page 9

Ten Foot Rule Summary ....................Page 13

Chimney Component Calculations ....Page 13

Special Offset Instructions ................Page 13

Offset Elevation Chart ........................Page 14

Vertical Elevation Chart ....................Page 15

Offset Calculations ............................Page 16

Installing Offsets ...............................Page 16

30° Offset through Floor/Ceiling .......Page 17

Glass Doors ......................................Page 17

Gas Line Installation ..........................Page 17

Cold Climate Insulation .....................Page 18

Fireplace Finishes ..............................Page 18

Mantels and Trim ..............................Page 18

Hearth Extensions/Wall Shields.........Page 18

Finish Requirements .........................Page 20

Accessories And Components ..........Page 20

PACKAGING LIST:

The assembled wood fireplace is packaged
with:
1 - One envelope containing the literature pack-

age which consists of the homeowner's
manual, installation instructions, warranty
and combustion air cover (located in the

firebox).
2 - One Combustion Air Kit (90L83).
3 - Two Door Sets.

IMPORTANT: PLEASE READ AND
UNDERSTAND THESE RULES TO
FOLLOW FOR SAFETY.

SAFETY RULES:

WARNING

To avoid the risk of damaging
fireplace materials and increas­ing the risk of fire, do not use the
fireplace to cook or warm food.

2

1. Before starting your fireplace installation,

read these installation instructions carefully
to be sure you understand them completely
and in entirety. Failure to follow them could
cause a fireplace malfunction resulting in
serious injury and/or property damage.

2. Always check your local building codes.

The installation must comply with all lo­cal, regional, state and national codes and
regulations.

3. These fireplaces must be installed with

Security Chimneys FTF8 (8" inside diameter)
Chimney System only. These systems are
intended for use in any application where
a traditional masonry type fireplace would
apply. The chimney system must always
vent to the outside of the building.

4. To ensure a safe fireplace system and to

prevent the build-up of soot and creosote,
inspect and clean the fireplace and chimney
prior to use and periodically during the heat­ing season.

5. Burn approved fuels only as defined in the

Homeowner's Care and Operation Manual.

6. DO NOT use charcoal or coal under any

circumstances.

7. NEVER use gasoline, gasoline-type lantern

fuel, kerosene, charcoal lighter fluid, or
similar liquids to start or “freshen up” a fire
in this fireplace. Keep any flammable liquids
a safe distance from the fireplace.

8. NEVER leave children unattended when there

is a fire burning in the fireplace.

9. Always keep flue damper open when heat is

present in the fireplace.

10. Before servicing, allow the fireplace to cool.

Always shut off any electricity or gas to the
fireplace while working on it. This will prevent
any possible electrical shock or burns.

11. This fireplace is not intended to heat an

entire home or be used as a primary heat
source. It is designed to ensure homeowner
comfort by providing supplemental heat to
the room.

12. Always ensure that an adequate supply

of replacement combustion air from the
outside of the house is accessible to the fire
to support normal combustion. Fireplaces
consume large volumes of air during the
normal combustion process.

• In the event the home is tightly sealed with
modern energy efficient features, the com­bustion air kit (provided) may not provide
all the air required to support combustion.

• The manufacturer is not responsible for any
smoking or related problems that may result
from the lack of adequate combustion air. It
is the responsibility of the builder/contractor
to ensure that adequate combustion air has
been provided for the fireplace.

13. Always ensure that the air inlet to the fireplace
is free from debris and any other obstructions
that can block the entrance of air.

14.DO NOT use a fireplace insert or any other
product not specified by the manufacturer of
this LHP appliance for use with this fireplace.
All gas log sets must be operated with the
damper clamped open.

NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.

WARNING

This fireplace has not been tested
with an unvented gas log set. To
reduce risk of fire or injury, do not
install an unvented gas into
this fireplace.

15. "Smoke free” operation is not warranteed

nor are we responsible for inadequate sys­tem draft caused by mechanical systems,
general construction conditions, inadequate
chimney heights, adverse wind conditions
and/or unusual environmental factors or
conditions beyond our control.

16. Never, under any circumstances, install

a fireplace, chimney component or any
accessories, that has visible or suspected
physical damage as a result of handling
or transportation. These items should be
inspected by your distributor or qualified fac­tory representative to ensure safe condition.
When in doubt, consult your distributor.

17. For additional safety considerations and

complete operating instructions, refer to
the Care and Operation Manual provided
with the fireplace.

TOOLS AND BUILDING SUPPLIES

NORMALLY REQUIRED

Tools Supplies

Phillips screwdriver
Hammer
Saw and/or sabersaw
Level
Measuring tape
Plumb line
Electric drill and bits
Pliers
Square

PRECAUTIONS

The most important areas of concern dealing
with the installation of factory-built fireplaces
are clearances to combustible materials, proper
assembly of component parts, height of the
chimney system, the proper use of accessories
supplied by the manufacturer and the techniques
employed in using finishing materials applied to
the wall surrounding the fireplace, hearth exten­sions and wall shields. Each of these topics will
be covered in thorough detail throughout this
manual. Please give each your special attention
as you progress with your installation.

Note: These fireplace systems are not difficult
to install. However, in the interest of safety, it is
recommended that the installer be a qualified or
certified “tradesman” familiar with commonly
accepted fireplace installation and safety tech­niques as well as prevailing local codes.

Framing materials
Wall finishing materials
Caulking materials
(noncombustible)
Fireplace surround and
hearth extension
materials

(noncombustible)

INTRODUCTION
General Information

The CST38MH Series is a radiant-heat, two­sided fireplace with standard glass doors and
an outside combustion air kit is provided.

A steel grate is also included to properly posi­tion the fire and limit the amount of fuel. IF A

REPLACEMENT GRATE IS NEEDED REPLACE
THE GRATE WITH MODEL SGR-38B ONLY.

Note: Illustrations shown 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.

These fireplaces have been tested and listed
by OMNI Test Labs (Report No. 116-F-20-4) to
U.L. standard 127. These units are intended for
installation in Manufactured Homes, residential
homes and other buildings of conventional
construction including commercial.

These fireplace systems are designed for in­stallation in accordance with the National Fire
Protection Standard for chimneys, fireplaces
and solid fuel burning appliances; NFPA 211­latest edition and in accordance with codes
such as the BOCA Basic/National Codes, the
Standard Mechanical Code and the Uniform
Building Codes.

TYPICAL INSTALLATION

Chimney and
Termination

Firestop
Thimble

WARNING

Failure to use manufacture
provided parts, variations in
techniques and construction
materials or practices other than
those described in this manual
may create a fire hazard and void
the limited warranty.

WARNING

Do not pack or fill required air
spaces with insulation or other
material. No material is allowed
in these areas. Secure the
airspace around the chimney
with the firestop/thimble before
completing the installation.
Maintain 2" clearance between
chimney and thimble.

WARNING

If insulation is used, the fireplace
must not be placed directly
against it. Insulation or vapor
barriers, if used, must first be
covered with gypsum board,
plywood, particle board or other
material to assure insulation
and vapor barriers remain in
place.

When complete these fireplace systems con­sists of four basic “sub-systems”:

1. The Fireplace

2. The Chimney and Termination

3. Glass Doors

4. Combustion Air Kit

CLEARANCES AND HEIGHT
REQUIREMENTS

The fireplace opening must be kept a minimum
of 8" (203 mm) from a protected combustible
side wall. A perpendicular side wall can not be
closer that 18" (457 mm). If there is a continu­ous perpendicular side wall closer than 18" from
the fireplace opening, it must be protected with
a 40" x 40" x 1/2" (1016 mm x 1016 mm x 13
mm) wall shield constructed of a durable non­combustible material with an equal or greater
insulating value than k=.84 BTU IN/FT2 HR °F
(refer to Pages 18, 19 and 20).

As with all chimney installations, avoid overhead
obstructions such as trees, power lines, etc.
Additionally chimney terminations must meet
certain clearance to roof requirements detailed in
the paragraph titled Ten-Foot Rule Summary.

The fireplace and chimney system must be
enclosed when installed in or passing through
a living area where combustibles or people may
come in contact with it. This is important to pre­vent possible personal injury or fire hazard.

For questions, please call your distributor or
the manufacturer. Special restrictions apply to
the front and facing of the fireplace and nearby
walls (See Pages 18, 19 and 20).

CHIMNEY SYSTEM

These fireplaces are designed and code listed
for use with Security Chimneys FTF8 chimney
System only. Always use Security Chimneys
FTF8 chimney components with these fireplaces.
Do not modify or alter these components as
this may cause a potential serious hazard and
void the Warranty.

*Construction Materials:

• Framing Materials • Paneling

• Particle Board • Flooring

• Dry Wall • Plywood

• Noncombustible Insulating Materials

• Etc.

Chimney Height

The total height of your Fireplace systems from
the surface the fireplace rests on to the chimney
top must not exceed 80' (24.4m) and must also
meet minimum system height chart.

Figure 1

Outside Combustion Air Kit

The fireplace may be placed on or near normal
construction materials*. The combustion air
kit, firestop spacer and roof flashing (not chase
flashings) may be placed directly on or against
normal construction materials.* The chimney
and fireplace outer wrapper require a minimum
2" and 1/2" air space to combustibles respectively.
A combustible mantel may be installed 12" above
the opening of the fireplace as per NFPA 211­latest edition.

NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.

Minimum System Height

Security's FTF8 Pipe
Vertical Installation 15' 0"
One Offsets 16' 0"

Two Offsets 25' 0"

Table 1

3

Wall
Covering

Black Portion Of Frame

Not To Be Covered With

Combustible Materials

Safe

Zone

30°

11-3/8”

18”

Door

Opening

1”

Insulate Joists
Same As Ceiling

Draft Stops

Firestop

CTDT
Termination

Note: Non­Combustible
Chase
Flashing
Must Be
Used To
Cover
Chase
Opening

Optional
Insulation
In Outside
Walls Of
Chase

8'

Level

Ground Level

Damper

Closed

Damper
Open

Lintel

Solid

Fireplace

Continuous
Surface

Base

Insulation
(Thermal Barrier)

Base Requirements

Note: Local codes may not require firestopping
at the ceiling levels for outside chimney enclo­sure installations. However, it is recommended
for safety and the reduction of heat loss.

WARNING

Do not obstruct the collar open­ings around the base of the chim­ney at the top of the fireplace.
Do not insulate the chase cavity
with blown or fill type insulation
materials.

ASSEMBLY OUTLINE
Before You Start

Check your inventory list to be sure you have
all the necessary parts supplied in good us­able condition. Check also for any concealed
damage.

Check the operation of the damper. The damper
is controlled through the use of a control lever
located within the firebox opening at the top
center just behind the firebox lintel (Figure 3).
The control lever snaps into place at the extreme
range of motion, up and back in the closed
position. When pulled forward and down, the
damper is open.

Figure 4

WARNING

This fireplace and chimney
system is not approved for use
in a bedroom or any room used
for sleeping.

Carefully consider the position of the fireplace
opening with respect to the location of adjacent
or nearby stairwells, bath or kitchen exhaust
fans and/or return air registers for forced air
furnaces/air conditioners that could cause a
smoking fireplace condition if the house is
tightly insulated.

4

Front Face
Model Shown

Figure 2

Chimney Enclosure

Construct a box-like framed structure to enclose
the fireplace and chimney within the confines
of the manufactured home, not necessarily
above the roof line.

As with all chimney installations, avoid overhead
obstructions such as trees, power lines, etc.
The chimney/fireplace enclosure should be
constructed and insulated just like any outside
wall. In a cold climate, we recommend the base
of the chimney/fireplace enclosure should also
be insulated between the solid continuous floor
beneath the fireplace and the chase bottom.
Insulation in a cold climate installation is not
required for safety.

When locating the fireplace, consideration must
be given to combustibles and final finishing. For
an example of this, see Figure 5 and confine
the final location of combustible finish materials
to the "Safe Zone".

DO NOT permanently place furniture or other
items such as decorative pillows within 60" of
the fireplace front face.

Figure 3

LOCATION OF FIREPLACE

Carefully select the proper location for heat
circulation, aesthetics, chimney obstructions
and clearance to side wall(s). With proper pre­planning, a slight adjustment of a few inches
can save considerable time and expense later
during construction and assembly.

Figure 5 - Clearances

NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.

ASSEMBLY STEPS

Hearth
Extension

Floor

Hearth
Extension

Metal Safety

Strips

Floor

Hearth
Extension

Floor

Hearth
Extension

Metal Safety

Strips

Platform

Note: 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. Install the chimney system.

3. Install outside combustion air kit.

4. Plumb gas line if a decorative gas appliance

will be used. (Gas connections should only
be performed by an experienced, licensed/
certified tradesman).

5. Install both “All-GlassTM” door assemblies.

6. Complete finish wall material, surround and

hearth extension to your individual taste.

7. Inststall the glass doors provided.

Study the three dimensional illustration (Figure

1) to get a general idea of each element of your
fireplace system.

PRE-INSTALLATION NOTES

2. Measure the square footage of the floor space

to be occupied by the system, surrounds and
hearth extensions.

3. Note the floor construction, i.e. 2 x 6’s, 2 x

8’s or 2 x 10’s, single or double joists, type
and thickness of floor boards.

4. Use this information and consult your local

building code to determine if you need ad­ditional support.

CAUTION

Do not block the heat-circulating
air inlet and outlet ports. Doing
so may result in a potential fire
hazard.

CAUTION

The structural integrity of the
manufactured home floor, wall,
ceiling and roof must be main­tained.

INSTALLING THE FIREPLACE

Step 1. Slide the fireplace into prepared framing

or position fireplace in its final position
and frame later.

The fireplace may not be recessed into a
combustible floor. Maintain the floor to hearth
clearance established by the fireplace lower
front face.

Step 2. Insert the provided metal safety strips,

beneath the fireplace as illustrated
(Figures 6 and 7). The safety strips
should overlap 1/2" for continual
coverage of the floor.

Note: Safety strips are not required when fire­place rests on a noncombustible surface.

The fireplace may be installed directly on a
combustible floor or raised on a platform of
an appropriate height. Do not place fireplace on
carpeting, vinyl or other soft floor coverings. It
may, however, be placed on flat wood, plywood,
particle board or other hard surfaces. Be sure
fireplace rests on a solid continuous floor or
platform with appropriate framing for support
and so that no cold air can enter the room from
under the fireplace.

The fireplace may be positioned and then the
framing built around it, or the framing may be
constructed and the fireplace positioned into
the opening.

Usually, no special floor support is needed for
the fireplace, however, to be certain:

1. Estimate the total weight of the fireplace

system including chimney and surround
materials such as brick, stone, etc., to be
installed. Shipping weights for the fireplace
may be found on Page 7.

The firestop thimble supplied with the unit must
be used on a manufactured home installation.
The firestop thimble must extend completely
though the roof cavity to the outermost plane
of the roof (See Figures 21, 22 and 23).
Maintain 1" clearance between the thimble and
the chimney.

If you plan to raise the fireplace and hearth
extension, build the platform assembly then
position fireplace and hearth extension on
top. Secure the platform to the floor to prevent
possible shifting.

CLEARANCES

Minimum clearance to combustibles for the
appliance is as follows: sides - 1/2" (12.5 mm),
floor - 0" (0 mm), adjacent wall - 18" (457 mm),
ceiling - 37-1/2" (953 mm).

Figure 6

Figure 7

Note: Install the hearth extension only as il-

lustrated.

NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.

5

Metal
Safety Strips

2" Min.

(51 mm)

Platform

Metal
Safety Strips

*

2" Min.

(51 mm)

*

*

4 x 6 Header

Spacer

2 x 4 False
Header

No Combustible
Materials in
Shaded Areas

No
Combustible
Materials in
Shaded Areas

IMPORTANT

Under no circumstances can the
fireplace top spacers (Figure

13) be removed or modified,
nor may you notch the header to
fit around or be installed lower
than the spacers. The header
may be in direct contact with
the top spacers but may not be
supported by them.

Figure 8

Figure 9

The safety strips should extend in front and
sides of the fireplace opening 2" (51 mm) . In
the event a wooden support is used to elevate
the fireplace above the floor, a “Z” type safety
strip should be fabricated and used to protect
the front surface of the wood support as well
as the floor beneath the hearth extension (see
Figures 8 and 9). The safety strips should be
tacked down to prevent possible movement.

Figure 10

If the appliance is to be elevated above floor
level, a solid continuous platform must be
constructed.

The header may rest on the top metal spacers,
but must not be notched to fit around them.

Consult all local codes.

Figure 11

Figure 12

6

Note: The “Z” type safety strip is not sup­plied.

Step 3. Refer to fireplace drawings and speci-

fications on Pages 7 and 8 for framing
dimensions and details. False header
may be positioned directly on top of
the fireplace spacers (see Figures 10,
11 and 12).

NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.

7" Min.

(178 mm)

23 ¹⁵⁄₁₆"

(608 mm)

42 ³⁄₄"

(1086 mm)

49"

(1245 mm)

40 ¹⁄₄"

(1022 mm)

4 x 4

Header

2 x 4

False Header

(Optional)

42 ³⁄₄"

(1086 mm)

49"

(1245 mm)

FIREPLACE SPECIFICATIONS

39-1/4"

(997 mm)

23-15/16"

(608 mm)

25-3/16"

(640 mm)

8"

(203 mm)

Front View

Top View

End View

12-1/2"

"

(318 mm)

48-3/4"

(1238 mm)

8-9/16"

8-13/16"

(217 mm)

3-7/8"

(98 mm)

42-1/2"

(1080 mm)

(224 mm)

Outside (combustion)
Air Inlet

12-1/2"

(318 mm)

48-3/4"

(1238 mm)

10-1/2"

(267 mm)

5-3/4"

(146 mm)

21"

(533 mm)

5-1/4"

(133 mm)

32"

(813 mm)

39-1/4" (997 mm)

38" (965 mm)

FOAK-6 Outside
Air Kit (provided)

Right Side of
Fireplace

Product Reference Information

Cat.

Model Ship.

No.

H4629 CST38MH 237 lb. 29.6 cu. ft.

Due to Lennox' ongoing commitment to quality,
all specifications, ratings and dimensions are
subject to change without notice.

All framing dimensions calculated for 1/2" dry wall
at the fireplace face. If sheathing the chase or
finishing with other thickness materials, calcula­tions will need to be made.

See Page 8 for Ceiling and Roof Framing
Dimensions

Diagrams & Illustrations Not to Scale

OTL Report No. 116-F-20-4

Weight

Notes

Ship.

Volume

Outside (combustion) Air Kit

Required in Manufactured Home Installations

Figure 13

NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.

End View

Front View

7

FRAMING WALL VARIATIONS

A

B

Ceiling Framing

C

D

Roof Framing

Nailing
Flange

Framing
Stud

As many as six (6) different framed wall con­figurations can be constructed to enclose the
Fireplaces. The following illustrations depict
these variations of wall enclosures. Several of
these designs may incorporate book shelves,
wood storage boxes, etc.

CST38MH - Wall Types

Framing Dimensions for Ceiling

Framing Dimensions for Ceiling

Inches (millimeters)

Figure 17

Figure 14

“C” Type Wall

“T” Type Wall

“L” Type Wall

“H” Type Wall

“Y” Type Wall

Parallel Wall

Flue Type A B

FTF8, Vertical
at 2" (51 mm)

FTF8 Offset 30°

At 2" (51 mm)

16 1/2"

(419 mm)

16 1/2"

(419 mm)

16 1/2"

(419 mm)

27"

(686 mm)

Figure 15

Framing Dimensions for Roof

Inches

FTF8 at 1" (USA)

Pitch

0/12
6/12

12/12

* Perpendicular to roof ridge

C D*

16 1/2" 16 1/2"

16 1/2"

16 1/2"

19"

23 1/2"

Figure 16

Step 4. The fireplace should be secured to side
framing members using nailing tabs. Use 8d
nails (Figure 17).

Note: The nailing tabs are exempt from the
fireplace clearances described on the fireplace
clearance label.

INSTALL THE COMBUSTION AIR KIT

(required in Manufactured Home installations)

Outside air drawn into the fireplace supplies
air to the fire for combustion. The outside air

kit (FOAK-6, Cat. No. 90L83) must be installed
before the fireplace is framed and enclosed in
the finished walls.

Install the air intake Collar (provided) as shown
in Figure 18.

There is a one-hand operated shut-off valve
located in the enclosed corner of the fireplace
opening behind the screen. Refer to label for
directions of operation. The combustion air
damper should be fully open when the fireplace
is in operation and fully closed when the fire­place is not in use to prevent outside air from
entering your home.

Connect the 6” (152 mm) Class 0 or Class 1 air
duct to the outside air collar on the appliance
with the tie strip in the outside air kit (provided).
See Figure 18.

Route the Class 0 or Class 1 air duct out the
back or side wall, up through the ceiling or floor
joists to an outside wall. The air duct should be
located above snow level.

Outside combustion air may be run upwards
or vertically through framing and ceiling joists,
with the hood installed through an outside
wall and 3' (914 mm) below the termination.
Ducting may also be run downward through
floor joists and under the home to a ventilated
crawlspace not considered part of the living
area of the home.

8

NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.