Monessen Hearth M400BFC Mounting instructions

647
BFC cover
8/18/00 djt
M400BFC
Balanced Flue (Closed Combustion)
Heat-Circulating Fireplace
For use in the U.S. / Canada
Underwriter’s Laboratories
Report No. MH7603
DO NOT DISCARD THIS MANUAL: Retain for future use.
87D1505 12/09 Rev. 3
Homeowner’s Installation and
Operating Manual

2
M400BFC Balanced Flue Heat-Circulating Fireplace
87D1505
M400BFC
Listed
UL127 / ULC-S610
Standard for Factory Built Fireplaces
Safety Information ......................................................................................3
Specifications and Framing .......................................................................4
Parts Identification ....................................................................................6
Chimney Requirements ............................................................................7
Planning Information ..................................................................................8
Installation .................................................................................................9
Replacement Parts ..................................................................................19
Accessories .............................................................................................21
Warranty...................................................................................................23
Table of Contents

3
M400BFC Balanced Flue Heat-Circulating Fireplace
87D1505
Safety Information
Please Read This Manual Before Installing and Using Fireplace
IMPORTANT: Read all instructions and warnings carefully before starting installation. Failure to follow these instruc-
tions may result in a possible fire hazard and will void the warranty.
Description
The M400BFC fireplace is a solid fuel, woodburning
fireplace. The M400BFC is a balanced flue (closed
combustion) heat-circulating fireplace which receives
outside combustion air through the chimney system.
The M400BFC is a decorative fireplace which provides
efficient supplemental heat compared to other wood
burning fireplaces. It should not be used as a primary
source of heat.
CAUTION: Overloading the firebox with wood may re-
sult in overfiring and damage to refractory components,
the grate and doors.
Precautions
MHSC fireplaces and component parts have been
thoroughly tested and will operate safely when installed
in accordance with instructions provided in this manual.
Carefully read and understand all instructions before
beginning installation.
If you notice any damage to fireplace or component
parts, immediately report damage to your Monessen
dealer.
Only use MHSC components or the warranty will be
voided and a fire hazard may be created.
MHSC warranty will be voided by and MHSC disclaims
any responsibility for the following actions:
• Installation by any other than a qualified
installer, preferably NFI or WETT (Canada)
certified.
• Installation of any damaged fireplace or chim-
ney component;
• Modification of fireplace, chimney assembly
or any component parts thereof; (except for
chase flashings as detailed in MHSC Chimney
Top installation instructions).
• Installation other than as instructed by MHSC;
or
• Installation and/or use of any component part
not manufactured or approved by MHSC in
combination or assembly with a MHSC fire-
place system, notwithstanding any indepen-
dent testing laboratory or other third party
approval of such component parts or acces-
sory.
Any such action may possibly cause a fire hazard.
Consult local building codes to ensure that you are in
compliance before installing the fireplace.
This fireplace and chimney system must be vented to
the out-of-doors.
Do not obstruct or modify air inlets/outlets in any
manner.
Do not install combustible materials on any of the
black fireplace surround.
Burn only solid wood fuel or gas logs.
The M400BFC is intended for operation only with
the doors closed.
Do not install a solid fuel burning insert or other
products not specified for use with this fireplace.
Drafts
The fireplace should not be located in areas that create
drafts (ie: frequently opened doors and central heating
air inlets/outlets) that hamper the normal flow of air into
the fire.
Gas Logs
If you plan to install a gas log, the gas line should be
installed before framing the fireplace. The gas line must
be installed by a certified gas line installer.
Proposition 65 Warning: Fuels used in gas, wood-
burning or oil fired appliances, and the products of
combustion of such fuels, contain chemicals known
to the State of California to cause cancer, birth de-
fects and other reproductive harm.
California Health & Safety Code Sec. 25249.6
WARNING: Check with your electronics manufac-
turer before installing a television or other electron-
ic device above this fireplace.

4
M400BFC Balanced Flue Heat-Circulating Fireplace
87D1505
M400BFC Balanced Flue Heat-Circulating Fireplace
Fig. 1 M400BFC specifications and framing.
6" (16mm)
56O" (13mm)
56O"
326"
(829mm)
41(6" (1064mm)
6"
(16mm)
56QE"
(49mm)
" (914mm)
"
(533mm)
56QE" (176mm)
56QE" (179mm)
Recessed
Nailing
Flange
647
BFC36 specs
8/18/00 djt
1356O" Dia.
(343mm)
Rough Opening Width 43"
Rough
Opening
Height
Rough
Opening
Depth
Gas Line
Access
5156QE" (1297mm)
5156QE"
(1297mm)
6QE" (1834mm)
6M"
(197mm)
23"
(584mm)
"
(610mm)
6QE"
(624mm)
3956M"
(997mm)
556QE"
(246mm)
35"
(889mm)
"
(279mm)
Gas Line
Access
56O"
(902mm)
36"
(914mm)
(1092mm)
11" Dia.
(179mm)
8" Dia.
(203mm)
56" (918mm)
A
B
C
FP1531
hearth dimensions
9/04 djt
Front Width Back Width Depth
A B C
M400BFC 32Z\x" 20M\zn" 17C\v"
(826 mm) (519 mm) (451 mm)
FP1531
Fig. 1a Hearth dimensions.

5
M400BFC Balanced Flue Heat-Circulating Fireplace
87D1505
FP554a
BFC
Fireplace and chase parts identification
circulating model
8/21/00 djt
Termination Cap
Storm Collar
Pan Flashing
Draftstop
Standoff
Surround
Trim Ledge
Standoff
Glass Door
Romex Pigtail
Gas Line Access Knock-
out (Each Side)
Air Inlet
Basket Grate
Bottom Grille
Metal Safety Strip(s)
Shown not inplace
(1,2 or 3 pieces)
Nailing Flange
Top Grille and Air Outlet
Gas Line Ac-
cess Hole
(Each Side)
Ceiling Level
Firestop
Batt Insulation
(Cut out around
firestop)
FP554c
Fig. 2 Fireplace and chase parts identification.

6
M400BFC Balanced Flue Heat-Circulating Fireplace
87D1505
D
Rise
BG
H
B
Offset
C
E
6 FT.
G
H
A
Hearth
Floor
Chimney
Section
CHIMNEY FLUE EXIT
Elbow
FP269
MBUF
5/16/96
rev. 5/25
TCS8A
Support
Example 1 Example 2 Example 3
Chimney Requirements - Offset Installations
Notes: G + H cannot exceed 20 feet.
Air Space Clearances: = 2” Min. to Combustibles
Illustration Key
The following safety rules apply to
offset installations (letters correspond
with illustration above):
A. Height of the chimney is measured
from the hearth to the chimney exit.
M400BFC
Maximum: 50’0”
Minimum:
Without Elbows 14’6”
With 2 Elbows* 14’6”
With 4 Elbows* 21’0”
B. Do not use more than 4 elbows per
chimney.
Attach the straps of the return (top)
elbow to a structural framing member.
The offset (first) elbow of any pair does
not have straps.
FP269
C. The chimney cannot be more than 30°
(45° in Canada) from the vertical plane in
any installation*.
D. The maximum length of the angled run
of the total chimney system is 20 feet. (G
plus H cannot exceed 20 feet.)
E. A chimney support (Model TCS8A)
is required every 6 feet of angled run of
chimney. Chimney supports are required
for every 30 feet and 60 feet of vertical
chimney height above the hearth.
Determine the offset distance of your
chimney arrangement from the centerline
of the fireplace to the centerline of the
chimney where it is to pass through the
first ceiling.
NOTE: This offset distance may not be
your full offset distance. See Examples 2
and 3.
Fig. 3 Chimney system requirements.
IWF282
0 0 0 0 0 3” 11”
1 0 0 0 0 8Z\v" 20"
0 1 0 0 0 11Z\v" 25Z\v"
2 0 0 0 0 13Z\x" 29Z\v"
1 1 0 0 0 16Z\x" 34Z\v"
0 0 1 0 0 20Z\v" 40C\v"
2 1 0 0 0 21C\v" 43Z\x"
0 0 0 1 0 26Z\v" 51Z\v"
0 1 1 0 0 28Z\x" 55Z\v"
1 0 0 1 0 31Z\x" 60Z\v”
0 1 0 1 0 34Z\x" 65Z\x"
0 0 2 0 0 37Z\x" 70C\v"
1 1 0 1 1 41Z\x" 77C\v"
0 0 1 1 1 45" 83C\v"
0 1 2 0 1 47Z\v" 87Z\x"
0 0 0 2 1 51" 94"
0 1 1 1 1 53Z\v" 98"
0 0 3 0 1 56Z\v" 103Z\v"
0 1 0 2 1 59Z\v" 108Z\x"
0 0 2 1 1 62Z\v" 113Z\x"
0 1 3 0 1 64Z\x" 117Z\x"
0 0 1 2 1 68Z\v" 124"
0 1 2 1 1 70Z\x" 128"
0 0 0 3 1 74Z\v" 134Z\x"
0 1 1 2 2 78" 140C\v"
0 0 3 1 2 81" 146"
0 1 0 3 2 84" 151Z\v"
0 0 2 2 2 87" 156Z\x"
0 1 3 1 2 89Z\v" 160Z\v"
0 0 1 3 2 93" 166C\v"
0 1 2 2 2 95Z\v" 170C\v"
0 0 0 4 2 99Z\v" 177C\v"
0 1 1 3 2 101Z\v" 181C\v"
0 0 3 2 2 104Z\v" 186Z\v"
0 1 0 4 2 107Z\v" 191Z\x"
0 0 2 3 2 110Z\v" 196C\v"
0 1 3 2 3 114" 203Z\v"
0 0 1 4 3 117C\v" 209C\v"
0 1 2 3 3 120" 213Z\x"
0 0 0 5 3 123C\v" 220"
30˚ Elbow Offsets
1’ 1¹⁄₂'3’ 4’
Chimney Support
Offset Rise
FP282
MBUF
5/26/96
Offset
Rise
30°
Return
Elbow
30°
Return
Elbow
30°
Offset
Elbow
30°
Offset
Elbow

7
M400BFC Balanced Flue Heat-Circulating Fireplace
87D1505
Planning Information
Preplanning an installation is very important to ensure
safety and to save time and money. An installer must
predetermine where a fireplace will be set and how the
chimney system will be run.
Mounting the Fireplace
A fireplace may only be mounted on the following sur-
faces:
1. A flat combustible surface.
2. A raised wooden platform.
3. A concrete block or other solid object placed be-
neath each of the four (4) corners of the fireplace.
The fireplace must be spaced 1” (25 mm) from a com-
bustible back wall and 1/2” (13 mm) from a combustible
side wall or support. (Page 13, Fig. 17)
Planning the Chimney Run
Determine how the chimney will be run, length of run
and chimney components required to complete the
job. (Fig. 4) Never install a chimney below minimum
heights.
In planning a chimney system, it is important to know:
1. The height of a chimney is measured from the
hearth to the exit point on the termination.
2. A chimney cannot be offset more than 30° from a
vertical plane.
3. A chimney may run straight up or it may be neces-
sary to offset it to avoid obstructions.
4. The maximum length of an angled run (total chimney
system) is 20’ (6 m).
5. No more than 2 offsets (4 total 30° elbows in U.S./or
2 total 45° elbows in Canada) per fireplace may be
used.
6. A guy wire stabilizer is required for chimneys extend-
ing more than 6’ (1.8 m) above a roof line.
The Ten Foot Rule
Major U.S. building codes specify a minimum chimney
height above the roof top. The “Ten Foot Rule” is a fire
safety rule and not a draft rule. To ensure proper draft,
it is recommended that you always meet or exceed the
“Ten Foot Rule,” especially when installing a termination
on a high pitch roof. (Fig. 5)
The key points of the “Ten Foot Rule” are:
1. If the horizontal distance from the chimney to the
peak of the roof is 10’ (3 m) or less, the top of the
chimney must be at least 2’ (610 mm) above the
peak of the roof, but never less than 3’ (914 mm)
in height above the highest point where it passes
through the roof.
2. If a horizontal distance from the chimney to the peak
of the roof is more than 10’ (3 m), a chimney height
reference point is established on the surface of the
roof a distance of 10’ (3 m) from the chimney in a
horizontal plane. The top of the chimney must be
at least 2’ (610 mm) above the reference point, but
never less than 3’ (914 mm) in height above the high-
est point where it passes through the roof.
L1
L1
LTTOTAL
LENGTH
(LT)
INSTALLED
LENGTH
(L1)
56O"
56O"
56O"
56O"
56O"
56O"
56O"
56O"
FP288A
MBUF-INSTALLED LENGTH
Triple wall
1/28/99 djt
TRIPLE
WALL
81
818
83
84
FP288a
Fig. 4 Installed lengths of chimney sections.
2’ Min.
2’ Min.
3’
Min.
0 To 10’
3’
Min.
0 To 10’
AC246
4/1/96
Reference
Point
AC246
Fig. 5 Ten Foot Rule illustration.

8
M400BFC Balanced Flue Heat-Circulating Fireplace
87D1505
Chimney Supports
The chimney system is supported by the fireplace for
vertical chimney heights less than 30’ (9 m) above the
hearth. Chimney supports are required if the vertical
height exceeds 30’ (9 m). Locate chimney supports
at ceiling holes or other structural framing at 30’ (9 m)
heights. Spacing between chimney supports must
not exceed 30’ (9 m). Use Chimney Support Model
TCS8A. (NOTE: The TCS8A cannot be mounted
directly to the fireplace.) Support provided by elbow
straps fulfills the support requirement only if they are
spaced as previously described. (A chimney support is
2Z\x" (64 mm) long when installed.)
Angled chimney runs require a support every 6’ 1.8 m)
in addition to the elbow straps. Chimney supports are
used for this function. (Fig. 6)
FP284a
TCS8A
8/21/00
Chimney Sup-
port Strap
TCS8A FP284a
Fig. 6 Chimney support installation.
Chase Installation
A chase is a vertical box-like structure which encloses
the fireplace and/or chimney. Chases are typically built
on the outside of the house with fireplace opening cut
into the outer wall of a room. (Page 4, Fig. 2)
If you need help in determining fireplace location or
how the chimney system should be run, contact your
Monessen dealer for assistance.
Installation
Insulating Fireplace Enclosure
for Cold Climates
If you live in a cold climate, it is not required but
highly recommended that you insulate fireplace
enclosure to eliminate cold air penetration as much
as possible.
Insulate base of fireplace with a noncombustible
insulation rated for a minimum of 300°F. Insulating
is very important for outside wall installations over
a concrete slab. If fireplace is installed on a platform,
insulation should be placed on top of the platform
before fireplace is set. (Fig. 7)
When a fireplace is installed in a chase or on a
outside wall, enclosure should be treated like any
outside wall in a home. Insulation should be installed
on the inside wall as well as the outside wall(s). In
a chase, it is also a good idea to install a firestop at
the first ceiling level above the fireplace and enclose
the chase with sheeting material. Insulation may
then be installed above sheeting material to assure
the space around the fireplace is totally protected.
(Fig. 2)
When installing the chimney, DO NOT caulk be-
tween outer pipe and firestop. It is vital that some air
be allowed to flow through this very thin gap.
CAUTION: When installing a fireplace in an insu-
lated enclosure, be sure all required air spaces
are maintained. (Page 13, Fig. 17)

9
M400BFC Balanced Flue Heat-Circulating Fireplace
87D1505
FPC555a
Platform insulation
BFC model
8/21/00 djt
Hard Flat
Surface
Insulation
Platform
FPC555a
Fig. 7 Insulating between platform and fireplace.
Framing
Framing can be constructed before or after the fireplace
is set in place, however, most installers build the frame
before setting the fireplace.
Frame fireplace with 2 x 4 lumber or heavier materi-
als. Refer to framing dimensions in Figure 1 for basic
fireplace specifications.
NOTE: Framing should be positioned to accommodate
wall covering and fireplace facing material.
Installing Electrical Wire
The fan requires 120VAC, 60 Hz power which may be
connected to the right side of the fireplace using the
romex pigtail provided with teh unit. This power must
be completed before the fireplace is secured and finish
material applied.
1. Attach the white wire from house power to the white
wire of the romex pigtail and secure with a wire nut.
2. Attach the black wire from the house power to the
black wire of the romex pigtail and secure with a
wire nut.
3. Attach the ground wire from house power to the
ground wire of the romex pigtail and secure with a
wire nut. (Fig. 8)
IMPORTANT: The wire nuts must be tight.
NOTE: Check local building codes to determine if
junction box is required at the romex pigtail/house wire
connection Also check junction box and speed control
(SCVS) installation instructions.
The Model FKSX-A blower assembly is preinstalled in
the M400BFC.
FP1062
romex pigtail
8/21/00 djt
Romex Pigtail
(Provided)
Fireplace Electrical
Coverplate
Wire Nuts
(Not pro-
vided)
Ground
Black
White House
Wiring
(120V
60Hz)
FP1062
Fig. 8 Wiring diagram.
Chimney Set-up
Since you have already preplanned the chimney run,
you should know exactly how the installation is to
be accomplished — how much pipe is required, the
number of elbows, if any, and type of termination to be
used.
CAUTION: REPORT TO YOUR DEALERS ANY
PARTS DAMAGED IN SHIPMENT, SPECIFICALLY
CHECK THE END CONNECTION OF CHIMNEY SEC-
TIONS AND ELBOWS.
NOTE: The M400BFC fireplace must use MHSC Model
triple wall 8” chimney components only. The installation
procedure described in this manual applies only to this
system.
Straight-Up Chimney Installation
To mark the centerline of the flue, put the fireplace in
final position and measure out from the wall: 8C\v" (222
mm). Mark a spot on the ceiling directly above the fire-
place. Draw a line parallel to the back wall through this
mark. (Fig. 9)
Using a plumb bob positioned directly over center point
of fireplace flue collar, mark the ceiling to establish the
chimney center point. (Fig. 9)

10
M400BFC Balanced Flue Heat-Circulating Fireplace
87D1505
Offset Installation
In order to clear an obstruction, it may be necessary to
offset chimney from vertical. This is accomplished by
using elbows. Use the 30° Offset Elbow table on Page
5 to determine proper offset and parts required.
Each offset requires two (2) elbows. The second elbow
is equipped with support straps. It is very important to
install the second elbow in each offset as close to the
ceiling or support as possible so that the elbow straps
can be secured to framing members to help support the
weight of the chimney.
Determine offset distance of your chimney arrangement
from centerline of fireplace to centerline of chimney
where it is to pass through ceiling.
Locate center point of the chimney on ceiling as though
a straight up chimney arrangement is to be used. Mea-
sure your offset dimension from straight up chimney
center point on ceiling.
Ceiling Chimney Hole/
Possible Obstructions
The size of the hole in ceiling will vary with the angle at
which the chimney passes through ceiling.
Drive a nail up through ceiling at marked chimney cen-
ter point. Go to floor above and see where hole will be
cut. Check to see where existing ceiling joists and other
possible obstructions are located...i.e. wiring, plumbing
etc... If necessary, re-position chimney and/or fireplace
to avoid obstructions.
Cutting the Hole
Cover fireplace collar opening and cut proper sized
chimney hole in chimney.
Framing the Ceiling Hole
Frame the ceiling chimney hole as shown in Figure
10. It is good practice to use framing lumber that is the
same size as the ceiling joists; this is a requirement at
attic level.
The inside dimension of the frame must be the same
as the hole size selected from Figure 11 in order to
provide required the 2” (51mm) air space between the
outside diameter of the chimney and the edges of the
framed ceiling hole.
FPC556a
BFC36
LOCATE CENTER LINE
Circulating model
8/21/00 djt
86M"
(222mm)
Chimney Centerline
Actual Center-
point
Plumb Line
Plumb Bob
Imaginary Center-
point
FPC556a
Fig. 9 Locate centerline of chimney with plumb line.
The following table gives firestop spacer model num-
bers:
Chimney Hole Size
Angle of Chimney
at Ceiling
Size of Chimney Vertical 30°
FS2A FS6A
8” Flue 17Z\x” x 17Z\x” 17M\₈” x 29⁵\₈”
(445 x 445mm) (454 x 753mm)
New
Framing
Members
Existing
Ceiling
Joists
Fig. 10 Typical frame for ceiling chimney hole.
FP551b
17 1/2"
Framing chimney hole
5/13/99 djt
Ceiling
Chimney
Hole
17Z\x”
(445mm) 17Z\x”
(445mm)
FP551b
Fig. 11 Ceiling chimney hole sizes necessary for installing
firestop spacer.

11
M400BFC Balanced Flue Heat-Circulating Fireplace
87D1505
Positioning, Safety Strips,
Securing the Fireplace
Slide fireplace into position.
Lift the fireplace front slightly and slide the metal safety
strips under front bottom edge about 1Z\x” (38 mm),
allowing the remainder to extend in front of firebox.
Overlap strips at least 1/2” (13 mm) to provide a posi-
tive joint. (Flat safety strips are packed with fireplace.)
(Fig. 12)
Safety strips are used to ensure that any combustible
materials in front of the fireplace are protected even
though a non-combustible hearth extension is required.
If fireplace is to be elevated above the floor, a “Z”
shaped metal safety strip must be fabricated and used
to protect combustible surfaces in front of the fireplace.
This “Z” shaped safety strip is not provided but must be
fabricated of metal with each horizontal leg at least 1Z\x”
(38 mm) wide and equal in length to the metals strips
provided with the fireplace.
NOTE: Safety strips are not required over non-com-
bustible floors where all supports at the base of the
fireplace are noncombustible.
Four (4) nailing flanges are supplied with the fireplace
(found on the fireplace hearth). To level the box and
secure it firmly in place, remove the nailing flanges from
the hearth and install at the sides of the fireplace as
shown in Figure 13.
FPC549a
BFC
Nail flange/standoff
circulating models
8/21/00 djt
Nail Top
Standoffs
Nail Side-
Nailing
Flanges
FPC549a
Fig. 13 Fasten fireplace in position.
WF557
BR
11/10/97
Metal Safety Strips
(1,2 or 3 pcs.)
“Z” Safety
Strip
(not sup-
plied)
Fire-
place
Plat-
form Hearth Ext.
Z\x” (13mm)
Min. Overlap
1Z\x”
(38mm)
FP557b
Fig. 12 Safety strip installation.

12
M400BFC Balanced Flue Heat-Circulating Fireplace
87D1505
Installing the
Chimney System
Start by attaching the first chimney section to the collar
on top of the fireplace.
Install the pipe as pictured in Figure 14. When you
get a good lock, you will hear the pipe clearly snap
together. Once sections are snap-locked in place, it is
extremely difficult to get them apart. Make sure the
pipe is firmly snapped and locked together as each
pipe section is mounted.
When installing elbows, only outer pipe will snap-
lock. Middle pipes simply slide into position. Be sure
to always attach straps on upper elbow to a structural
framing member. (Fig. 15)
Continue installing the pipe as required until pipe is
installed up through the ceiling. At this point, you must
install a firestop spacer.
Installing the Firestop Spacer
in the Ceiling Hole
A firestop spacer is used to keep pipe spaced properly
and required for safety.
Nail the firestop spacer (at each corner) to the framing
members of the ceiling hole. NOTE: A firestop spacer
is not required at the roof.
Hole sizes listed in Figure 11 for angled firestop spac-
ers provide minimum required air space to chimney
pipe for ceiling thickness up to 8” (203 mm). When
combined thickness of ceiling material, ceiling joists
and flooring material exceeds 8” (203 mm), adjustments
must be made in framing to assure that minimum air
spaces to chimney are maintained.
Proper Firestop Spacer Installation
Figure 16 shows different installation procedures for
both an area that is an attic and an area that is not an
attic.
If the area above the ceil-
ing is not an attic, position
the firestop spacer with the
flange on the ceiling side
and the angled portion ex-
tending up into the hole.
If the area above the ceil-
ing is an attic, position the
firestop spacer with the
flange on the top of the
framed hole and the angled
portion extending down into
the hole.
UP
FPC558a
BFC
Pipe install
Circulating models
8/21/00 djt
Pipe Section
Pipe
Rim
Hem
Lance
Pipe
Hem
FPC558a
Fig. 14 Install pipe, listening for the snap-lock to fasten.
FP270/271
CR Series
2/19/99 djt
Support Structure
Ceiling
Hole Fram-
ing
Elbow Strap
(must be tight)
Angled Firestop
Chimney Support Strap
(must be tight)
Elbow Strap
Angled Strap
FP270/271
Fig. 15 Attach straps to a structural framing member.
FP593
SR/C
11/20/97
Nails (4)
Firestop
Spacer
Joist
Firestop
Spacer
Nails (4)
Joist
Attic Installation Ceiling Installation
FP593
Fig. 16 Installing firestop spacer.
NOTE: If the attic insulation shield is used, the
firestop is not required in the attic installation.

13
M400BFC Balanced Flue Heat-Circulating Fireplace
87D1505
Firestop spacers are not available for, nor are they
required on vertical walls.
DO NOT put any sealant around the area where the
outer pipe slides through the firestop spacer. If you
seal this area, it may cause a fire hazard.
Canadian Requirements
for Insulation Shield
In Canada, an attic insulation shield is required to
prevent attic insulation from contacting the chimney
section. NOTE: If the attic insulation shield is used, the
firestop is not required in the attic installation. Fram-
ing dimensions for the chimney hole should measure
17Z\x” x 17Z\x” (445 x 445 mm). An attic shield MUST
be installed on top of attic joists (above the floor level).
(Fig. 17)
A chimney support is 2Z\x" (64 mm) long when installed.
Consider this dimension when determining how many
straight chimney sections are needed.
NOTE: Chimney supports are generally used in long
runs in a chase installation.
Additional Ceilings
If you encounter additional ceilings, repeat same steps
required for first ceiling installation. See firestop illus-
tration in Page 11, Figure 16.
Penetrating the Roof
Run pipe to roofline. Since chimney system must be
vented to the out-of-doors, you must use an approved
MHSC termination.
If a chase is used, refer to the installation manual pro-
vided with the termination cap.
Locate Chimney Centerpoint On Roof
Use same procedure detailed in locating center point of
the flue system.
Drive a nail up through roof at the center point. This will
determine center point on outside of the roof.
Cut and Frame Roof Hole
Size of roof hole varies with the type of chimney
termination installed. Refer to installation instructions
provided with MHSC chimney termination to find correct
size of roof hole.
There must be a 1Z\x” (38 mm) air space between out-
ermost portion of chimney sections and any adjacent
combustible surfaces. (Combustible surfaces include
burnable materials such as: ceiling members, joists,
flooring, combustible insulation and roof structures.)
WARNING: Do not pack required air spaces with
insulation or other materials.
Mark an outline of the roof hole around the center of the
point nail. NOTE: Hole dimensions given in the chim-
ney top installation instructions are horizontal dimen-
sions; therefore, the hole size must be marked on the
roof accordingly.
Cover the opening of the installed chimney so debris
cannot get into the system.
Cut and frame the hole. It is good practice to use fram-
ing lumber that is the same size as the rafters. Install
the frame securely because the chimney top and flash-
ing anchored to the frame must be able to withstand
heavy winds.
Install Remainder of Chimney Sections
Since you have already preplanned the height of your
termination according to the Ten Foot Rule, continue to
install pipe to the predetermined height.
NOTE: In the U.S., it is a good idea, although not al-
ways required, to install an attic insulation shield where
blown-in insulation is planned to be used in the attic.
Install the attic insulation shield with the flanges on its
base extending down into the framing hole. Nail each
corner of attic insulation shield to the framing members
of the ceiling hole using 8d nails. Attic shields are not
required at the roof.
Continue Installing Pipe to Complete Run
Continue attaching pipe sections to complete system
to next level always being careful that the pipe is firmly
snap-locked in place before proceeding to next pipe
section.
Chimney Supports
If chimney supports are required, they are installed the
same as elbows. Nail chimney support straps to ad-
jacent structural framing, as shown on Page 8, Figure
9. Bend straps as necessary and make sure they are
secure so they will support the weight of the chimney.
IGF263
MBUF
5/9/96
Attic Insula-
tion Shield
Nails
(4 required)
Attic Joist
Ceiling
Base Flanges
FP263
Fig. 17 Attic shield installation (Canadian requirement).

14
M400BFC Balanced Flue Heat-Circulating Fireplace
87D1505
FRONT VIEW SIDE VIEW
Air Space Clearances
FPC559a
BFC
AIR SPACES
circulating models
8/21/00 djt
Standoff
Combustible framing material MUST NOT
penetrate AIR SPACE (shaded areas).
2”
Z\x” air space to
sides
Firestop
1” Air
Space to
Back
Z\x” Air
Space to
Sides
0” Clearance to
Floor
Hearth Extension
Only noncom-
bustible material
may be applied as
facing to the black
fireplace surround.
Wall
Shield
FPC559a
Fig. 18 Minimum clearances to combustibles.
Check the chimney top installation instructions for
details on how high above the roof top the chimney sec-
tions (all pipes) should extend.
Installing Top Housing
or Termination
Follow the installation instructions provided with the
MHSC chimney termination you have selected.
Installing Chimney in a Chase
Refer to Page 4, Figure 2 for an illustration of a typical
chase installation.
CAUTION: Treatment of firestop spacers and construc-
tion of chase may vary with type of building. These
instructions are not a substitute for local building codes.
You must check your local building codes to determine
specific requirements for your city or state. NOTE:
Other building materials may be required in addition to
firestop spacers.
Finishing
CAUTION: All joints between the finished wall and the
fireplace surround (top/sides) must be sealed with non-
combustible material to prevent cold air leakage into
the room. Only noncombustible material may be applied
to the facing of the fireplace surround. (Black painted
area) (Fig. 18)
Finish Wall
Finish the wall with material of your choice. Do not
install a combustible mantel shelf less than 12”
(305 mm) above the grille opening. Do not install a
mantel face plate less than 6” (159 mm) from top
of grille opening. (Fig. 20) If a combustible material is
used below a flat mantel shelf, consult your local build-
ing codes for minimum clearance from top of fireplace
opening to bottom of mantel shelf.
All joints (top, bottom and sides) where wall or deco-
rative facing material meets fireplace surround must
be completely sealed with a noncombustible material.
(Figures 19 and 20)
NOTE: No side wall protection is required for fireplaces
installed at 45° to two (2) side walls (corner installation).

15
M400BFC Balanced Flue Heat-Circulating Fireplace
87D1505
MA81
rev. 8/5/97
1Z\x"
Ref. B
C
Combustible materials are
permitted within a shaded area
shown in Figure 21 titled
Minimum Wall Clearances.
*
* *
MA81
Fig. 20 Combustible mantel clearances.
* 12” from top of grille opening.
** 6” from top of grille opening.
Face Plate
FP531b
mantel clearances
9/03 djt
Z\x"
12"
(305mm)
Max.
12" (305mm)
Min.
1Z\x"
(38mm)
6"
(159mm)
Min.
Fig. 19 Mantel clearance.
Combustible
Mantel Shelf
and Trim Finished Wall
Stud
Standoff
Circulating
Front
Noncombustible
Material
Fireplace Opening
2 x 4 Stud
Finished Wall
Must be sealed with noncom-
bustible material
Fireplace
Front
Side View
FP531b

16
M400BFC Balanced Flue Heat-Circulating Fireplace
87D1505
Side Wall Protection
Adjacent combustible side walls that are within mini-
mum dimensions shown in Figure 24 of the fireplace
opening must be protected with MHSC Wall Shield
Model SP40 or a specifically built wall shield described
in Figure 18.
The special wall shield design described in Figure 18 is
an alternate method of adding protection to side walls
and can be used in place of the SP40 with the same
wall clearances specified for the SP40. Rt must =1.85
minimum.
Examples of wall shield insulation:
1. Manville - CERAFORM 126, K=.27,
1/2 inches thick
2. EH2416, K = .458,
1 inch thick required.
Hearth Installation
A hearth extension is required to protect a combustible
floor in front of the fireplace. Refer to Figure 21 for mini-
mum dimensions and mounting detail.
Note: Hearth Extension must not cover the air inlet
opening of a fireplace.
The hearth extension described in Figure 21 must be
a durable non-combustible material with a minimum
(total) Rt value of 1.09; refer to Figure 22 for examples.
The overall height (above a combustible floor), depth
and width must be as indicated, with the extension cen-
tered to the fireplace opening.
The top of insulation must be covered with a non-com-
bustible decorative covering or a piece of .018” mini-
mum sheet metal, to protect hearth extension material.
(Fig. 21)
Secure the hearth extension to the floor to prevent
shifting, using trim molding or other similar means at
three (3) outer edges. Seal crack between the fireplace
hearth and hearth extension with a non-combustible
material. (Figs. 21 and 23)
Minimum Wall Clearances
WITH
Noncombustible
Surround Facing
WITHOUT
Noncombustible
Surround Facing
Minimum Hearth Extension Dimensions
(for On-Site Construction)
G
HG
J
Seal cracks
between the
fireplace
and hearth
extension with
noncombustible
material
Safety strips
must overlap
56O" minimum
May install
noncombustible
decorative
covering
OR .018" min.
sheet metal Fireplace
Hearth
Combustible
Floor
Minimum
Insulation
Value "R"
4" MIN.
FP594b
BFC combustible min.
8/21/00 djt
Firebox
Opening
A - Min. clearance
to combustible
perpendicular wall
B - Min. clearance
to combustible
perpendicular wall when
using noncombustible wall shield*
Side
Wall Side
Wall
F**
C**
E
ED
4" Brick
(Example material)
Combustible material permitted within shaded area.
* Noncombustible wall shield requires 1" EH2416
insulation (minimum R Value = 1.85) between decorative
noncombustible rigid covering and combustible wall.
Minimum height and width is 40" x 40".
** Dimension/degree of angle will vary depending on thickness
of noncombustible surround facing.
Shaded area
starts 1/2" from
away from edge
of unit 4"
FP594b
Fig. 21 Combustible side wall protection and hearth extension dimensions.
A B C D E F G H J
M400BFC 26” 12” 17° 25° 12” 8” 8” 18” 47Z\v”
660 mm 305 mm 305 mm 203 mm 203 mm 457 mm 1200 mm

17
M400BFC Balanced Flue Heat-Circulating Fireplace
87D1505
WARNING: Hearth extension must be installed in
accordance with Figure 23 and must not cover the
bottom front opening of the circulating model.
Alternate noncombustible materials may be used pro-
viding the (total) thermal resistance (Rt value) of the al-
ternate material employed is greater than or equal to R
= 1.09 Thermal resistance (R) or thermal conductivity
(K), may be obtained from manufacturer of the material.
Factors are related by the formula K = 1/R. (Fig. 24)
T = given thickness
R = thermal resistance for a given thickness (T)
K = thermal conductivity
Noncombustible material with a lower R value may
be used, provided thickness of material is sufficiently
greater to maintain an equivalent (total) thermal resis-
tance (Rt).
COMMON MATERIALS AND FACTORS
MATERIAL K* RMINIMUM
THICKNESS
EH2416
Common Brick
0.458
5.0
1.09 0.50 in.**
0.10 5.46 in.**
(MHSC)
R Value is for 1/2 inch.
* Units of K = BTU/SQ FT/HR/˚F/IN
** Thickness of Listed Material
FP533ADD
Addendum
6/1/99 djt
8/4/99 changed .2 to .1
one inch to 1/2 inch djt
FP533ADD
Fig. 22 Hearth extension material factors.
Example of Determining Hearth Extension
Equivalents
To determine the thickness required for any new mate-
rial:
NEW K of new material (per inch) thickness
required = --------------------------------------- X of listed
thickness K of listed material (per inch) material
Example for Common Brick
T (new) = 5.0/0.458 x 0.50 in. = 5.46 in. (new required
thickness).
FP550
BR/BC - SEALING
DETAILS
9/29/97
Wall Covering
Noncombustible
Decorative Fac-
ing
Seal all cracks
between fireplace
surround and wall
materials with non-
combustible material.
Noncombus-
tible Decorative
Covering
Hearth Exten-
sion Insulation
2 x 4” Header
- Do not notch at
standoffs
Seal crack between
fireplace and hearth
extension with noncom-
bustible material
Safety Strips -
Must be overlapped 1/2”
minimum
Side View
FP550
Fig. 23 Sealing gaps.
KT108b
BFC
Correct door position
8/23/00 djt
Correct Wrong
Fig. 28 Correct door position.
KT108b
Glass Door Operation
The M400BFC is intended for use only with the doors
fully closed. (Fig. 28)

18
M400BFC Balanced Flue Heat-Circulating Fireplace
87D1505
Installing Line for Gas Logs
MHSC fireplaces are designed to accept a 1/2” (13 mm)
gas line for installation of an approved gas appliance.
(MHSC manufactures a wide variety of gas logs for use
in MHSC fireplaces.)
Be sure to have the appliance installed in accordance
with building codes.
Gas connection may enter from either left or right side
of the fireplace.
Locate appropriate gas line in the outer casing of fire-
place and remove insulation from gas line tube. (Fig.
29)
From inside the fireplace, locate the knockout on the
firebrick -- be sure you are on the appropriate or “gas
line” side of the fireplace. Using a flat bladed screw-
driver or small chisel and hammer, carefully tap around
the knockout until it loosens and falls out.
Install 1/2” (13 mm) certified gas pipe through opening.
After gas pipe installation is complete, use insulation
that was removed from gas line tube to repack space
around the pipe. Material should be inserted from
outside of the fireplace and packed tightly to totally seal
between the pipe and tube.
Note: Gas pipe should not come in contact with
any wood structures until it has reached a point at
least 1” (25 mm) away from fireplace side.
1"
Min.
FP560a
BFC
Gas line knockout
8/00
1/2"
Hole in Outer Casing
Gas Line
Tube
Ceramic
Knockout
Supply
Line
Repack Insu-
lation
Hole in
Outer Cas-
ing
Ceramic Knockout
(both sides)
FP560a
Fig. 29 Gas line access.
Fireplace Top View
BTU input of a gas appliance installed in fireplace
should be rated less than 100,000 BTU/Hr.
Gas pipe installation is intended for connection to a
decorative gas appliance only when (1.) incorporating
an automatic shutoff device and (2.) complying with the
Standard for Decorative Gas Appliances for Installa-
tion in Vented Fireplaces (ANSI Z21.60) or CSA draft
requirements for Gas-Fired Log Lighters for Woodburn-
ing Fireplaces (Draft No. 4, August 1993).
Decorative gas appliance should be installed in accor-
dance with the National Fuel Gas Code, ANSI Z223.1/
NFPA 54 (latest edition).
CAUTION: When using decorative gas
appliance, flue damper must be set in fully
open position. Glass doors on the fireplace
must also be fully opened.
WARNING: Do not operate an unvented gas
log set in this fireplace with the chimney
removed.
WARNING: When installing an unvented
gas log set, the model CABL or CABR 4”
adjustable hood must be used.
Operation
Before the first fire, the location of the upper refractory
baffle (ceiling panel) should be checked. This part floats
intentionally and may move out of place during ship-
ping or installation of the fireplace. If the baffle is out
of place, the resulting improper air flow will cause dirty
glass and improper combustion. The baffle should be
centered side-to-side between the refractory sidewalls
and be pulled forward (toward the glass doors) until it
rests on the front sheet metal ledge.
Refer to the publication “How to Enjoy Your Woodburn-
ing Fireplace” for starting and maintaining a wood fire.
Note that the M400BFC does not have a damper to
open or close. This is a tremendous efficiency increas-
ing advantage since there is no damper to potentially
leave open after a fire dies down. House air will not
escape up the chimney. Note also that the doors should
remain closed at all times except when starting or
reloading a fire.
Burn only seasoned firewood. Typically, only two or
three burning logs are needed to provide efficient sup-
plemental heat and a bright decorative fire. In general,
fresh wood should not be loaded higher than about 2/3
the height of the firebox.

19
M400BFC Balanced Flue Heat-Circulating Fireplace
87D1505
647
BFC parts 2008
2/08 djt
1
2
3
5
6
7
8
9
10
11 12 13
14 16
15
19
18
17
4
24
20
22
21
25
23
23
26 27
28
29
MHSC reserves the right to make changes in design, materials, specifications, prices and discontinue colors and products at any time, without
notice.
M400BFC Balanced Flue Fireplace
Ref. Description M400BFC
1. Top Grille - Painted 3126160
2. Bottom Grille - Painted 3126160
3. Grate Assembly 7579218
4. Left Door Assembly Complete 30004361
5. Right Door Assembly Complete 30004362
6. Rear Firebrick 2353145
7. Side Firebrick (two per fireplace) 2353146
8. Hearth Firebrick 2353140
9. Nailing Flange (four per fireplace) 2422198
10. Fiberglas Rope Gasket (Outer Collar) 7547137
11. Top Refractory 2353147
12. Front Brick Retainer 2353163
13. Cable Clip (For Blower Assembly) 7522241
14. Plug Button (two per fireplace) 7522239
15. Left Door Gasket 20013999
16. Right Door Gasket 20013998

20
M400BFC Balanced Flue Heat-Circulating Fireplace
87D1505
M400BFC Balanced Flue Fireplace (continued)
17. Blower Assembly - FKSX-A 20000620
18. Grate Retainer 2353179
19. Junction Box Assembly 3126161
20. Ceramic Glass Panel (two per fireplace) 30004352
21. Flat Gasket 3/4” Wide (two per fireplace) 20013997
22. Knob (two per fireplace) 1600657
23. Bushing (four per fireplace) 1201895
24. Pan Hd, PH 1/4-20 x 1 Black (two per fireplace) 1200907
25. Spacer (two per fireplace) 1600070
26. Spring Clip 30004450
27. #8-18 x 1/2” Decorative Screw 7521180
28. Hinge Spacer (two per fireplace) 30004360
29. BFC Door Assembly 20014006
Ref. Description M400BFC