Mason-Lite MGFP39 User manual

Instructions
Models MGFP39/44/49
Equipped with Safety Pilot System / Remote Control Valve
Do not store or use gasoline or other
flammable vapors and liquids in the
vicinity of this or any other appliance.
WHAT TO DO IF YOU SMELL GAS:
Do not try to light any appliance.
Do not touch any electrical switch; do
not use any phone in your building.
Immediately call your gas supplier from
a neighbor’s phone and follow the gas
supplier’s instructions.
If you cannot reach your gas supplier,
call the fire department.
Installation and service must be
performed by a qualified installer, service
agency, or the gas supplier.
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•
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•
nWARNING:
Iftheinformationintheseinstructionsis
not followed exactly, a fire or explosion
may result causing property damage,
personal injury or death.
REV 10/23/2012
Gas Fireplace with Masonry Firebox
The logs and burner must be permanently installed in and
are only for use in this fireplace. This fireplace must be
connected to a working flue meeting the requirements of
the ANSI Z21.50 standard.
Solid-fuels shall not be burned in this fireplace.
This appliance must be vented vertically through the
roof. This appliance is not for installation in manufactured
or mobile homes. The installation, including provisions
for combustion, ventilation air, and required minimum
permanent vent opening, must conform with the National
Fuel Gas Code (ANSI Z223.1/NFPA 54) and applicable
local building codes. This gas fireplace is designed to
burn with yellow flames; thus adequate ventilation is
absolutely necessary.
IMPORTANT: READ THESE INSTRUCTIONS
CAREFULLY BEFORE STARTING
INSTALLATION OF THIS FIREPLACE.
nWARNING:
This gas appliance must not be connected to a chimney
fuel servicing a solid fuel burning appliance.
Do not store gasoline or other flammable vapors and liquids in the vicinity of this or any other appliance.
Report No. 08-154
ICC Evaluation Services
Report No. 2401
This appliance is only for use with the type
of gas indicated on the rating plate. This
appliance is not convertible for use with
other gases, unless a certified kit is used.
Installer: Leave these instructions with the consumer.
Consumer: Retain for future reference.

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1
Contents .......................................................................................................................................... Pg. 1
Fireplace Parts List ..........................................................................................................................Pg. 2, 3
Burner and Logs Parts List ..............................................................................................................Pg. 4
Product Overview ............................................................................................................................ Pg. 5, 6
Clearance To Combustibles............................................................................................................. Pg. 7
Mason-Lite Fireplace & Chimney Systems...................................................................................... Pg. 7
Chimney System Heights ................................................................................................................ Pg. 7
Supporting Floor Systems ............................................................................................................... Pg. 8, 9
What You Will Need......................................................................................................................... Pg. 10
Fireplace Assembly Procedures ......................................................................................................Pg. 11, 12
Mason-Lite Firebrick Liner ...............................................................................................................Pg. 13
Installing Outside Air ........................................................................................................................ Pg. 14
Mason-Lite Chimney Systems .........................................................................................................Pg. 14
Determining Finished Height for Fireplace ...................................................................................... Pg. 14, 15
Installing Vent Plate and Chimney Systems .................................................................................... Pg. 15
Venting Installation........................................................................................................................... Pg. 16
Specifying Chimney Heights............................................................................................................ Pg. 17
Chimney Termination Units.............................................................................................................. Pg. 17
Important Pre-installation Information.............................................................................................. Pg. 17
Installing the Valve/Control Box Assembly....................................................................................... Pg. 18
Install Spill Switch and Baffle Assembly .......................................................................................... Pg. 18
Owner’s Operation & Precautions ................................................................................................... Pg. 18, 19
Attaching the Burner and Grate....................................................................................................... Pg. 19
Checking and Adjusting the Pilot ..................................................................................................... Pg. 19
Placing the Decorative Lava Rock................................................................................................... Pg. 19
Adjusting Air Mixers ......................................................................................................................... Pg. 19
Log Placement................................................................................................................................. Pg. 20
Lighting and Operating Instructions................................................................................................. Pg. 21
Maintenance and Service ................................................................................................................Pg. 22
Troubleshooting ............................................................................................................................... Pg. 22
Appendix I........................................................................................................................................ Pg. 23
Appendix II....................................................................................................................................... Pg. 24
Warranty .......................................................................................................................................... Pg. 25
CONTENTS
CONTENTS
Below is a sample picture of the rating plate that is located inside the lower dome side of your fireplace. Model Number, Date Of Manufacture
and Serial Number should be stamped on the plate where indicated.
NG LP
MFI
Masonry
Fireplace
Industries, LLC
315 WEST 3RD ST.
SANTA ANA, CA 92701
DATE OF MFG. SERIAL No.
This appliance is not for installation in manufactured or mobile homes.
rev 18 NOV 2009
GAS
TYPE:
FOR MANTEL CLEARANCES
CONSULT OWNER’S MANUAL
DO NOT REMOVE THIS LABEL
See MFI’s installation and operating instructions for this
model. Contact local building officials about restrictions
and installation specifications in your area.
THIS FIREPLACE IS DESIGNED
FOR USE ONLYWITHTHEANSI
Z21.50 DECORATIVE GAS LOGS
AND BURNER TESTEDAND
APPROVED FOR THIS FIREPLACE.
Consult instructions included with this
firebox for further information.
!
WARNING:
Use only approved, listed chimneys
MGFP-39/44/49:
10” B-Type Vent and DM-12-10” system
MGFPST-43:
12” B-Type Vent and DM-12-12” system, UL103
chimney or a 12” classAchimney if preferred.
Chimney Heights:
Max.: 40 ft.
Min.: 14 ft. (17 ft. with 1 or 2 offset
sections maximum)
IMPORTANT: Refer to pipe
manufacturer’s instructions.
!
WARNING:
THIS FIREPLACE HAS BEEN TESTED
FOR USE ONLYWITHAPPROVED
GLASS DOORS. TO REDUCETHE
RISK OF FIRE OR INJURY, CONSULT
OWNER’S MANUAL.
THIS APPLIANCE NEEDS FRESH AIR FOR SAFE OPERATION AND MUST BE INSTALLED
SO THERE ARE PROVISIONS FOR ADEQUATE COMBUSTION AND VENTILATION AIR.
!
WARNING: THIS FIREPLACE IS NOT INTENDED FOR BURNING SOLID FUELS.
!
WARNING: This gas appliance must not be connected to a chimney fuel servicing a solid fuel burning appliance.
!
FIREPLACE CLEARANCES TO COMBUSTIBLES:
UNIT FRONT, SIDES, REAR...............................0” (0 mm)
COMBUSTIBLE FLOOR......................................0” (0 mm)
COMB. SHEATHINGABOVE OPENING TOP.....8” (200 mm)
SHEATHING OR TRIMTO OPENING SIDES....12“ (300 mm)
OPENING TO SIDE WALL..................................20”(500 mm)
HEARTH EXTENSION BEYOND SIDES............12“ (300 mm)
INSULATION FROM FIREBOX............................0” (0 mm)
Tested &
Listed By
The installation, including provisions for combustion, ventilation air, and required minimum permanent vent opening,
must conform with the National Fuel Gas Code (ANSI Z223.1/NFPA 54) and applicable local building codes.
MODEL
No.:
MGFPST-43 MGFP-39 MGFP-44 MGFP-49
Report No.
08-154
ICC Evaluation
Services Report
No. 2401
EXAMPLE ONLY

2
Fireplace Parts List
Fireplace Parts List
See Page 8 and 9 for framing anchoring components.
WARNING
Failure to position the parts in
accordance with these diagrams or
failure to use only parts specifically
approved with this appliance may result
in property damage or personal injury.
Figure 1
1
2
4
5
7
8
9
10
16
15
14
12
6
3
3A
7
8
11
17
10
18
19

3
* ITEMS NOTED ARE SOLD SEPARATELY.
ITEMS INDICATED AS “NOT SUPPLIED” CAN BE
OBTAINED FROM YOUR LOCAL HARDWARE STORE.
Optional Outside Ø4”
Combustion Air Kit
Model No.: MFP4-AK
(Ø4” Ducting not included)
Only the following
doors have been tested
and approved for use
with this fireplace:
Crown-Breckinridge
or
McKenzie-Pendelton
Refractory Firebrick Liners
(Herringbone Pattern shown, also available
in Running Bond - see Pg.27)
MFP(39,44,49)SHBL- Herringbone
MFP(39,44,49)FRBL- Running Bond
MGFP39/44/49 Fireplace Parts List
MGFP39/44/49 Fireplace Parts List
ITEM P/N DESCRIPTION QTY
1MFP39-1
MFP44-1
MFP49-1
HEARTH (Left or Right) 2
2MFP39-2
MFP44-2
MFP49-2
REAR WALL 3
3MFP39-3
MFP44-3
MFP49-3
SIDE WALL 7
3A MFP39-3A
MFP44-3A
MFP49-3A
SIDE WALL with 4” opening for Air Kit 1
4MFP39-4
MFP44-4
MFP49-4
SMOKE SHELF (Downdraft Diverter) 1
5MFP39-5
MFP44-5
MFP49-5
DOME REAR - LOWER 1
6MFP39-6
MFP44-6
MFP49-6
LINTEL 1
7MFP39-7
MFP44-7
MFP49-7
DOME SIDE - LOWER 2
8MFP39-8
MFP44-8
MFP49-8
DOME SIDE - UPPER 2
9MFP39-9
MFP44-9
MFP49-9
DOME TOP Ø10” 1
10 MFP39-10
MFP44-10
MFP49-10
DOME FRONT/REAR 2
11 MFP186-1 RATING PLATE 1
12 MFP-DD* 10” DRAFT HOOD 1
14 MFP-211 SMOKE DIVERTER 1
15 MFP-212 SMOKE DIVERTER EDGE PIECE 2
16 MFP-213 SPILL SENSOR SWITCH 1

4
Burner & Logs Parts List
Burner & Logs Parts List
ITEM P/N DESCRIPTION QTY
1GMLB-39/44-01(P)
GMLB-49-01(P)
Pilot, Burner assembly 1
2RR-1A Remote trans./recvr. w/ batt. 1
3CK-5-18HC Source connector kit 1
4CK-5-24HC Burner connector kit 1
5CE-01 Valve/Control box w/ batt. 1
6OCC-10 Lava Rock, 10 lb. bag (4) 1
7LML-15T Top log 15” 1
8LML-17T Top log 17” 1
9LML-18T Top log 18” 1
10 LML-20T Top log 20” 1
11 LML-24BR
LML-30BR
Rear bottom log 24”
Rear bottom log 30”
1
12 LML-24BF
LML-30BF
Front bottom log 24”
Front bottom log 30”
1
13 MFP-214 Burner Grate Brackets (2) 2
Before beginning installation, be sure the burner system is complete by comparing its contents with this Parts List. Parts may
differ depending upon the size of the set purchased. Be sure you know the model number and size of your set when ordering
replacement or optional parts and accessories.
2
9
7
8
10
LML-24 shown.
11
12
1
Diagrams shown are not to scale.
13
6
Receiver pre-assembled
into control box.
5
4
3
Contact MFI for replacement parts and
accessories as listed in these parts lists.

5
Product Overview
Introduction
We extend a warm welcome from all of us at Masonry
Fireplace Industries, LLC. (MFI), proud manufacturers of
Mason-Lite Fireplaces. Thank you for Choosing MFI.
You may have thought long and hard before you chose the
fireplace which would grace your home. Rest assured that
every component of the Fireplace has been tested to ensure
long-term durability.
Product Overview
Mason-Lite Fireplaces are designed as factory-built blocks
to be assembled on-site. These fireplaces may be installed on
either combustible or non-combustible floors. In order to func-
tion, the system requires a 10” B-vent chimney.
The main components of the Mason-Lite Fireplace are:
Mason-Lite Firebox and Smoke Dome
Gas burner, logs and control system
B-vent
Careful step-by-step instructions for each phase of the in-
stallation procedure will be given for the Mason-Lite fireplace.
Those instructions generally fall into the following categories:
Spacing and clearance as it relates to combustible materials
Familiarity of installation for all components
The strength of the floor on which it rests
Chimney system measurements
Set up and use of the gas burner system.
Choice of materials and craftsmanship in fireplace and hearth
finishing.
Figure 4 - Typical Installations
Internal
Wall
Installation Corner
Installation
Flush
Installation
Full
Projection
Installation
Note that each of these topics will be covered in detail and that
the installer is expected to understand each phase completely
before going on to subsequent instructions.
Attention: Be advised that all the illustrations in this manual
are for general reference only. Do not scale drawings. Actual
design elements will vary from case to case. Pay attention to
specified minimum clearances to combustibles.
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WARNING! Under no circumstances should you allow children
to remain unattended while a fire is burning in the fireplace! Be
sure to keep all objects – furniture, drapes, rugs, etc. at least
48” (48 inches) away from the opening of the fireplace!
Attention: You may need a residential building permit to install
a Mason-Lite Fireplace. Consult local jurisdictions before you
get started!
The MASON-LITE gas fireplace is not designed to serve as a
primary heat source, rather, the fireplace was expressly created
as a supplemental source of heat. This unit is designed for use
with the provided gas burner and approved logs only.
Testing and listing for the MASON-LITE gas fireplace has been
undertaken by PFS Test Laboratories, Inc. to ANSI Z21.50.
Under no circumstances should the MASON-LITE gas
fireplace be considered for other than in-residence buildings of
conventional construction.
These components make up the MASON-LITE gas fireplace
and in the following pages, you will learn how they work
together to create an exceptional unit that will give years of
service and pleasure!
40 5/8"
4 3/8"
7 3/8"
A/2
11"
28"
21"
23"
C
B
4 1/4"
A
32 7/8"
63-1/2”
D
ø4” OUTSIDE AIR
ACCESS - CAN
BE INSTALLED
ON THE LEFT
SIDE ALSO
Figure 5
Overall Dimensions MASON-LITE Fireplaces
Model A B C D
MGFP39 43” 39” 30-1/4” 27-3/4”
MGFP44 48” 44” 35-1/4” 32-3/4”
MGFP49 53” 49” 40-1/4” 37-3/4”

6
Required Gas Pressure
The minimum inlet gas supply pressure for the purpose of
input adjustment is 5” of water column (w.c.) for natural gas.
The maximum inlet gas supply pressure is 10.5” w.c. for
natural gas. The minimum inlet gas supply pressure for the
purpose of input adjustment is 11” of water column (w.c.) for
propane gas. The maximum inlet gas supply pressure is 13”
w.c. for propane gas.
Testing the Gas Supply System
The gas fireplace and its required individual shut-off valve
must be disconnected from the gas supply piping system
while performing any tests of the piping system at pressures in
excess of 1/2 psig.
The gas fireplace must be isolated from the gas supply
piping system by closing its individual manual shut-off valve
during any pressure testing of the gas supply piping system at
test pressures equal to or less than 1/2 psig.
This is accomplished by closing the gas supply line valve
required by NFPA 54.
A fireplace screen must be replaced after service and be
in place when the appliance is in operation and, unless other
provisions are provided, the screen shall have an opening for
introduction of combustion air.
When glass fireplace doors are used, operate the gas
fireplace with the doors open. Use only doors rated for this
appliance.
Important
To comply with building code acceptances, and for safe
operation and proper performance of this fireplace, use ONLY
MASON-LITE parts and accessories.
Use of other controls, parts, and accessories which are not
designed for use with MASON-LITE gas fireplaces is prohibited
and will void all warranties, certifications, listings, and building
code approvals, and may cause property damage, personal
injury, or loss of life.
The burner included with this gas fireplace is non-convertible
and only meant to be used with the gas listed on the rating
plate.
GUIDELINES FOR USE:
All current and future users of Mason-Lite Fireplaces
are charged with the responsibility for full knowledge of the
information contained within this manual which includes:
Strict requirements for assembly.
Detailed instructions for installation.
Cautionary guidelines for use.
On-going maintenance instructions.
It is the responsibility of the distributor, subcontractor and/
or the general contractor – whoever shoulders the liability
for installation of this product – to see to it that the work is
in complete compliance with the guidelines and instructions in
this manual.
Note that the general contractor is the party accountable for
seeing that adequate clearances are provided from all firebox
surfaces per specifications in this manual.
DONOT USEAFIREPLACEINSERTOROTHER PRODUCTS
NOT SPECIFIED FOR USE WITH THIS FIREPLACE.
The Mason-Lite is Designed for Use Only with:
- The supplied burner and log system
- Plumbed LPG or Natural Gas.
DO NOT USE OR STORE GASOLINE OR OTHER
FLAMMABLE LIQUIDS OR GASES IN OR NEAR THE
FIREPLACE!
ATTENTION: A fire or an explosion could occur causing
property damage, injury or loss of life if you do not follow the
information in this manual!
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•

7
Clearance to Combustibles
Clearance to Combustibles
The distance to be maintained from the surfaces of the
fireplace to combustibles must be observed. Below is a list of
the most common combustible materials to name a few:
Drywall Wood flooring Plywood
Sub-flooring Wood Framing Particle board
Mill board Plywood paneling
Maintain the following minimum clearances:
Unit front, sides, rear 0” (0 mm)
Combustible floor 0” (0 mm)
Sheathing or trim to opening sides 8” (203 mm)
Combustible sheathing above opening top 8” (203 mm)
Mantel above opening 12” (305 mm)
Opening to side wall 20” (508 mm)
Insulation from firebox 0” (0 mm)
Due to high temperatures, never install this fireplace in a
recreational vehicle, in high traffic areas, drafty areas, or
where curtains, furniture, clothing, or other flammable objects
are less than 36” from the front or side and 42” from the top of
the fireplace.
CAUTION: This gas fireplace attains high temperatures. Keep
children and adults away from hot surfaces to avoid ignition of
clothing and/or burns. Even after the fireplace is shutdown it
will remain hot for a time afterward. Allow the surface to cool
before touching it.
Carefully supervise young children when they are in the room
with the fireplace.
All fireplace openings for both combustion air and exhaust
must remain open and unobstructed at all times when the
fireplace is in operation.
The MASON-LITE fireplace has been designed, tested
and approved for zero clearance to combustible floors.
Be certain that the MASON-LITE fireplace is installed with
the finished fire brick floor of the fireplace so that it is at least
4-1/2” (four and a half inches) above the combustible floor
system.
Warning to the structural engineer and/or building contractor:
It is your responsibility to be certain that the fireplace can be
properly supported by the combustible floor system on which
the fireplace will rest. Be advised that this engineering equation
will be in addition to any live or dead weights that the floor has
to carry.
Mason-Lite Fireplace & Chimney Systems
Mason-Lite Fireplace & Chimney Systems
Before Getting Started…
Even if you consider yourself an expert in the field of
fireplace installation, we at Masonry Fireplace Industries
caution you to take the time to totally familiarize yourself with
the instructions to follow.
We can assure you that there will be information that will
make the installation go smoother and, above all, safer, for
everyone concerned.At the least, reading these procedures will
save you time and, at the most, it will prevent any malfunction
that could result in property damage or serious injury.
Do not start the installation until you have checked out all
the local, regional, state and national rulings, laws and codes
as they apply to fireplaces and fireplace installations. Every
community is different so do not assume that because you
know the requirements for one locality, it will be the same in
the next. Avoid bureaucratic hassles and do your homework
WELL BEFORE you start your project!
The MASON-LITE gas fireplace is designed to be
installed with a B-vent metal chimney system, UL 103
chimney. Such chimney systems are acceptable where
any traditional masonry fireplace has been specified.
Note that the chimney system must always vent to the
outside of the building.
This Mason-Lite fireplace is intended as a supplemental heat
source only. It is not intended as a primary heat source.
It is the responsibility of the contractor installer (not the
manufacturer) to ensure that adequate combustion air is
provided for proper function of this fireplace. Fireplaces
take up a large volume of replacement air from outside the
house and if the house is of airtight construction, smoke
spillage may occur if proper draft is not achieved.
There are many conditions beyond a manufacturer’s
control when it comes to the operation of the fireplace.
The manufacturer cannot be responsible for “smoke free”
operation, nor can the manufacturer take on the responsibility
for problems with surrounding construction; chimneys that
have not been built at the right heights; system drafts caused
by faulty mechanical systems; adverse weather conditions
or any other inclement environmental situations over which
the manufacturer has no control.
Inspect all fireplace & chimney components for evidence
of damage prior to starting installation. Consult your local
distributor for replacement parts if necessary.
Under no circumstances should you make any adjustments
or modifications to the chimney system during the
installation procedure. If you do, you are not only liable
for negating the warranty, but you could very well cause a
serious malfunction of the fireplace. You must follow these
chimney instructions.
Chimney System Heights
When installed, the maximum overall height of the Fireplace is
40’-0” (forty feet). The minimum installed height of the
completed fireplace is 14’ 0” (fourteen feet), given that the
chimney is straight. If the chimney includes one or more offset
sections, the measurement is 17’ 0” (seventeen feet).
1)
2)
3)
4)
5)
6)

8
Supporting Floor Systems
It is the ultimate responsibility of the installer to ensure that
proper concrete slab supports are used.
WARNING to the licensed design professional and/or building
contractor: It is your responsibility to be certain that the Mason-
Lite can be properly supported by the combustible floor system
on which the fireplace will rest.
For fireplace support foundations installed on concrete refer to
Appendix I and II (pages 31 & 32) for specific instructions.
Rebar locations
Lay-out the position of the fireplace and drill holes where
the rebar will be located. Secure the #3 rebar 4 inches into
the concrete foundation with ITW Epoxy or Simpson Epoxy.
Follow manufacturer’s instructions for installation of rebar into
slab.
Wood Floor
Anchorage of fireplace to wood floor construction is required.
Refer to Figure 9 for anchorage dimensions. Four anchors are
required to attach to the sub-flooring framing.
Crawl Space or Upper Floor:
For installation of firebox over combustible crawl spaces or
upper floors, anchorage of the firebox is required. Illustrations
of examples of possible anchorage methods are shown in
Figures 6 thru 8 depending upon the type of floor framing. Final
method of anchorage is to be determined by licensed design
professional.
For conventional framing, where the floor joists are parallel
with the sides of the firebox, the addition of floor joists to align
with the anchor brackets allows the brackets to be directly
connected to the floor joists.
Note that additional floor joists may be required to support
the weight of the firebox and chimney. Where the floor joists
run parallel to the front of the firebox, anchorage can be
accomplished in like manner as shown in Figure 6 using
blocking between the floor joist.
For floors supported by I-Joists, the method of anchorage is
illustrated in Figures 7 and 8. Figure 11 illustrates the general
arrangement of anchorage to floor framing.
It is important to take into consideration that the load for
the Mason-Lite Fireplace must be considered as additional
dead load that will have to be supported by the floor framing.
Additional floor joists or I-joists may be required as determined
by the licensed design professional.
The dead weights for the fireplace are noted in Table I. It is
the task and responsibility of the general contractor/installer
to see that the proper reinforcement for weight loads are
made by a licensed design professional prior to the fireplace
installation.
As stated above, it is desirable to place additional framing
for alignment of anchor rods. Refer to Figure 9 for anchor rod
locations.
Figure 6
Floor Sheathing
not shown for
clarity
Metal Base
Assembly
EXAMPLE ONLY
2X FLOOR JOIST
2X FLOOR JOIST
A35 Brackets
(16 required)
I-Joist
Simpson
Strong-Tie
A-35 or
equivalent
Figure 7
I-Joist Anchoring
Top View
Example Only
I-JOISTS
Anchor
Brackets
Figure 8
I-Joist
Anchoring
Bottom
View
Example Only

9
MASON-LITE Weight Determination
The following are dead load weight estimates for the Mason-Lite Fireplace.
Table I
Fireplace Model MGFP39 MGFP44 MGFP49
Fireplace Weight 1,194 lbs. 1,250 lbs. 1,359 lbs.
Mortar, Rebar &
Ready Mix Concrete 350 lbs. 357 lbs. 364 lbs.
Firebrick Lining 333 lbs. 345 lbs. 356 lbs.
Draft Hood 17 lbs. 17 lbs. 17 lbs.
Floor Area 42” x 28” (8.12 ft²) 48” x 28” (9.33 ft²) 53” x 28” (10.30 ft²)
Other Weight Considerations:
Fireplace finished facing (surround): This information needs to be obtained from the contractor.
Weight of metal flue: See chimney manufacturer’s weight specifications. Some chimney systems can weigh up to 50 lbs per
lineal foot.
Table II - Deflection Limits
Construction L S or W D +L1
Floor Members I/360 --- I/240
1For wood structural members having a moisture content of less than 16 per cent at time of installation and used under dry
conditions, the deflection resulting from L + 0.5D is permitted to be substituted for the deflection resulting from L + D.
Note that MASON-LITE cannot accept responsibility for structural floor support details. All drawings are presented as mere
illustrations to indicate the presence of the underlying floor system. It is the responsibility of the general contractor/installer to
consult with a local licensed design professional for guidance in building a proper floor support system.
1)
2)
F
10"
4"
Figure 9
A
Model A
MGFP39 38-3/4”
MGFP44 43-3/4”
MGFP49 48-3/4”
Figure 10
Fireplace
outline
10”
Typical Anchorage
Layout
EXAMPLE ONLY
SECTION VIEW
ROTATED 90CW
Figure 11

10
ATTENTION: Figure that these totals for the dead loads are
in addition to the actual live load as well as other dead load
requirements for the specified site’s proposed floor. Only the
MASON-LITE weights are known. Other weights are estimates
and are subject to material choices of the installer or owner.
What You Will Need
You will find that the MASON-LITE Fireplace is designed to be
completely assembled on-site, consisting of interlocking precast
parts. The parts of the fireplace are made of Mason-Lite’s
incredibly strong blend of specialty cement and a light weight
aggregate.
IMPORTANT! When applying mortar, it is imperative that the
concrete blocks be maintained moist (not soaking) so they don’t
absorb the water out of the mortar and cause adhesion to fail.
Frequently run a damp sponge to the parts before mortar is
applied!
The installation of an anchor plate/damper is required but not
supplied. You may purchase it from any chimney manufacturer
or MFI. Also, an optional combustion air inlet MFP4-AK can be
obtained from MFI.
Refractory Firebrick Liners also need to be installed. These
should be a minimum of 1-1/8” (one and one-eight inches) thick.
The liner will be applied within the walls and hearth area of the
firebox. These are available from MFI. See page 27.
Tools needed for installations:
One 4’ level
Roto-hammer with ½” drill bit (needed for concrete slab
install only)
Drill motor with mixer blade (to mix Mason-Lite Mortar)
Two empty 5 gallon buckets (to mix Mason-Lite Mortar)
One wheelbarrow and shovel to mix concrete.
Grout bag
Triangular masonry trowel
Rubber hammer
Sponge and water bucket to wipe down and moisten parts
prior to applying mortar.
Materials needed for concrete slab installations
MGFP39:
Six (6) pieces 3/8” rebar x 36” long (included with unit)
Six (6) pieces of rebar x 12” long (included with unit)
MGFP44/49:
Eight (8) pieces 3/8” rebar x 36” long (included with unit)
Eight (8) pieces of rebar x 12” long (included with unit)
ALL UNITS:
Epoxy for securing rebar in footing / foundation.
Three (3) - 90 lb. bags of Ready-Mix Concrete with 1/4” or
smaller aggregate.
Materials needed for wood floor installations
MGFP39:
Six (6) pieces 3/8” rebar x 36” long (included with unit)
Six (6) ea. All-thread x 12” long (with nuts and washers)
MGFP-44/49:
●
●
●
●
●
●
●
●
●
●
●
Eight (8) pieces 3/8” rebar x 36” long (included with unit)
Eight (8) ea. All-thread x 12” long (with nuts and washers)
ALL UNITS:
Three (3) - 90 lb. bags of ready mix concrete with 1/4” or smaller
aggregate.
SURFACE CRACKS - The MASON-LITE FIRE-PLACES are
manufactured using high quality materials. During the
drying process, surface cracking may occur. These small
cracks (under 1/16” will not affect the fireplace safety or
performance). During the assembly process, fill surface
cracks with thin-set mortar and brush when drying for a
smooth surface finish.
Field Assembly Procedures
Mixing the MASON-LITE mortar – The mortar comes
premixed and should be dry. Be sure to use clean water and
work it up into a mixture that is pasty but not lumpy. If it’s too
thin and the surfaces don’t stay moist, the components will
not adhere. Load the mixture into a standard grout bag.
Apply about ½” (one-half inch) thread of mortar. The mortar
bead should be approximately ½” (one-half inch) away from
all edges. The mortar has a considerable amount of holding
power so do not overload the components with too much
mortar. Keep the components moist at all times!
Some mortar will “ooze out” when placing components
together, this is normal. Wipe excess away with a trowel. Do
not cover component surfaces completely with mortar. Do
not apply the mortar in thick bands even if the component
you are working with is larger than the rest. You will want to
apply “stripes” of mortar in these situations.
Make sure components are level. It’s extremely important
that you pay careful attention to how you are assembling
the Mason-Lite Fireplace since every component builds on
the next. If you have to make any kind of an adjustment,
do not try to do it “by loading an opening” with mortar, this
will only result in a fireplace that will not be plumb or level.
Use wood shims instead. You will find these small wood
shims supplied with the Mason-Lite Fireplace and
you can nudge them in between openings to achieve the
precision you need in making component adjustments.
Once you have removed any shims, you will want to cover
any gaps that may have resulted with the mortar.
a)
b)
c)
d)

11
Fireplace Assembly Procedures
Fireplace Assembly Procedures
Place the Mason-Lite fireplace hearth on the floor where the
fireplace is to be installed. For concrete slabs, supporting
floor needs to be rated at ASTM 90.
Draw an outline of the hearth area based on the dimensions
shown in Figure 12. Position Hearth slabs and mark rebar
center locations. Drill 4 inches into concrete slab and secure
the 8 pieces of 12 inch rebar with epoxy. For other than
concrete slabs, draw an outline of the hearth area based on
the dimensions in Figure 5 taking special consideration on
the position of where the all-thread studs will be located in
relation to the anchoring locations. All-thread rods should
stick up through the holes on the hearth slabs.
Figure 12
Model W
MGFP-39 43”
MGFP-44 48”
MGFP-49 53”
W
28”
Apply mortar
between joints
Left Side Hearth 2nd
Right Side Hearth 1st
12 inch rebar
Mix a batch of mortar and prepare Right Side Hearth bottom
surface to be bonded as shown in Figure 13.
Align Right Side Hearth to the outline created. The overall
width should allow for an approximate gap of 1/8” between
slabs for the additional mortar to unite the remaining slab.
Check for surface flatness, level if necessary.
Figure 13
1/2” away
from edges
1/2” mortar
bead (typical)
Hearth section shown prepared
for Right Side position
Apply mortar bead to
all mating surfaces.
Apply mortar to the remaining Hearth except this time
apply beading on surface to be facing floor as shown in
Figure 14.
1.
2.
3.
4.
5.
Figure 14 Hearth shown prepared
for Left Side position
Before installing side walls, confirm placement of outside
combustion air access (if required), this can be installed
either side depending on which side is accessible to outside
combustion air (all diagrams in this manual show the
combustion air inlet hole on the right side). Prepare side
wall and rear wall mating surfaces with the prepared mortar
and begin assembly.
Figure 15 Side Wall shown prepared for Right
Side Air Access.
For Left Side, bead opposite side.
1/2” AWAY
FROM EDGES
Keep the assembly of the next sections of the firebox side
walls moving up, keeping components moist, mixing mortar
as you need it and threading the mortar appropriately as
you stack each section, one onto the next. Constantly check
for squareness and levelness while building each course of
block. As you complete each section, make certain that you
adhere the mortar at each and every joint.
Figure 16
Combustion Air Access
Right or Left (Right shown).
Apply
mortar
Apply mortar
Side Wall
Rear Wall
Side Wall
6.
7.

12
Install Downdraft Diverter and final row of Side Walls
(Figure 17). Then place #3 rebar (8 each, 36 inch long)
vertically through the cells until they reach bottom. Position
them adjacent to the rebar or all-thread sticking up from the
hearth.
All components must be level. Mix approx. 2 cu. ft. of Ready-
Mix Concrete. Fill all cells with Ready-Mix Concrete mix.
Figure 17 Downdraft
Diverter
12 inch
rebar or
all-thread
Set the Lintel and Lower Rear Dome as shown in Figure
19. Check that all is level. If adjustments are needed, use
shims and fill gaps with an appropriate amount of mortar.
Note: Although you are cautioned to use MASON-LITE
mortar sparingly because it does have such holding power,
you should look over the firebox assembly at the end and fill
in any gaps, especially joint connections, with the mortar.
Figure 19
Lintel
Lower Rear
Dome
Important:Adjustments can only be made while the mortar
is still wet when correcting for squareness and leveling.
8.
9.
10.
Assemble Lower Dome Sides as shown in Figure 20. The
beveled face lines up with the inward angles of the lintel
sides. Resulting top surfaces should be level.
Figure 20 Lower Dome Sides (Rating
Plate faces inside)
Verify that the smoke dome side, front and rear walls are
aligning correctly and that the surfaces are smooth and
uniform. Make sure connections are covered with an
adequate amount of mortar. Remember that you have the
option of using shims but they must be removed and any
holes filled. Make any adjustments to the fireplace alignment
before continuing to the next step.
Assemble Upper Dome and Dome Sides as shown in
Figure 21. Check your assembly here. If things are
proceeding as they should be, the finished top surface
should be flat and level.
Figure 21 Upper Dome Sides
Upper Dome
Front/Rear
Finally, set the Dome Top into position. Be sure that it is
flush in every direction as you place it on the crest of the
smoke dome wall assembly. After this is done, proceed to
section on “Installing Damper and Chimney System”.
Note: The chimney hole on the Dome Top is not centered from
front to back - it should be offset closest to the rear of the
fireplace (see Figure 22).
Figure 22 Center of chimney hole is
offset towards the rear.
10”
12-1/2”
MGFP-39/44/49
11.
12.
13.
14.

13
Mason-Lite Firebrick Liner
The firebrick lining is not supplied as part of your Mason-Lite
fireplace but can be purchased from MFI. They are available in
split herringbone and full running bond patterns. (see Figures
24 and 25)
You also have the option to have custom firebrick installed,
but it must be at least 1-1/8” thick.
Before you install the lining, you will need to drill all the
required gas and electrical line feeds and the combustion air
supply access holes.
Disclaimer: Masonry Fireplaces Industries cannot be held
liable for the way firebrick or firebrick mortar performs. It is
not unusual for heat stress cracks to appear on the firebrick or
firebrick mortar during the life of the fireplace.
Insertion of Leg Bracket
Insert metal grate leg lock bracket underneath the rear bricks as
shown and cement in place.
Insert leg here
Firebrick
Bracket
Width of back
grate legs (cen-
ter)
One-way
screw
Burner
leg
Cement in place
Figure 23
Figure 24
Figure 25
Fireplace Finishes & Combustible Trim Clearances
Mantel and Mantel Shelf Clearances – As with any radiant
heat fireplaces, all Mason-Lite Fireplaces must comply with
building code safety clearances, per units that have
openings of 6 sq. ft. (six square feet) or greater. You must
keep combustibles such as trim 8” away from the firebox
opening (for mantel clearances, see Figure 26).
Combustible material
Figure 26 Shelf or trim
safe zone
12”
1”
8”
3”
1.5”
Distances to underside
of shelf or trim
Upper
fireplace
area
Mantel and side clearances
Attention: The manufacturer suggests that when building
out a fireplace, that the owner and installer opt for complete
safety. MFI, therefore, advises that combustible mantel
shelves feature clearances that are more than the 12”
(twelve inch) minimum equal to the projection of the shelf.
As a guide, figure that a 10” (ten inch) wide shelf should be
20” (twenty inches) above the fireplace opening.
Walls That Adjoin – Safety codes and all practical outlooks
insist that your fireplace cannot be installed closer than 2 ft.
(two feet) to any walls in the room the fireplace is housed in
or to any walls of adjoining rooms.
1.
2.

14
Caution in Regards to Combustibles – If any part of the
fireplace or objects in the room (curtains, rugs, paint,
cushions, etc.) start to show warping or discoloration due to
heat from the fireplace, it is time to take immediate action.
Each installation requires a different set of circumstances
to deal with the problem, but one thing is certain: do not
use the fireplace until you have figured out how to address
the problem. You are facing a potential fire hazard. The
manufacturer of the MASON-LITE gas fireplace cannot be
responsible for the make-up of material on the exterior of the
fireplace you have chosen, nor can MFI be held responsible
for the materials in a room that may be responding negatively
to heat. However, in almost all cases, there is a solution to
the problem, either by making adjustments to airflow or the
room itself.
Installing Outside Air
Be mindful that outside, fresh air is not required for the
operation of the Mason-Lite Fireplace. However, local
building codes may require combustion air and it is an
excellent choice in some situations, especially in weather
conditions where homes are very well insulated and
tightly sealed. Check local building codes for specific
requirements.
Install Outside Air Kit - MFP4-AK into the Mason-Lite
Firebox either through the side wall opening provided. The
tubing that goes out of the firebox wall must feed into a
flexible metal conduit as the source for outside combustible
air. It can go straight out through an outside wall or into a
ventilated crawl space. If crawl space is used, check codes
for proper termination.
Be sure that you carefully check the source of the outside
air before you choose the site for your air intake. You don’t
want a place where snow will collect, where bushes or trees
will be growing or a location that is too close to any other
structure.
The suggested maximum height for the air intake tubing
is 50 ft. (fifty feet) above the hearth. That height is if the
intake finishes off at a minimum of 3 ft. (three feet) below
the chimney cap level.
Install a screened termination cap to keep out animals.
Mason-Lite Chimney Systems
Overview
This Mason-Lite gas fireplace may be installed with an
approved 10” B-vent chimney system. A metal chimney adapter
is required to attach the chimney to the top of the firebox. This
can be purchased from FMI: part number MFP-DD.
Installers are cautioned to put the chimney system together
exactly as instructed and shown in chimney manufacturer’s
guide. Any variations may have serious consequences resulting
in an accident or malfunction. If instructions are not followed,
the warranty on the product will become null and void.
3.
1.
2.
3.
4.
5.
Note that the most important aspect of the installation is the
maintenance of minimum required clearances to combustible
materials. Those specific installation requirements must
be followed with great precision as you are dealing with the
potential of fire hazard if the correct combustible limit is not met
and maintained. When you look at the drawings provided in this
section, you will see that actual installations may vary due to
individual design preferences. That is to be expected.
Design and framing specifics may vary from the drawing
to installationy. Clearances to combustibles is a stringent
requirement.
WARNING:
If you do not use chimney manufacturer’s parts and/or if you
do not follow exact instructions for installation of chimney
components, you may be responsible for fireplace malfunction,
an accident or a fire hazard.
Attention: Be advised that your choice of Chimney System
meets the following standards and requirements:
Designed for installation in accordance with National Fire
Protection Standard
Meets requirements of NFPA 211
Designed in accordance with BOCA Basic National Codes
Meets Uniform Building Codes.
General Chimney Requirements for Height and Clearance
When installed, the maximum overall height of the chimney
system from bottom of fireplace to the top/termination chimney
is 40 feet. The minimum installed height of the completed
Chimney System is 14 feet with a straight flue stack, 17 feet if
the chimney includes one or two offset sections.
Throughout the length of the chimney – along the outer
periphery of the flue you must have at least 1” (one inch) of
clearance all around the circumference. When the chimney is
passing through a living space, it must be completely closed off.
A “live” chimney is never allowed to be within reach of humans;
the chimney must be completely designed to be hidden from
view and protected, away from human interaction.
Note that it is acceptable for the chimney’s firestop space and
roof flashing to come in direct contact with common construction
materials, such as drywall, flooring, paneling, plywood, millboard,
particle board and a variety of normal framing materials. Always
follow the specific installation requirements of your selected
chimney manufacturer.
Determining Finished Height for Fireplace
Overview
Figuring out the exact height of the Mason-Lite Fireplace you
are about to install is relatively easy if you follow a few simple
steps. It is a matter of determining the number of chimney
sections and the chimney components that will be required for
the installation. Bear in mind that the minimum height of the
MASON-LITE once installed is 14’0” (fourteen feet) and that it
●
●
●
●

15
is higher if offsets are used. Here is how to calculate the height
of the completed fireplace:
First, ascertain the height of the chimney. This includes the
distance from the very top of the smoke dome to where the
top of the flue ends. That is where the smoke leaves the
flue.
Aside from the chimney sections, include all the components
that you will be using in your installation - anchor plate
damper, firestop spacers, stabilizers, and offsets.
Create a Component Height Chart by measuring each
component and completing the following:
Anchor Plate = 4 ”
Firestop Spacers = _ _ _ _ _ _
Support box = _ _ _ _ _ _
Stabilizers = _ _ _ _ _ _
Offsets = _ _ _ _ _ _
Pipe Sections = _ _ _ _ _ _
(Stabilizer – Must be present on vertical chimneys every
30 feet and on offset chimneys every 10 feet.)
Take the total height of every component that will be included
in your installation and then subtract that from the desired
total height you wish the finished fireplace system to be.
You will need to refer to the chimney manufacturer’s
information in order to figure out the available lengths and
the quantity of the sections that you will need.
The Special Case of Offset Installation
Overview
Special, detailed installation instructions must be given for the
proper handling of offsetting for the chimney system. Maximum
offset is 30 degrees off of vertical and there should be no
more than one offset sequence per chimney system. Under no
circumstances should two offsets be attached to comprise a
60 degree offset configuration. Always maintain at least 2” (two
inches) of clearance around all offset installation for air space
and necessary clearance from combustibles.
Working with Floors and Ceilings
It is quite probable that when your installation must pass through
a floor or ceiling, you will have to opt for a 30 degree angle in
which case you are advised to use a firestop spacer. Should
the length of the chimney below the floor or ceiling be less than
10’ (ten feet), support the chimney at the juncture of the floor/
ceiling with a stabilizer. As in all phases of chimney component
installation, you will want to be sure you are making allowances
at every juncture for the 2” (two inch) clearance space from
combustibles.
1.
2.
3.
4.
5.
Background Information on Offset Installation
When obstructions are present, it will be necessary to
offset sections of the chimney using the 30 degree offset
component and, for every offset component, two elbow
components.
One elbow begins the installation procedure and the second
elbow is used to finish off each section. In all likelihood, a 30
degreeoffsetelbowwill probablybethe firsthardware usedoff
the top of the anchor plate damper.
Note: Under no circumstances should you use an offset
elbow in place of a return elbow. They have distinct purposes
in the configuration of the offset installation and they cannot
be interchanged, part for part.
Depending on the configuration you are contending with,
you may either attach the elbows and offset piping together
or you may need to insert sections of the vertical chimney.
Whatever the scenario, you cannot allow sections of the
chimney to measure more than 20’ (twenty feet) between
the elbows.
Assuming you have sections of vertical pipe that are more
than 10’ (ten feet) measuring between elbows, you must
insert – at midpoint – a chimney stabilizer. When installing
the stabilizer, pull out the support straps with a good amount
of tension and hammer to the frame.
If your offset sections go over 6’ (six feet) in length, you
will need to give added support using a sheet metal screw
– a # 8 x ½” is recommended. The screw will be fastened
underneath the joint.
To ensure a tight fit for the screw, drill a hole that is 1/8”
(one-eighth inch) in diameter right at the chimney joint’s
underside. Be sure that you position the drill at the very
center of where the joint overlaps. Be very careful not to
drill through the inner casting; drill only through the outer
chimney.
Installing Vent Plate and Chimney System
Before installing your B-Vent to the Mason-Lite Firebox you
must install a steel vent plate. The vent plate mudt be installed
in the vertical (open) position on the outside of the vent pipe
and is designed to close-off the chimney in the event the pipe
is removed or fails, thus alerting the operator of a problem.
Next, attach the masonry anchor plate (supplied). The
anchor plate is pre-drilled with holes for four (4) cement wedge-
anchors.
Place the plate and mark the top of the firebox. Then remove
the plate to carefully pre-drill holes for the wedge anchors.
Using the supplied vent plate, apply a 1/4” (one quarter
inch) bead of gasket cement around the base damper lead
pipe. Apply ceramic rope gasket on to the gasket cement.
Apply balance of gasket cement in a 1/4” (one quarter
inch) bead on top of smoke dome top approx. 3” (3 inches)
outside of outlet hole. Install damper on top of unit pressing
damper into cement. Attach using four (4) #8 cement
wedge-anchors.
1.
2.
3.
4.
5.
1.
2.
3.

16
A “B-type” venting system must be connected to the
appliance for venting to outside of building. The following
section is provided as a guide to a standard B-type vent
installation.
Standing codes requirements concerning B-type vent
installations may vary within your state, province or local codes
jurisdiction. Therefore, it is recommended that you check with
your local building codes for specific requirements or in absence
of local codes, follow Section 7.0 of the current National Fuel
Gas Code ANSI Z223.1/NFPA 54 for Category I systems using
double wall B-1 vent pipe.
This gas appliance must be vented to the outdoors only
and may not be terminated into an attic space or into a chimney
flue servicing a solid fuel burning appliance.
This appliance may be vented through a manufactured
chimney system or a masonry chimney using a B-vent adapter
or a chimney liner system if the system is listed, inspected
and approved by local codes and/or building authorities. The
examples shown in Fig. 2 are typical of most B-vent installations
and codes practices.
Example 1: Shows the minimum allowable system height and
lateral offset for an inclination of 60° or greater.
Code specifies that offsets of 60° or greater are considered
horizontal and must follow the 75% rule for lateral to total
vertical system height.
Codes also allows only one offset in the total system when
at 60° or greater.
The total vertical height in this example represents the
minimum height of 8 ft. and therefore the allowable lateral is 6
ft. when the 75% rule applies.
If the lateral length must exceed 75% then the system must
be sized in accordance with the Category I venting tables.
Example 2: Shows a multiple offset each at a 45° inclination.
Multiple offsets are permitted if they do not exceed a 45°
inclination. The total lengths of the two offsets are not required
to meet the 75% allowable rule.
Example 3: Shows a single offset at 45° of inclination and
therefore the lateral length at 10 ft. of offset does not have to
meet the 75% rule.
In each case the offsets must be supported and firestops
must be positioned wherever the vent must pass through a
sub-floor, ceiling joist or an attic overhang.
The vent pipe must terminate vertically into a listed type
vent cap and extend a sufficient height through an approved
roof flashing, roof jack or a roof thimble. At all points the listed
clearances must be maintained.
Vent terminations must be located in accordance with
height and proximity rules of NFPA No. 54.
These rules apply to vents at 12” diameter or less and
require a minimum height in accordance with the roof pitch and
a minimum of 8 ft. distance from a vertical wall or obstruction
(see Fig. 3).
If venting horizontally through a side wall becomes
necessary, a listed thimble approved for use with B-type vent
must be used. Check with your local codes before venting
through a side wall.
Some codes areas allow the use of existing B-type vent
systems if the system is at or above the recommended diameter
of the flue.
The flue connection must be made using listed B-type
connectors and the existing system must be code inspected
for damage and proper installation.
It is not recommended that this appliance be common
vented with an existing gas burning appliance. However, if it
becomes necessary to common vent this appliance, the venting
system must be sized and configured in accordance with the
common venting guides Appendix G of the current National
Fuel Gas Code NFPA No. 54/ANSI Z223.1.
Note: Before connecting this appliance to an existing vent
system or a common venting system, consult with your local
architect, planner, or building official.
Venting Installation
Venting Installation
Figure 2

17
Specifying Chimney Heights
Specifying Chimney Heights
If the horizontal distance from the mid-point of the chimney
to the peak of the roof ridge is less than 10 feet, the top of the
chimney must be at least 2 feet above the roof ridge. This is
called the “2 foot in 10 foot” rule.
If the horizontal distance from the chimney’s center
measured across to the ridge of the roof is more than 10 feet,
the top of the chimney still needs to be at least 2 feet above a
point measured from a distance of 10 feet horizontally along
the roof.
Figure 3
Though there are many configurations in meeting these
requirements, chimney height cannot be less than 3 feet above
the roof at the edge of the chimney.
If the roof is flat, the chimney must extend no less than 3
feet from where it intersects the roof. If the chimney is entering
the roof at an angle, measure the shorter angle where the
chimney intersects the roof which should be at least 3 feet.
Note: The previous guidelines do not take into consideration
outside conditions which may require a higher chimney due
to foliage, other buildings, power lines and weather conditions
in your area. Follow the chimney manufacturer’s installation
guide for further information.
Chimney Termination Units
Chimney Termination Units
You will be installing at or possibly near the top of the
chimney chase flashing. A top termination unit is the essential
piece of equipment in keeping sparks out of the atmosphere.
Before installing this important piece of equipment, you will have
to make a judgment call as to whether or not the termination
unit – like all the other exterior exposed chimney components,
for that matter – should be painted in order to protect it/them
from rusting and weathering. Particularly if you are installing
the fireplace and chimney near water or in a high humidity area,
the manufacturer recommends a top quality, rust-proof paint
especially formulated for metal. Follow the paint manufacturer’s
directions, applying the paint well before you are scheduled to
install the round top termination unit or any of the flashings or
flues that will be exposed to outside weather conditions.
Venting terminals shall not be recessed into walls or siding.
This appliance, when installed, must be electrically grounded
in accordance with local codes and in the absence of local
codes, with the National Electrical Code, ANSI NFPA 70, or the
Canadian Electrical Code, CSA C22.1.
Important Pre-installation Information
Important Pre-installation Information
Before you begin, review the information and safeguards
below regarding the installation and operation of the gas
Fireplace.
This fireplace may only be connected to the gas supply
listed on the label. Never use propane gas in a gas fireplace
designed for natural gas or natural gas in a gas fireplace
designed for use with propane gas.
The gas fireplace must be installed by an MFI Certified or
other qualified professional installer. The installation, including
provisions for combustion and ventilation air, must conform
with local codes, or, in the absence of local codes, with the
latest edition of the National Fuel Gas Code, ANSI Z223.1, and
NFPA54.
Keep the fireplace area clear and free from combustible
materials, gasoline, and other flammable vapors and liquids.
The fireplace must have a gas supply line that has been
installed by a qualified technician in accordance with all local
codes.
The gas supply line must be 1/2” minimum interior diameter. If
the gas line to the fireplace is longer than 5’, a larger diameter
line may be necessary.
Burner P/N BTU*
(x 1000)
Orifice Drill
Size (top/front) Included in
Nat LP
GML-24-01(N)(P) 60 28/48 47/56 MGFP-39 or
-44
GML-30-01N 90 19/41 MGFP-49
GML-30-01P 84 40/55
*Nominal BTU based on gas inlet pressure. Nominal gas inlet
pressure for natural gas is 5” W.C.

18
Figure 27
Vent Plate Installation
Attention: Clearance to combustible construction can not be
reduced during course of construction. For the safe operation of
the finished fireplace, these clearances must be followed when
building the framework to house the chimney system.
Installing the valve/control box assembly
Fasten the valve/control box assembly to a stud such that
the control switch is facing in the desired direction and
flush with the future location of the finished wall or other
enclosure.
Install the two ‘D’ batteries into the battery holder within the
control box.
Run the wires for the spill switch through the small hole
in the upper wall. Important: This control box must remain
accessible and removable for service after installation.
Installing Spill Switch and Baffle assembly
Connect the blade connectors on the spill switch wires to
the matching wires from the valve/ control box assembly
coming through the upper hole in the firebox.
Center the black steel baffle with the spill switch sensor
pointed toward the room (out of the fireplace).
Use six (6) drywalls screws to fasten it in place on the front-
most part of the firebox ceiling as shown through the six (6)
pre-drilled holes.
Attach the trim plates to the left and right side of the baffle
with the sheet metal screws so that the edges are flush with
the firebrick.
Important: This baffle assembly and only this the supplied
assembly (with spill switch) must be properly installed for
the safe operation of this gas fireplace.
1.
2.
3.
1.
2.
3.
4.
Figure 28
Figure 29
Figure 30
Trim
plate
Spillover
switch Trim
plate
Spill sensor
wires to
valve/
control box
Owner’s Operation & Precautions
Installers of the Mason-Lite are urged to call the attention of
fireplace owners to the following precautions.
The installer should hand-deliver this owner’s manual to the
owner or leave behind with the unit after it the installation is
complete.
Warning: Use only the included fireplace grate or manufacturer
approved replacement.
Warning: Do not attempt to operate your fireplace without a fire
safety screen installed.