Monessen Hearth Vent-Free Fireplace Systems DBX24C* User manual

VENT-FREE FIREPLACE SYSTEMS
INSTALLATION AND OPERATING INSTRUCTIONS
READ AND SAVE THESE INSTRUCTIONS
MODELS
DFX24C
DBX24C*
DFX32C
Natural Gas or
Propane/LPG
Manual or Milli-Volt
*Thermostat Control Only
This is an unvented gas-fired heater. It
usesair(oxygen)fromtheroominwhich
it is installed. Provisions for adequate
combustion and ventilation air must be
provided. See page 9.
WARNINGS
If the information in this manual is not followed
exactly, a fire or explosion may result causing
property damage, personal injury or loss of
life.
– Do not store or use gasoline or other flammable
vapors and liquids in the vicinity of this or any other
appliance.
– WHAT TO DO IF YOU SMELL GAS
• Do not try to light any appliance.
• Do not touch any electrical switch; do not use any
phone in your building.
• Immediatelycallyourgassupplierfromaneighbor's
phone. Follow the gas supplier's instructions.
• If you cannot reach your gas supplier, call the fire
department.
– Installation and service must be performed by
a qualified installer, service agency or the gas
supplier.

2 33D4047
CONTENTS
Important Safety Information.....................................3
Product Features.......................................................5
Product Features and Specifications.........................6
Getting Started ..........................................................7
General Installation Information ................................8
Location of Fireplace ..............................................16
Clearances and Height Requirements ....................17
Fireplace Framing ...................................................18
Connecting the Gas ................................................20
Checking Gas Pressure ..........................................21
Electrical Wiring (Milli-volt) ......................................22
Log Placement ........................................................24
Flame Appearance .................................................26
Installing Rock Wool and Checking Burner Flame..27
Operating Instructions ............................................29
For Your Safety Read Before Lighting...............29
Manual Control Lighting Instructions ................30
Thermostat Control Lighting Instructions ..........31
Milli-Volt Control Lighting Instructions ..............32
Match Lighting Instructions ...............................33
Cleaning and Servicing ...........................................34
Blower and Optional Equipment..............................34
Illustrated Parts
Cabinet Accessories..........................................35
DFX24C Milli-Volt, DFX24C Manual..................36
DFX32C Milli-volt, DFX32C Manual..................38
DBX24C T-stat ..................................................40
Troubleshooting ......................................................42
Warranty .................................................. Back Cover
DFX24C and DFX32C gas log appliances described in this manual feature the
TRIPLE PLAY BURNER SYSTEM® technology
with exclusive triple effect technology
producing a full random yellow flame, full depth ember bed and glowing logs.

33D4047 3
9. This unit complies with ANSI Z21.11.2 unvented heaters
standard.
10. Do not install the DFX Model in a bathroom or bedroom.
The DBX Model may be installed in a bedroom, but not
in a bathroom.
11. Correct installation of the ceramic fiber logs, proper loca-
tion of the heater, and annual cleaning are necessary to
avoid potential problems with sooting. Sooting, resulting
from improper installation or operation, can settle on sur-
faces outside the fireplace. See log placement instructions
for proper installation.
12. Avoid any drafts that alter burner flame patterns. Do not
allow fans to blow directly into fireplace. Do not place
a blower inside burn area of firebox. Ceiling fans may
create drafts that alter burner flame patterns. Sooting and
improper burning will occur.
13. CAUTION: Candles, incense, oil lamps, etc. produce
combustion by-products including soot. Vent-free appli-
ances will not filter or clean soot produced by these types
of products. In addition, the smoke and/or aromatics
(scents) may be reburnt in the vent-free appliance which
can produce odors. It is recommended to minimize the
use of candles, incense, etc. while the vent-free appliance
is in operation.
14. An unvented gas-fired heater uses air (oxygen) from the
room in which it is installed. Provisions for adequate
combustion and ventilation air must be provided. See
installation guidelines.
IMPORTANT
Read these instructions carefully before installing or trying to operate a vent-free gas heater in this firebox.
IMPORTANT SAFETY INFORMATION
1. Due to high temperatures, the appliance be
located out of traffic and away from furniture and
draperies.
2. Children and adults should be alerted to the hazard
of high surface temperature and should stay away
to avoid burns or clothing ignition.
3. Young children should be carefully supervised when
they are in the same room with the appliance.
4. Do not place clothing or other flammable material
on or near the appliance.
5. Any safety screen or guard removed for servicing
an appliance, must be replaced prior to operating
the heater.
6. Installation and repair should be done by a qualified
service person.
7. To prevent malfunction and/or sooting, an unvented
gas heater should be cleaned before use at least
annually by a professional service person. More
frequent cleaning may be required due to excessive
lint from carpeting, bedding material, etc. It is
imperative that control compartments, burners and
circulating air passageways be kept clean.
8. CARBON MONOXIDE POISONING: Early signs of
carbon monoxide poisoning are similar to the flu with
headaches, dizziness and/or nausea. If you have these
signs, obtain fresh air immediately. Have the heater ser-
viced as it may not be operating properly. Continued on page 4
WARNING
• Any change to this heater or its controls can be dangerous.
• Improper installation or use of the heater can cause serious injury or death from
fire, burns, explosion or carbon monoxide poisoning.
• Do not allow fans to blow directly into the fireplace.Avoid any drafts that alter burner
flame patterns.
• Do not use a blower insert, heat exchanger insert or other accessory, not approved
for use with this heater where applicable.
INSTALLER
Please leave these instructions with the appliance.OWNER
Please retain these instructions for future reference .

4 33D4047
IMPORTANT SAFETY INFORMATION
This appliance may be installed in an aftermarket,
permanently located, manufactured (mobile)
home, where not prohibited by local codes.
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.
15. Keep room area clear and free from combustible materi-
als, gasoline and other flammable vapors and liquids.
16. Unvented gas heaters are a supplemental zone heater.
They are not intended to be a primary heating appli-
ance.
17. Unvented gas heaters emit moisture into the living area.
In most homes of average construction, this does not pose
a problem. In houses of extremely tight construction,
additional mechanical ventilation is recommended.
18. During manufacturing, fabricating and shipping, various
components of this appliance are treated with certain oils,
films or bonding agents. These chemicals are not harmful
but may produce annoying smoke and smells as they are
burned off during the initial operation of the appliance;
possibly causing headaches, or eye or lung irritation. This
is a normal and temporary occurrence.
The initial break-in operation should last two to three
hours with the burner at the highest setting. Provide
maximum ventilation by opening windows or doors to
allow odors to dissipate. Any odors remaining after this
initial break-in period will be slight and will disappear
with continued use.
19. Input ratings are shown in BTU per hour and are for
elevations up to 2,000 feet. For elevations above 2,000
feet, input ratings should be reduced 4 percent for each
1,000 feet above sea level. Refer to the National Fuel Gas
Code.
20. The appliance and its appliance main gas valve must be
disconnected from the gas supply piping system during
any pressure testing of that system at test pressures in
excess of 1/2 psig (3.5 kPa).
21. The appliance must be isolated from the gas supply piping
system by closing its equipment shutoff valve during any
pressure testing of the gas supply piping system at test
pressures equal to or less than 1/2 psig (3.5 kPa).
22. Do not use this room heater if any part has been under
water. Immediately call a qualified service technician to
inspect the room heater and to replace any part of the
control system and any gas control which has been under
water.
23. Never burn solid fuels in a fireplace where a unvented
room heater is installed.
24. Always have a fireplace screen in place when the appli-
ance is in operation, and unless other provisions for
combustion air are provided, the screen shall have an
opening(s) for induction of combustion air.
25. Do not fill spaces around the firebox with insulation or
other materials. These spaces must be maintained to pre-
vent the firebox from coming in contact with combustible
materials.

33D4047 5
Piezo
Ignition
Fireplace Screen
Control
Knob
PRODUCT FEATURES
Your vent-free fireplace must be mounted on the floor or on the optional fireplace hearth.
OPERATION
This unvented gas heater requires no outside venting and burns cleanly with high heating efficiency.
This zero-clearance unvented gas heater can be installed against (or recessed into) any wall that is accessible to a gas line.
Figure 1 - Unvented Gas Heater
(Control Access Door Shown Open)
On/Off
Switch

6 33D4047
NATURAL GAS Manual and T-Stat Pressure
Regulator Pressure Setting 4 in. w.c.
Gas Inlet Pressure: Max. 10.5 in. w.c.
Min. 5 in. w.c.
PRODUCT FEATURES and SPECIFICATIONS
IGNITION CONTROLS
Piezo ignitor allows ignition of the pilot without the use of matches or batteries.
Manual control has four (4) positions:
OFF - All gas to the gas logs is shut off at the valve.
IGN - Valve position to light/maintain a standing pilot.
ON - Valve position to turn ON/OFF log set with remote switch/thermostat.
LOW/HI - Variable position to control flame height (heat output). Both front and rear burners are in operation to
provide realistic glow and yellow flame.
Thermostat control has three (3) positions:
OFF - All gas to the gas logs is shut off at the valve.
IGN - Valve position to light/maintain a standing pilot.
LOW/HI - Variable position corresponding to desired temperature.
Continued
Model Number Type Gas Rate Number of
Burners
Max BTU/Hr Min BTU/Hr
DFX24PMC Manual 22,000 17,000 1
DFX24PVC Milli-Volt 22,000 17,000 1
DFX32PMC Manual 26,000 15,000 1
DFX32PVC Milli-Volt 26,000 20,000 1
DBX24PTC T-Stat 10,000 — 1
Milli-Volt Pressure
Regulator Pressure Setting 3.5 in. w.c.
Pilot Regulator 3.5 in. w.c.
Gas Inlet Pressure: Max. 10.5 in. w.c.
Min. 5 in. w.c.
PROPANE / LPG
Note: An external regulator is required to reduce supply pressure to a maximum of 13" w. c.
T-Stat, Manual and Milli-Volt Pressure
Regulator Pressure Setting 10 in. w.c.
Gas Inlet Pressure: Maximum 13 in." w.c.
Minimum 11 in. w.c.
Model Number Type Gas Rate Number of
Burners
Max BTU/Hr Min BTU/Hr
DFX24NMC Manual 22,000 15,000 1
DFX24NVC Milli-Volt 22,000 17,000 1
DFX32NMC Manual 26,000 15,000 1
DFX32NVC Milli-Volt 26,000 20,000 1
DBX24NTC T-Stat 10,000 — 1

33D4047 7
PILOT
The gas log heater is fitted with a specially designed safety pilot light which senses the amount of oxygen available in the
room and shuts the gas log heater off if the oxygen level begins to drop below a satisfactory level. The pilot can only be relit
when adequate fresh air is available.
THERMAL GENERATOR
The milli-volt gas log pilot is fitted with a milli-volt generator to provide power for remote activation.
GETTING STARTED
Make sure you have received all parts:
Check your packing list to verify that all listed parts have been received. You should have the following:
• Unvented gas heater • Two (2) 90°-angle brackets • Trim kit
• Installation/operating instructions • Canopy and three (3) screws • Two (2) anchoring screws
• Ceramic fiber logs • Four (4) black screws
Millivolt controlled heater designed to be operated with optional devices for ON/OFF functions.
• Hand held Remote with receiver • Wall T-stat with 20' wire
• Wall switch with 20' wire • Hand held Thermostat Remote w/receiver
PRODUCT SPECIFICATIONS and GETTING STARTED
Carefully inspect the contents for shipping damage. If any parts are missing or damaged, immediately inform the dealer
from whom you purchased the appliance. Do not attempt to install any part of the appliance unless you have all parts
in good condition.
What you will need for installation:
You must have the following items available before proceeding with installation:
• External regulator (for propane/LPG only) • Manual shutoff valve
• Piping which complies with local codes • Sediment trap
• Phillips head screwdriver • Tee joint.
• Pipe sealant approved for use with propane/LPG • Pipe wrench
(Resistant to sulfur compounds)
CAUTION
• Handle the gas log burner assembly by the grate only. Do not pick the unit up by
the burners.
• Gloves are recommended when handling ceramic fiber logs to prevent skin irritation
from loose fibers. Logs are fragile — handle with care.
Milli-Volt control has four (4) positions:
OFF - All gas to the gas logs is shut off at the valve.
IGN - Valve position to light/maintain a standing pilot.
ON - Valve position to turn ON/OFF log set with remote switch/thermostat.
LOW/HI - Variable position to control flame height (heat output). Both front and rear burners are in operation to
provide realistic glow and yellow flame.

8 33D4047
J
K
I
E
CD
A
B
H
L
GN
M
F
In planning the installation for the fireplace it is necessary to determine where the unit is to be installed and whether optional
accessories are desired. Gas supply piping should also be planned. The following steps represent the normal sequence of
installation. Each installation is unique, however, and might require a different sequence.
1. Position fireplace in desired location. See the Location of Fireplace and Clearances and Height Requirements, and
Firebox Framing sections found in this manual.
Note: Be sure all packing material has been removed from underside the unit.
2. Install canopy and logs per instructions found in this manual. The canopy MUST be installed for safe operation of the
unit.
3. Field wire main power supply to units with fan kit. See the Electrical Section found in this manual. (Electrical connec-
tions should only be performed by an experienced, licensed certified tradesman).
4. Install optional ON/OFF kit on units with millivolt control. See installation instruc-
tions included with the kit and also See the Electrical Wiring section found in this
manual.
5. Plumb gas line. See the Connecting the Gas section found in this
manual. (Gas connections should only be performed by an experienced,
licensed/certified tradesman).
6. Complete finish wall material and/or surround.
Figure 2 - Firebox Dimensions with Screen and Log Sets Removed
GENERAL INSTALLATION INFORMATION
DFX24C/DBX24C DFX32C
A14 213/4
B131/8171/2
C117/8133/8
D910
5/8
E21 27
F47/85
G17 201/4
H11
5/8
I221/2283/4
J11
5/8
K241/232
L45/843/4
M101/212
N261/230

33D4047 9
GENERAL INSTALLATION INFORMATION
ADEQUATE COMBUSTION AND VENTILATION AIR
This heater shall not be installed in a confined space or unusually tight construction unless provisions are provided for
adequate combustion and ventilation air.
The National Fuel Gas Code defines a confined space as a space whose volume is less than 50 cubic feet per 1,000 BTU per
hour (4.8 m3 per kw) of the aggregate input rating of all appliances installed in that space. An unconfined space is defined
as a space whose volume is not less than 50 cubic feet per 1,000 BTU per hour (4.8 m3 per kw) of the aggregate input rating
of all appliances installed in that space. Rooms communicating directly with the space in which the appliances are installed,
through openings not furnished with doors, are considered a part of the unconfined space.
UNUSUALLY TIGHT CONSTRUCTION IS DEFINED AS CONSTRUCTION WHERE…
a) walls and ceilings exposed to the outside atmosphere have a continuous water vapor retarder with a rating of 1 perm (6
x 1011 kg per-pa-sec-m2) or less with openings gasketed or sealed, and
b) weather striping has been added on openable windows and doors, and
c) caulking or sealant are applied to areas such as joints around windows and door frames; between sole plates and doors;
between wall-ceiling joints; between wall panels; at penetrations for plumbing, electrical, and gas lines; and at other
openings.
CODES
Adhere to all local codes or, in their absence, the latest edition of THE NATIONAL FUEL GAS CODE ANSI Z223.1 or
NFPA54 which can be obtained from…
American National Standards Institute, Inc.
1430 Broadway
New York, NY 10018
or
National Fire Protection Association, Inc.
Batterymarch Park
Quincy, MA 02269
WARNING
Do not install the heater
• where curtains, furniture, clothing, or other
flammableobjects are less than42" from the front
of the heater.
• in high traffic areas.
• in windy or drafty areas.

10 33D4047
GENERAL INSTALLATION INFORMATION
Figure 3 - Sample Room for Determining the Maximum Heater Rating
WARNING
If the area in which the heater may be operated is smaller than that defined as an
unconfined space or if the building is of unusually tight construction, provide adequate
combustion and ventilation air by one of the methods described in the National Fuel
Gas Code, ANSI Z223.1, 1992, Section 5.3 or applicable local codes.
The following formula can be used to determine the maximum heater rating per the definition of unconfined space:
BTU/Hr = (L1 + L2) Ft x (W) Ft x (H) Ft. x 1000 BTU/Hr
50
Consider two connecting rooms with an open area between, with the following dimensions:
L1= 151/2Ft., L2= 12 Ft., W = 12 Ft., H = 8 Ft.
BTU/Hr = (151/2+ 12) x (12) x (8) x 1000 = 52800 BTU/Hr
50
If there were a door between the two rooms the calculation would be based only on the room with the heater.
BTU/Hr = (151/2) x (12) x (8) x 1000 = 29760 BTU/Hr
50

33D4047 11
GENERAL INSTALLATION INFORMATION
INSTALLING OPTIONAL FIREBRICK PANELS
1. Remove optional firebrick panels from packaging. Check to See that you have the following:
• 3 firebrick panels • two (2) retainer brackets • two (2) black screws
If any part or parts are missing, contact dealer where you bought fireplace.
2. Turn off fireplace and allow to cool.
3. Remove fireplace screen (See Figure 14, page 14) and logs.
4. Place rear firebrick panel on back wall of firebox. Set bottom of panel behind the bracket tabs of the grate. See
Figure 4.
5. Place one of the side firebrick panels in cabinet. Line up the hole in the retainer clip with the hole inside the firebox.
Using Phillips screwdriver, attach the retainer bracket to inside of firebox. See Figure 5.
6. Repeat step five for the other firebrick side panel.
Figure 4 - Installing Back Firebrick Panel
Figure 5 - Installing Side Firebrick Panel
Bracket
Tabs
Rear
Firebrick
Panel
Retainer
Clip
Side Firebrick
Panel Screw
Hole

12 33D4047
GENERAL INSTALLATION INFORMATION
BLACK TRIM INSTALLATION (DFX24C/DBX24C)
1. Remove black trim from protective packaging. Remove four (4) black screws and 2 (two) 90°-angle trim
brackets from owner’s manual packaging.
2. Lay trim on floor and match corners of side trims to top trim (See Figure 6).
3. Use one 90°-angle trim bracket to join the corner of one piece of side trim to the corner of the top trim piece (See Figure
6). A rubber hammer or handle of a claw hammer will help secure the corners.
4. Repeat for other side.
NOTE: If you do not attach the trim at the correct corners, use a hammer and screwdriver to tap on
the one end of the 90°-angle bracket. This will separate the two pieces of trim (See Figure 8).
5. Place assembled black trim on front of heater. Using four (4) black screws, secure black trim to sides of heater (See
Figure 8).
Figure 6 - Matching and Joining Corners of Black
Trim with 90°-angle Trim Brackets
Figure 7 - Removing the 90°-angled Trim Bracket Figure 8 - Attaching Assembled Black
Trim to Heater
Matched Corners
90°-angle Trim Brackets
Assembled
Black Trim
Black Screw
Holes for Black
Screws
Side Trim
Top Trim
90°-angle Trim Bracket

33D4047 13
GENERAL INSTALLATION INFORMATION
45°-angled
Corners
Back of Trim
Assembly
Top Trim Piece
Side Trim Pieces
90°-angled
Shim
90°-angled
Bracket
Outside Corner Slot
Outside
Corner Slot
Bracket
Screws
BLACK TRIM INSTALLATION (DFX32C)
1. Remove trim from protective packaging. Be careful not
to scratch the trim. Remove two (2) 90°-angled mounting
brackets and two (2) 90°-angled shims.
2. Lay trim face down on the floor. Line up the 45°-angled
corners of the top trim with the 45°-angled corners of the
side trims.
Note: Both ends of the top piece of trim are
mitered. See Figure 9.
3. Slide one (1) 90°-angled bracket (with attached screws)
and one (1) 90°-angled shim in the outside corner slot
where the top and side trims meet. See Figure 10.
4. Hold the corners together securely. Tighten screws on
bracket with flat head screwdriver. Make sure the corners
are flush and there are no spaces. Do not over tighten
screws. See Figure 11.
5. Repeat for other side trim.
6. Slide assembled trim over the top and down the sides of
the fireplace. Flush trim with front of fireplace as shown
in Figure 12.
7. Align holes in assembled trim with holes in side of fire-
place. Using a Phillips screwdriver, attach trim with four
(4) screws provided — two for each side of fireplace.
Tighten snuggly. See Figure 13.
Figure 10 - Securing Corners Together
Figure 11 - Making Sure Corners Are Flush
Assembled Trim
No Spaces
where
Corners Join
Figure 13 - Securing Trim to Heater with Four (4)
Screws Provided
Screws
Screw
Screw
Figure 12 - Sliding Assembled Trim Over the Top
of the Heater
Figure 9 - Lining Up Corners of Trim Kit
Trim Flushed
with Front of
Fireplace
Holes

14 33D4047
REMOVING SCREEN
1. Remove bottom louver. See Figure 14.
2. Removing fireplace screen frame panel by pushing screen frame panel up and out. See Figure 14.
GENERAL INSTALLATION INFORMATION
Figure 15 - Canopy Installation
INSTALLING CANOPY
1. Push louvers up and out to remove top louver assembly.
2. Align the black canopy with the holes in the top frame assembly. See Figure 15.
3. Install the three (3) screws (in owner’s manual packaging) which attach the canopy to the top frame assembly. See
Figure 15.
4. Tighten all screws. Make sure the canopy is level and secure. Install top louver assembly.
Figure 14 - Removing Fireplace Screen Frame Panel
NOTE: Fireplace screen must be removed to access log box and to install canopy.
Canopy
Fireplace
Screen
Canopy
Screws
WARNING
Do not operate the unit without the
screen frame panel and canopy
installed.
Louver

33D4047 15
GENERAL INSTALLATION INFORMATION
SECURING HEATER TO FLOOR OR HEARTH
Note: Clearance requirements as detailed in “CLEARANCES and HEIGHT REQUIREMENTS” section on
page 17 of this manual, must be met before securing the heater in place.
To prevent movement, the heater must be secured to the floor or hearth.
1. Open the control access door and remove the screen.
2. Remove carton containing the four-log set.
3. To remove the grate and base assembly, take out two (2) screws as shown in Figure 16.
4. Lift grate and base assembly out of the firebox.
5. Secure the firebox with two anchoring screws (3/16" x 11/4" length) supplied with the fireplace system. See Figure 17.
Note: If the unit is mounted on carpeting, tile or combustible material without the hearth, a metal or wooden
base covering the entire width and depth of the base must be installed.
Figure 16 - Removing Grate Figure 17 - Securing Heater to Floor or
Hearth
Grate
Screws
3/16" x 1 1/4"
Anchor Screws

16 33D4047
LOCATION OF FIREPLACE
Carefully select the best location for installation of your unvented fireplace. The following factors should be taken into
consideration.
• Clearance to side wall, ceiling, woodwork and window or other combustibles. See Clearances and Height Requirements
section on page 17. Minimum clearances to combustibles must be maintained.
• Location must not be affected by drafts caused by kitchen exhaust fans, ceiling fans, return air registers for forced air
furnaces/air conditioners, windows or doors.
• Installation must provide adequate ventilation and combustion air.
• DO NOT INSTALL THE DFX MODEL IN A BEDROOM OR BATHROOM.
THE DBX MODEL MAY BE INSTALLED IN A BEDROOM, BUT NOT IN A BATHROOM.
• Location should be out of high traffic areas and away from furniture and draperies due to heat from firebox.
• Never obstruct the front opening of the unvented fireplace or restrict the flow of combustion and ventilation air.
• Minimize modifications to existing construction. See Figure 18 below for location suggestions.
• Do not install in the vicinity where gasoline or other flammable liquids may be stored. The unvented firebox must be
kept clear and free from the combustible materials.
Figure 18 - Suggested Locations

33D4047 17
9"
Minimum
42"
Minimum
9"
Minimum
12"
2 1/2"
10"
19"
CLEARANCES and HEIGHT REQUIREMENTS
Figure 20 - Minimum Mantel Clearances
Canopy
Ensure that minimum clearances shown in Figures 14 and 15 are maintained. Left and right clearances are determined when
facing the front of the firebox.
Follow these instructions carefully to ensure safe installation. Failure to follow these requirements may create a fire
hazard.
1. Sidewall Clearances — The clearance from the inside of the appliance to any combustible adjacent wall should not
be less than 9" for the DBX24C/DFX24C and DFX32C. See Figure 19.
2. Ceiling Clearance — The ceiling must be at least 42" from the top of the firebox opening. See Figures 19 and 20.
3. Back Wall Clearance — The appliance may be placed against a combustible back wall.
4. Floor Clearance — The fireplace may not be installed onto any combustible flooring material, such as carpeting, vinyl
or tile without the hearth or a min. 22 Ga (0.030") metal or a minimum 1/2" wooden base covering the entire width and
depth of the base. Combustible material must be installed at least 1" away from the front face of the unit.
5. Mantel clearances — The canopy supplied with the unit must be installed. If a combustible mantel is installed. It
must meet the clearance requirements detailed in Figure 20.
Figure 19 - Clearances and Height Requirements for
DFX24C/DBX24C/DFX32
WARNING
The dimensions shown in Figures 19 and 20 are minimum clearances to maintain in
installing this heater. Left and right clearances are determined when facing the front
of the heater.
Follow these instructions carefully to ensure safe installation. Failure to follow
instructions exactly can create a fire hazard.

18 33D4047
H
G
D
F
E
A
C
C
G
A
1/ " 5/ "
B
A
1
/ 2
"
or
5
/ 8
"
C
A
G
DFX24C DBX24C DFX32C
A243/4243/4321/2
B263/4263/4301/4
C14 14 213/4
D101/2101/2141/2
E421/2421/2533/4
F21 21 263/4
G101/2101/2121/4
H30 30 38
FIREPLACE FRAMING
If unit is to be “built in”, fireplace framing can be built before or after the appliance is set in place. BE SURE THAT ALL
PACKING MATERIAL HAS BEEN REMOVED FROM THE UNDERSIDE OF THE UNIT PRIOR TO SETTING
THE FIREBOX IN PLACE. Construct fireplace framing following Figures 21 through 24. See Figure 2 on page 8 for
fireplace dimensions. The framing headers may rest directly on top of the firebox.
The fireplace may be installed directly on a combustible floor or a raised platform of an appropriate height. Do not place
fireplace on carpeting, vinyl, tile or other soft floor coverings. It may, however, be placed on flat wood, plywood, particle
board or other hard surfaces. Be sure fireplace rests on a solid continuous floor or platform with appropriate framing for
support and so that no cold air can enter from under the firebox.
Anchor fireplace to the side framing members using nailing flanges.
Figure 21 - Corner Installation
Figure 22 - Inside Chase Installation
Figure 24 - Recessed Installation
Figure 23 - Stud Location
Unfinished/rough
framing surface
Unfinished/rough
framing surface
Unfinished/rough
framing surface
5/8" or equivalent
clearance for
drywall/finishing
materials
5/8" or
equivalent
clearance
for drywall/
finishing
materials

33D4047 19
H
J
Nail Sides
Through Nailing
Flanges
1. Bend out the nailing flanges located on each side of the firebox.
2. Slide the firebox into prepared framing or position firebox in its final position and frame later.
3. Level the firebox by checking the top edge of the firebox. Shim if necessary.
4. Anchor firebox to the side framing members using 8d nails or other suitable fasteners. See Figure 26.
5. The canopy must be installed for safe operation of the heater. See page 14 for canopy installation details.
When finishing a custom cabinet, mantel, or other built-in enclosure,
the opening size to accommodate the fireplace with trim installed is
as follows:
FIREPLACE FRAMING
DFX24C w/ trim DBX24C w/ trim DFX32C w/trim
H25 " 25" 3213/16 "
J263/4 "26
3/4 "31 1/4 "
Figure 25 - Custom Cabinet
Figure 26 - Location of Nailing Flanges
WARNING
The fireplace must be installed giving full
consideration to the clearance and height
requirements identified in this manual.

20 33D4047
Pipe Coupling
To Heater
Valve
3"
Minimum
CAUTION
CONNECTING THE GAS
NOTICE: A qualified gas appliance installer must connect the heater to the gas supply. Consult all local
codes.
IMPORTANT: Loosen the pipe adapter on the flex tube before installing to the system piping.
CHECK GAS TYPE: The gas supply must be the same as stated on the heater’s rating plate. If the gas supply is different,
DO NOT INSTALL THE HEATER. Contact your dealer for the correct model.
Always use an external regulator for all propane/LPG heaters only, to reduce the supply tank pressure to a maximum
of 13" w.c. This is in addition to the internal regulator in the heater valve.
Manual Shutoff
Valve
Pipe
Tee Joint
Sediment Trap Pipe Nipple
Cap
Stainless
Flexible Tube
Figure 27 - Gas Connection
CAUTION
Use new black iron pipe, steel pipe, copper tubing or internally tinned copper tubing.
Internally tinned copper tubing can only be used per National Fuel Code, section 2.6.3,
providing gas meets sulfide limits, and where permitted by local codes. Gas piping
system must be sized to provide minimum inlet pressure (listed on Data Plate) at the
maximum flow rate (BTU/Hr). Undue pressure loss will occur if the pipe is too small.
A manual shutoff valve must be installed upstream of the appliance. Union tee and
plugged 1/8" NPT pressure tapping point should be installed upstream of the appliance.
See Figure 27.
A sediment trap should be installed upstream to prevent moisture and contaminants
from passing through the pipe to appliance controls and burners. Failure to do so
could prevent the appliance from operating reliably. See Figure 27.