Monessen Hearth AVFL42NTSC-SR Manual

AVFL Vent Free Fireplace System
Installation & Operating Instructions
Models: AVFL42NTSC-SR
This is an unvented gas-red heater. It uses air
(oxygen) from the room in which it is installed.
Provisions for adequate combustion and ventil-
ation air must be provided. Refer to Page 8.
INSTALLER: Leave this manual with the appliance.
CONSUMER: Retain this manual for future
reference.
• Do not store or use gasoline or other
ammable 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.
– Leave the building immediately.
– Immediately call your gas supplier from
a neighbor's phone. Follow the gas
supplier's instructions.
– If you cannot reach your gas supplier,
call the re department.
• Installation and service must be performed
by a qualied installer, service agency or
the gas supplier.
WARNING: If the information in this manual
is not followed exactly, a re or explosion may
result causing property damage, personal
injury or loss of life.
Monessen • AVFL42NTSC-SR Installation Instructions • 4116-900 Rev. B • 10/19

2
AVFL Vent Free Fireplace
Monessen • AVFL42NTSC-SR Installation Instructions • 4116-900 Rev. B • 10/19
CONTENTS
Thank you and congratulations on your purchase of a Monessen replace.
PLEASE READ THE INSTALLATION AND OPERATION INSTRUCTIONS BEFORE USING THE APPLIANCE!
IMPORTANT: Read all instructions and warnings carefully before starting installation.
Failure to follow these instructions may result in a possible re hazard and will void the warranty.
Standard Work Checklist........................................... 3
Important Safety Information .................................... 4
Building Code Information ......................................... 5
Product Features......................................................... 6
AVFL42 Controls ...................................................... 6
Gas Specications & Orice Size ............................. 6
Gas Pressures .......................................................... 6
Fireplace and Framing Dimensions .......................... 7
Pre-installation Information........................................ 8
Getting Started ......................................................... 8
What You Will Need .................................................. 8
Planning the Installation ........................................... 8
Adequate Combustion and Ventilation Air ................ 8
Fireplace Location .................................................... 9
Clearances & Height Requirements ....................... 10
Good Faith Guidelines for TV Installations ............. 11
Fireplace Installation................................................. 12
Secure Fireplace to Framing .................................. 12
Finishing Material ................................................... 12
Noncombustible Facing Installation ........................ 12
Connect the Gas .................................................... 13
Check Gas Pressure .............................................. 14
Electrical Installation................................................. 15
Wiring Junction Box ............................................... 15
Signature Command®Wiring Diagram ................... 16
Final Installation ........................................................ 17
Bulb Installation ...................................................... 17
Installation of Air Deection Glass .......................... 19
Glass Only Placement ............................................ 19
Glass & Optional Stone Kit Placement ................... 19
Placement of Optional Logs ................................... 20
Operating Instructions.............................................. 21
For Your Safety Read Before Lighting .................... 21
Turning On Unit ...................................................... 22
To Turn Off Gas to Appliance .................................. 22
Signature Command®System Operation ................ 23
Features ................................................................. 23
Battery Installation .................................................. 23
System Conguration/Setup ................................... 23
Cold Climate Option ............................................... 23
Functions/Operation ............................................... 25
Touch Screen Remote Control Operation ............... 26
Troubleshooting ...................................................... 31
Maintenance and Cleaning ....................................... 32
Flame Appearance ................................................. 32
Check the Pilot Flame ............................................ 32
Check Burner Flame Appearance .......................... 32
Cleaning and Servicing .......................................... 33
Replacing Light Bulbs ............................................. 33
Operation and Optional Accessories ...................... 35
Operating Information ............................................. 35
Optional Accessories .............................................. 35
Troubleshooting ........................................................ 36
Signature Command®System ................................ 37
Service Parts.............................................................. 38
Firebox ................................................................... 38
Logs ........................................................................ 39
Signature Command®System ................................ 40
Limited Lifetime Warranty Policy............................. 41
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3
AVFL Vent Free Fireplace
Monessen • AVFL42NTSC-SR Installation Instructions • 4116-900 Rev. B • 10/19
Gas (Pg 13-14)
Proper appliance for fuel type.
Leak check performed and inlet pressure verified.
Verified proper air shutter setting for installation type.
Customer:
Lot/Address:
Model (circle one): AVFL42NTSC-SR
Date Installed:
Location of Fireplace:
Installer:
Dealer/Distributor Phone #
Serial #:
Comments: Further description of the issues, who is responsible (Installer/ Builder/ Other Trades, etc) and corrective
action needed _____________________________________________________________________________________
Comments Communicated to party responsible ____________________ by ______________________on ___________
(Builder / Gen. Contractor/) (Installer) (Date)
?YHW , ON F I SEY
___________________________
___________________________
___________________________
___________________________
___________________________
Appliance Install (Pg. 8-12)
Verified that the chase is insulated and sealed.
Required non-combustible board is installed.
Verifi ed clearances to combustibles.
Fireplace is leveled and secured.
Adequate provisions for combustion and ventilation air have been verified.
___________________________
___________________________
___________________________
___________________________
___________________________
Finishing (Pg 10-12)
Verifi ed all clearances meet installation manual requirements.
Mantels and wall projections comply with installation manual requirements.
___________________________
___________________________
___________________________
___________________________
___________________________
Manual bag and all of its contents are removed from inside/
under the appliance and given to party responsible for use and
operation. Started appliance and veried no gas leaks exist.
___________________________
___________________________
4116-982A 08/19
 = Contains updated information.
Hearth & Home Technologies recommends the following:
• Photographing the installation and copying this checklist for your file.
• That this checklist remain visible at all times on the appliance until the installation is complete.
This standard work checklist is to be used by the installer in conjunction with, not instead of, the instructions contained in this
installation manual.
WARNING! Risk of Fire or Explosion! Failure to install appliance according to these instructions could
lead to a fire or explosion.
ATTENTION INSTALLER:
Follow this Standard Work Checklist
Media & Accessories (Pg 17-21)
All packaging and protective materials removed (inside & outside of appliance).
Media installed correctly.
Accessories installed properly.
Electrical (Pg 15)
Unswitched power (110-120 VAC) provided to the appliance.
Switch wires properly installed.
STANDARD WORK CHECKLIST

4
AVFL Vent Free Fireplace
Monessen • AVFL42NTSC-SR Installation Instructions • 4116-900 Rev. B • 10/19
IMPORTANT SAFETY INFORMATION
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 re, burns,
explosion or carbon monoxide poisoning.
• Do not allow fans to blow directly into the replace. Avoid any drafts that alter burner ame
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 .
1. Due to high temperatures, the appliance should be
located out of trafc 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 ammable 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 quali-
ed service person. To prevent malfunction and/or
sooting, an unvented gas heater should be cleaned
before use and at least annually by a professional
service person. More frequent cleaning may be
required due to excessive lint from carpeting,
bedding materials, etc. It is imperative that control
compartments, burners and circulating air passage-
ways be kept clean.
7. WARNING: Any change to this heater or its controls
can be dangerous.
8. Unvented gas heaters are a supplemental zone
heater. They are not intended to be the primary
heating appliance.
9. CARBON MONOXIDE POISONING: Early signs of
carbon monoxide poisoning are similar to the u with
headaches, dizziness and/or nausea. If you have these
signs, obtain fresh air immediately. Have the heater
serviced as it may not be operating properly.
10. The installation must conform with local codes or, in
the absence of local codes, with the National Fuel
Gas Code, ANSI Z223.l/NFPA54.
11. This unit complies with ANSI Z21.11.2 Unvented
Heaters, latest edition.
12. Do not install the heaters in a bathroom or bedroom.
13. Correct installation of the ceramic ber logs, proper
location of the heater, and annual cleaning are neces-
sary to avoid potential problems with sooting. Sooting,
resulting from improper installation or operation, can
settle on surfaces outside the replace. Refer to log
placement instructions for proper installation.
14. Avoid any drafts that alter burner ame patterns. Do not
allow fans to blow directly into replace. Do not place
a blower inside burn area of rebox. Ceiling fans may
create drafts that alter burner ame patterns. Sooting
and improper burning will occur.
15. Caution: Candles, incense, oil lamps, etc. produce
combustion byproducts including soot. Vent-free
appliances will not lter or clean soot produced by
these types of products. In addition, the smoke and/
or aromatics (scents) may be reburned 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.
16. This is an unvented gas-fired heater. It uses air
(oxygen) from the room in which it is installed. Provi-
sions for adequate combustion and ventilation air must
be provided. Refer to Page 8.
17. This heater shall not be installed in a room or space
unless the required volume of indoor combustion air is
provided by the method described in the National Fuel
Gas Code, ANSI Z223.1/NFPA 54, the International
Fuel Gas Code or applicable local codes.
18. Keep room area clear and free from combustible mate-
rials, gasoline and other ammable vapors and liquids.
19. 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.
20. During manufacturing, fabricating and shipping, various
components of this appliance are treated with certain
oils, lms or bonding agents. These chemicals are not

5
AVFL Vent Free Fireplace
Monessen • AVFL42NTSC-SR Installation Instructions • 4116-900 Rev. B • 10/19
IMPORTANT SAFETY INFORMATION
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. Provide maximum ventilation by opening win-
dows 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.
21. 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.
22. 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).
23. The appliance must be isolated from 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).
24. Do not use this room heater if any part has been under
water. Immediately call a qualied 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.
25. Never burn solid fuels in a replace where a unvented
room heater is installed.
BUILDING CODE INFORMATION
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
This appliance may be installed in an after-
market, 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.
WARNING: This product and the
fuels used to operate this product (liquid
propane or natural gas), and the products
of combustion of such fuels, can expose
you to chemicals including benzene, which
is known to the State of California to cause
cancer and reproductive harm. For more
information go to: www.P65Warnings.
ca.gov.

6
AVFL Vent Free Fireplace
Monessen • AVFL42NTSC-SR Installation Instructions • 4116-900 Rev. B • 10/19
PRODUCT FEATURES
GAS PRESSURES
GAS SPECIFICATIONS & ORIFICE SIZE
AVFL42 CONTROLS
MODEL FUEL
INPUT
(BTU/h)
ORIFICE
SIZE
AVFL42NTSC-SR N AT. 24,500 #50
NATURAL
Inlet Minimum 5.0" w.c.
Inlet Maximum 10.5" w.c.
Regulator Pressure
Setting 3.5" w.c.
Pilot Regulator 3.5" w.c.
FP3020
AVFL controls
Control Board FP3020
Thermocouple
Module
Command Center
AC Module
Figure 1 –
AVFL42 Controls (Control Access Door Shown Open)

7
AVFL Vent Free Fireplace
Monessen • AVFL42NTSC-SR Installation Instructions • 4116-900 Rev. B • 10/19
FIREPLACE AND FRAMING DIMENSIONS
48 3/4" (1238 mm)
48 3/4" (1238 mm)
34 1/2"
(876 mm)
68 15/16" (1751 mm)
13 1/8"
(333 mm)
13 1/2"
(343 mm)
Minimum
Rough
Depth
44" (1118 mm)
Rough Opening Width
1/2"(13 mm)
or 5/8"(16 mm)
43" (1092 mm)
37 1/2" (953 mm)
32"
(813 mm)
Minimum
Rough
Height
32"
(813 mm)
28"
(711 mm)
15 3/16"
(386 mm)
13 1/2"
(343 mm)
5467
AVFL dims
2 1/4"
(57 mm)
4 5/8"
(118 mm)
6 1/16"
(154 mm)
39 3/4" (1010 mm)
Figure 2 –
Fireplace and Framing Dimensions

8
AVFL Vent Free Fireplace
Monessen • AVFL42NTSC-SR Installation Instructions • 4116-900 Rev. B • 10/19
GETTING STARTED
Check your packing list to verify that all listed parts have
been received. You should have the following:
• Unvented gas heater
• Two (2) anchoring screws
• Installation/operating instructions
• 5" non-combustible board
• 2" x 32" deector glass
• Two (2) bags reglass
• Twelve (12) 15 watt bulbs
• One (1) 90 watt bulb
• TSFSC remote control
• One (1) 1-1/8" eyebrow
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
You must have the following items available before pro-
ceeding with installation:
• Manual shutoff valve
• Piping which complies with local codes
• Sediment trap
• Phillips head screwdriver
• Tee joint.
• Pipe sealant approved for use with Natural Gas
(Resistant to sulfur compounds)
• Pipe wrench
PRE-INSTALLATION INFORMATION
WARNING
Gloves are recommended when handling
ceramic ber logs to prevent skin irritation
from loose bers. Logs are fragile — handle
with care.
PLANNING THE INSTALLATION
In planning the installation for the replace 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, how-
ever, and might require a different sequence.
1. Position replace in desired location. Refer to the Fire-
place Location (page 9, Figure 3) and Clearances and
Height Requirements (page 10, Figure 5) sections and
Fireplace and Framing Dimensions (page 7, Figure 2)
illustration found in this manual.
NOTE: Be sure all packing material has been removed
from under the unit.
2. Install following the instructions found in this manual.
3. Field wire main power supply to junction box. Refer to
the Electrical Installation section (page 15). (Electrical
connections should only be performed by an experi-
enced, licensed certied service person).
4. Plumb gas line. Refer to the Connect the Gas (page
13, Figure 7) section found in this manual. (Gas
connections should only be performed by an experi-
enced, licensed/certied service person).
5. Complete nish wall material and/or surround.
ADEQUATE COMBUSTION AND VENTILA-
TION AIR
This heater shall not be installed in a conned space or
unusually tight construction unless provisions are provided
for adequate combustion and ventilation air.
The National Fuel Gas Code, (ANSI Z223.1/NFPA54),
denes a conned space as a space whose volume is less
than 50 cubic feet per 1,000 BTU per hour (4.8m3per kw) of
the aggregate input rating of all appliances installed in that
pace, and an unconned space as a space whose volume
is not less than 50 cubic feet per 1,000 BTU per hour (4.8
m3per 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 a conned space.
Unusually tight construction is dened 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 stripping has been added on openable win-
dows and doors, and
WARNING
Do not install the heater:
•Where curtains, furniture, clothing, or
other ammable objects are less than
36" from the front of the heater.
• In high trafc areas.
• In windy or drafty areas.

9
AVFL Vent Free Fireplace
Monessen • AVFL42NTSC-SR Installation Instructions • 4116-900 Rev. B • 10/19
PRE-INSTALLATION INFORMATION
FP3029
c. Caulking or sealants are applied to areas such as joints
around window and door frames, between sole plates
and oors, between wall-ceiling joints, between wall
panels, at penetrations for plumbing, electrical and gas
lines and other openings.
The following formula can be used to determine the maxi-
mum heater rating per the denition of unconned space:
BTU/Hr = (L1+ L2) Ft x (W) Ft x (H) Ft
50
Consider two connecting rooms with an open area
between, with the following dimensions:
L1 = 151/2 Ft., L2 = 12 Ft., W = 12 Ft., H = 8 Ft.
BTU/Hr = (151/2 + 12) x (12) x (8)
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)
50
FIREPLACE LOCATION
This unvented gas heater requires no outside venting and
burns cleanly and efciency. As a zero-clearance unvented
gas heater, it can be installed against (or recessed into)
any wall that is accessible to a gas line.
Carefully select the best location for installation of your
unvented replace. The following factors should be taken
into consideration.
• Clearance to side wall, ceiling, woodwork and window
or other combustibles. Refer to Clearance and Height
Requirements section on Page 10. Minimum clear-
ances 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 THIS MODEL IN A BEDROOM
OR BATHROOM.
• Location should be out of high trafc areas and
away from furniture and draperies due to heat from
rebox.
• Never obstruct the front opening of the unvented re-
place or restrict the ow of combustion and ventilation
air.
• Minimize modications to existing construction. Refer
to Figure 3 below for location suggestions.
• Do not install in the vicinity where gasoline or other
ammable liquids may be stored. The unvented re-
box must be kept clear and free from the combustible
materials.
WARNING
If the area in which the heater may be
operated does not meet the required volume
for indoor combustion air, combustion and
ventilation air shall be provided by one
of the methods described in the National
Fuel Gas Code, ANSI Z223.1/NFPA 54, the
International Fuel Gas Code or applicable
local codes.
W
H
Counter
Fireplace
FP3029
replace locations
Figure 3 –
Possible Fireplace Locations

10
AVFL Vent Free Fireplace
Monessen • AVFL42NTSC-SR Installation Instructions • 4116-900 Rev. B • 10/19
PRE-INSTALLATION INFORMATION
CLEARANCES AND HEIGHT REQUIREMENTS
Ensure that minimum clearances shown in Figures 4 and
5 are maintained. Left and right clearances are determined
when facing the front of the rebox.
Follow these instructions carefully to ensure safe instal-
lation. Failure to follow these requirements may create a
re hazard.
Sidewall & Mantel Leg Clearances — The clearance from
the inside of the appliance to any combustible adjacent
wall should not be less than 6". Mantel leg clearances are
projected out at a 45° angle. Figure 5
Ceiling Clearance — The ceiling must be at least 36" from
the rebox opening. Figure 5
Back Wall Clearance — The appliance may be placed
against a combustible back wall.
WARNING
The dimensions shown in Figures 4 and
5are minimum clearances to maintain
when 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.
Floor Clearance — The replace may be installed directly
on a combustible oor or a raised platform of an appropriate
height. Do not place replace on carpeting, vinyl, tile or
other soft oor coverings. It may, however, be placed on at
wood, plywood, particle board or other hard surfaces. Be
sure replace rests on a solid continuous oor or platform
with appropriate framing for support so that no cold air can
enter from under the rebox. See note below regarding
oor installation with wide contemporary faces.
Mantel clearances — Must meet the clearance require-
ments detailed in Figure 5. This is for combustible and
non-combustible mantels.
NOTE: When installing at oor level and using the wide
contemporary face, the replace must be raised up a
minimum of 3/4" to allow clearance for ooring material.
Eyebrow
Screws
Eyebrow must be installed with the three (3) screws
provided. Figure 4.
Figure 4 –
Eyebrow Installation
Figure 5 –
Sidewall, Mantel Leg and Ceiling Clearances
14"
18"
12"
6"
FP3007
mantel clearances
36"
Top of Fireplace
Opening
SIDE VIEW
Wall
Insulation
Board
Stud
Standoff
6"
5"
3"
4¹⁄₂"
45°
1"
3¹⁄₂"
FP3008
mantel leg
1¹⁄₂"
2¹⁄₂"
Fireplace
Opening
TOP VIEW
Ceiling
Sidewall