Monessen Hearth DIS33 User manual

This is an unvented gas-fired heater.
It uses air (oxygen) from the room
in which it is installed. Provisions for
adequate combustion and ventilation
air must be provided. Refer to page 9.
READ AND SAVE THESE INSTRUCTIONS
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.
• 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
fire department.
– Installation and service must be performed by
a qualified installer, service agency or the gas
supplier.
MODEL: DIS33
Natural Gas or Propane/LPG
Control Type: Milli-Volt, T-Stat, or
Hi/Lo Remote Control
VENT-FREE FIREPLACE SYSTEMS
INSTALLATION AND OPERATING INSTRUCTIONS
WARNINGS

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CONTENTS
Important Safety Information ..................................3
Product Features......................................................5
Operation..............................................................5
Natural Gas ..........................................................6
Propane/LPG........................................................6
Specifications ...........................................................6
Ignition Controls....................................................6
Pilot.......................................................................6
Thermal Generator ...................................................6
Getting Started..........................................................7
General Installation Information .............................8
Removing Screen .................................................8
Installing Canopy ..................................................8
Codes ...................................................................9
Adequate combustion and Ventilation Air .............9
Clearances and Height Requirements..................11
Fireplace Framing ..................................................14
Securing Heater to Floor........................................15
Connecting the Gas................................................16
Checking Gas Pressure .........................................18
Electrical Wiring (Milli-Volt) ...................................19
Electrical Wiring (Fan)............................................21
Log Placement........................................................22
Fame Appearance...................................................23
Checking the Burner Flame...................................24
Operating Instructions...........................................25
What to Do if You Smell Gas ..............................25
Hi/Lo Control Lighting Instructions......................26
Milli-Volt Control Lighting Instructions.................27
Match Lighting Instructions.................................28
Cleaning and Servicing..........................................29
Troubleshooting .....................................................30
Illustrated Parts Breakdown..................................32
Fireplace Assembly ...........................................32
Gratre and Base Assembly ................................34
Logs ...................................................................36
Warranty ..................................................Back Cover

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9. The installation must conform with local codes or, in
the absence of local codes, with the National Fuel Gas
Code, ANSI Z223.l/NFPA54.
10. This unit complies with ANSI Z21.11.2-2001 Unvented
Heaters.
11. Do not install the heaters in a bathroom or bedroom.
12. Correct installation of the ceramic ber logs, proper
location of the heater, and annual cleaning are necessary
to avoid potential problems with sooting. Sooting,
resulting from improper installation or operation,
can settle on surfaces outside the replace. See log
placement instructions for proper installation.
13. 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.
14. 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 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.
15. This is an unvented gas-red heater. It uses air (oxygen)
from the room in which it is installed. Provisions
for adequate combustion and ventilation air must be
provided. See page 9.
INSTALLER
Please leave these instructions with the owner.
OWNER
Please retain these instructions for future reference .
IMPORTANT
Read these instructions carefully before installing or trying to operate this vent-free gas heater.
IMPORTANT SAFETY INFORMATION
8. 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.
Continued on page 4
• 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 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.
WARNING
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.
7. 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 passageways be kept clean.

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IMPORTANT SAFETY INFORMATION
Continued from page 3
16. Keep room area clear and free from combustible
materials, gasoline and other ammable vapors and
liquids.
17. Unvented gas heaters are a supplemental zone heater.
They are not intended to be the primary heating
appliance.
18. 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.
19. During manufacturing, fabricating and shipping, various
components of this appliance are treated with certain
oils, lms 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.
20. 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.
21. 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).
22. 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).
23. 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.
24. Never burn solid fuels in a replace where a unvented
room heater is installed.
25. Always have a fireplace screen in place when the
appliance is in operation and, unless other provisions
for combustion air are provided, the screen must have
an opening(s) for induction of combustion air.
THIS APPLIANCE MAY BE
INSTALLED IN AN AFTERMAR-
KET, PERMANENTLY LOCATED,
MANUFACTURED (MOBILE)
HOME, WHERE NOT PROHIB-
ITED 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.

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Control Access Door
Your vent-free replace must be mounted to the oor or the replace hearth.
OPERATION
This unvented gas heater requires no outside venting and burns cleanly with high heating efciency.
Piezo Ignitor
Fireplace
Screen
Control Knobs
PRODUCT FEATURES
Optional
Face Plate
Figure 1 - Unvented Gas Heater with Control Access Door Open
On/Off Switch
Optional Blower
Optional T-Stat
Sensor

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NATURAL GAS
Milli-Volt and T-Stat Pressure Hi/Lo Pressure
Regulator Pressure Setting: 3.5" w.c. Regulator Pressure Setting: 3.5" w.c.
Pilot Regulator: 3.5" w.c. Pilot Regulator: 3.5" w.c.
Gas Inlet Pressure: Max. 10 1/2" w. c. Gas Inlet Pressure: Max. 11" w.c.
Min. 5" w.c. Min. 6" w.c.
PRODUCT FEATURES AND SPECIFICATIONS
PROPANE/LPG
Note: An external regulator is required to reduce supply pressure to a maximum of 13" w.c.
Milli-Volt and T-Stat Pressure Hi/Lo Pressure
Regulator Pressure Setting: 10" w.c. Regulator Pressure Setting: 10" w.c.
Gas Inlet Pressure: Max. 13" w.c. Gas Inlet Pressure: Max. 13: w.c.
Min. 11" w.c. Min. 12" w.c.
Gas Rate
Model Number Control Max BTU/Hr Min BTU/Hr
DIS33NTC MILLI-VOLT 28,000 18,000
DIS33NVC T-STAT 28,000 18,000
DIS33NHC HI/LO REMOTE 28,000 18,000
IGNITION CONTROLS
Piezo ignitor allows ignition of the pilot without the use of matches or batteries.
Hi/Lo valve control has four (4) positions:
OFF - All gas to the gas logs is shut off at the valve.
PILOT - Valve position to light/maintain a standing pilot.
ON - Valve position to turn ON.
HI/LOW - Variable position corresponding to desired ame height back to pilot.
Milli-Volt and T-Stat 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 ame height (heat output). Both front and rear burners are in operation
to provide realistic glow and yellow ame.
PILOT
The gas log heater is tted with a specially designed safety pilot light (ODS assembly) 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 tted with a milli-volt generator to provide power for remote activation.
Gas Rate
Model Number Control Max BTU/Hr Min BTU/Hr
DIS33PTC MILLI-VOLT 28,000 20,000
DIS33PVC T-STAT 28,000 20,000
DIS33PHC HI/LO REMOTE 28,000 21,000

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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:
• Installation/Operating instructions • Brass Louvers (5)
• 33" unvented gas heater with simulated brick panels. • Canopy
• Plastic bag containing crushed volcanic rock • Two (2) anchoring screws
• Mounting screws for canopy • Remote Control (Hi/Lo Model Only)
• Log box contains a four (4) piece log set, refer to installation instructions
Accessory face plates available to nish the insert.
• DIFACESM Black small face 33"H x 43"W • DIFACELG Black large face 36"H x 50"W
• JADE Jade simulated marble small face 33"H x 43"H
Accessories include brass trim and mounting hardware
The milli-volt controlled version of this heater is the only style designed to be operated with optional devices for
ON/OFF functions. The following options may be used with the milli-volt controlled heater. These options are not
packaged with the log set.
• Hand held Remote with Receiver • Wall switch with 15' wire. • Wall T-stat with 15' wire.
• Hand held Thermostat Remote with Receiver • Thermostat Sensor
• 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.
WARNING
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 / L.P.G. and 1/2 lb. Natural Gas Systems only)
• Piping which complies with local codes • Sediment trap
• Tee joint • Pipe wrench or appropriate size crescent wrench set
• Phillips head screwdriver • Drill with 5/32" bit
• Optional face plate kit. • Manual shutoff valve
• Optional trim kit for installation into wall or free standing Mantle without three piece faceplate
• Pipe sealant approved for use with propane / LP.G (Resistant to sulfur compounds)

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REMOVING SCREEN
Remove replace screen by pushing screen frame panel
up and out. See Figure 2.
Figure 2 - Removing Fireplace Screen
GENERAL INSTALLATION INFORMATION
INSTALLING CANOPY
1. Remove the replace screen as described in the previous section.
2. Align canopy with the holes in the top frame assembly. See Figure 3.
3. Install the ve (5) screws (in owner’s manual packaging) which attach the canopy to the top frame assembly.
See Figure 3.
4. Tighten all screws. Make sure the canopy is level and secure. Install the replace screen.
Figure 3 - Installing Canopy
Do not operate the unit without
the screen frame panel and canopy
installed.
WARNING
NOTE: Fireplace screen must
be removed to access log box
and to install canopy.

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GENERAL INSTALLATION INFORMATION
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
ADEQUATE COMBUSTION AND VENTILATION 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 (4.8 m3 per kw) of the aggregate input rating of all appliances installed in that
space 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
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 unconned 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 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 at other openings.
Do not install the heater …
• Where curtains, furniture, clothing, or other flammable objects are less than 42"
from the front of the heater.
• In high traffic areas.
• In windy or drafty areas.
WARNING

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

WARNING
The following formula can be used to determine the maximum 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
GENERAL INSTALLATION INFORMATION
Figure 4 - Example of a Large Room with 1/2 Wall Divider
Counter
Fireplace
x 1000
x 1000 = 52800 BTU/Hr
x 1000 = 29760 BTU/Hr
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/NFPA54, Section 5.3 or applicable local codes.
WARNING