Monessen Hearth MAGNUM MCUF36E-F User manual







     
    


Installation and
Operating Instructions
264720
MCUF cover
 
     

 
  
  

      


  

     
    

      
     
Do Not Build a Wood Fire.

     
     



   



26D4720 2/13 Rev. 10

26D4720
2
MCUF Series Vent-Free Firebox 
 
 
Before You Start .......................................................................................................... 5
What You Will Need for Installation ............................................................................. 5
Firebox and Framing Dimensions ............................................................................... 6
Minimum Hearth Dimensions ...................................................................................... 6
 
 
 
 

 
 
Brass or Chrome Trim ............................................................................................... 15
Optional Wide Canopy .............................................................................................. 15
Forced Air Kit ............................................................................................................ 15
 
 





3
26D4720
MCUF Series Vent-Free Firebox


Please leave these instructions with the appliance.

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.
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 exces-
sive lint from carpeting, bedding material, etc. It is
imperative that control compartments, burners and
circulating air passageways be kept clean.
8.    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.
9. The installation must conform with local codes or, in
the absence of local codes, with the  

10. This unit complies with ANSI Z21.91 ventless rebox
enclosures for gas-red unvented decorative room
heaters.
11. Do not install heater in a bathroom or bedroom.
12. Correct installation of the 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.  Candles, incense, oil lamps, etc. produce
combustion byproducts including soot. Vent-free appli-
ances will not lter or clean soot produced by these
types of products. In addition, the smoke and/or aro-
matics (scents) may be reburnt in the vent-free appli-
ance which can produce odors. It is recommended to
minimize the use of candles, incense, etc. while the
vent-free appliance is in operation.
15. An unvented gas-red 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.
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 a primary heating appli-
ance.
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.

26D4720
4
MCUF Series Vent-Free Firebox 
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 pres-
sures 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 replace screen in place when the
appliance is in operation, and unless other provisions
for combustion air are provided, the screen shall have
an opening(s) for induction of combustion air.
26. Do not ll spaces around the rebox with insulation or
other materials. These spaces must be maintained to
prevent the rebox from coming in contact with com-
bustible materials.
Nous recommandons que nos
appareils de chauffage au gaz
soient installés et entretenus par
des professionnels qui ont été
accrédités aux È.U. par le National
Fireplace Institute ® (NFI) comme
étant des spécialistes du NFI en
matièred’appareils de chauffage
au gaz.


It is normal for replaces fabricated of steel
to give off some expansion and/or contraction
noises during the start up or cool down cycle.
Similar noises are found with your furnace heat
exchanger or car engine.


It is not unusual for gas replace to give off some
odor the rst time it is burned. This is due to the
manufacturing process.



It is recommended that you burn your replace
for at least ten (10) hours the rst time you use it.
Place the fan switch in the “OFF” position during
this time.

     



5
26D4720
MCUF Series Vent-Free Firebox


       





The MCUF36 and MCUF42 Series are vent-free reboxes.
They feature a self contained heat-circulating system.
This installation manual will enable you to obtain a safe,
efcient and dependable installation of your vent-free
rebox.
Do not alter or modify the rebox or its components under
any circumstances. Any modication or alteration of the
rebox system, including but not limited to the rebox and
accessories, may void the warranty, listings and approvals
of this system and could result in an unsafe and potentially
dangerous installation.

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 the parts in good condition.

Check your packing list to verify that all listed parts have
been received. You should have the following:
1. Vent-Free Gas Firebox
2. Canopy
3. Installation and Operating Instructions
4. Five (5) sheet metal screws for canopy


• Phillips screwdriver • Square
• Framing materials • Hammer
• Saw and / or sabersaw • Tee joint
• Level • Pipe wrench
• Measuring tape • Pliers
• Electric drill and bits
• Fireplace surround materials (noncombustible)
• Caulking material (noncombustible)
• Piping complying with local codes
• Wall nishing materials
• Pipe sealant approved for use with propane/L.P.G.
(resistant to sulfur compounds)
Refer to the installation instructions provided with the log
sets for items required for log set installation.

     
   

    

   
    
     

In planning the installation for the appliance 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 rebox prior to framing or into prepared fram-
ing.
2. Field wire main power supply to models with fan kit.
(Electrical connections should only be performed by an
experienced, licensed /certied tradesman).
3. Plumb gas line. (Gas connections should only be per-
formed by an experienced, licensed/certied trades-
man).
4. Install vent-free gas log heater per the instructions
provided with the vent-free gas log heater.
5. Complete nish wall material, surround and optional
hearth extension to your individual taste.

26D4720
6
MCUF Series Vent-Free Firebox 
E
D
F
G
556M”
3256”
256O”
6”
A
B
256O”
2656M"
96M”
856M”
376”
C
264720
MCUF dims
Min. Rough
Opening
Depth
Min. Rough
Opening
Height
H - Min. Rough Opening Width
K
J
J
L
376M”
I
  
A 41Z\v" 47"
B 36" 42"
C 18Z\v" 18Z\v"
D 32" 38"
E 20C\v" 20C\v"
F 27Z\v" 33Z\v"
G 33M\," 39M\,"
H 41Z\v" 47Z\v"
I 17C\v" 17C\v"
J 48C\v" 53"
K 68M\," 74M\,"
L 34Z\x" 37Z\x"
Figure 1 -
Firebox and Framing Dimensions
A
B
C
DE
FP2686
hearth dims
    
A 26Z\v" 25C\v" 32Z\v" 31C\v"
B 15" 14C\v" 15" 14C\v"
C 32B\," 31Z\," 38B\," 38Z\,"
D 25" 25" 25" 25"
E 20Z\x" 20Z\x" 20Z\x" 20Z\x"
Figure 2 -
Minimum Hearth Dimensions

7
26D4720
MCUF Series Vent-Free Firebox


Carefully select the best location for installation of your
vent-free rebox. The following factors should be taken
into consideration:
• Clearance to side wall, ceiling, woodwork and windows.
Refer to “Clearances/Height Requirements on Page 8.
Minimum clearances to combustibles 

• 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 com-
bustion air.
• Location should be out of high trafc or windy or drafty
areas.
• 


• Never obstruct the front opening of the vent-free rebox
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 vent-free rebox
must be kept clear and free from these combustible
materials.
FP2440
fireplace locations
Figure 3 -
Possible Firebox Locations

Ensure that minimum clearances shown in Figures 4
through 7 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.
1. The clearance from the inside
of the appliance to any combustible wall should not be
less than 6". Figure 4
2. The ceiling must be at least 42”
from the top of the rebox opening. Figure 4
3.    The appliance may be placed
against a combustible back wall.
6"
Minimum
42"
Minimum
6"
Minimum
FP2687
minimum clearances
FP2687
Figure 4 -
Clearance and Height Requirements
 This inner chamber rebox oor must
be installed at least 6" above any combustible ooring
material, such as carpeting or asphalt tile, which is
closer than 14" to the base of the rebox. Figure 5
Or
The inner chamber rebox oor may be installed nearer
to the oor if a minimum of 14" of noncombustible mate-
rial such as slate or marble is installed between the base
of the rebox and the combustible ooring. Figure 6

26D4720
8
MCUF Series Vent-Free Firebox
FP2688
min floor combustible
Combustible
Material
6" Minimum
FP2688
Figure 5 -
Minimum Clearance above Combustible Flooring
14” Minimum
FP2689
min floor clear noncomb
Noncombustible
Material
May be Less
than 6"
FP2689
Figure 6 -
Minimum Clearances above Combustible Flooring with
Noncombustible Material Installed at Base of Fireplace

5. The canopy supplied with the unit
must be installed. If a combustible mantel is installed,
it must meet the clearance requirements as shown in
Figure 7a. However, if lower mantel height is desired,
refer to Figure 7b.
 The Vermont Castings Group Barrington Cabinet
Mantel Model series BWC300, BWC400 and BWC500 are
specially designed to comply with all mantel temperature
requirements. Any custom-built mantel must comply with all
clearance requirements shown in this instruction manual.
12”
10”
8”
6”
256O”
12”
16”
19”
21”
23”
FP2842
Mantel clearances
Figure 7a -
Mantel Clearances
FP2842
12”
8”
8”
14”
FP2691
mantel clear wide canopy
Figure 7b -
Mantel Clearances for Wide Prole Canopy Only
FP2691
45°
1”
256O”
3”
5”
6”
56O”
56O”
56O”
FP2692
mantel leg clearance
Fireplace Finish Wall
Combustible
Material Area
Hood
FP2692
Figure 8 -
Mantel Leg Clearance

9
26D4720
MCUF Series Vent-Free Firebox

Firebox framing can be built before or after the appliance
is set in place. Construct rebox framing following Figure
1. Refer to Figure 1 on Page 6 for rebox dimensions. The
framing headers may rest on the top of the rebox.
The rebox may be installed directly on a combustible oor
or raised on a platform of an appropriate height. When
the rebox is installed directly on carpeting, tile, or other
combustible material, other than wood ooring, the rebox
shall be installed on a metal or wood panel extending the
full width and depth of the enclosure.
Combustibles may not come any closer to the top of the
enclosure than the standoffs will allow.

      
     

1. Bend out the nailing anges located on each side of the
rebox.
2. Slide the rebox into prepared framing or position rebox
in its nal position and frame later.
3. Level the rebox by checking the top edge of the rebox.
Shim if necessary.
4. Anchor rebox to the side framing members using 8d
nails or other suitable fasteners. Figure 9
5. The canopy must be installed for safe operation of
the heater. Refer to Page 11 for canopy installation
details.
FP2693
nailing flanges
Nail Sides
Through
Nailing
Flanges
FP2693
Figure 9 -
Side Nailing Flanges

      
    

When nishing a custom cabinet, mantel, or other built-in
enclosure, the opening size to accommodate the replace
with trim installed is as follows:
 
A 42" 47C\v"
B 38Z\," 38Z\,"
A
B
FP2694
custom cabinet
FP2694
Figure 10 -
Custom Cabinet

26D4720
10
MCUF Series Vent-Free Firebox 

    



 
    
      


      


Consult all local codes. All gas piping must be installed to
comply with local codes, or in the absence of local codes,
with the latest edition of the National Fuel Gas Code ANSI
Z223.1/NFPA54.
Remove the baseplate for ease of gas line installation.
Remove three (3) screws along the front edge of the base-
plate. Remove four (4) screws which secure the baseplate
to the combustion casing (two at rear and one along each
side). Replace baseplate prior to connecting gas line to
heater. Consult heater installation and operating instruc-
tions for correct installation of the heater into the rebox.
The 1/2" gas line may enter either from the left side or right
side of the rebox. Gas access holes are provided on both
sides of the rebox.
A listed manual shutoff valve must be installed upstream
of the appliance. A union tee and plugged 1/8" NPT pres-
sure tapping point should be installed upstream of hte
appliance.
 Install main gas valve (equipment shutoff
valve) in an accessible location. The main gas valve is for
turning on or shutting off the gas to the replace.
A sediment trap may be upstream of the heater to prevent
moisture and contaminants from passing through trap to
the heater controls and burners. Failure to do so could
prevent the heater from operating reliably. Consult appli-
cable codes.
An external regulator must be used on all propane / L.P.G.
heaters, in addition to the regulator tted to the heater, to
reduce the supply tank pressure to 13" w.c. (maximum).
Any copper tubing used to supply propane / L.P.G. from
the tank must be internally tinned.
      








After completing connection, test all gas joints from the
gas meter to the gas heater regulator for leaks. Using
soap and water solution or a gas sniffer. DO NOT USE
AN OPEN FLAME.