Desa VJM50, VJM42, VJM36 User Manual

RESIDENTIAL AND OUTDOOR WOODBURNING FIREPLACE

OWNER’S OPERATION AND INSTALLATION MANUAL

(V)JM36, (V)JM42 AND (V)JM50

WOOD BURNING MASONRY FIREPLACES WITH INSULATION

SAVE THIS BOOK
This book is valuable. In addition to instructing you
on how to install and maintain your appliance, it also
contains information that will enable you to obtain re­placement parts or accessory items when needed. Keep
it with your other important papers.

This fireplace is approved for use as a wood burning
fireplace or for use with a vented gas log approved to
ANS Z21.60, Z21.84 or RGA 2-72 standards or for use
with a vent-free gas log heater approved to ANS Z21.11.2
standard.

This wood burning fireplace complies with UL127­CAN/ULS-S610-M87 standard as a FACTORY BUILT
APPLIANCE.

FOR CANADA: The authority having jurisdiction (such
as the municipal building department, fire department,
etc.) should be contacted before installation to deter­mine the need to obtain a permit.

Save this manual for future reference.

For more information, visit www.desatech.com

WARNING: Improper installation, adjustment, altera­tion, service or maintenance can cause injury, property
damage or loss of life. Refer to this manual for assis
tance or additional information. Consult a qualified
installer or local distributor.

TABLE OF CONTENTS

Safety Information ............................................... 2

Specifications ......................................................

Fireplace Installation ........................................... 6

Venting Installation ..............................................

Optional Gas Line Installation ........................... 12

Brick Installation ................................................ 13

5

Glass Door Installation ...................................... 20

Operation and Maintenance Guidelines ............ 21

Technical Service ..............................................

8

Replacement and Accessory Parts ................... 23

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22

SAFETY INFORMATION

IMPORTANT: Check local codes
before installing this fireplace.

Before beginning the installation of the fireplace,
read these instructions through completely.

• This DESA fireplace and its components are
safe when installed according to this installation
manual. Unless you use DESA components,
which have been designed and tested for the
fireplace system, you may cause a fire hazard.

• The DESA warranty will be voided by and
DESA disclaims any responsibility for the
following actions.

a. Modification of the fireplace, components,

doors, air inlet system and damper control.

b. Use of any component part not manufac

tured or approved by DESA in combination

with a DESA fireplace system.
Proper installation is the most important step in
ensuring safe and continuous operation of the
fireplace. Consult the local building codes as to
the particular requirements concerned with the
installation of all factory built fireplaces.

WARNING: Do not install a
fireplace insert in this box unless
the manufacturer's instructions
with the insert specifically state
this fireplace has been tested for
use with this insert.

FOR YOUR SAFETY

• Do not store or use gasoline
or any other flammable vapors
or liquids in the vicinity of this
or any other appliance.

• Due to high temperatures, the
appliance should be located
out of traffic and away from
furniture and draperies.

• Do not place clothing or other
flammable materials on or near
the appliance.

• Never leave children unat
tended when a fire is burning
in the fireplace.

-

WARNING: Use solid wood
or processed solid fuel firelogs
only. When processed wood fuel
fire logs are used, do not poke or
stir the logs while they are burn­ing. Use only fire logs that have
been evaluated for the application
in fireplace and refer to fire log
warnings and caution markings
on packaging prior to use.

This fireplace is not intended to be
used as a substitute for a furnace
to heat an entire home. Use for
supplemental heat only.

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2

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117541-01A

SPECIFICATIONS Continued

10.50

15.375

0.625

45.000

29.0

0

26.625

22.000

36.000

21.500

3.50

10.7

5

1.000

49.000

8.000

58.000

30.000

36.000

45.000

12.000

9.50

7.0

67.000

7.50

0

11/2" AIR SPACE

BACK AND SIDES

0" TO

BOTTOM

GAS LINE

KNOCKOUTS

12" EACH SIDE

COMBUSTIBL

E

WA

LL BOARD

NO COMBUSTIBL

E

MATERIAL ON FA

CE

MINIMUM 12" TO
PERPENDICULA

R

SIDEWA

LL

HEARTH EXTENSION
60" X 20"

1" CHIMNEY AIRSPACE
CLEARANCE TO
COMBUSTIBLE MATERIAL

TERMINATIO

N

SQUARE CHASE-TOP

ROUND TOP TERMINATION

OUTSIDE AIR

20.000

GAS LINE
KNOCK OUTS

AIR KI

T

KNOCK OUT

LEFT SIDE

MODELS VJM36 AND JM36

117541-01A 3

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SPECIFICATIONS Continued

10.50

17.0

0

0.625

51.000

30.500

28.500

21.250

41.250

23.500

24.250

3.50

13.0

0

1.000

49.000

8.000

58.000

30.000

42.000

51.000

12.000

9.50

8.50

67.000

11.000

GAS LINE

KNOCK OUTS

AIR KI

T

KNOCK OUT

LEFT SIDE

OUTSIDE AIR

11/2" AIR SPACE

BACK AND SIDES

0" TO

BOTTOM

GAS LINE

KNOCKOUTS

12" EACH SIDE

COMBUSTIBLE
WALL BOARD

NO COMBUSTIBL

E

MATERIAL ON FA

CE

MINIMUM 18" TO
PERPENDICULA

R

SIDEWA

LL

HEARTH EXTENSION
66" X 20"

2" CHIMNEY AIRSPACE
CLEARANCE TO
COMBUSTIBLE MA

TERIAL

ROUND TOP TERMINATION

TERMINATIO

N

SQUARE CHASE-TOP

MODELS VJM42 AND JM42

4

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117541-01A

MODELS VJM50 AND JM50

10.50

17.0

0

50.000

23.500

32.750

3.50

13.0

0

9.50

8.50

2" CHIMNEY AIRSPACE
CLEARANCE TO
COMBUSTIBLE MA

TERIAL

TERMINATIO

N

SQUARE CHASE-TOP

ROUND TOP TERMINATION

COMBUSTIBLE
WA

LL BOARD

NO COMBUSTIBL

E

MATERIAL ON FA

CE

0" TO

BOTTOM

OUTSIDE AIR

11/2" AIR SPACE

BACK AND SIDES

GAS LINE

KNOCKOUTS

12" EACH SIDE

MINIMUM 18" TO
PERPENDICULA

R

SIDEWALL

HEARTH EXTENSION
74" X 20"

0.625

59.000

38.500

28.500

21.250

11.000

1.000

49.000

8.000

58.000

30.000

50.000

59.000

12.000

67.000

LEFT SIDE

GAS LINE

KNOCK OUTS

AIR KIT

KNOCK OUT

SPECIFICATIONS

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117541-01A 5

FIREPLACE INSTALLATION

30.125

59.250 (50")

58.125

67.125

51.250 (42")

45.250 (36")

28.250 (36")

71.000 (50")

100.000 (50")

65.000 (42")

92.000 (42")

86.500 (36")

61.000 (36")

MAINTAIN 1 1/2"
CLEARANCE AT
SIDES AND BACK
OF FIREPLACE

1 1/2" CLEARANCE
NOT REQUIRED AT
NAILING FLANGES

SELECTING LOCATION

To determine the safest and most efficient location
for the fireplace, you must take into consideration
the following guidelines:

1. The location must allow for proper clearances
(see Figures 1 and 2).

2. Consider a location where the fireplace will
not be affected by drafts, air conditioning
ducts, windows or doors.

3. A location that avoids the cutting of joists or
roof rafters will make installation easier.

4. An outside air kit is available with this fireplace
(see Optional Outside Air Kit on page 8).

MINIMUM CLEARANCE TO
COMBUSTIBLES

Back and sides of fireplace 1 1/2" minimum*

Front of fireplace 48" minimum

Floor** 0" minimum

Perpendicular wall to opening 18" minimum
12" min. JM36

Top spacers 0" minimum

Mantel clearances

Chimney outer pipe surface 2" minimum
1" min. JM36

* Not required at nailing flanges
** See step 2 of Framing

see Mantels, page 7

FRAMING

1. Frame the opening for the fireplace using the
dimensions shown in Figures 1 and 2.

2. If the fireplace is to be installed directly on
carpeting, tile (other than ceramic) or any
combustible material other than wood floor
ing, the fireplace must be installed upon a
metal or wood panel extending the full width
and depth of the fireplace.

3. Set the fireplace directly in front of this open
ing and slide the unit back until the nailing
flanges touch the side framing.

4. Check the level of the fireplace and shim with
sheet metal if necessary.

5. Before securing fireplace to prepared framing,
the ember protector (provided) must be placed
between the hearth extension (not supplied)
and under the bottom front edge of the fire
place to protect against glowing embers falling
through. If the fireplace is to be installed on
a raised platform, a Z-type ember protector
(not supplied) must be fabricated to fit your
required platform height. The ember protector
should extend under the fireplace a minimum
of 1 1/2". The ember protector should be made
of galvanized sheet metal (28 gauge minimum
to prevent corrosion.

6. Using screws or nails, secure the fireplace to
the framing through flanges located on the
sides of the fireplace.

-

-

-

WARNING: Do not pack re­quired air spaces with insulation
or other materials.

Minimum/Maximum Chimney Height for
Residential Installation

The minimum height of the chimney, measured
from the base of the fireplace to the flue gas outlet
of the termination, is 16 feet for straight flue or a
flue with one elbow set. The maximum distance
between elbows is 6 feet. For systems with two
elbow sets, the minimum height is 22 feet. The
maximum height of any system is 50 feet. This
measurement includes the fireplace, chimney sec­tions and the height of the termination assembly
at the level of the flue gas outlet (see Figure 15,
page 11).

Minimum/Maximum Chimney Height for
Outdoor Installation

The minimum height of the chimney, measured
from the base of the fireplace to the flue gas outlet
of the termination, is 9.5 feet (minimum of 4 feet
of chimney pipe sections required for outdoor
installation).

6

Figure 1 - Framing Dimensions

Figure 2 - Corner Installation

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117541-01A

FIREPLACE INSTALLATION

FIREBOX

SAFE ZONE

Continued

Note: For outdoor installations, the fireplace en­closure must allow for adequate drainage and fresh
air ventilation. It is recommended that a sealed,
corrosion resistant catch pan with provision for
drainage be installed under the fireplace within
the fireplace enclosure.

HEARTH EXTENSION

A hearth extension projecting a minimum of 20"
in front of and a minimum of 12" beyond each
side of the fireplace opening is required to protect
combustible floor construction in front of the fire
place. Fabricate a hearth extension using a material
which meets the following specifications: a layer
of noncombustible, inorganic material having a
thermal conductivity of K=0.84 BTU IN/FT, HR.
F (or less) at 1" thick. For example, if the material
selected has a K factor of 0.25, such as glass fiber,
the following formula would apply:

0.25 x 1.0" = 0.30" thickness required

0.84

Thermal conductivity "K" of materials can be
obtained from the manufacturer or supplier of the
noncombustible material. If the hearth extension
is to be covered, use noncombustible material such
as tile, slate, brick, concrete, metal, glass, marble,
stone, etc. Provide a means to prevent the hearth
extension from shifting and seal gap between the
fireplace frame and hearth extension with a non
combustible material (see Figure 3).

WARNING: Hearth extension
is to be installed only as shown

MANTELS

A mantel may be installed if desired (see Figure

4). Woodwork such as wood trims, mantels or any
other combustible material projecting from the
front face must not be placed within 12" (JM36) or
18" (JM42/50) of the fireplace opening. Combus
tible materials above 12" (JM36) or 18" (JM42/50)
and projecting more than 1 1/2" from the fireplace
must not be placed less than 15" (JM36) or 21"
(JM42/50) from the top opening of the fireplace
(NFPA STD 211, Sec. 7-3.3.3).

Mantels or any other combustible material also
may come up to the side edge of the black metal
face of the fireplace just as long as the projection

-

from the front face fall within the limit shown in
Figure 4.

Combustible
Material

Safe
Zone for
Projection of
Combustible
Materials

Upper

Section of

Fireplace

6"

Ref.

15" Min.

(JM36)

21" Min.

(JM42/50)

-

12" Min. (JM36)

18" Min. (JM42/50)

1

12

/

" Ref.

4

33°

3" Nom.

1

1

/

" Max.

2

Fireplace
Opening

in Figure 3.

Fireplace Front

Seal Gap

Ember Protector

Fireplace Front
Raised Hearth

Ember Protector

Hearth

Extension

Fireplace Front
Elevated

Seal Gap

Ember Protector

Figure 3 - Hearth Extension

117541-01A 7

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Top View of Fireplace

7.75" (JM36)

11.5" (JM42/50)

33°

Min. to

Perpendicular

Side Wall

12" - JM36

18" - JM42/50

Figure 4 - Mantel Clearances to

Combustible Material

3" Max.

4.5"

-

VENTING INSTALLATION

OPTIONAL OUTSIDE AIR KIT
(MODEL AK4/AK4F)

The installation of an outside air kit should be per­formed during the rough framing of the fireplace
due to the nature of it's location. Outside combus
tion air is accessed through a vented crawl space
(AK4F) or through a sidewall (AK4).

CAUTION: Combustion air
inlet ducts shall not terminate
in attic space.

Secure to Collars with Metal Tape,
Screws or Straps (Min. of 1/4" x 20"
in size)

Air Inlet
Location
Must Allow
For Bushes
or Snow

LINEAL GAIN

PART NO.

Georgian Fireplace 66 1/2"
12-12DM

12-12HT

18-12DM

-

18-12HT

24-12DM

24-12HT

36-12DM

36-12HT

48-12DM

48-12HT
RLT-12D

RLT-12HT

STL-12D

* The lineal gain for the terminations is mea­sured to the flue gas outlet height.

12" Galvanized
Outer Pipe

DESCRIPTION GAIN (IN)

Pipe Section 10 5/8"

Pipe Section 16 5/8"

Pipe Section 23 5/8"

Pipe Section 34 5/8"

Pipe Section 46 5/8"

Round Termination

Square Chase-Top

with Slip Section

7" to 15"*

7 3/4"

*

Air Inlet
Eyebrow

Vented Crawl Space
(Check Local Codes
Before Installing in a
Vented Crawl Space)

Figure 5 - Outside Air Kit

Vent Hood
Required for
Wall Installation

CHIMNEY PIPE

The DESA chimney system consists of 12, 18, 24,
36 and 48" snap-lock, double-wall pipe segments,
planned for maximum adaptability to individual
site requirements. Actual lengths gained after
fitting overlaps must be taken into consideration
(lineal gain) and are given in the lineal gain chart
(see Figure 6). Lineal Gain is the actual mea
surable length of a part after two or more parts
are connected. For Canada, use chimney parts
designated "HT".

WARNING: The opening in the
collar around the chimney at the
top of the fireplace must not be
obstructed. Never use blown insula­tion to fill the chimney enclosure.

3

"

/

12

8

Stainless
Inner Pipe

Figure 6 - Lineal Gain

Hemmed
End

ASSEMBLY AND INSTALLATION OF
DOUBLE WALL CHIMNEY SYSTEM

Each double wall chimney section consists of a
galvanized outer pipe, a stainless steel inner flue
pipe and a wire spacer. The pipe sections must be as­sembled independently as the chimney is installed.
When connecting chimney directly to the fireplace,
the inner flue pipe section must be installed first with
the lanced side up. The outer pipe section can then
be installed over 5 the flue pipe section with the
hemmed end up. Press down on each pipe section

-

until the lances securely engage the hem on the fire
place starter. The wire will assure the proper spacing
between the inner and outer pipe sections.

Continue to assemble chimney sections as outlined
above, making sure that both the inner and outer
pipe sections are locked together. When install
ing double wall snap-lock chimney together, it is
important to assure the joint between the chimney
sections is locked. Check by pulling chimney
upward after locking. The chimney will not come
apart if properly locked. It is not necessary to add
screws to keep the chimney together (exception

- see Figure 9, page 10).

-

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8

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117541-01A