Desa M36B Safety guide

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NATURAL GAS MODELS
M36(B,H), M42(B,H), VM36(B,H)
AND VM42(B,H)
PROPANE/LP GAS MODELS
M36P(B,H), M42P(B,H),
VM36P(B,H) AND VM42P(B,H)
B-VENT DECORATIVE GAS FIREPLACE
OWNER’S OPERATION AND INSTALLATION MANUAL
FOR YOUR SAFETY
— Donotstoreorusegasolineoranyotherammable
vapors or 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re
department.
— Installationandservicemustbeperformedbyaquali-
edinstaller,serviceagencyorthegassupplier.
INSTALLER:Leavethismanualwiththeappliance.
CONSUMER:Retainthismanualforfuturereference.
WARNING:Iftheinformationintheseinstructions
isnotfollowedexactly,areorexplosionmayresult
causingpropertydamage,personalinjuryordeath.
O-TL REPORT # 114-F-16-4

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 WARNING: Improper installation, adjustment, al-
teration, service or maintenance can cause injury or
propertydamage.Refertothismanualforcorrectin-
stallation and operational procedures. For assistance
or additional information consult a qualied installer,
service agency or the gas supplier.
NOT FOR USE WITH SOLID FUEL
CHECK LOCAL CODES PRIOR TO INSTALLATION
SAVE THIS BOOK
Thisbookisvaluable.Inadditiontoinstructingyouon
howtoinstallandmaintainyourappliance,italsocon-
tainsinformationthatwillenableyoutoobtainreplace-
mentpartsoroptionalaccessoryitemswhenneeded.
Keepitwithyourotherimportantpapers.
Thisappliancemaybeinstalledinanaftermarket*,per-
manentlylocated,manufactured(mobile)home,where
notprohibitedbystateorlocalcodes.
Thisapplianceisonlyforusewiththetypeofgasindi-
cated on the rating plate.
This appliance is not convertible for use with other
gases,unlessacertiedkitisused.
*Aftermarket:Completionofsale,notforpurposeofresale,fromthemanufacturer.
StateofMassachusetts:Theinstallationmustbemade
byalicensedplumberorgastterintheCommonwealth
of Massachusetts.
TABLE OF CONTENTS
Safety .................................................................. 3
Unpacking............................................................ 4
Introduction.......................................................... 4
Selecting Location ............................................... 5
Product Specications......................................... 6
Pre-Installation Preparation................................. 7
Venting Installation .............................................. 9
Installation ..........................................................11
Operation........................................................... 19
Inspecting Burners ............................................ 20
Cleaning and Maintenance................................ 21
Wiring Diagram.................................................. 22
Replacement Parts............................................ 22
Service Hints ..................................................... 22
Technical Service............................................... 22
Troubleshooting................................................. 23
Parts .................................................................. 26
Accessories ....................................................... 31
Warranty ..............................................Back Cover

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108795-01V 3
SAFETY
1. 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 unless a certied kit is used.
2. For propane/LP replace, do not place
propane/LP supply tank(s) inside any
structure. Locate propane/LP supply
tank(s) outdoors. To prevent performance
problems, do not use propane/LP fuel tank
of less than 100 lbs. capacity.
3. If you smell gas
• shut off gas supply
• 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 you gas supplier, call
the re department.
4. Never install the replace
• in a recreational vehicle
• where curtains, furniture, clothing or
other ammable objects are less than
42" from front, top or sides of replace
• in high trafc areas
• in windy or drafty areas
5. This replace reaches high temperatures.
Keep children and adults away from hot
surfaces to avoid burns or clothing igni-
tion. Fireplace will remain hot for a time
after shutdown. Allow surfaces to cool
before touching.
6. Carefully supervise young children when
they are in the room with replace.
7. A hearth extension is not required with this
appliance. If one is installed, it is for aes-
thetic purposes only and does not have
to meet the standard requirements.
8. Turn replace off and let cool before ser-
vicing or repairing. Only a qualied service
person should install, service or repair
this replace. Have replace inspected
annually by a qualied service person.
9. You must keep control compartments,
burners and circulating air passages clean.
More frequent cleaning may be needed due
to excessive lint and dust from carpeting,
bedding material, etc. Turn off the gas valve
and pilot light before cleaning replace.
10. Have venting system inspected annually by
a qualied service person. If needed, have
venting system cleaned or repaired. See
Cleaning and Maintenance, page 21.
WARNING: This product con-
tainsand/orgenerateschemicals
knowntotheStateofCalifornia
tocausecancerorbirthdefects
orotherreproductiveharm.
IMPORTANT:Readthisowner’s
manualcarefullyandcompletely
before trying to assemble, op-
erate or service this replace.
Improper use of this replace
cancauseseriousinjuryordeath
from burns, re, explosions,
electrical shock and carbon
monoxidepoisoning.
DANGER:Carbonmonoxide
poisoningmayleadtodeath!
This replace is a vented product. This replace
will not produce any gas leakage into your home
if properly installed. This replace must be
properly installed by a qualied service person.
If this unit is not properly installed by a qualied
service person, gas leakage can occur.
CarbonMonoxidePoisoning: Early signs of
carbon monoxide poisoning resemble the u,
with headaches, dizziness or nausea. If you
have these signs, the replace may not have
been installed properly. Getfreshairatonce!
Have replace inspected and serviced by a
qualied service person. Some people are more
affected by carbon monoxide than others. These
include pregnant women, people with heart or
lung disease or anemia, those under the inu-
ence of alcohol and those at high altitudes.
Propane/LP gas and natural gas are both
odorless. An odor-making agent is added
to each of these gases. The odor helps you
detect a gas leak. However, the odor added
to these gases can fade. Gas may be present
even though no odor exists.
Make certain you read and understand all
warnings. Keep this manual for reference. It
is your guide to safe and proper operation of
this replace.
WARNING: Any change to
thisreplaceoritscontrolscan
bedangerous.

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11. Keep the area around your fireplace
clear of combustible materials, gasoline
and other ammable vapor and liquids.
Do not run fireplace where these are
used or stored. Do not place items such
as clothing or decorations on or around
replace.
12. Do not use this replace to cook food or
burn paper or other objects.
13. Do not use any solid fuels (wood, coal,
paper, cardboard, etc.) in this replace.
Use only the gas type indicated on re-
place nameplate.
14. This appliance, when installed, must be
electrically grounded in accordance with
local codes or, in the absence of local
codes, with the National Electrical Code,
ANSI/NFPA 70 or the Canadian Electrical
Code, CSA C22.1.
15. Do not obstruct the ow of combustion
and ventilation air in any way. Provide
SAFETY
Continued
INTRODUCTION
adequate clearances around air open-
ings into the combustion chamber along
with adequate accessibility clearance for
servicing and proper operation.
16. Do not install replace directly on carpet-
ing, vinyl tile or any combustible material
other than wood. The replace must set
on a metal or wood panel extending the
full width and depth of the replace.
17. Do not use replace if any part has been
exposed to or under water. Immediately
call a qualied service person to arrange
for replacement of the unit.
18. Do not operate fireplace if any log is
broken.
19. Do not use a blower insert, heat exchang-
er insert or other accessory not approved
for use with this replace.
20. Provide adequate clearances around air
openings.
UNPACKING
The following items are packed inside the
rebox. Remove before positioning rebox
into framing.
• Transition Collar - For vent connection
• Ceramic Log Pack - Shrink-wrapped on
cardboard
• Three (3) plastic bags containing lava rock,
pan and ember materials
• Rear Log - Remove the two plastic quick
ties from around the burner and grate
• Grate Stand - Lift off of burner pan
Check all items for any shipping damage. If
damaged, promptly inform dealer or distributor
where you bought the product.
Safely retain these items for later installation.
Models M36(P)(B,H), VM36(P)(B,H),
M42(P)(B,H) and VM42(P)(B,H) are vented
gas replaces that use a millivolt gas control
valve with a millivolt ignition system. A 6" B-
Type venting system and a listed type vent cap
are not supplied but are required for proper
operation. See venting instructions on pages
9 and 10.
WARNING: This gas appli-
ancemustnotbeconnectedto
achimneyueservicingasolid
fuelburningappliance.
BEFORE YOU BEGIN
Before beginning the installation of your
appliance, read these instructions through
completely.
This DESA Heating, LLC appliance and its
approved components are safe when installed
according to this installation manual and are
operated as recommended by DESA Heating,
LLC. Unless you use DESA Heating, LLC ap-
proved components tested for this appliance,
YOUMAYCAUSEAFIREHAZARD!
The DESA Heating, LLC warranty will be
voided by and DESA Heating, LLC disclaims
any responsibility for the following actions :
A) Modication of the appliance or any of the
components.
B) Use of any component part not approved
by DESA Heating, LLC in combination
with this appliance.
C) Installation and/or operation in a manner
other than instructed in this manual.
D) Burning of anything other than the type of
gas approved for use in this gas appliance.

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108795-01V 5
The installation must conform with local codes
or, in the absence of local codes, with the cur-
rent National Fuel Gas Code, ANSI Z223.1/
NFPA 54. This appliance complies with ANSI
Z21.50/CSA 2.22.
WARNING: Installation of
thisapplianceshould bedone
by a qualied service person
well trained in the installation
of such appliances. You will
alsoneedabuildingpermitfrom
your local Building and Safety
Commissionerbeforeinstalling
this appliance; otherwise your
insuranceco.maynotcoverthis
appliance.
NOTICE: This appliance is not
intendedtobeusedasaprimary
source of heat.
INTRODUCTION
Continued
Figure 1 - Possible Locations for
Installing Appliance
INTERNAL WALL
INSTALLATION
CORNER
INSTALLATION
FULL
PROJECTION
INSTALLATION
FLUSH
INSTALLATION
CAUTION: Do not connect
appliancebeforepressuretest-
inggaspiping.Damagetogas
valvemayresultandanunsafe
conditionmaybecaused.
The appliance and it’s individual shutoff valve
must be disconnected from gas supply piping
system during any pressure testing of that
system at test pressures in excess of 1/2
psig (3.5 kPa).
The appliance must be isolated from the gas
supply piping system by closing its individual
manual 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).
For the purpose of input adjustment two
pressure taps (for IN and OUT pressures)
are provided on the gas control valve for test
gauge connections to the appliance.
Flush installations are recommended where
living space is limited or at a premium and
since the space required to enclose the ap-
pliance would be located beyond an outside
wall, this would also reduce the cutting of
joists, roof rafters and such. Check local
codes for any restrictions.
Projected installations can extend any
distance into the room. A projection may
be ideal for a new addition on an existing,
nished wall.
Corner installations make use of space
that may not normally be used and provides
a wider and more efcient range for radiant
heat transference.
Internalwallinstallations provide a discreet
option for room separation and can also be
ideal as an addition to an existing wall.
SELECTING LOCATION
To determine the safest and most efcient
location for your appliance, you must take into
consideration the following guidelines:
1. The location must allow for proper clear-
ances (see Clearances, page 7).
2. Consider a location where heat output
would not be affected by drafts, air con-
ditioning ducts, windows or doors.
3. A location that avoids the cutting of joists
or roof rafters will make installation easier.
Figure 1 shows a plan view of a few com-
mon locations.

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PRODUCT SPECIFICATIONS
GAS RATING - NATURAL
M36(B,H),VM36(B,H) M42(B,H),VM42(B,H)
Max. Input Rating: 40,000 Btu/Hr 45,000 Btu/Hr
Manifold Pressure: 3.5" WC (.87 kPa) 3.5" WC (.87 kPa)
Minimum Supply Pressure: 4.5" WC (1.12 kPa) 4.5" WC (1.12 kPa)
Maximum Supply Pressure: 10.5" WC (2.66 kPa) 10.5" WC (2.66 kPa)
Orice Size: # 30 # 29
GAS RATING - PROPANE/LP
M36P(B,H),VM36P(B,H) M42P(B,H),VM42P(B,H)
Max. Input Rating: 40,000 Btu/Hr 45,000 Btu/Hr
Manifold Pressure: 10" WC (2.49 kPa) 10" WC (2.49 kPa)
Minimum Supply Pressure: 11" WC (2.74 kPa) 11" WC (2.74 kPa)
Maximum Supply Pressure: 13" WC (3.23 kPa) 13" WC (3.23 kPa)
Orice Size: # 52 # 51
S
T
P
Q
R
X
Outside Air
Kit Location
(Optional)
K
7"
J
I
M
LV
13.5"
1.5"
Glass Door
(Optional)
W
O
N
Alternate Gas
Supply Inlet
7"
G
H
F
A
Stand Off
Collar
For Use With
6"Ø Type B-1
Ve nt Pipe Only
B
E
D
C
DIMENSIONS
HEARTH AREA
7"
Figure 2 - Appliance Dimensions
Model 36 Model 42 Model 36 Model 42 Model 36 Model 42
A 29" 36" I 40 1/4" 44 1/4" Q 13 7/8" 14"
B5/8" 5/8" J 21" 24" R 10 1/2" 12 1/2"
C 41" 48" K 8" 9" S 2 1/2" 2 1/2"
D 12" 14" L 34 3/4" 42" T 8 1/8" 8 1/8"
E 21 1/4" 23" M 42" 49" U 11" 12 3/4"
F 22 1/4" (24" w/o Brick) 29 1/4" (31" w/o Brick) N 36" 40" V 7" 7"
G32 5/8" (34" w/o Brick) 39 1/2" (41 1/4" w/o Brick) O 37" 41" W 2 1/4" 2 1/4"
H 15 3/4" (16 3/4" w/o Brick) 17 3/4" (18 3/4" w/o Brick) P 8 5/8" 10 1/2" X 5" 4 1/2"

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108795-01V 7
PRE-INSTALLATION PREPARATION
Figure 3 - Minimum Clearances
(Top View)
0"
0" Clearance
Nailing
Flange
Front Face
Left Side
Surround
Back
Drywall
2 x 4 Stud
Figure 4 - Minimum Clearances
(Front View)
** **
42" (106.7 cm)
Min. Clearance
from Opening to
Ceiling 0" Clearance
Ceiling
1" (2.5 cm)
Min. Clearance
to "B" Vent's
Outer Pipe
Maintain 2" (5.1 cm)
Min. Clearance to
Transition Pipe as
Measured at Outer
Ve nt Collar
Required air
spaces are
indicated with
an "
*
". Do not
pack with
insulation or
any other
material.
DO NOT BLOCK
OR OBSTRUCT
OPENINGS
0" Clearance to
Combustible or
Noncombustible
Flooring
MANTEL CLEARANCES AND WALL
DETAILS
A combustible mantle shelf maybe installed
a maximum 12" (22.9 cm) from the wall.
Figures 5 and 6 show the minimum allow-
able distances from various combustible
mantle components in relation to fireplace
opening.
Spacer
3" (7.6 cm)
1
1
/
2
"
(3.8 cm) Max.
B
6" (15.2 cm)
A
12"
(22.9 cm)
Combustible
Materials
Header
Figure 5 - Mantel Clearances - Side View
(Cross Section)
M36(B,H),
M36P(B,H)
VM36(B,H),
VM36P(B,H)
M42(B,H),
M42P(B,H)
VM42(B,H),
VM42P(B,H)
A14" (35.6 cm) 15" (38 cm)
B 8" (20.3 cm) 9" (22.9 cm)
1
1
/
2
"
(3.8 cm)
Max. 3" (7.6 cm)
Max.
6" (15.2 cm)
Max. A
B
Outer Surround Combustible
Material May
Be Used
TOP VIEW
SAFE
ZONE
Perpendicular
Wall
Figure 6 - Side Clearances - Top View
(Cross Section)
CLEARANCES
Minimum clearances to combustibles are:
Back and Sides of Outer Surround 0" min.
Drywall to Sides of Front Face
(Nailing Flanges) 0" min.
“B” Vent Surfaces 1" min.
Ceiling to Opening 42" min.
Floor 0" min.
Perpendicular Wall See Figure 6
 CAUTION: Do not block
required air spaces with insu-
lationoranyothermaterial.Do
not obstruct effective opening
of appliance with any type of
facingmaterial.
M36(B,H),
M36P(B,H)
VM36(B,H),
VM36P(B,H)
M42(B,H),
M42P(B,H)
VM42(B,H),
VM42P(B,H)
A9" (22.9 cm) 6" (15.2 cm)
B 12" (30.5 cm) 9" (22.9 cm)

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PRE-INSTALLATION PREPARATION
Continued
FRAMING
1. Frame appliance enclosure as illustrated
in Figures 7 and 8.
Note: If a wall covering is used to line the
enclosure, then all measurements must
be from the surface of the covering.
2. Place the appliance into the framing and
secure it.
Note: If appliance is to be raised above
oor level, a platform must be built to
support the appliance.
3. Install the supply line to the appliance
using a 1/2" NPT black iron gas line ter-
minating 2 5/16" above the bottom of the
appliance. The gas line must be installed
through the lower left side access point or
alternate access hole in the bottom of the
appliance (see Figure 19, page 13).
4. Repack insulation around the gas line to
cover any remaining openings in the con-
duit sleeve. Prepare the incoming gas line
with teon tape or pipe joint compound
and hook-up incoming gas line to the
exible gas line.
Note: If 1/2" NPT black iron pipe does not
mate with tting at the end of exible gas
line, remove tting and replace with a 37°
are 3/4"-12, 1/2" NPT (female) tting.
 WARNING: When nishing
appliance,donotoverlapcom-
bustiblematerialontotheblack
front face. Brick, tile or other
noncombustiblematerialsmay
beappliedtothefaceprovided
that any gap is between the
material used and the face is
caulkedwithanoncombustible
caulking.
Figure 7 - Rough Opening for Installing
in Wall
B
C
A
M36(B,H),
M36P(B,H)
VM36(B,H),
VM36P(B,H)
M42(B,H),
M42P(B,H)
VM42(B,H),
VM42P(B,H)
A 40 3/8" (102 cm) 44 3/8" (112 cm)
B21 3/8" (54.3 cm) 23 1/8" (58.7 cm)
C 41 1/4" (104.8 cm) 48 1/4" (122.6 cm)
Figure 8 - Corner Installation Guidelines
A
B
C
D
M36(B,H),
M36P(B,H)
VM36(B,H),
VM36P(B,H)
M42(B,H),
M42P(B,H)
VM42(B,H),
VM42P(B,H)
A 24 1/2" (62.2 cm) 27 9/16" (70 cm)
B73 7/8" (187.6 cm) 83 7/8" (213 cm)
C 52 3/16" (132.6 cm) 59 5/16" (150.6 cm)
D 17 1/4" (43.8 cm) 19 1/2" (49.5 cm)
These Dimensions Allow for a 3/4"
Clearance at Sides and Back of Fireplace.
However, 0" Clearance is Permitted.
3/4" Clearance Not Required
at Nailing Flanges

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108795-01V 9
INSTALLING TRANSITION PIPE AND
STARTER COLLAR
The transition pipe and starter collar shown
in Figure 9 are supplied with the replace,
unattached and ready for installation. Re-
move starter collar and set aside. Slide
transition pipe over vent collar and attach
with a minimum of three screws. Replace
starter collar over transition pipe and attach
using four screws located on leg stands (ve
used on model M42). To install B-vent piping,
slide the rst piece of B-vent over transition
pipe and attach with either a minimum of two
screws or other means approved by the vent
manufacturer. Figure 9 - Installing Transition Pipe and
Starter Collar
B-Vent Piping
Transition Pipe
Starter Collar
Vent Collar
PRE-INSTALLATION PREPARATION
Continued
VENTING INSTALLATION
60° or greater. The total vertical height in this
example represents the minimum height of 8
feet and therefore the allowable lateral is 6
feet when the 75% rule applies. If the lateral
length must exceed 75% then the system
must be sized in accordance with Category I
venting tables.
Example2: Shows a multiple offset each at
45° of inclination. Multiple offsets are permit-
ted if they do not exceed 45° of inclination. The
total lengths of the two offsets are not required
to meet the 75% allowable rule.
Example3:Shows a single offset at 45° of
inclination and therefore the lateral length at
10 feet of offset does not have to meet the
75% rule.
In each case the offsets must be supported
and restops must be positioned wherever
the vent must pass through a sub-oor, ceil-
ing joist or an attic overhang. The vent pipe
must terminate vertically into a listed type vent
cap and extend a sufcient height through
an approved roof ashing, roof jack or a roof
thimble. At all points listed clearances must
be maintained.
Vent terminations must be located in ac-
cordance with height and proximity rules of
NFPA No. 54. These rules apply to vents at
12" diameter or less and require a minimum
height in accordance with the roof pitch and a
minimum of 8 ft. distance from a vertical wall
or obstruction (see Figure 11, page 10).
A B-type venting system must be connected
to the appliance for venting to the outside of
the building.
The following section is provided as a guide
to a standard B-type vent installation.
Standing codes requirements concerning B-
type vent installations may vary within your
state, province or local codes jurisdiction.
Therefore, it is recommended that you check
with your local building codes for specic
requirements or in absence of local codes,
follow Section 7.0 of the current National Fuel
Gas Code ANSI Z223.1/NFPA 54.
This gas appliance must be vented to the
outdoors only and may not be terminated into
an attic space or into a chimney ue servicing
a solid fuel burning appliance.
This appliance may be vented through a
manufactured chimney system or a masonry
chimney using a B-vent adapter or a chim-
ney liner system if all are listed, inspected
and approved by local codes and/or building
authorities.
The examples shown in Figure 10, page 10
are typical of most B-vent installations and
codes practices.
Example1: Shows the minimum allowable
system height and lateral offset for a 60° or
greater inclination. Code species that offsets
at 60° or greater are considered horizontal
and must follow the 75% rule for lateral to
total vertical system height. Codes also allow
only one offset in the total system when at

www.desatech.com 108795-01V10
Maintain
Listed
Clearance
Maintain
Listed
Clearance
12' Min.
12' Min. 45°
45°
6'
8'
12' Min.
60° 45°
Position
Firestop
Position
Firestop
Position
Firestop
Listed
Vent Cap
Listed
Vent Cap
Listed
Vent Cap
Maintain
Listed
Clearance
Maintain
Listed
Clearance
Maintain
Listed
Clearance
Maintain
Listed
Clearance
Support Each
Lateral At
Least Every
6 Feet
Maintain
Listed
Clearance
10'
EXAMPLE 3EXAMPLE 2
EXAMPLE 1
Figure 10 - Typical B-Vent Conguration
VENTING INSTALLATION
Continued
Some codes areas allow the use of existing
B-type vent systems if the system is at or
above the recommended diameter of the ue,
in this case 6".
The ue connection must be made using
listed B-type connectors and the existing
system must be code inspected for damage
and proper installation.
It is not recommended that this appliance be
common vented with an existing gas burning
appliance.
Note: Before connecting this appliance to an
existing vent system consult with your local
architect, planner or building ofcial.
WARNING: This appliance
must be properly connected
to a system and must not be
connected to a chimney ue
servicing a separate solid fuel
burningappliance.
Lowest
Discharge
Opening
Listed
Ve nt Cap
8 Ft. Min.
Roof Pitch x/12
Listed Clearance
12
x
Listed
Gas
Ve nt
H (Min)
Height
From Roof
Roof Pitch
H(Min.)
Feet Meter
Flat to 6/12 1.0 ax 0.30
6/12 to 7/12 1.25 0.38
Over 7/12 to 8/12 1.5 0.46
Over 8/12 to 9/12 2.0 0.61
Over 9/12 to 10/12 2.5 0.76
Over 10/12 to 11/12 3.25 0.99
Over 11/12 to 12/12 4.0 1.22
Over 12/12 to 14/12 5.0 1.52
Over 14/12 to 16/12 6.0 1.83
Over 16/12 to 18/12 7.0 2.13
Over 18/12 to 20/12 7.5 2.27
Over 20/12 to 21/12 8.0 2.44
Figure 11 - B-Vent Terminations

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108795-01V 11
CHECKING FOR PROPER VENTING
After completing and checking electrical,
gas and vent connections, follow the lighting
instructions and allow main burner to run
for approximately 5 minutes. Hold a lighted
match or cigarette near the top edge of re-
place opening and play it along entire length
of opening (see Figure 12). Proper venting
should tend to draw the ame or smoke into
the appliance. Improper venting or escaping
of spillage of burned gas, is indicated when
the match ickers or goes out. Smoke from a
cigarette will also tend to disperse away from
the appliance.
If appliance is found to be improperly vent-
ing, shut it off and notify your installer or a
qualied service agency to inspect the vent-
ing system.
VENTING INSTALLATION
Continued
Check this area
along entire top
edge of replace
opening. Smoke
or ame should be
drawn into appliance
opening.
Figure 12 - Checking for Spillage
INSTALLATION
Figure 13 - Removing Front Refractory
Access Panel
NOTICE: This appliance is
equipped with a vent safety
shutoff switch which will shut
downtheapplianceinthecase
of a venting problem. Do not
bypasstheventsafetyswitch.If
theapplianceshouldshutdown,
contactaqualiedinstaller,ser-
vice agency or your gas supplier
tohavetheventinspectedbefore
operating.
WALL SWITCH INSTALLATION
The installation of a wall switch allows you to
activate the gas control valve without normal
household electricity since valve operates on
millivolt current supplied by heat generated by
the thermopile. To install wall switch:
1. Remove front refractory access panel by
lifting up and angling out of rebox open-
ing (see Figure 13).
2. Use wire and connectors provided. Attach
red wire to terminal marked TH/TP on
control valve. Attach white wire to blade
connector on open end of safety circuit
wiring (see Wiring Diagram, page 22).
Note: If any of the original wire from unit con-
trol must be replaced, use the same type or a
higher rated wire (25 ft. maximum length).
WARNING:Donotwire re-
motewallswitchtomainpower
supply (Standard 120v house-
holdcurrent).
3. Locate wall switch in a convenient location.
4. After wire connections are complete,
replace refractory access panel.

www.desatech.com 108795-01V12
Conduit Sleeve
To Safety Circuit Route Millivolt
Through Gas Line
To Thermopile
Wires (Supplied)
Wall Switch
(Not Supplied)
(Back View)
IN
TH
TP
THTP
IN OUT
O
F
F
P
I
L
O
T
O
N
Note: If any of the original wire
as supplied must be replaced,
use 18 AWG TYPE CL2 (UL)
105 C (25 ft. length MAXIMUM)
or equivalent.
INSTALLATION
Continued
Figure 14 - Wall Switch Wiring Diagram
Figure 15 - Installing Remote Receiver
(Shown from Rear of Mounting Bracket)
Receiver
Mounting Bracket
Plastic
Mounting
Clips
Figure 16 - Installing Battery in Receiver
Battery
Clip
9-Volt Battery
Receiver
Terminal
Wires
OPTIONAL WIRELESS HAND-HELD
REMOTE CONTROL INSTALLATION
Note: If using optional wireless hand-held
remote control, the wall switch is no longer
operational.
Installing Receiver
1. Remove front refractory access panel by
lifting up and angling out of rebox open-
ing (see Figure 13, page 11) to expose
controls.
2. Disconnect wall switch wires from TH and
TH/TP terminals on control valve (see
Figure 14).
3. Install remote receiver unit onto mounting
bracket using two plastic mounting clips
(see Figure 15).
4. Connect wires to control circuit. Connect
white wire to terminal marked TH/TP on
control valve. Connect red wire to male
blade connector provided at open end of
safety circuit wiring (see Wiring Diagram,
page 22).
5. Locate battery clip mounted on back of
receiver (see Figure 16).
6. Slide 9-volt battery (not included) through
clip. Note: Only use alkaline battery.
7. Attach terminal wires to battery (see Fig-
ure 16).
8. Replace refractory brick access panel.

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108795-01V 13
GAS LINE HOOK-UP
WARNING:Gaslinehookup
should be done by your gas
supplier or a qualied service
person.
WARNING: Before you pro-
ceed,makesureyourgassupply
is OFF.
A manual shutoff valve has been included in
the appliance’s gas supply system. You may
consider installing an extra gas shutoff valve
outside appliance’s enclosure (check with
local codes) where it can be accessed more
conveniently with a key through a wall as
shown in Figure 18.
In conformance with local codes, route a
1/2" NPT gas line to appliance through hole
in left side of rebox or sub-oor as shown
in Figure 19.
CAUTION:Donotkinkex-
iblegasline.
Installing 9-Volt Battery in Hand-Held
RemoteControlUnit
1. Remove battery cover on back of remote
control unit.
2. Attach terminal wires to battery (not
included). Place battery into battery hous-
ing. Note: Only use alkaline battery.
3. Replace battery cover onto remote control
unit.
Figure 17 - Installing Battery in Hand-
Held Remote Control Unit
Battery Cover
9-Volt
Battery
Terminal
Wires
Remote
Control Unit
Battery
Housing
INSTALLATION
Continued
DESA Heating, LLC recommends that a black
iron gas line be routed from the gas source,
through a sediment trap (see Figure 20) and
into appliance. Once connected through ap-
pliance, a exible gas line may be used for
ease of installation to gas control valve (see
Figure 21, page 14).
Before connecting black iron gas line to inside
of appliance a sediment trap must be included
outside appliance between gas line and gas
shutoff valve. It must extend down 3" beyond
center of pipe. Prepare incoming black iron
gas line with teon tape or pipe joint com-
pound (Check with local building codes).
Figure 18 - Manual Shutoff Valve
Installation
Typical Exterior Wall Gas
Shutoff Installation
Key
Extension
Shutoff
Valve
Figure 19 - Routing Incoming Gas Line
A
1/2" NPT
Incoming Black
Iron Gas Line
7"
7"
Alternate Gas Supply
Through Sub-Floor
M36(B,H),
M36P(B,H
VM36(B,H),
VM36P(B,H)
M42(B,H),
M42P(B,H)
VM42(B,H),
VM42P(B,H)
A 8 5/8" (21.9 cm) 10 1/2" (26.7 cm)
Incoming
1/2" Gas Line
Permitted by
Local Codes
Sediment
Trap (Not
Supplied)
Figure 20 - Sediment Trap
3" Min.
(7.6 cm)

www.desatech.com 108795-01V14
P
I
L
O
T
ON
OFF
IN OUT
Figure 21 - Connecting Flexible Gas Line to Millivolt Valve
Gas Shutoff
Valve
Flexible Gas Line
Do NOT Kink
1/2" NPT
Incoming
Gas Line
Note:
1) Wire Connections
Not Shown for Clarity
2) * 1/8" NPT Plugged
Tapping
Red Surface Indicates For
Propane/LP Use Only Pilot Adj
Inlet Pressure Tap
Outlet
Pressure Tap
CAUTION:Compoundsused
onthreadedjointsofgaspiping
shallberesistanttotheaction
of Liqueed Petroleum (LP or
propane)andshouldbeapplied
lightlytoensureexcesssealant
does not enter the gas line.
WARNING: All gas piping
andconnectionsmustbetested
forleaksaftertheinstallationis
completed.
After ensuring that the gas valve
ison,applyacommercialleak
detection solution to all con-
nectionsandjoints.Ifbubbles
appear, leaks can be detected
and corrected.
Donotuseanopenameforleak
testing and do not operate any
applianceifaleakisdetected.
INSTALLATION
Continued
Complete your gas installation by connect-
ing incoming gas line with exible gas line.
Secure tightly with wrench but DO NOT
OVERTIGHTEN.
EMBER AND PAN MATERIAL
PLACEMENT
1. Open bag(s) of vermiculite and ll entire
burner pan until burner tube is completely
covered (see Figure 22).
2. Smooth pan material just even with edges
of burner pan.
3. Remove ember material from bag and
atten small amounts into quarter size
pieces and lay on top of surface of pan
material (see Figure 23).
4. Place just enough to cover entire surface
and leave about a 1/2" gap under lower
grate members to allow air to ow (see
Figure 24, page 15).
Figure 22 - Fill Entire Burner Pan with
Vermiculite
Figure 23 - Ember Material on Surface of
Pan Material (Vermiculite)
Vermiculite
(Pan Material)
Burner Pan
Grate
Ember
Material Burner
Pan
Vermiculite (Pan Material)
Grate

www.desatech.com
108795-01V 15
0.5"
0.5"
Figure 24 - Pan and Ember Material
Clearances
Grate
Burner Pan
Pan and Ember
Material
INSTALLATION
Continued
LOGPLACEMENTFORM36,M36P,
VM36 AND VM36P MODELS
1. Place small front right log (log 1) on right
front of grate as shown in Figure 25.
2. Place large back log (log 2) onto grate
making sure notches rest over grate as
shown in Figure 25.
3. Place log 3 into notch on log 2, resting
front end on top of log 1 (see Figure 26).
4. Place upper end of log 4 into notch on log
2 as shown in Figure 26. Rest lower end
of log 4 onto middle grate nger as shown
in Figure 27.
5. Place upper end of log 5 into notch on left
of log 2 (see Figure 27). Rest lower end
of log 5 on grate as shown in Figure 28.
6. Insert lower end of log 6 between rst
two grate ngers as shown in Figure
28 and position upper end of log 6 into
notched area on front of log 2 as shown
in Figure 28.
As an option to enhance the look of the hearth,
you may place the lava rock provided around
front and sides of burner.
Figure 25 - Installing Logs 1 and 2
Log 1
Log 2
Notch
Figure 26 - Installing Logs 3 and 4
Log 3
Log 4
Log 2
Log 1
Notches
NOTICE:Donotputlavarockin-
sideburnerpanoraroundtheair
mixertting.Placinglavarock
inside burner pan or blocking
openings of the propane/LP air-
mixercouldcauseperformance
problems.
Figure 27 - Installing Logs 5 and 6
Log 5
Log 6
Log 4
Notch
Notch
Figure 28 - Logs Installed for M36, M36P,
VM36 and VM36P Models

www.desatech.com 108795-01V16
INSTALLATION
Continued
LOGPLACEMENTFORM42,M42P,
VM42 AND VM42P MODELS
1. Place large back log (log 1) onto grate
making sure notches rest over grate (see
Figure 29).
2. Insert lower end of log 2A between rst
two grate ngers and position upper end
into notch on front of log 1. See Figure 29.
Place log 2B on front right side of grate as
shown in Figure 29.
3. Place log 3 into notch on top left of log 1,
resting lower end on left two grate ngers
(see Figure 30).
4. Place upper end of log 4 into notch on log
1 as shown in Figure 30. Rest lower end
of log 4 on middle grate nger as shown
in Figure 31.
5. Place upper end of log 5 into notch on top
inner right of log 1 (see Figure 31). Rest
lower end of log 5 on middle grate nger
as shown in Figure 32.
6. Place log 6 into notch on top right of log
1 (see Figure 31). Rest lower end of log
6 on top of log 2B (see Figure 32).
As an option to enhance the look of the hearth,
you may place the lava rock provided around
front and sides of burner pan.
NOTICE: Do not put lava rock
insidetheburnerpanoraround
theairmixertting.Placinglava
rock inside the burner pan or
blockingtheopeningsofthepro-
pane/LPair-mixer couldcause
performanceproblems.
Figure 29 - Installing Logs 1, 2A and 2B
Log 2A
Log 2B
Log 1
Notch
Figure 30 - Installing Logs 3 and 4
Log 4
Log 3
Log 1
Notches
Figure 31 - Installing Logs 5 and 6
Figure 32 - Logs Installed for M42, M42P,
VM42 and VM42P Models
Log 6
Log 5
Notch
Log 1
Log 2B

www.desatech.com
108795-01V 17
INSTALLATION
Continued
COMBUSTION AIR KIT MODEL AK4
(OPTIONAL)
The outside air kit may be installed on the left
side of replace only. The vent can be installed
through any outside wall a minimum of three
feet below fireplace termination cap. The
handle to operate damper door for outside
air inlet will be located inside the left “screen
pocket” of rebox (see Figure 33). Pull handle
to open or push to close.
CAUTION: Air inlet ducts are
nottoterminateinatticspace.
Figure 33 - Air Kit Handle Location
Air Kit
Handle
Screen
Pocket
APPLIANCE ENCLOSURE
Before nishing enclosure around appliance,
inspect all joints around outer surround. Any
gaps between nailing anges and framing
should be sealed with noncombustible insula-
tion or caulking.
If appliance is mounted on a raised platform,
it must be a continuous surface and not
on blocks without a solid surface. This will
prevent the entry of cold air by means of con-
duction through the total bottom of appliance
(see Figure 34).
Side
Framing
Side
Framing
Caulk Here Pack Insulation
Figure 34 - Sealing Between Appliance
and Framing
INSTALLING OPTIONAL GLASS
DOOR ACCESSORY
CAUTION: Use only glass
doorscertiedforusewiththis
appliance.
Note: Glass door may be heavy for some
individuals. Please request help if needed.
The M36, VM36, M42 and VM42 B-vent
replaces are approved for use with optional
bi-fold glass doors (see Accessories, page
31). Glass panels may be ordered and in-
stalled anytime after replace installation is
complete.
Follow these steps to install left and right
panels:
1. With handle at the bottom, completely fold
panel on its hinges.
2. With handle facing center of rebox open-
ing, insert lower pivot pin on glass door
panel into hole in pivot plate on bottom edge
of replace opening (see Figure 35).
3. Keeping folded door tilted, slide upper two
pins into guide track found under upper
facial edge of rebox opening.
4. Tilt glass assembly fully vertical until outer
pivot pin snaps into mounting hole in up-
per spring clip (see Figure 35).
5. Once top and bottom pins are secured,
unfold door into the closed position.
Figure 35 - Installing Optional Glass
Door
Spring Clip
Insert Pin Into Spring Clip
Insert Bottom Pivot Pin Into
Pivot Plate and Swing Door
Into Vertical Position
Pivot Plate
Slide Top
Pin Into
Door Track

www.desatech.com 108795-01V18
6. Repeat the process for the opposite door
assembly.
7. To adjust doors, slide them partially open.
Using a screwdriver, loosen hold-down
screws in the spring clip (see Figure 36)
and pivot plate.
8. Close both doors until evenly joined at the
middle and note the gap at outer edges of
face.
9. Reopen one door at a time and retighten
upper and lower hold-down screws.
10. Repeat process until both doors are even-
ly joined, spaced and working freely.
CAUTION: The glass pan-
els become very hot while the
appliance is operating. Do not
attempt to adjust or clean the
glass doors until the appliance
has fully cooled.
The doors may be removed for replacement
or cleaning as follows:
1. Partially open door and press up on upper
spring clip with a screw driver until outer
top pivot pin is free of clip.
2. Fully fold frame assembly and slide upper
edge towards center of rebox opening
until guide pins are free of frame rail (see
Figure 37).
 CAUTION: Always operate
theappliancewiththedoorsei-
ther fully opened or fully closed.
Operating the appliance with
the doors partially open can re-
sultinimproperventingofue
products.
INSTALLATION
Continued
Figure 36 - Adjusting Glass Doors
Spring
Clip
Hold-Down
Screw
Side
Front
Face
Partially
Opened
Door
Figure 37 - Removing Glass Doors
Spring Clip
Press
Spring Clip
to Release
Pivot Pin
Remove Bottom Pin From
Pivot Plate While Sliding Door
Out of the Upper Track Pivot Plate
Fold Bi-Fold
Door After
Releasing
Spring Clip
and Slide
Door Out of
Upper Track
OPENING VENT DAMPER
Vent damper must be locked in the full open
position before operating replace. If vent
damper is not open, replace will not light.
CLOSEOPEN
VENT DAMPER MUST BE LOCKED
IN THE FULL OPEN POSITION
TO OPERATE THE APPLIANCE
Figure 38 - Opening Vent Damper

www.desatech.com
108795-01V 19
OPERATION
1. STOP! Read the safety information, col-
umn 1.
2. Turn wall switch to the OFF position.
3. Turn off all electric power to appliance.
4. Fully open glass doors if installed.
5. Remove front refractory brick access
panel.
6. Turn gas control knob clockwise
to the OFF position (see Figure 39).
7. Wait ve (5) minutes to clear out any gas.
Then smell for gas, including near the
oor. If you smell gas, STOP! Follow “B”
in the safety information, column 1. If you
don’t smell gas, go to the next step.
8. Turn control knob counterclockwise
to the PILOT position.
9. Push in knob all the way and hold in.
Immediately light the pilot manually. Con-
tinue to hold control knob in for about one
minute after pilot is lit. Release knob and
it will pop back up. Pilot should remain lit.
If it goes out, repeat steps 5 through 9.
• If knob does not pop up when released,
stop and immediately call your service
technician or gas supplier.
• If the pilot will not stay lit after several
tries, turn the gas control knob to OFF
and call your service technician or gas
supplier.
10. Turn gas control knob counterclockwise
to O”. Knob can be turned to ON
only if the control knob is popped out.
11. Replace front refractory brick access
panel.
12. Fully close glass doors if installed.
13. Turn on all electric power to appliance.
P
I
L
O
T
ON
OFF
IN OUT
IN
Figure 39 - Control Knob in the PILOT
position
Position Indicator
Gas Control Knob Pilot Adjustment Screw
FOR YOUR SAFETY
READ BEFORE LIGHTING
WARNING: If you do not fol-
lowtheseinstructions exactly,
a re or explosion may result
causingpropertydamage,per-
sonalinjuryorlossoflife.
A. Thisappliancehasapilotwhichmust
be lighted by hand. When lighting
the pilot, follow these instructions
exactly.
B. BEFORE LIGHTING smell all around
the appliance area for gas. Be sure to
smellnexttotheoorbecausesome
gasisheavierthanairandwillsettle
ontheoor.
WHAT TO DO IF YOU SMELL GAS
•Donottrytolightanyappliance.
•Donottouchanyelectric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redepartment.
C. Use only your hand to push in or turn
thegascontrolknob.Neverusetools.
Iftheknobwillnotpushinorturnby
hand,don’ttrytorepairit,callaquali-
edservicetechnicianorgassupplier.
Forceorattemptedrepairmayresultin
areorexplosion.
D. Do not use this appliance if any part
has been under water. Immediately
call a qualied service technician to
inspect the appliance and to replace
any part of the control system and
anygascontrolwhichhasbeenunder
water.
LIGHTING
INSTRUCTIONS
NOTICE: During initial operation
ofnewheater,burninglogswill
giveoffapaper-burningsmell.
Orangeamewillalsobepres-
ent.Opendamperorwindowto
ventsmell.Thiswillonlylasta
fewhours.

www.desatech.com 108795-01V20
TO TURN OFF GAS
TO APPLIANCE
1. Turn off wall switch.
2. Turn off all electric power to appliance if
service is to be performed.
3. Fully open glass doors if installed.
4. Remove front hearth brick and control
access panel.
5. Turn gas control knob clockwise
to OFF. Do not force.
6. Replace front refractory brick access
panel.
7. Fully close glass doors if installed.
OPERATION
Continued
Figure 40 - Pilot
Thermopile
Pilot
Burner
Ignitor
Figure 41 - On/Off Hand-Held Remote
Control Unit HRC100
Control
Button
Indicator
Light
INSPECTING BURNERS
OPTIONAL HAND-HELD
REMOTE OPERATION
Note: The receiver and hand-held remote
control kit must be purchased separately (see
Accessories, page 31). Follow installation
instructions on page 10 of this manual.
1. After lighting, let pilot ame burn for about
one minute. Turn control knob to the ON
position. Slide the selector switch to the
REMOTE position.
Note: Burner may light if hand-held remote
was on when selector switch was last
turned off. You can now turn burner on
and off with the hand-held remote control
unit.
IMPORTANT: Do not leave selector switch
in the REMOTE or ON position when pilot
is not lit. This will drain the battery.
2. Press control button on hand-held remote
to turn burner on. Press control button
again to turn burner off (see Figure 41).
3. To Lock press both buttons on remote
control until light stops ashing. Remote is
now locked. If the re is on it will be turned
off automatically. In the locked state, the
light will not light up when any button is
pressed.
4. ToUnlock press both buttons together on
remote control until light stops ashing.
The remote is now unlocked.
Check pilot ame pattern and burner ame
patterns often.
PILOT ASSEMBLY
The pilot assembly is factory preset for the
proper ame height. Alterations may have
occurred during shipping and handling. The
pilot is located on the back right hand side
of the burner.
The height of the thermopile must be 3/8" to
1/2" above the pilot ame. The ame from
the pilot burner must extend beyond the
thermopile.
If your pilot assembly does not meet these
requirements:
• Turn adjustment screw marked pilot clock-
wise to decrease or counterclockwise to in-
crease the ame to proper size (see Figure
39, page 19). Do not remove adjustment
screw.
• see Troubleshooting, page 23