Reznor SCE Series Owner's manual

Revision: I-SCE (09-18) PN207697R9
SEPARATED-COMBUSTION,
PACKAGED FURNACE/BLOWER,
MODEL SCE
INSTALLATION/OPERATION/MAINTENANCE
⚠ WARNING ⚠
FIRE OR EXPLOSION HAZARD
• Failure to follow safety warnings exactly could result in serious injury, death, or
property damage.
• Be sure to read and understand the installation, operation, and service instructions
in this manual.
• Improper installation,adjustment,alteration, service,or maintenance can cause serious
injury, death, or property damage.
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.
• Leave the building immediately.
• Immediately call your gas supplier from a phone remote from the building. Follow the
gas suppliers 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.
DO NOT DESTROY. PLEASE READ CAREFULLY. KEEP IN A SAFE PLACE FOR FUTURE REFERENCE.
Supersedes: I-SCE (5-15) PN207697Rev8
TABLE OF CONTENTS
IMPORTANT SAFETY INFORMATION .................................................................. 2
GENERAL INFORMATION ............................................................................ 3
Installation Codes ................................................................................. 3
Special Installations (Aircraft Hangars/Garages) .......................................................... 3
Warranty ........................................................................................ 4
INSTALLATION..................................................................................... 4
Dimensions ...................................................................................... 4
Uncrating/Unpacking ............................................................................... 5
Clearances....................................................................................... 6
Location ......................................................................................... 6
Weights ......................................................................................... 6
Suspension ...................................................................................... 6
Mounting ........................................................................................ 7

2I-SCE (09-18) PN207697R9
IMPORTANT SAFETY INFORMATION
⚠ WARNING ⚠
Gas-fired appliances are not designed for use in hazardous atmospheres containing flammable
vapors or combustible dust, in atmospheres containing chlorinated or halogenated hydrocarbons,
or in applications with airborne silicone substances.
Please read all instructions before servicing this equipment. Pay attention to all dangers, warnings, cautions, and
notes highlighted in this manual. Safety markings should not be ignored and are used frequently throughout to
designate a degree or level of seriousness.
TABLE OF CONTENTS—CONTINUED
Duct Connections.................................................................................. 8
Venting and Combustion Air ......................................................................... 9
Venting Options ................................................................................... 14
Horizontal Vent Terminal/Combustion Air Package Kit (Option CC6) .......................................... 14
Vertical Vent Terminal/Combustion Air Package Kit (Option CC2) ............................................ 18
Gas Piping and Pressures ........................................................................... 21
Electrical Supply and Connections .................................................................... 24
INSTALLATION—CONTINUED
Electrical Supply and Connections ....................................................................25
Control Thermostat ................................................................................27
Combustion Air Proving Switch .......................................................................27
Blower Fan Control ................................................................................27
Limit Control......................................................................................28
Motor Load and Amps ..............................................................................28
Belts, Blowers, and Drives...........................................................................28
Operating Valve ...................................................................................29
Optional Two-Stage Operation—Heating Only Application ..................................................30
Optional Two-Stage Operation—Makeup Air Application ...................................................30
Optional Electronic Modulation .......................................................................31
Pilot and Ignition Systems ...........................................................................35
Burners, Burner Orifices, and Carryover System..........................................................35
Burner Air Shutters ................................................................................36
OPTIONAL EQUIPMENT .............................................................................37
Optional Condensation Drain for Duct Furnaces ..........................................................37
Optional Dampers and Controls.......................................................................37
Optional Filter Rack and Filters .......................................................................38
Optional Dirty Filter Switch...........................................................................39
INSTALLATION AND STARTUP CHECKLISTS ...........................................................39
Pre-Startup Checklist...............................................................................39
Startup Checklist ..................................................................................40
Post-Startup Checklist ..............................................................................40
SERVICE AND MAINTENANCE........................................................................41
Operating Gas Valve Maintenance ....................................................................41
Vent/Combustion Air System Maintenance ..............................................................42
Burner Rack Maintenance ...........................................................................42
Cleaning Pilot and Burners ..........................................................................43
Spark Ignition System Maintenance ...................................................................44
Cleaning Heat Exchanger ...........................................................................44
Venter Motor Maintenance...........................................................................44
Air Circulation System Maintenance ...................................................................45
Limit Control Check ................................................................................45
TROUBLESHOOTING ...............................................................................45
INSTALLATION RECORD ............................................................................47

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I-SCE (09-18) PN207697R9
DANGER: A danger statement describes a potentially hazardous situation that if not avoided, will result in severe
personal injury or death and/or property damage.
WARNING: A warning statement describes a potentially hazardous situation that if not avoided, can result in severe
personal injury and/or property damage.
CAUTION: A caution statement describes a potentially hazardous situation that if not avoided, can result in minor
or moderate personal injury and/or property damage.
NOTE: A note provides important information that should not be ignored.
GENERAL INFORMATION
NOTE: Model SCE units are not certified for residential use.
The instructions in this manual apply to the model SCE blower-type unit heater with blower cabinet (see Figure 1).
Installation should be performed by a qualified agency in accordance with the instructions in this manual and in
compliance with all codes and requirements of authorities having jurisdiction.
Model SCE is design-certified by the Canadian Standards Association to ANSI Standards and is available for use with
either natural or propane gas. The type of gas, the rate, and the electrical characteristics are on the unit rating plate.
This separated-combustion unit is designed and manufactured in accordance with the ANSI definition of separated
combustion, which reads, “Separated Combustion System Appliance: A system consisting of an appliance and
a vent cap(s) supplied by the manufacturer, and (1) combustion air connections between the appliance and the
outside atmosphere, and (2) flue gas connections between the appliance and vent cap, of a type(s) specified by the
manufacturer but supplied by the installer, constructed so that, when installed in accordance with the manufacturer’s
instructions, air for combustion is obtained from the outside atmosphere and flue gases are discharged to the outside
atmosphere.”
Separated-combustion units are designed to separate air for combustion and flue products from the environment of
the building in which the unit is installed. Separated-combustion appliances are recommended for use in dust-laden
and some corrosive-fume environments or in buildings with negative pressure (up to 0.15 IN WC). As the definition
states, all separated-combustion, power-vented equipment must be equipped with both combustion-air and exhaust
piping to the outdoors.
INSTALLATION CODES
These units must be installed in accordance with local building codes. In the absence of local codes, in the United
States, the unit must be installed in accordance with the National Fuel Gas Code NFPA 54/ANSI Z223.1 (latest
edition). The code is available from CSA Information Services, 1-800-463-6727. Local authorities having jurisdiction
should be consulted before installation is made to verify local codes and installation procedure requirements.
These gas-fired products are certified by ANSI Z83 family of standards governing the safe usage of heating equipment
in the industrial/commercial marketplace. This includes using the heaters in makeup air applications to supply corridor
pressurization in commercial buildings such as office structures and apartment complexes.
The heaters are not certified as residential heating equipment and should not be used as such.
Clearances from the heater and vent to combustible construction or material in storage must conform with the National
Fuel Gas Code ANSI Z223.1 (latest edition) pertaining to gas-burning devices, and such material must not attain a
temperature over 160°F (71°C) by continued operation of the heater.
Figure 1. Model SCE Unit Heater
FRONT VIEW REAR VIEW

4I-SCE (09-18) PN207697R9
SPECIAL INSTALLATIONS (AIRCRAFT HANGARS/GARAGES)
Installations in aircraft hangars should be in accordance with NFPA No. 409 (latest edition), Standard for Aircraft
Hangars, in public garages in accordance with NFPA No. 88A (latest edition), Standard for Parking Structures, and
for repair garages in accordance with NFPA No. 88B (latest edition), Standard for Repair Garages. In Canada,
installations in aircraft hangars should be in accordance with the requirements of the enforcing authorities and in
public garages in accordance with CSA B149 codes.
WARRANTY
Refer to the limited warranty information on the Warranty Card in the Owner’s Envelope.
Warranty is void if . . .
a. Separated-combustion heaters are used in atmospheres containing flammable vapors or atmospheres containing
chlorinated or halogenated hydrocarbons or any contaminant (silicone, aluminum oxide, etc.) that adheres to
the spark ignition flame sensing probe.
b. Wiring is not in accordance with the diagram furnished with the heater.
c. Unit is installed without proper clearance to combustible materials.
INSTALLATION
DIMENSIONS
All dimensions for the model SCE unit heater are shown in Figure 2 and are listed in Table 1.
Figure 2. Model SCE Dimensions in Inches (±1/8 (mm ±3))
STANDARD MODEL SCE
MODEL SCE WITH OPTIONAL HORIZONTAL INLET WITH DUCT FLANGES

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I-SCE (09-18) PN207697R9
Table 1. Model SCE Dimensions
Dimension
Code from
Figure 2
Model
125 150 and 175 200 and 225 250 300 350 400
Inches ±1/8 (mm ±3)
A 32-1/4 (819) 35-1/4 (895)
B 25-1/4 (641) 30-3/4 (781) 36-1/4 (921) 43-1/2 (1105) 44-1/2 (1130) 50 (1270) 55-1/2 (1410)
D 15-1/4 (387) 20-3/4 (527) 26-1/4 (667) 33-1/2 (851) 34-1/2 (876) 40 (1016) 45-1/2 (1156)
E 8-1/8 (206) 10-3/4 (273) 9-3/4 (248) 10-3/4 (273)
F 16-1/4 (413) 21-3/4 (552) 27-1/4 (692) 34-1/2 (876) 35-1/2 (902) 41 (1041) 46-1/2 (1181)
G 7 (178) 10 (254) 9 (229) 10 (254)
H 17-3/4 (451) 23-1/4 (591) 28-3/4 (730) 36 (914) 37 (940) 42-1/2 (1080) 48 (1219)
J 17-3/8 (441) 22-7/8 (581) 28-3/8 (721) 35-5/8 (905) 38-5/8 (930) 42-1/8 (1070) 47-5/8 (1210)
K 17 (432) 18-3/8 (467) 17 (432) 16 (406) 17 (432) 18-3/8 (467) 17 (432)
L 1/2 (13) 3/4 (19)
M 40-1/4 (1022) 39 (991) 40-1/4 (1022) 39-1/4 (997) 40-1/4 (1022) 39 (991) 40-1/4 (1022)
N 27-3/4 (705) 30-3/4 (781)
UNCRATING/UNPACKING
The furnace is shipped completely-assembled. Immediately upon uncrating, check the gas specifications and electrical
characteristics of the unit to be sure that they agree with the gas and electric supply at the installation site.
Check the unit for any damage that may have been incurred during shipment. If damage is found, document the
damage with the transporting agency and immediately contact your distributor. If you are an authorized distributor,
follow the FOB freight policy procedures.
NOTE: After removing the shipping clips that fasten the unit to the crate, it is required that the
bolts that attach the shipping clips be reinstalled for support.
The bottom corners are fastened to the crate using angled shipping clips. Remove the bolts from the shipping clips
and remove the clips. Reinstall the bolts on the heater legs to support the corner leg and the heater bottom.
To protect the unit during shipping, blower models have special supports that must be removed before installation.
Remove the special supports as follows:
• Blower Support Legs: Remove the blower support legs and screws.
• Motor Shipping Block: Remove the wooden block located under the motor bracket. Find the two rubber pads
shipped in the instruction envelope. Place these pads on the ends of the motor bracket bolts.
• Motor Shipping Plate: Units equipped with motors of 1-1/2 HP or less have a metal shipping plate attached between
the motor and the blower housing. The shipping plate must be removed and the plate and screws discarded. on
a unit factory-equipped with an optional belt guard, the belt guard must be removed to reach the shipping plate.
Vent Terminal/Combustion Air Inlet Kit with Concentric Adapter Box
The concentric adapter box assembly in the venting/combustion air kit (option CC2 or CC6) is required on all
separated-combustion models. Ensure that the concentric adapter box carton is at the installation site (refer to parts
list in Table 6 or Table 8).
Shipped-Separate Parts
Some gas control options have parts that are either shipped loose—with the heater—or shipped separate. Before
beginning installation, ensure that any shipped-separate parts ordered are available at the site. Shipped-separate
options could include a shutoff valve, a condensate drain kit, a thermostat, a remote console, a disconnect switch, or
high-temperature vent sealing tape. Also, if your unit is equipped with any of the gas control options listed in Table
2, ensure that these parts are available at the job site.
Table 2. Shipped-Separate Parts for Gas Control Options
Application Option Part(s)
Heating AG7 Thermostat (PN 48033)
Makeup air
AG3 Control switch (PN 29054)
AG8 Control switch (PN 29054); sensor and mixing tube (PN 48041)
AG9 Control switch (PN 29054); remote temperature selector (PN 48042); sensor and mixing tube (PN 48041)
AG15
&
AG16
Control switch (PN 29054); remote temperature selector (PN 115848); stage adder module (PN 115849); discharge
air sensor holder (PN 115850); discharge air sensor holder bracket (PN 213612); AG16 also includes temperature
display (PN 115852)
AG39 Remote temperature selector (PN 174849); temperature sensor (PN 133228); mixing tube (PN 90323)
NOTE: If an optional remote console is ordered, the control switch and temperature selector may be mounted on the console.

6I-SCE (09-18) PN207697R9
CLEARANCES
Clearance to combustibles is defined as the minimum distance—from the heater to a surface or object—that is
necessary to ensure that a surface temperature of 90°F (50°C) above the surrounding ambient temperature is not
exceeded. For safety and convenience, ensure that the clearances listed in Table 3 are provide as shown in the
following table. Minimum clearances are also listed on the heater rating plate.
Table 3. Clearances
Unit Surface Minimum Clearances (Inches (mm))
Top 6 (152)
Control side 6 (152) + width of unit
Side opposite controls 6 (152)
Bottom, to combustibles 6 (152)
Bottom, to noncombustibles 0 (0)
LOCATION
⚠ CAUTION ⚠
Do not locate the heater where it may be exposed to water spray, rain, or dripping water.
For best results, the heater should be placed with certain rules in mind. In general, a unit should be located from
8 to 12 feet (2.6 to 3.6 M) above the floor. Units should always be arranged to blow toward or along exposed wall
surfaces, if possible. Where two or more units are installed in the same room, a general scheme of air circulation
should be maintained.
Suspended heaters are most effective when located as close to the working zone as possible, and this fact should
be kept in mind when determining the mounting heights to be used. However, avoid directing the discharged air
directly on the room occupants.
Partitions, columns, counters, or other obstructions should be taken into consideration when locating the unit heater,
so that a minimum quantity of airflow will be deflected by such obstacles. When units are located in the center of the
space to be heated, the air should be discharged toward the exposed walls. In large areas, units should be located
to discharge air along exposed walls with extra units provided to discharge air in toward the center of the area.
At those points where infiltration of cold air is excessive, such as at entrance doors and shipping doors, it is desirable
to locate the unit so that it will discharge directly toward the source of cold air from a distance of 15 to 20 feet (4.5
to 6 M).
WEIGHTS
Before installation, check the supporting structure to ensure that it has sufficient load-carrying capacity to support
the weight of the unit. Refer to Table 4, which lists unit weight based on unit size.
Table 4. Unit Weight
Net Weight Model
125 150 and 175 200 and 225 250 and 300 350 400
Pounds (kg) 313 (142) 358 (162) 382 (173) 482 (219) 498 (226) 560 (254)
SUSPENSION
⚠ WARNING ⚠
Units must be level for proper operation. Do not place additional weight on or add additional weight
to the suspended unit.
Model SCE has four-point suspension (see hanger center line dimensions shown in Figure 2). At each suspension
point, the unit is factory-equipped with a free-turning, female, 1-inch NPT pipe hanger. Suspend the unit by connecting
the pipe hanger to a 1-inch threaded pipe. See Figure 3 for the standard and alternative suspension methods. The
factory-installed pipe hanger may be removed and the heater may be suspended as shown in the right view of Figure 3.

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I-SCE (09-18) PN207697R9
Figure 3. Suspension Methods
MOUNTING
Model SCE requires six mounting support locations—three on each side—as shown in Figure 4.
Figure 4. Support Locations
NOTE: Support is required where furnace and blower cabinets meet.
Supports (PN 74487) available from the manufacturer or field-fabricated legs, as shown in Figure 5, may be used at
the four corner support locations. Do not use this type of support at the center support locations between the furnace
and the blower section. At the center locations, a field-fabricated angle-iron brace support must extend horizontally,
jointly supporting a portion of both the furnace and the blower cabinet. All supports must be noncombustible.
Figure 5. Corner Mounting Supports
Field-supplied supports between
the blower cabinet and the furnace
must extend horizontally support-
ing both sections.
Support Locations
FIELD-FABRICATED
AVAILABLE AS A PA RT

8I-SCE (09-18) PN207697R9
DUCT CONNECTIONS
Refer to Figure 6 for duct connection dimensions.
Size G
125 15-1/4"(387mm)
150, 175 20-3/4"(527mm)
200, 225 26-1/4"(667mm)
250, 300 34-1/2"(876mm)
350 40"(1016mm)
400 45-1/2"(1156mm)
Figure 6. Duct Connection Dimensions
Requirements and Suggestions for Connecting and Installing Ducts
• Type of Ductwork: The type of duct installation to be used depends in part on the construction type of the roof—
whether wood or steel bar joist, steel truss, or pre-cast concrete—and the ceiling—whether hung, flush, etc.
• Ductwork Material: Rectangular duct should be constructed of galvanized iron—not lighter than No. 26 US gauge
—or aluminum—No. 24 B&S gauge.
• Ductwork Structure: All duct sections 24 inches (610 mm) or wider and over 48 inches (1219 mm) in length
should be cross-broken on top and bottom and should have standing seams or angle-iron braces. Joints should
be S and drive strip or locked.
• Through Masonry Walls: No warm air duct should come in contact with masonry walls. Insulate around all air
duct through masonry walls with 1-inch (not less than 1/2-inch) of insulation.
• Through Unheated Space: Insulate all exposed warm air ducts passing through an unheated space with 1-inch
(not less than 1/2-inch) of insulation.
• Duct Supports: Suspend all ducts securely from adjacent buildings members. Do not support ducts from unit
duct connections.
• Duct Sizing: Proper sizing of the supply air ductwork is necessary to ensure a satisfactory heating installation. The
recognized authority for duct size is the Air Conditioning Contractor’s Association, 2800 Shirlington Road, Suite 300,
Arlington, VA 22206 (www.acca.org). A manual covering duct sizing in detail may be purchased directly from them.
⚠ CAUTION ⚠
To prevent possible motor overloading, ensure that the external duct system static pressure is
within the limits shown on the rating plate and that the motor pulley and belt are properly adjusted.
• Horizontal Discharge Duct Length: To reduce losses at the furnace outlet, a minimum horizontal duct run of 24
inches (610 mm) is recommended before turns or branches are made in the duct system.
⚠ CAUTION ⚠
The joint where the supply air duct attaches to the furnace must be sealed securely to prevent
air leakage into draft hood or burner rack area. Leakage can cause poor combustion and pilot
problems, can shorten heat exchanger life, and can cause poor performance.

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I-SCE (09-18) PN207697R9
• Supply Air Duct/Furnace Horizontal Connection: The seal between the furnace and the duct must be mechanical
using U-type flanges on the top and bottom of the connecting duct to to ensure tight joints and an airtight fit. Refer
to Figure 7 and perform the following steps:
(1) Ensure that flanges on the furnace (heat exchanger) turn out as shown.
(2) Shape duct connection as shown: U-type on top and bottom and L-type on sides.
(3) Slide U-channels over furnace top and bottom flanges making connection.
(4) Form U-channels to seal sides (see DETAIL A) and drill and lock with sheet metal screws.
• Access Panels: Install removable access panels (see Figure 7) on both the upstream and downstream sides of
the furnace. The access panels must be accessible when the furnace is in service and should be a minimum of
6 ×10 inches (152 ×254 mm) in size so smoke or reflected light may be observed inside the casing to indicate
the presence of leaks in the heat exchanger. Ensure that the access panels are installed in such a manner so as
to prevent leakage.
• Return Air Duct/Furnace Connection: All return air ducts should be attached and sealed to the return air flanges
to provide airtight connections.
• Return Air Duct/Grill Size: Ensure that return air ducting or grills have a free area equal to the size of the return
duct connection.
DETAIL A
Figure 7. Connecting Ductwork to Furnace
VENTING AND COMBUSTION AIR
⚠ WARNING ⚠
Do not use an existing venting system.This heater requires installation of the combustion air/vent
system ordered with the unit (either Option CC2 or Option CC6). Vent installation to be any listed
vent system manufacturer. Do not intermix different vent system parts from different manufacturers
in the same venting system.
All separated-combustion, power-vented units MUST BE equipped with both combustion air and exhaust piping to
the outdoors. The unique concentric adapter box designed for use with this heater allows for both combustion air
and exhaust piping with only one horizontal or vertical penetration hole in the building.
These instructions apply to installation and use of the concentric adapter and vent/combustion air kit (option CC2 or
CC6) designed for use with all Reznor separated-combustion products. The systems illustrated in this manual are
the only venting/combustion air systems approved for these separated-combustion units. Do not use this concentric
adapter box with any other products.
Installation should be done by a qualified agency in accordance with these instructions. The service agency installing
this separated-combustion system is responsible for the installation.
Hazards of Chlorine
⚠ WARNING ⚠
SC Series separated-combustion units are not designed or approved for use in atmospheres
containing flammable vapors or atmospheres highly-laden with chlorinated vapors.

10 I-SCE (09-18) PN207697R9
VENTING AND COMBUSTION AIR—CONTINUED
Hazards of Chlorine—Continued
Remember, chlorine is heavier than air. This fact should be kept in mind when determining the
installation location of heaters and building exhaust systems. The presence of chlorine vapors in the
combustion air of heating equipment presents a potential corrosion hazard. Chlorine, found usually in the form of
Freon or degreaser vapors, when exposed to flame will precipitate from the compound and form a solution with
any condensation present in the heat exchanger or associated parts. The result is hydrochloric acid, which readily
attacks all metals, including 300 grade stainless steel. Care should be taken to separate these vapors from the
combustion process. This may be done by wise location of the unit vent terminal and combustion air inlet with regard
to exhausters or prevailing wind directions.
Specific Venting Requirements: Piping
⚠ WARNING ⚠
Do not use an existing venting system. This heater requires installation of the combustion air/
vent system ordered with the unit (either Option CC2 or Option CC6). Vent installation to be
any listed vent system manufacturer. Do not intermix different vent system parts from different
manufacturers in the same venting system.
All pipe is field-supplied. Requirements for both the vent pipe and the combustion air inlet pipe are as follows:
• Vent Pipe: Vent pipe approved for a Category III appliance OR single-wall, 26-gauge or heavier galvanized (or a
material of equivalent durability and corrosion resistance) vent pipe is required between the heater and the concentric
adapter box. Double-wall (type B) vent pipe is required for the vent terminal section. The length of vent pipe that
extends through the box and runs concentric through the combustion air pipe must be one piece with no joints.
• Combustion Air Pipe: Sealed, single-wall galvanized pipe is recommended for combustion air.
• Pipe Length and Diameter: Vent pipe diameters and maximum indoor vent lengths apply to both horizontal and
vertical vents. Pipe diameter and length requirements listed for the indoor sections of pipe—between the heater
and the concentric adapter box—are listed in Table 5.
NOTE: Add all straight sections and equivalent lengths for elbows. The total length of the
straight sections and elbows must not exceed the maximum length.
Table 5. Pipe Diameter and Maximum Pipe Length from Heater to Concentric Adapter Box
Diameter/Length Model
125–175 200–400
Diameters (Inches (mm))
Vent pipe 6 (152)
— 7 (178)
Inlet air pipe 6 (152)
— 7 (178)
Lengths (Feet (M))
Minimum 5 (1.5)
Maximum, 6-inch pipe 50 (15)
Maximum, 7-inch pipe — 70 (21)
Equivalent straight length for 45-degree elbow 4 (1.2)
Equivalent straight length for 90-degree elbow 8 (2.4)
• Outdoor Concentric Pipes Length and Diameter: The lengths of the outside (terminal) concentric pipes depend on
the installation. The diameters are 8 inches (203 mm) for the inlet air pipe and 5 inches (127 mm) for the vent pipe.
Specific Venting Requirements: Venter Outlet and Combustion Air Inlet Connections
Model SCE heaters have both an inlet air and a venter outlet connection. Both are 6 inches (152 mm) in diameter
for all unit sizes.
NOTE: If using 7-inch pipe on heater size 200–400, use a tapered 6- to 7-inch enlarger to attach
the vent pipe and a 7- to 6-inch reducer to attach the combustion air pipe.

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I-SCE (09-18) PN207697R9
Figure 8. Joining Double-Wall (Type B) Pipe to Vent Terminal Cap (Horizontal or Vertical)
• To seal the joint between the terminal section of double-wall vent pipe and a single-wall or Category III
vent pipe: follow the illustrated step-by-step instructions in Figure 9. Make this connection no more than 6 inches
(152 mm) from the concentric adapter box.
STEP 1
Place a continual 3/8” bead of silicone sealant
around the circumference of the vent cap col-
lar. This will prevent any water inside the vent
cap from running down the double-wall pipe.
Do STEP 2 immediately following STEP 1.
STEP 2
Insert the collar on the vent cap inside the
inner wall of the double-wall pipe. Insert
as far as possible.Add additional silicone
sealant to fully close any gaps between
the vent cap and the double wall pipe.
This is necessary to prevent water from
entering the double wall pipe.
Secure the vent cap to the double-wall pipe by drilling and inserting a 3/4” long
sheetmetal screw into the vent cap collar. Do not overtighten screw.
STEP 3
Figure 9. Joining Double-Wall (Type B) Pipe to Single-Wall or Category III Vent Pipe
Using Tapered Reducer
STEP 1
On the taper-type reducer, place a con-
tinual 1/4” bead of silicone sealant
around the circumference.
STEP 2
Insert the collar of the reducer into the
inner pipe of the double-wall pipe until
the bead of sealant contacts the inner
pipe creating a sealed joint.
STEP 3
Spaced equally around the double-wall
pipe, drill three small holes below the
sealant ring. Insert 3/4 inch long
sheetmetal screws to secure the joint. Do
not overtighten screws.
5" I.D.
Double-
Wall
Pipe
6" to 5" or
7" to 5"
Taper-
Type
Reducer
DoSTEP 2
immediately
following
STEP1.
Specific Venting Requirements: Joints and Sealing
Seal pipe joints as follows:
• To seal joints in Category III vent pipe: follow the pipe manufacturer’s instructions for joining and sealing
Category III vent pipe sections.
• To seal joints in single-wall vent and combustion air pipe: secure slip-fit pipe connections using sheet metal
screws or rivets. Seal all joints with aluminum tape or silicone sealant.
• To seal the joint in the terminal section of double-wall vent pipe (allowed ONLY ABOVE the concentric
pipes on a VERTICAL vent):follow the pipe manufacturer’s instructions for joining and sealing double-wall
vent pipe sections.
• To seal the joint between the terminal section of double-wall vent pipe and the vent cap: follow the illustrated
step-by-step instructions in Figure 8.
NOTE: Pipes and vent caps may not look exactly as shown in the illustrations. Instructions ap-
ply to both horizontal and vertical vent kits.

12 I-SCE (09-18) PN207697R9
VENTING AND COMBUSTION AIR—CONTINUED
Specific Venting Requirements: Support
Support horizontal runs every six feet (1.8 M). Support vertical runs of type “B” double-wall or Category III vent pipe
in accordance with the requirements of the pipe manufacturer. Support single-wall vertical pipe in accordance with
accepted industry practices. Do not rely on the heater or the adapter box for support of either horizontal or vertical
pipes. Use noncombustible supports on vent pipe.
NOTE: The double-wall vent terminal pipe does not attach to the concentric adapter box and
must be supported during installation.
Specific Venting Requirements: Clearance
Do not enclose the vent pipe or place pipe closer than 6 inches (152 mm) to combustible material.
Specific Venting Requirements: Concentric Adapter Box
The concentric adapter box (PN 205885) is included in the vent/combustion air kit. Installation instructions depend
on whether the vent system is horizontal (option CC6) or vertical (option CC2). All separated-combustion installations
require a concentric adapter box as shown in Figure 10.
Figure 10. Concentric Adapter Box
View of Heater Connection Side
View of Vent Terminal Connection Side
Collar for connecting
indoor portion of the
combustion air pipe
Opening for
double-wall vent
pipe to pass
through the box.
Collar for
attaching outside
concentric portion
of the combustion
air pipe
Concentric Adapter Box Airow

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I-SCE (09-18) PN207697R9
Specific Venting Requirements: Concentric Adapter Box Pipe Connections
NOTE: Do NOT make actual connections until after reading the instructions and length require-
ments for installing the vent/combustion air kit. The connection requirements are the same for
both vertical and horizontal systems, but the length of the double-wall pipe will vary.
When pipe diameters differ, depending on direction of airflow, join the pipes with either a tapered reducer or enlarger
as shown in Figure 11.
Figure 11. Concentric Adapter Box Connections

14 I-SCE (09-18) PN207697R9
Table 6. Parts List for Horizontal Vent Terminal/Combustion Air Package (Option CC6)
PN Description Qty
205883 Kit, Horizontal Vent 1
205885 Assembly, Concentric Adapter Box (see Figure 10) 1
53316 Assembly, Screened Exhaust (see Figure 13) 1
205894 Inlet Guard (see Figure 13) 1
37661 Screw, Inlet Guard, #10-16 ×1/2 L 4
207232 Bracket, Concentric Adapter Box (see Figure 14) 2
53335 Sealant, High Temperature (450°F), Silicone (Tube) 1
Figure 12. Horizontal and Vertical Venting Options
Horizontal Vent Terminal/Combustion Air Package Kit (Option CC6)
Field-supplied components required for installation of the horizontal vent kit are as follows:
•Vent and combustion air piping (refer to Table 5)
•Tapered vent pipe diameter reducers and/or increasers, as required
•Thimble (not required if wall is of non-combustible construction)
•Flashing
•Sheet metal screws, tape, and sealant, as required
Factory-supplied components for installation of the horizontal vent kit are listed in Table 6.
VENTING OPTIONS
Both venting options described below are shown in Figure 12.
Figure 13. Screened Exhaust Assembly and Inlet Guard
Option CC6 Installation Instructions
⚠ DANGER ⚠
To prevent combustion products from entering the occupied space, all vent terminals must be
positioned or located away from fresh air intakes, doors, and windows. Failure to comply could
result in severe personal injury or death and/or property damage.
1. Determine vent terminal location on outside wall:
a. Refer to Table 5 to ensure that location complies with vent length requirements.
b. For most applications, ensure that vent terminal is level with heater mounting height.
HORIZONTAL VENTING
(OPTION CC6)
VERTICAL VENTING
(OPTION CC2)
SCREENED EXHAUST ASSEMBLY INLET GUARD

15
I-SCE (09-18) PN207697R9
c. Allow downward pitch of 1/4-inch per foot (6 mm per 305 mm) for condensate drain.
NOTE: Local codes supersede all provisions in these instructions and in National Fuel Gas
Code Z223.1.
d. Ensure that distance of vent terminal from adjacent public walkways and buildings and window and building
openings complies with local codes. Absent any local codes, distance must comply with National Fuel Gas
Code Z223.1.
NOTE: Products of combustion can cause discoloration of some building finishes and deterio-
ration of masonry materials. A clear silicone sealant normally used to protect concrete drive-
ways may be used to protect masonry materials from discoloration and deterioration. If discol-
oration is an esthetic problem relocate the vent or install a vertical vent.
e. Refer to Table 7 to ensure that location complies with minimum clearance requirements.
⚠ DANGER ⚠
• To prevent combustion products from entering the occupied space, all vent terminals must be
positioned or located away from fresh air intakes, doors, and windows. Failure to comply could
result in severe personal injury or death and/or property damage.
• Consider local snow depth conditions. The vent must be at least 6 inches (152 mm) above the
anticipated snow depth.
Table 7. Minimum Clearance Requirements for Horizontal Vent Terminal
Component/Structure Minimum Clearance, All Directions Unless Specified (Feet (Meters))
Forced air inlet within 10 feet (3.1 M)*3 (0.9) above
Combustion air inlet of another appliance 6 (1.8)
Any building opening (door, window, or gravity air inlet) 4 (1.2) horizontal and below
1 (305) above
Gas meter,** electric meter, and relief equipment US: 4 (1.2) horizontal
Canada: 6 (1.8) horizontal
Gas regulator** US: 3 (0.9) horizontal
Canada: 6 (1.8) horizontal
Adjoining building or parapet 6 (1.8)
Adjacent public walkway 7 (2.1) above
Grade (ground level) 3 (0.9) above
*Does not apply to the inlet of a direct vent appliance.
**Do not terminate the vent directly above a gas meter or service regulator.
2. Install vent pipe and combustion air pipe runs:
a. Connect piping to heater in accordance with specifications listed above in Specific Venting Requirements:
Piping and Specific Venting Requirements: Venter Outlet and Combustion Air Inlet Connections.
b. Seal all joints in accordance with specifications listed above in Specific Venting Requirements: Joints and
Sealing. Due to high temperature considerations, do not enclose exhaust pipe or place pipe closer than 6
inches (152 mm) to combustible material.
c. Extend piping runs close to wall location selected in step 1 and support piping in accordance with specifications
listed above in Specific Venting Requirements: Support.
NOTE: The larger diameter combustion air pipe serves as clearance for the vent pipe on non-
combustible construction. A thimble may be required depending on wall construction and/or
local codes.
3. Cut hole through outside wall for combustion air pipe.
a. Ensure that outside wall construction thickness is between 1 inch (25 mm) minimum and 48 inches (1143
mm) maximum.
b. Ensure that hole accommodates 8-inch (203-mm) combustion air pipe.

16 I-SCE (09-18) PN207697R9
VENTING OPTIONS—CONTINUED
Option CC6 Installation Instructions—Continued
4. Connect concentric adapter box:
a. Refer to Figure 14 to attach brackets to box.
b. Connect outside portion of combustion air pipe to box. Determine length by measuring bracket length from
box to wall plus wall thickness and plus 2 inches (51 mm). Inlet air pipe should extend beyond outside wall
approximately 2 inches (51 mm).
c. Secure inlet air pipe to collar of concentric adapter using sheet metal screws and seal.
d. Refer to Figure 14 to attach concentric adapter box brackets to wall
e. Insert combustion air pipe through wall and caulk or flash inlet air pipe on outside. Flashing is field-supplied.
5. Install air inlet guard:
a. Position air inlet guard over end of combustion air pipe in accordance with Figure 15.
b. Secure air inlet guard to inlet air pipe using four 1/2-inch-long screws provided.
NOTE: If vent pipe is inserted from outside, the exhaust cap may be attached before the double-
wall vent pipe is installed. If cap is attached first, ensure that the baffle strips are positioned cor-
rectly when attaching the vent terminal pipe to the vent run (refer to step 6d below).
6. Install double-wall terminal vent pipe:
NOTE: The length of the vent pipe is determined by the installation within maximum and mini-
mum requirements.The vent pipe extending through the box and the inlet air pipe must be one
piece of double-wall vent pipe without joints.
a. Refer to Figure 15 to determine lengths of each pipe segment and to calculate total length required. Transi-
tion to single-wall or Category III vent pipe run must be made maximum of 6 inches (152 mm) from heater
side of box.
b. Ensure that double-wall terminal vent pipe is in proper direction and slide end of pipe through box. Position
pipe so that it will extend between 16–24 inches (406–610 mm) past end of combustion air pipe and no more
than 6 inches (152 mm) out of box toward heater.
c. Attach 5-inch double-wall vent pipe to 6- or 7-inch single-wall or Category III vent pipe run using tapered
reducer (see Figure 9).
d. Ensure that exhaust cap is aligned so that its baffle strips are positioned on horizontal and vertical center lines
(see Figure 15). Install cap in accordance with Figure 8.
e. Ensure that double-wall section of vent pipe has slight downward drop of 1/4-inch per foot (6 mm per 305 mm)
toward vent terminal end.
f. Seal vent pipe using silicone sealant. Completely seal circumference of pipe at opening of box.
Figure 14. Concentric Adapter Box Brackets

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I-SCE (09-18) PN207697R9
Figure 15. Option CC6 Installation
SIDE VIEW
TOP VIEW
*
*
*
*Clearances for protecting building
materials from degradation by flue
gases and flue gas recirculation
g. Install indoor combustion air pipe. If using 6-inch piping, secure single-wall combustion air pipe run to collar
on concentric adapter box using sheet metal screws. If using 7-inch piping (sizes 200–400), install tapered
enlarger as shown in Figure 11.
h. Seal pipe joints with tape or sealant.
7. Verify compliance with Figure 15 and with all specific venting requirements listed above.

18 I-SCE (09-18) PN207697R9
VENTING OPTIONS—CONTINUED
Vertical Vent Terminal/Combustion Air Package Kit (Option CC2)
Field-supplied components required for installation of the horizontal vent kit are as follows:
•Vent and combustion air piping (refer to Table 5)
•Tapered vent pipe diameter reducers and/or increasers, as required
•Thimble (not required if wall is of non-combustible construction)
•Flashing
•Sheet metal screws, tape, and sealant, as required
Factory-supplied components for installation of the vertical vent kit are listed in Table 8.
Table 8. Parts List for Vertical Vent Terminal/Combustion Air Package (Option CC2)
PN Description Qty
205896 Kit, Vertical Vent 1
205885 Assembly, Concentric Adapter Box (see Figure 10) 1
110052 Exhaust (Vent) Terminal (see Figure 16) 1
53330 Inlet, Combustion Air (see Figure 16) 1
207232 Bracket, Concentric Adapter Box (see Figure 14) 2
53335 Sealant, High Temperature (450°F), Silicone (Tube) 1
Figure 16. Exhaust (Vent) Terminal and Combustion Air Inlet
Option CC2 Installation Instructions
⚠ DANGER ⚠
To prevent combustion products from entering the occupied space, all vent terminals must be
positioned or located away from fresh air intakes, doors, and windows. Failure to comply could
result in severe personal injury or death and/or property damage.
1. Determine vent terminal location on outside wall:
a. If more than one vertical vent terminal is being installed, minimum spacing between vent center lines is
determined by minimum outdoor design temperature (coldest outdoor condition at installation site). Refer to
Table 9 to ensure that location complies with minimum outdoor design temperature requirements.
EXHAUST (VENT) TERMINAL
COMBUSTION AIR INLET
b. Select location away from fresh air intakes, allowing space for concentric adapter box inside. Vent terminal
must be located away from adjacent buildings as shown in Figure 17.
Table 9. Minimum Spacing Between Center Lines of Vertical Vent Pipes
Minimum Outdoor Design Temperature Minimum Spacing Between Center Lines of Vertical Vent Pipes
(Inches (mm))
≥31°F (≥0°C) 36 (914)
−10 to 30°F (−23 to −1°C) 60 (1524)
< −10°F (< −23°C) 84 (2134)

19
I-SCE (09-18) PN207697R9
Figure 17. Option CC2 Installation
SIDE
VIEW
REAR
VIEW
2. Install vent pipe and combustion air pipe runs:
a. Connect piping to heater in accordance with specifications listed above in Specific Venting Requirements:
Piping and Specific Venting Requirements: Venter Outlet and Combustion Air Inlet Connections.
b. Seal all joints in accordance with specifications listed above in Specific Venting Requirements: Joints and
Sealing. Due to high temperature considerations, do not enclose exhaust pipe or place pipe closer than 6
inches (152 mm) to combustible material.
c. Extend piping runs close to roof at location selected in step 1 and support piping in accordance with specifications
listed above in Specific Venting Requirements: Support.
NOTE: The larger diameter combustion air pipe serves as clearance for the vent pipe on non-
combustible construction.
3. Cut hole through outside wall for combustion air pipe.
a. Ensure that hole accommodates 8-inch (203-mm) combustion air pipe.
b. A thimble may be required depending on wall construction and/or local codes.
4. Connect concentric adapter box:
a. Refer to Figure 14 to attach brackets to box.
b. Refer to Figure 18 to connect outside portion of combustion air pipe to box. Determine length of combustion
air pipe so that dimension X in Figure 18 is equal to bracket length plus roof thickness and plus anticipated
snow depth. Ensure that length of combustion air pipe does not exceed 48 inches (1219 mm) or does not
extend less than 18 inches (457 mm) above roof.
c. Secure inlet air pipe to collar of concentric adapter box using sheet metal screws.
d. Insert combustion air pipe through roof as shown in Figure 18, DETAIL A

20 I-SCE (09-18) PN207697R9
Figure 18. Vertical Vent Piping Installation
DETAIL A
e. Refer to Figure 14 to attach concentric adapter box brackets to wall
f. Flash combustion air pipe on outside. Flashing is field-supplied.
5. Install double-wall terminal vent pipe:
NOTE: The length of the vent pipe is determined by the installation within maximum and mini-
mum requirements.The vent pipe extending through the box and the inlet air pipe must be one
piece of double-wall vent pipe without joints.
a. Refer to Figure 18 to determine lengths of each pipe segment and to calculate total length required. Determine
length by adding requirements: starting at top, vent pipe must extend minimum of 22 inches (559 mm) beyond
top of inlet air pipe plus width of roof, plus length of brackets, plus 6 inches (152 mm) through box, and plus
6 inches (152 mm) extending out of box on heater side.
VENTING OPTIONS—CONTINUED
Option CC2 Installation Instructions—Continued