Reznor SCE, SCE 150, SCE 125, SCE 175, SCE 250 Installation Operation & Maintenance

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Revision: I-SCE (09-18) PN207697R9

Supersedes: I-SCE (5-15) PN207697Rev8

INSTALLATION/OPERATION/MAINTENANCE

SEPARATED-COMBUSTION,

PACKAGED FURNACE/BLOWER,

MODEL SCE

⚠ 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.

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

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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

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.

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DANGER: A danger statement describes a potentially hazardous situation that if not avoided, will result in severe

FRONT VIEW REAR VIEW

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).

Figure 1. Model SCE Unit Heater

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.

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SPECIAL INSTALLATIONS (AIRCRAFT HANGARS/GARAGES)

STANDARD MODEL SCE

MODEL SCE WITH OPTIONAL HORIZONTAL INLET WITH DUCT FLANGES

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))

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Table 1. Model SCE Dimensions

Dimension Code from

Figure 2

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)

125 150 and 175 200 and 225 250 300 350 400

Model

Inches ±1/8 (mm ±3)

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

Makeup air

NOTE: If an optional remote console is ordered, the control switch and temperature selector may be mounted on the console.

AG7

Thermostat (PN 48033)

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

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)

AG16 AG39

Remote temperature selector (PN 174849); temperature sensor (PN 133228); mixing tube (PN 90323)

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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

Pounds (kg) 313 (142) 358 (162) 382 (173) 482 (219) 498 (226) 560 (254)

125 150 and 175 200 and 225 250 and 300 350 400

Model

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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Figure 3. Suspension Methods

Field-supplied supports between the blower cabinet and the furnace

must extend horizontally supporting both sections.

Support Locations

FIELD-FABRICATED

AVAILABLE AS A PART

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.

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Figure 5. Corner Mounting Supports

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DUCT CONNECTIONS

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)

Refer to Figure 6 for duct connection dimensions.

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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• Supply Air Duct/Furnace Horizontal Connection: The seal between the furnace and the duct must be mechanical

DETAIL A

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.

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.

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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

Diameters (Inches (mm))

Vent pipe

Inlet air pipe

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)

125–175 200–400

— 7 (178)

Model

6 (152)

• 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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STEP 1

Place a continual 3/8” bead of silicone sealant around the circumference of the vent cap collar. 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

STEP 1

On the taper-type reducer, place a continual 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

Do STEP 2 immediately following STEP 1.

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 apply to both horizontal and vertical vent kits.

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.

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Figure 9. Joining Double-Wall (Type B) Pipe to Single-Wall or Category III Vent Pipe

Using Tapered Reducer

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VENTING AND COMBUSTION AIR—CONTINUED

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

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

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Speciﬁc Venting Requirements: Concentric Adapter Box Pipe Connections

NOTE: Do NOT make actual connections until after reading the instructions and length requirements 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.

I-SCE (09-18) PN207697R9

Figure 11. Concentric Adapter Box Connections

Page 14

VENTING OPTIONS

SCREENED EXHAUST ASSEMBLY INLET GUARD

Both venting options described below are shown in Figure 12.

HORIZONTAL VENTING

(OPTION CC6)

VERTICAL VENTING

(OPTION CC2)

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.

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 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.

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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 deterioration of masonry materials. A clear silicone sealant normally used to protect concrete driveways may be used to protect masonry materials from discoloration and deterioration. If discoloration 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)* Combustion air inlet of another appliance 6 (1.8)

Any building opening (door, window, or gravity air inlet)

Gas meter,** electric meter, and relief equipment

Gas regulator**

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.

3 (0.9) above

4 (1.2) horizontal and below

1 (305) above

US: 4 (1.2) horizontal

Canada: 6 (1.8) horizontal

US: 3 (0.9) horizontal

Canada: 6 (1.8) horizontal

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 noncombustible 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.

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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.

Figure 14. Concentric Adapter Box Brackets

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 doublewall vent pipe is installed. If cap is attached ﬁrst, ensure that the bafﬂe strips are positioned correctly 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 minimum 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.

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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.

Figure 15. Option CC6 Installation

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VENTING OPTIONS—CONTINUED

EXHAUST (VENT) TERMINAL

COMBUSTION AIR INLET

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 ⚠

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.

Table 9. Minimum Spacing Between Center Lines of Vertical Vent Pipes

Minimum Outdoor Design Temperature

≥31°F (≥0°C) 36 (914)

−10 to 30°F (−23 to −1°C) 60 (1524) < −10°F (< −23°C) 84 (2134)

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.

Minimum Spacing Between Center Lines of Vertical Vent Pipes

(Inches (mm))

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SIDE VIEW

REAR VIEW

Figure 17. Option CC2 Installation

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 noncombustible 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

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VENTING OPTIONS—CONTINUED

Option CC2 Installation Instructions—Continued

DETAIL A

Figure 18. Vertical Vent Piping Installation

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:

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.

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Page 21

b. Ensure that double-wall terminal vent pipe is in proper direction and slide end of pipe into box and out through

SECOND, Install the Exhaust (Vent) Terminal. Follow the instructions in FIGURE 2, page 3.

FIRST, Install Combustion Air Inlet.

1) Slide the combustion air inlet over the vent pipe.

2) Fasten bottom of inlet to the combustion air pipe with sheetmetal screws. Be sure not to penetrate the vent pipe.

3) At the top, completely seal the space between the vent pipe and the air inlet with silicone.

Double-wall Vent Pipe

Cold Climate NOTE: In geographic areas where the design ambient is

-10°F or lower, this minimum height is 24” (610 mm)

Single-wall Combustion Air Pipe

combustion air pipe. Position vent pipe to lengths determined above.

NOTE: The double-wall vent pipe does not attach to the box. The installer must provide support.

c. Connect double-wall vent pipe to single-wall or Category III vent pipe run using tapered reducer (see Figure 9).

d. Seal vent pipe using silicone sealant. Completely seal circumference of pipe at opening of box.

6. Install combustion air inlet and exhaust vent terminal:

a. On outside, slide combustion air inlet over vent pipe and fasten collar to combustion air pipe using sheet metal

screws (see Figure 19).

b. Using silicone sealant, seal opening at top between vent pipe and combustion air inlet to prevent water leakage.

c. Install exhaust vent terminal (see Figure 19) in accordance with Figure 8.

Figure 19. Combustion Air Inlet and Vent Terminal Installation

d. 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.

e. Seal pipe joints with tape or sealant.

7. Verify compliance with Figure 17 and with all speciﬁc venting requirements listed above.

GAS PIPING AND PRESSURES

⚠ WARNING ⚠

This appliance is equipped for a maximum gas supply pressure of 1/2 psi, 3.5 kPa, or 14 IN WC. Supply pressures higher than 1/2 psi require installation of an additional service regulator external to the unit.

Pressure Testing Gas Supply Piping

• To test piping when gas supply pressure is above 1/2 psi: Disconnect the heater and manual valve from the

gas supply line that is to be tested. Cap or plug the supply line.

• To test piping when gas supply pressure is below 1/2 psi: Before testing, close the manual valve on the heater.

Manifold gas pressure must never exceed 3.5 IN WC for natural gas or 10 IN WC for propane gas.

I-SCE (09-18) PN207697R9

⚠ WARNING ⚠

Page 22

GAS PIPING AND PRESSURES—CONTINUED

Pressure Testing Gas Supply Piping—Continued

• All piping must be in accordance with requirements outlined in the National Fuel Gas Code ANSI/Z223.1 (latest edition) or CSA B149.1 and B149.2 (refer to Installation Codes). Gas supply piping installation should conform with good practice and with local codes.

• These separated-combustion units for natural gas are oriﬁced for gas having a heating value of 1000 (±50) BTUh per cubic foot. If the gas at the installation does not meet this speciﬁcation, consult the factory for proper oriﬁcing.

• Pipe joint compounds (pipe dope) shall be resistant to the action of liqueﬁed petroleum gas or any other chemical constituents of the gas being supplied.

Gas Connections

Gas connections are shown in Figure 20.

Figure 20. Gas Connections

Gas connections sizes are listed in Table 10.

Table 10. Gas Connection Sizes

Model

Gas Type

Natural Gas 1/2 3/4

Propane Gas 1/2

NOTE: The above are not supply line sizes. They are gas connection sizes for a standard unit.

125–250 300–400

Connection Size (Inches)

• Seal the opening for the gas supply pipe with the grommet provided (see Figure 20).

• Install a ground joint union and manual shutoff valve upstream of the unit control system. The 1/8-inch plugged tapping in the shutoff valve provides connection for the supply line pressure test gauge. The National Fuel Gas Code requires the installation of a trap with a minimum 3-inch drip leg. Local codes may require a longer drip leg, typically 6-inch (see Figure 20).

⚠ DANGER ⚠

All components of a gas supply system must be leak tested prior to placing the equipment in service. NEVER TEST FOR LEAKS WITH AN OPEN FLAME.

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Page 23

• After all connections are made, disconnect the pilot supply at the control valve and bleed the system of all air. Reconnect the pilot line and leak test all connections by brushing on a soap solution.

Sizing Gas Supply Lines

NOTE: When sizing supply lines, consider the possibility of future expansion and increased requirements. Refer to National Fuel Gas Code for additional information on line sizing.

Sizing of gas supply lines depends on piping capacity and is based on the following:

• Cubic feet per hour based on a 0.3 IN WC pressure drop

• Speciﬁc gravity for natural gas: 0.6 (1000 BTU per cubic feet)

• Speciﬁc gravity for propane gas: 1.6 (2550 BTU per cubic feet)

Variables for sizing gas supply lines are listed in Table 11.

Table 11. Gas Supply Line Sizes

Diameter of Pipe (Inches)

Length of Pipe

(Feet)

20 92 56 190 116 350 214 730 445 1100 671 2100 1281 30 73 45 152 93 285 174 590 360 890 543 1650 1007 40 63 38 130 79 245 149 500 305 760 464 1450 885 50 56 34 115 70 215 131 440 268 670 409 1270 775 60 50 31 105 64 195 119 400 244 610 372 1105 674 70 46 28 96 59 180 110 370 226 560 342 1050 641 80 43 26 90 55 170 104 350 214 530 323 990 604

90 40 24 84 51 160 98 320 195 490 299 930 567 100 38 23 79 48 150 92 305 186 460 281 870 531 125 34 21 72 44 130 79 275 168 410 250 780 476 150 31 19 64 39 120 73 250 153 380 232 710 433 175 28 17 59 36 110 67 225 137 350 214 650 397 200 26 16 55 34 100 61 210 128 320 195 610 372

1/2 3/4 1 1-1/4 1-1/2 2

Natural

Gas

Propane

Gas

Natural

Gas

Propane

Gas

Natural

Gas

Propane

Gas

Cubic Feet per Hour

Natural

Gas

Propane

Gas

Natural

Gas

Propane

Gas

Natural

Gas

Propane

Gas

Manifold or Oriﬁce (Valve Outlet) Pressure Settings

Measuring manifold gas pressure cannot be done until the heater is in operation (see Post-Startup Checklist). The following warnings and instructions apply.

• For natural gas: When the heater leaves the factory, the combination valve is set so that the outlet gas pressure of a single-stage valve or high ﬁre of a two-stage valve is regulated to 3.5 IN WC. Low ﬁre on a two-stage valve is set to 1.8 IN WC. Inlet supply pressure to the valve must be a minimum of 5 IN WC or as noted on the rating plate and a maximum of 14 IN WC.

NOTE: Always check the rating plate for minimum gas supply pressure.

• Minimum natural gas supply pressure: Requirements vary based on size of burner and the gas control option.

Most units require a minimum of 5 IN WC natural gas as stated above, but sizes 350 and 400 with electronic modulation require a minimum of 6 IN WC natural gas supply pressure. Sizes 300 and 350 with mechanical modulation require 7 IN WC.

• For propane gas: When the heater leaves the factory, the combination valve is set so that the outlet gas pressure of a single-stage valve or high ﬁre of a two-stage valve is 10 IN WC. Low ﬁre on a two-stage valve is set to 5 IN WC. Inlet pressure to the valve must be a minimum of 11 IN WC and a maximum of 14 IN WC.

⚠ WARNING ⚠

Before attempting to measure or adjust manifold gas pressure, the inlet (supply) pressure must be within the speciﬁed range for the gas being used, both when the heater is in operation and when it is on standby. Incorrect inlet pressure could cause excessive manifold gas pressure immediately or at some future time.

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GAS PIPING AND PRESSURES—CONTINUED

Instructions to Check Valve Outlet (Manifold) Pressure

NOTE: A manometer (ﬂuid-ﬁlled gauge) is recommended rather than a spring-type gauge due to the difﬁculty of maintaining calibration of a spring-type gauge.

1. With the manual valve (on the combination valve) positioned to prevent ﬂow to the main burners, connect a manometer to the 1/8-inch pipe outlet pressure tap in the valve.

2. Open the valve and operate the heater. Measure the gas pressure to the manifold. To measure the low-stage pressure on units equipped with a two-stage valve, disconnect the wire from the HI terminal on the valve. Be sure to reconnect the wire.

3. Normally, adjustments to the factory-preset regulator should not be necessary. If adjustment is necessary, set pressure to correct settings by turning the regulator screw IN (clockwise) to increase pressure. Turn the regulator screw OUT (counterclockwise) to decrease pressure. Consult the valve manufacturer’s literature provided with the furnace for more detailed information.

ELECTRICAL SUPPLY AND CONNECTIONS

• All electrical wiring must be completed in accordance with local, state, and national codes and regulations and with the National Electric Code (ANSI/NFPA 70) or, in Canada, the Canadian Electric Code, Part 1 (CSA C.22.1).

• Check any local ordinances or gas company requirements that apply.

• Check the rating plate on the heater for the supply voltage and for current requirements. A separate line voltage supply with fused disconnect switch should be run directly from the main electrical panel to the unit, making connections in the junction box (see Figure 2).

• Seal all electrical entrance openings with ﬁeld-supplied bushings.

• Refer to Table 12 for ﬁeld-supplied wiring sizes—from disconnect to electrical box—for connection to the motor contactor or starter.

Table 12. Field-Supplied Wiring Sizes

Voltage/Phase Motor HP Wire Gauge BX Cable

120/1 1/4– 1/2 14 3/8

208–230/1

208–230/3 1/4–3 14 3/8

460/3

575/3 1/2–5 14 3/8

1 12 3/8

1–1-1/2 14 3/8

5 12 3/8

1/4–5 14 3/8

⚠ CAUTION ⚠

If any of the original wire as supplied with the appliance must be replaced, it must be replaced with wiring material having a temperature rating of at least 105°C, except for the sensor lead and the optional bypass damper combustion air safety circuit (option AG39 or AG40) wires, which must

be rated at 150°C.

• A disconnect switch is available as optional equipment or may be supplied locally. When installing the disconnect switch, ensure that the conduit and switch housing are clear of all service panels. Allow at least 4 feet (1.2 M) of service room between the disconnect switch and any removable service panels. When providing or replacing fuses in a fusible disconnect switch, use dual-element time delay fuses sized at 1.25 × maximum total input amps.

• The heater is equipped with a low-voltage (24V) control circuit.

• Refer to Table 13 for ﬁeld-supplied control wiring sizes.

Table 13. Field-Supplied Control Wiring Sizes

Distance from Unit to Control

(Feet (Meters))

75 (23) #18 150 (46) 125 (38) #16 250 (76) 175 (53) #14 350 (107)

Minimum Recommended Wire Gauge

(AWG)

Total Wire Length

(Feet (Meters))

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Page 25

A speciﬁc wiring diagram can be found in the heater junction box. Optional equipment is identiﬁed on this wiring diagram. Refer to separate instruction sheets for any optional equipment provided. See Figure 21 and Figure 22 for typical wiring diagrams.

Figure 21. Typical Wiring Diagram: Model SCE with Single-Stage Gas Control

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ELECTRICAL SUPPLY AND CONNECTIONS—CONTINUED

Figure 22. Typical Wiring Diagram: Model SCE with Two-Stage Gas Control

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Page 27

CONTROL THERMOSTAT

A thermostat is not supplied with the furnace. Use either an optional or a ﬁeld-provided low-voltage (24V) thermostat. Install the thermostat according to the manufacturer’s instructions.

A low-voltage thermostat is equipped with a heat anticipator that levels out unit cycling for optimum temperature control. Set the anticipator at 1.0 amps for standard controls. Refer to Table 14 for amp ratings of optional controls.

⚠ CAUTION ⚠

Control circuit amps should be within the anticipator amp rating of the thermostat used.

Table 14. Amp Ratings of 24-Volt Optional Controls

Control Ampere Rating (Amps)

Fan control 0.12

Time delay heater 0.14

RBM relay coil 0.12

Contactor coil 0.45

Spark ignition system 0.10

Maxitrol gas control system 0.51

Honeywell gas valve 0.50

White-Rodgers gas valve 0.60

COMBUSTION AIR PROVING SWITCH

⚠ DANGER ⚠

Safe operation requires proper venting ﬂow. Never bypass the combustion air proving switch or attempt to operate the unit without the venter running and proper ﬂow in the vent system. Hazardous conditions could result.

The combustion air proving switch ensures that proper combustion airﬂow is available. The switch is a single-pole, double-throw switch, which senses pressure caused by the ﬂow of combustion air from the venter. The switch is designed to close when a decreasing pressure is sensed in the outlet duct of the gas collection box.

At startup when the furnace is cold, the sensing pressure is at the most negative level, and as the furnace and the ﬂue system warm up, the sensing pressure becomes less negative. After the system has reached equilibrium (approximately 20 minutes), the sensing pressure levels off. If a restriction or if excessive ﬂue length or turns cause the sensing pressure to become less than the switch setpoint, the pressure switch will function to shut off the main burners. The main burners will remain off until the system has cooled and/or the ﬂue system resistance is reduced. Refer to Table 15 for approximate water column negative pressure readings and combustion air proving switch setpoints for sea level operating conditions.

Table 15. Combustion Air Proving Switch Settings at Sea Level Operating Conditions

Factory Setpoint Startup Cold Equilibrium

−0.58 IN WC (±0.05 IN WC) −1.0 IN WC −0.70 IN WC

NOTE: These settings apply to furnaces that are not equipped with air and gas modulation option AG39 or AG40. For pressure switch settings for units equipped with option AG39 or AG40, refer to Table 18.

BLOWER FAN CONTROL

NOTE: To replace the blower fan control on units manufactured before NOV 2004, a replacement kit is required. Order PN 209184.

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BLOWER FAN CONTROL—CONTINUED

The blower fan is controlled as follows:

• After the gas valve opens, there is a time delay of blower fan operation to prevent the discharge of cold air.

• Blower fan operation continues after the thermostat is satisﬁed, as determined by the fan time delay.

• To ensure that the blower fan can continue to operate, the power supply to the furnace MUST NOT be interrupted except for when servicing the unit.

• If the customer wants the furnace off at night, the gas valve circuit SHOULD BE OPENED by a single-pole switch wired in series with the thermostat. Some thermostats are provided with this feature. Multiple units controlled from a single thermostat are shut off in the same manner. For proper operation, ensure that the blower fan control is wired correctly.

LIMIT CONTROL

All models are equipped with an automatic, nonadjustable, reset limit control that acts to interrupt the electric supply to the redundant main operating valve in case of motor failure or lack of airﬂow due to restrictions at the inlet or outlet.

MOTOR LOAD AND AMPS

• Amps may be adjusted downward by reducing blower rpm or by increasing duct system static pressure. Use an ammeter to check blower motor amps.

• See the motor rating plate for exact motor speciﬁcations. Do not exceed the amp rating on the motor nameplate.

• Venter motor amps are 1.5 amps for a 115- or 575-volt unit or 0.8 amps for a 208-, 230-, or 460-volt unit.

• Table 16, which lists the Full Load Amps (FLA) of blower motors (open) based on Horsepower (HP) and Voltage (V), can be used for sizing line wiring but should not be interpreted as the exact motor amps.

Table 16. FLA of Blower Motors (Open, Single-Speed, Average Values)

Voltage/Phase

115V/1PH 4.60 5.60 8.80 11.00 13.00 18.20 20.40 24.80 — 208V/1PH 2.50 3.10 5.10 6.10 7.20 10.10 11.30 13.70 28.00 230V/1PH 2.30 2.80 4.40 5.50 6.50 9.10 10.20 12.40 26.00 208V/3PH 1.70 1.80 2.20 2.90 3.60 5.80 7.30 9.30 14.60 230V/3PH 1.50 1.60 2.00 2.60 3.20 5.20 6.60 8.40 13.20 460V/3PH 0.75 0.80 1.00 1.30 1.60 2.60 3.30 4.20 6.60 575V/3PH — — — — 1.30 2.10 2.60 3.40 5.30

1/4 1/3 1/2 3/4 1 1-1/2 2 3 5

FLA

BELTS, BLOWERS, AND DRIVES

Checking and Adjusting Belt Tension

Proper belt tension is important to the long life of the belt and motor. A loose belt will cause wear and slippage. Too much tension will cause excessive motor and blower bearing wear. Check belt tension as shown in Figure 23.

3/4" (19 mm)

Figure 23. Checking Belt Tension

If the belt cannot be depressed 3/4 inches (19 mm), as shown in Figure 23, adjust the belt tension as follows:

1. Ensure that belt is aligned in pulley grooves properly and is not angled from pulley to pulley.

2. Loosen adjusting screw locknut on motor base and turn adjusting screw until belt can be depressed 3/4 inches (19 mm).

3. When correct belt tension is achieved, retighten adjusting screw locknut.

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Adjusting Blower Speed

Blower speed may be adjusted to achieve the desired outlet temperature as long as the adjustment is within the temperature rise and static pressure limits shown on the furnace rating plate. Motors are factory-set between maximum and minimum blower speeds.

If the duct resistance is low, the blower may deliver too high an air volume. If the resistance is very low, the blower may deliver excess air to overload the motor, causing the overload protector to cycle the motor. Reducing the blower speed will correct these conditions. If ductwork is added to an installation, it may be necessary to increase the blower speed. Decreasing blower speed increases outlet temperature. Increasing blower speed decreases outlet temperature.

At ﬁnal adjustment, amperes should not exceed motor nameplate amp rating. The installation must be adjusted to obtain a temperature rise within the range speciﬁed on the furnace rating plate.

The belt drive on these units is equipped with an adjustable pulley that permits blower speed adjustment. Adjust the blower speed as follows:

1. Shut off gas and electric power.

2. Loosen belt tension and remove belt.

3. Loosen setscrew on side of pulley away from motor.

4. To increase blower speed and decrease outlet temperature, turn adjustable half of pulley inward. To decrease

blower speed and increase outlet temperature, turn adjustable half of pulley outward. One turn of pulley changes speed 8–10%.

5. Tighten setscrew on ﬂat portion of pulley shaft.

6. Replace belt and adjust belt tension in accordance with Checking and Adjusting Belt Tension.

7. Turn on gas and electric power and light heater in accordance with instructions on lighting instruction plate.

8. Check motor amps using ammeter (maximum motor amp rating on motor nameplate must not be exceeded).

When adjustment is complete, check for proper operation.

Blower Rotation

Each blower housing is marked for proper rotation. Rotation may be changed on single-phase motors by rewiring in the motor terminal box. Rotation may be changed on three-phase motors by interchanging two wires on the threephase supply connections.

Optional Variable Frequency Drive

If the system is equipped with an optional variable frequency drive, the motor will operate at speeds determined by the electrical frequency: 60 Hertz (Hz) is maximum speed. Speed must be within the temperature rise range of a Model SCE Series 6 heater: 30–90°F.

Follow the variable frequency controller manufacturer’s instructions that are packaged with the heater (in the owner’s envelope) to program the variable frequency drive settings. The formula for motor speed is as follows:

N = 120 × f/p

where N is speed, f is frequency, and p is number of poles

A 3600-rpm motor has two poles and an 1800-rpm motor has four poles.

For example, for an 1800-rpm motor at 60Hz, N = 120 × 60/4 = 1800 (1800 is synchronous speed, assume 2% slip). The motor will run between 1750 and 1790 rpm at full load depending on design. For the same motor run at 45Hz, 120 × 45/4 = 1350 (1350 rpm less 2% slip equals about 1300 rpm).

OPERATING VALVE

⚠ WARNING ⚠

The operating valve is the prime safety shutoff. To ensure positive closure, all gas supply lines must be free of dirt or scale before connecting the unit.

All furnaces are equipped with a 24-volt combination valve that includes the automatic, electric on/off valve controlled by the room thermostat, the pressure regulator, the safety pilot valve, and the manual shutoff valve. The standard gas valve allows for single-stage control from a single- stage, 24-volt thermostat.

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OPTIONAL TWO-STAGE OPERATION—HEATING ONLY APPLICATION

A = B = ONE-ST

The standard combination control valve is replaced with a two-stage combination gas control valve providing for low ﬁre or high ﬁre operation controlled by a two-stage thermostat. The ﬁrst stage (low ﬁre) is factory-set (not ﬁeldadjustable). Both low ﬁre and high ﬁre stages are controlled by a Servo regulator that maintains constant gas input under wide variations in gas supply pressure. See the instructions provided with the unit for speciﬁc gas valve speciﬁcations, wiring, and operating instructions.

OPTIONAL TWO-STAGE OPERATION—MAKEUP AIR APPLICATION

Two-stage makeup air units are equipped with a two-stage gas valve, but instead of control from a two-stage room thermostat, the outlet air temperature is monitored and controlled by a two-stage ductstat. When discharge air temperature drops to the setpoint, low ﬁre is energized. If low ﬁre cannot satisfy the ductstat setting, high ﬁre is energized.

Makeup air applications are usually adjusted to maintain discharge air temperature between 65°F and 75°F. In all applications, the allowable temperature rise of the furnace in the installation dictates the limits of the ductstat temperature setting.

Depending on the option selection, the factory-installed sensor is either ﬁeld-connected by capillary tubing to the unit-mounted ductstat (see Figure 24), which is factory-set at 70°F, or electrically-connected to a remote electronic temperature selector (see Figure 25), which is available with or without a display module.

Figure 24. Unit-Mounted Ductstat (Option AG3)

TEMPERAT URE-SELECTING MODULE

AGE ADDER MODULE

Figure 25. Remote Temperature Selector (Option AG15 or AG16)

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Optional Ductstat with Capillary Tubing (Option AG3): The unit-mounted ductstat shown in Figure 24 has an

1. Remove access panel in ductwork adjacent to control compartment access panel.

2. Element is retained by spring clips.

3. Round gasket and metal retaining

plate provide airtight seal for capillary and must be removed to remove the element.

adjustable range between 0°F and 100°F with a ﬁxed differential of 3°F. Due to different cfm settings and outside air temperatures, the average downstream outlet temperature may not match the ductstat setting exactly. After the installation is complete, adjust the setpoint of the ductstat to achieve the desired average outlet air temperature.

Optional Ductstat with Electronic Remote Setpoint Module (Option AG15 or AG16): The ﬁeld-installed sensing probe is ﬁeld-wired to the remote temperature selector shown in Figure 25, which has a temperature operating range to 130°F. The remote modules and sensing probe are shipped separately for ﬁeld-installation. Follow the wiring diagram provided with the unit and the manufacturer’s instructions for wiring and installation. One module is for selecting temperature, one module is a one-stage adder module, and the digital display module is optional.

⚠ CAUTION ⚠

Ensure that heat/cool selector switch on remote temperature selector is positioned to “Heat”.

Figure 26 shows how to access the factory-installed sensor with either the unit-mounted ductstat (see Figure 24)

or the remote temperature selector (see Figure 25).

Figure 26. Accessing Duct Temperature Sensor

OPTIONAL ELECTRONIC MODULATION

NOTE: Sizes 350 and 400 with electronic modulation require a minimum natural gas supply pressure of 6 IN WC.

Depending on heat requirements established by the thermistor sensor, the burner modulates up to 100% ﬁring. The thermistor is a resistor that is temperature sensitive in that as the surrounding temperature changes, the resistance (ohms) changes through the thermistor. This change is monitored by the solid-state control center (ampliﬁer), which provides a varying DC current to the modulating valve to adjust the gas input.

Each modulating valve is basically a regulator with electrical means of raising and lowering discharge pressure. When no DC current is fed to this device, it functions as a gas pressure regulator that supplies 3.5 IN WC pressure to the main operating valve.

Refer to the wiring diagram supplied with the furnace for proper wiring connections for the electronic modulation system.

The type and capability of the electronic modulation system, depend on the option selected.

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OPTIONAL ELECTRONIC MODULATION—CONTINUED

Note: Arrangement may vary slightly depending on gas valve; components are the same.

AMPLIFIER SIGNAL CONDITIONER

Electronic Modulation Between 50% and 100% Firing Rate (Option AG7, AG8, or AG9)

Electronic modulation for heating that is controlled by a specially-designed room thermostat (60–85°F) is identiﬁed as option AG7. Electronic modulation for makeup air application that is controlled by a duct sensor and temperature selector (55–90°F) is identiﬁed as option AG8 or AG9. The temperature selector setting for option AG8 is on the ampliﬁer (see Figure 27). Option AG9 has a remote temperature selector. Both systems are available with an override thermostat.

Computer-Controlled Electronic Modulation Between 50% and 100% Firing Rate (Option AG21)

With option AG21, the furnace is equipped with a Maxitrol signal conditioner (see Figure 27) that operates much the same way as the ampliﬁer above to control the regulator valve. The conditioner accepts an input signal of either 4–20 milliamps or 0–10V from a customer-supplied control device such as a computer. With the dip switches on the conditioner positioned to ON, the conditioner accepts a 4–20 milliamp signal. With the dip switches on the conditioner positioned to OFF, the conditioner accepts a 0–10V signal. The conditioner converts the signal to the 0–20V DC current required to control the modulating valve.

Figure 27. Maxitrol Ampliﬁer and Signal Conditioner

Electronic Modulation Between 20–28% and 100% Firing Rate (Option AG39)

NOTE: Option AG39 (US Patent 6,109,255) is available only with natural gas and is not available on size 350.

Depending on its size, a furnace equipped with option AG39 has a 20–28% turndown ratio. The furnace will ignite at any input rate in the available range and will maintain average thermal efﬁciencies equal to or greater than the thermal efﬁciency at full ﬁre.

The gas train includes a single-stage gas valve, a modulating valve, and two gas pressure switches (see Figure

28). The burner rack is equipped with one ﬂash carryover and a regulated gas lighter tube system. The carryover

lighter tube receives its gas supply through the regulator, simultaneously with the gas to the burner. Control of the system is through a Maxitrol ampliﬁer (see Figure 27) with a corresponding remote temperature dial.

Figure 28. Option AG39 Manifold Arrangement

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The gas supply (refer to pressure requirements in Table 17) connects to the single-stage gas valve. To compensate for additional pressure loss through the modulating valve, the single-stage gas valve has a custom outlet pressure setting higher than when it is used on a standard gas manifold. The pilot tubing connects to the pilot port on the single-stage gas valve. When the valve receives a call for heat from the ampliﬁer and pilot is established, gas ﬂow from the single-stage valve goes to both the modulating valve and the regulated lighter tube system. When the signal from the ampliﬁer to the modulating valve requires less-than-high ﬁre operation, the modulating valve functions to lessen the gas ﬂow to the burner to reduce the input rate to that required to maintain the desired temperature. When the input rate is reduced enough to decrease the gas pressure to 1.1 IN WC, the primary gas pressure switch in the manifold activates the gear motor that controls the bypass damper in the venter/combustion air system. The bypass damper opens to divert some of the incoming air directly into the ﬂue duct and to reduce air ﬂow through the burner. Safety switches monitor the position of the bypass damper. When the gas pressure increases above 1.1 IN WC, the bypass damper closes.

Table 17. Options AG39 and AG40 Pressure Requirements

Model Maximum Turndown MBH Input Range

125 20% 25–125 3.9 5.0 150 27% 40.3–150 3.7 5.0 175 23% 40.3–175 3.7 5.0 200 26% 51.8–200 3.9 5.0 225 23% 51.8–225 3.9 5.0 250 28% 69–250 4.0 5.0 300 23% 69–300 4.0 5.0 400 25% 100–400 4.4 6.0

Factory-Set Inlet Pressure

to Modulating Valve

(IN WC)

Gas Supply Pressure

Required

(IN WC)

Sensor Location: For the convenience of the installer, the duct temperature sensor is factory-installed in the cabinet

leg (see Figure 26). Although the sensor has a mixing tube, at this distance from the discharge it does not receive a true mix, so the temperature read by the sensor will be slightly higher than the actual air entering the ductwork. The system will provide comfort level heat if the selector is set slightly higher to compensate for this reading. If a direct correlation of these two temperatures is required, move the duct sensor to a location in the ductwork about 10–12 feet (3–3.7 M) from the furnace discharge.

Wiring and Service: For wiring, consult the wiring diagram provided with the furnace. All wires in the electrical box that connect to modulation controls must have a temperature rating of 150°C. This is a unique system which includes custom-built components and custom settings. If service is required, follow the general guide in TROUBLESHOOTING and the special troubleshooting guide shown in Figure 29.

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OPTIONAL ELECTRONIC MODULATION—CONTINUED

Symptom Main Assumes available and

General

check to ensure that the wiring is not defective and that the wiring connections

Symptom S Assumes

Electronic Modulation Between 20–28% and 100% Firing Rate (Option AG39)—Continued

Instructions: For each step,

are secure.

- Part 1:

burners are inoperative.

that 24 volts is between Terminal 2

Terminal 7.

Check combustion

damper lower end switch

adjustment. Replace end

switch if necessary.

Is there 24 volts

between Terminal 2 on #1

Time Delay Relay and

Terminal 7?

Is there 24 volts

between Terminal 84 and

Terminal 7?

YES

Is the

damper open?

Is there voltage

between Terminal 87 and

Terminal 7?

YES

Place a jumper across Terminal

86 and Terminal 7.

YES

Go to Troubleshooting Chart for heater.

Replace primary

manifold

pressure switch.

Is there voltage

between Terminal 88 and

Terminal 7?

YES

Is there voltage

between Terminal 4 on

ignition permissive relay and

Terminal 7?

YES

Replace #1 time

delay relay.

Check combustion

damper lower end switch

adjustment. If necessary,

NONO

replace end switch.

Replace ignition

permissive

relay.

Replace combustion

damper gear motor.

- Part 2:

teady call for heat - burner cycles.

that 24 volts is available between Terminals 11 and 7 and Terminals 2 and 7.

When the

manifold pressure is

BELOW 1.0" w.c., is there a steady

voltage between Terminal 95

and Terminal 7?

YES

Replace secondary

manifold pressure

switch.

damper close?

Measure manifold

pressure

during burner cycling.

While the

burner is cycling, is

there a steady voltage

between Terminal 84 and

Terminal 2?

YES

Replace the

primary manifold

pressure switch.

Did the

YESNO

When the

manifold pressure is

ABOVE 1.5" w.c., is there a steady

voltage between Terminal 95

and Terminal 7?

Replace secondary

manifold pressure

switch.

Replace motor

run time delay

relay.

YES

Is there voltage

between Terminal 4 of the

ignition premissive relay and

Terminal 7?

Replace ignition

permissive

relay.

Figure 29. Troubleshooting Guide for Checking Bypass Combustion Air Damper Safety Circuit

on Units with Option AG39 or AG40

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Computer-Controlled Electronic Modulation Between 20–28% and 100% Firing Rate (Option AG40)

NOTE: Option AG40 (US Patent 6,109,255) is available only with natural gas and is not available on size 350.

With option AG40, the furnace is equipped with a Maxitrol signal conditioner (see Figure 27) that receives an input signal of either 4–20 milliamps or 0–10V from a customer-supplied control device such as a computer. With the dip switches on the conditioner positioned to ON, the conditioner accepts a 4–20 milliamp signal. With the dip switches on the conditioner positioned to OFF, the conditioner accepts a 0–10V signal. The conditioner converts the signal to the 0–20V DC current required to control the modulating valve. The heater functions and is equipped in the same way as option AG39 except that with computer control, the temperatures are selected through the software and there is no temperature selector or duct sensor.

Refer to Table 17 for option AG40 pressure requirements and to Figure 29 for troubleshooting option AG40.

Combustion Air Pressure Switch Settings for Options AG39 and AG40: This uniquely-designed modulation system requires combustion air pressure settings different from the standard system. Refer to Table 18 for the approximate combustion air proving switch settings at sea-level operation.

Table 18. Combustion Air Proving Switch Settings (Options AG39 and AG40)

Model Factory Setpoint Startup Cold Equilibrium

125–225 −1.00 IN WC (±0.02 IN WC) −1.30 IN WC (±0.20 IN WC) −1.05 IN WC (±0.10 IN WC)

250–300 and 400 −0.70 IN WC (±0.05 IN WC) −1.20 IN WC (±0.20 IN WC) −0.95 IN WC (±0.10 IN WC)

PILOT AND IGNITION SYSTEMS

⚠ WARNING ⚠

Due to high voltage on the pilot spark wire and pilot electrode, do not touch when energized.

Pilot: All pilots are vertical, target-type with a lint-free feature. Pilot ﬂame should be approximately 1-1/4 inches

in length. Pilot gas pressure should be the same as the supply line pressure. Pilot gas is supplied through the combination valve. Pilot gas ﬂow is controlled by an adjustment screw located in the valve body. For maintenance, refer to Burner Rack Maintenance and Cleaning Pilot and Burners.

Ignition System (Lockout): Natural gas units are equipped with a spark-ignited intermittent safety pilot system (lockout) that shuts off pilot gas ﬂow between heat cycles. Propane units (or as an option on natural gas units) require a lockout device that stops gas ﬂow to the pilot if the pilot fails to light in 120 seconds. The lockout device requires manual set by interruption of the thermostat circuit. Refer to the wiring diagram provided with the unit for pilot system identiﬁcation and proper wiring. Pilot with lockout is option AH3. Spark pilot without lockout is option AH2.

Ignition Controller: As part of the intermittent safety pilot system, the ignition controller provides high voltage spark to ignite pilot gas and also acts as the ﬂame safety device. After ignition of the pilot gas, the ignition controller electronically senses the pilot ﬂame. A low voltage DC electrical signal is imposed on the separate metal probe in the pilot assembly. The metal probe is electrically insulated from ground. The pilot ﬂame acts as a conduction path to ground, completing the DC circuit and proving pilot ﬂame. Proper operation of the electronic spark ignition system requires a minimum ﬂame signal of 0.2 microamps DC, as measured by a microampmeter. With pilot ﬂame proven, the ignition controller energizes the main gas valve.

BURNERS, BURNER ORIFICES, AND CARRYOVER SYSTEM

NOTE: Natural gas units have a dual ﬂash carryover system and do not require a carryover oriﬁce.

Burners: Individually-formed steel burners capable of operating on either natural or propane gas are used in this

heater. These burners have accurate, machine-formed ports to provide controlled ﬂame stability and operation without lifting or ﬂashback. All burners are lightweight and factory-mounted in an assembly that permits all of the burners to be removed as a unit for inspection or service.

Burner Oriﬁces: Heaters are shipped with burner oriﬁces of proper size and type for the speciﬁed gas. Refer to

Table 19 for burner and carryover oriﬁce speciﬁcations.

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BURNERS, BURNER ORIFICES, AND CARRYOVER SYSTEM—CONTINUED

Table 19. Burner and Carryover Oriﬁce Speciﬁcations

Burner Oriﬁce Carryover Oriﬁce

Model

125 5 84437 #42 61652 1.45 mm 9870 #70 150 7 11833 #44 11830 #55 9680 #65 175 7 84437 #42 61652 1.45 mm 9680 #65 200 9 11828 #43 11830 #55 9680 #65 225 9 84437 #42 61652 1.45 mm 9680 #65 250 12 11833 #44 11830 #55 10370 #59 300 12 84437 #42 61652 1.45 mm 10370 #59 350 14 84437 #42 61652 1.45 mm 9791 #56 400 16 84437 #42 61652 1.45 mm 9791 #56

Natural gas units have a dual ﬂash carryover system and do not require a carryover oriﬁce.

Qty

Natural Gas Propane Gas Propane Gas

PN Drill Size PN Drill Size PN Drill Size

Burner Carryover Systems: All natural gas burners, except when equipped with electronic modulation option AG39

or AG40, are equipped with two carryover systems—one on each end of the burner rack.

NOTE: Natural gas burner racks on furnaces manufactured before before Series 6 units have a gas lighter tube carryover and one ash carryover.

All propane gas burners are equipped with one ﬂash carryover and a regulated gas tube system. The carryover lighter tube receives its gas supply through a regulator, simultaneously with the gas to the burner oriﬁces.

During regular service, check the main burner ports, the carryover assemblies, and the oriﬁces for cleanliness.

Typical natural gas and propane gas burner racks are shown in Figure 30.

(NOT APPLICABLE TO FURNACES WITH OPTION AG39 OR AG40)

Auxiliary

NATURAL GAS BURNER RACK

Pilot

Flash Carryover

Sensor

Carryover Regulator

BURNER RACK WITH PROPANE GAS PILOT

Pilot

Carryover Lighter Tube

Auxiliary Flame Probe

Propane Gas Pilot

Flash

Carryover

Natural Gas Pilot

Flash

Carryover

Figure 30. Typical Burner Rack

BURNER AIR SHUTTERS

⚠ DANGER ⚠

Failure to adjust air shutters according to directions could cause property damage, personal injury, and/or death.

Air shutters are required on propane gas units but are optional on natural gas units. A slotted burner air adjustment screw on the end of the manifold bracket (see Figure 31) moves the air shutters and adjusts all burners simultaneously. Turn the adjustment screw clockwise to open the air shutter or counterclockwise to close the air shutter.

After the furnace has been in operation for 15 minutes, close the air shutter until the ﬂame turns yellow. Open the shutter until yellow disappears.

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Burner Air

Shutter

Adjustment

Screw

Figure 31. Burner Air Shutter Adjustment Screw

#10-32 x 1”Lg Machine Screw & Nut

RTV Sealant

Seal holes in bottom pan with RTV sealant

OPTIONAL EQUIPMENT

OPTIONAL CONDENSATION DRAIN FOR DUCT FURNACES

Model SCE furnaces are certiﬁed for installation upstream or downstream from a cooling coil. When installed downstream from a refrigeration system, condensation will form and, therefore, adequate provision must be made to dispose of condensate.

Periodic cleaning of the condensate collection and disposal system is required. Install the drain connection, option CS1 (PN 31765), on the furnace casing as shown in Figure 32.

Figure 32. Optional Condensate Drain Connection

Terminate the drain outside the building. Provide a trap to prevent air from entering the combustion zone. Periodic cleaning of the condensate collection and disposal system is required.

NOTE: Requires a four-inch (102 mm) minimum clearance under the furnace if a 90-degree street elbow is used.

OPTIONAL DAMPERS AND CONTROLS

For information on damper and control options, refer to the wiring diagram supplied with the unit and see Figure 33.

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arm.

(1) (2) (3) (4)

OPTIONAL DAMPERS AND CONTROLS—CONTINUED

Damper Linkage -When units are equipped with dampers, the dampers are closed during shipment. When there are both return

NOTE: The illustration is intended to show location only of various air control accessories and does not represent suggested combinations of accessories.

Outside Air Damper

Return Air Damper

Damper Motor Potentiometer

(5) Potentiometer (6) Mixed Air Controller (7) Warmup Control (8) Remote Potentiometer

Figure 33. Optional Dampers and Controls

air and outside air dampers,

the return damper linkage must be adjusted prior to use.

1. Loosen the set screw on the return air damper rod at the damper

2. Manually open the return air dampers. While the dampers are open-

ing, the damper rod and arm will automatically move to their correct positions.

3. Tighten the set screw.

OPTIONAL FILTER RACK AND FILTERS

Filter racks and ﬁlters are factory-installed optional equipment on indoor systems. 1- or 2-inch ﬁlters are available in disposable, pleated disposable, or permanent ﬁlter options. Filter and metal ﬁller speciﬁcations are listed in Table

20, and ﬁlter arrangements—including ﬁlter and ﬁller quantities—are shown in Figure 34.

Table 20. Filter and Metal Filler Speciﬁcations

Letter Designation (See Figure 34)

Model

125 20 × 20 — — — — — 150 and 175 20 × 25 — — — 13/16 200 and 225 16 × 25 16 × 20 16 × 25 16 × 20 — — — 250 and 300 20 × 25 20 × 20 20 × 25 20 × 20 — — —

350 20 × 25 20 × 20 — 4-13/16 —

400 16 × 25 20 × 25 16 × 25 20 × 25 16 × 25 2-5/8 1-1/16

MODELS 125–175 MODELS 200–350 MODEL 400

A B C D E F1 F2

Filters Metal Fillers

Size (Inches)

Figure 34. Filter Arrangements

Page 39

OPTIONAL DIRTY FILTER SWITCH

The optional dirty ﬁlter pressure switch is used to provide warning to the user by energizing an indicator light on an optional remote console. The light indicates that the ﬁlters are in need of cleaning or changing. The adjustable, single-pole/normally-open differential switch closes when an increase in pressure differential above the setpoint, is sensed across the ﬁlter bank. The dirty ﬁlter switch is located in the furnace section. After the unit is started but before continuous operation, the dirty ﬁlter switch must be set.

Instructions for Setting Dirty Filter Switch: With clean ﬁlters in place, blower doors closed, and the blower operating, decrease the pressure setting by adjusting the setscrew on the switch (see Figure 35) clockwise until the indicator light is energized or the setscrew is bottomed out. At that point, adjust the setscrew three full turns counterclockwise or until the setscrew is top-ended. At that setpoint, the indicator light will be activated at approximately 50% ﬁlter blockage.

Set screw (on front of switch) must be manually adjusted after the system is in operation.

Negative pressure connection is toward the

"back or bottom" of the switch (senses

blower side of

Positive pressure connection is toward the "front or top" of the switch (senses air inlet side of

Figure 35. Dirty Filter Switch

INSTALLATION AND STARTUP CHECKLISTS

PRE-STARTUP CHECKLIST

Installation Checks

 Verify suspension/mounting methods and clearances (refer to Suspension, Mounting. and Clearances)

 Verify that bolts removed from shipping clips have been returned to heater cabinet (refer to Uncrating/Unpacking)

 Check duct connections (refer to Duct Connections)

 Check venting (refer to Venting and Combustion Air) and ensure that ﬂue discharge and combustion air openings

are free of obstructions

 Ensure that electrical entrance and gas supply pipe openings are sealed

 Ensure that all condensate drains are open (refer to Optional Condensation Drain for Duct Furnaces)

Electrical Checks

 Ensure that electrical supply matches voltage rating of furnace (refer to rating plate)

 Check all ﬁeld wiring against wiring diagram and ensure that wire gauges are as required for electrical load

 Ensure that fuses or circuit breakers are in place and are sized correctly

Gas Supply Checks

 Check piping for leaks and proper gas line pressure and bleed trapped air from gas lines (refer to Gas Piping

and Pressures)

a. Turn OFF manual shutoff valve

b. Turn ON gas supply

c. Observe gas meter for movement or attach pressure gauge readable to 0.1 IN WC and, after turning gas on

for 10 seconds, turn OFF gas supply; no change in pressure should occur over 3-minute period

d. If step c indicates leak, locate leak by brushing soapy solution on all ﬁttings; bubbles will appear at any leaks

e. Repair any leaks and repeat test

Page 40

PRE-STARTUP CHECKLIST—CONTINUED

Blower Checks

 Check blower pulley and motor pulley to ensure that they are secure to shafts; check belt tension and alignment

(refer to Belts, Blowers, and Drives)

 Check blower rotation (refer to Belts, Blowers, and Drives)

 Verify removal of all shipping supports (refer to Uncrating/Unpacking)

 Check damper linkage (refer to Optional Dampers and Controls)

STARTUP CHECKLIST

 Close all panels tightly

 Turn ON electric and gas supply to furnace

 Adjust thermostat or ductstat so that call for heat exists; observe for complete sequencing of safety pilot and ignition

 Ensure complete sequencing of furnace operation as follows:

a. Set thermostat at its lowest setting

b. Turn ON electric and gas supply to furnace

c. Turn ON manual gas valves

d. Set thermostat at desired setting; thermostat calls for heat:

(1) Venter motor is energized after 15-second (approximate) time delay

(2) Venter ﬂow switches from N.C. to N.O. contacts to energize pilot gas valve and spark gap to produce pilot

ﬂame on each operating cycle

(3) Sensing probe proves presence of pilot ﬂame and energizes safety switch portion of control to deenergize

spark gap and energize main valve

(4) Main gas ignites and unit ﬁres at full rate

(5) If ﬂame is extinguished during main burner operation, safety switch closes main valve and recycles spark gap

NOTE: On units equipped with a controller that includes lockout control, if the pilot is not established within 120 seconds (approximately), the unit locks out for 1 hour or must be reset by interrupting the power to the control circuit (refer to lighting instructions on unit).

e. Blower motor operates from fan time delay

f. Thermostat is satisﬁed

(1) Solenoid gas valve deenergized

(2) Pilot gas valve deenergized

(3) Ignition controller deenergized

(4) Time delay relay keeps venter motor on for approximately 1 minute (post-purge)

g. To shut down, set thermostat to lowest setting; blower motor remains on as determined by fan time delay

POST-STARTUP CHECKLIST

 Observe burner ﬂame at full ﬁre. Natural gas ﬂame should be about 1-1/2 inches in height with blue coloring.

Propane gas ﬂame should be approximately the same height with blue coloring. Yellow tipping may appear on propane gas. If yellow extends beyond 1/2- to 3/4-inch, adjust air shutters (refer to Burner Air Shutters). If shutter adjustment does not reduce yellowing, check for gas leaks at the control manifold or oriﬁce ﬁtting.

 Turn the unit OFF and ON, pausing 2 minutes between each cycle. Observe to verify smooth ignition. On two-

stage or modulating burner systems, manipulate temperature adjustment slowly up and down to see if control is sequencing or modulating properly. Raising temperature setting drives burner on or to full ﬁre.

 Using a manometer or slant gauge readable up to 14 IN WC, check oriﬁce manifold for operating pressure on

full ﬁre. Natural gas should be 3.5 IN WC at this point. Propane gas should be 10 IN WC at this point. Variations from these pressures are not recommended, as ignition and efﬁciency performance can be adversely affected by improper pressure adjustment (refer to Gas Piping and Pressures).

 If the system is equipped with an optional dirty ﬁlter switch, refer to Optional Dirty Filter Switch for instructions

to set the switch.

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 Place the Owner’s Envelope containing the Limited Warranty Card, this booklet, and any optional information in

an accessible location near the heater. Follow the instructions on the envelope.

⚠ DANGER ⚠

• The gas burner in this gas-ﬁred equipment is designed and equipped to provide safe, controlled, complete combustion. However, if the installation does not permit the burner to receive the proper supply of combustion air, complete combustion may not occur. The result is incomplete combustion, which produces carbon monoxide, a poisonous gas that can cause death.

• Safe operation of separated-combustion, indirect-ﬁred gas burning equipment requires a sealed, properly-operating vent system that vents all ﬂue products to the outside atmosphere. FAILURE TO PROVIDE PROPER VENTING WILL RESULT IN A HEALTH HAZARD THAT COULD CAUSE SERIOUS PERSONAL INJURY OR DEATH.

• Install either the horizontal (see Figure 15) or vertical (see Figure 17) combustion air/vent system using the concentric adapter supplied. Always comply with the combustion air requirements in the installation codes and instructions.

• Combustion air at the burner should be regulated only by manufacturer-provided equipment. NEVER RESTRICT OR OTHERWISE ALTER THE SUPPLY OF COMBUSTION AIR TO ANY HEATER. CHECK THE COMBUSTION AIR/VENT SYSTEM FOR SOUNDNESS AND FUNCTION AND MAINTAIN IT IN PROPER OPERATING CONDITION.

SERVICE AND MAINTENANCE

⚠ WARNING ⚠

If you turn OFF the power supply, turn OFF the gas.

NOTE: Use only factory-authorized replacement parts.

This unit will operate with a minimum of maintenance. To ensure long life and satisfactory performance, a furnace that is operating under normal conditions should be inspected every four months. If the furnace is operating in an area where an unusual amount of dust, soot, or other impurities are present in the air, more frequent inspection is recommended.

OPERATING GAS VALVE MAINTENANCE

⚠ WARNING ⚠

The operating valve is the prime safety shutoff. To ensure positive closure, all gas supply lines must be free of dirt or scale before connecting the unit.

Remove external dirt accumulation and check wiring connections.

The combination gas valve must be checked annually to ensure that the valve is completely shutting off gas ﬂow. Perform this annual check in accordance with the following steps:

a. Locate 1/8-inch FPT INLET pressure tap on combination gas valve (see Figure 36).

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Single-Stage Valve

Two-Stage Valve

1/8" INLET

Pressure Tap

1/8 Outlet Pressure Tap

1/8" INLET

Pressure Tap

1/8 Outlet Pressure Tap

OPERATING GAS VALVE MAINTENANCE—CONTINUED

Figure 36. Combination Gas Valve Test Connections

NOTE: A manometer (ﬂuid-ﬁlled gauge) with an inches water column scale is recommended.

a. With ﬁeld-installed manual valve closed to prevent ﬂow to gas valve, connect manometer to 1/8-inch FPT

INLET pressure tap (see Figure 36).

b. With ﬁeld-installed manual valve closed, turn up thermostat to ﬁre unit and to allow unit to go through one trial

for ignition.

c. Reset thermostat to shut OFF unit and observe manometer for 2 to 3 minutes for indication of gas pressure.

No pressure should be indicated on manometer. If manometer indicates gas pressure, ﬁeld-installed manual gas valve must be replaced or repaired before combination gas valve can be checked.

d. If manometer does not indicate gas pressure, slowly open ﬁeld-installed manual gas valve. After manometer

indicates that gas pressure has reached equilibrium, close manual shutoff valve.

NOTE: Refer to Gas Piping and Pressures for operational pressure settings and instructions for checking pressure settings.

e. Observe gas pressure on manometer. There should be no loss of gas pressure. If manometer indicates loss

of gas pressure, replace combination gas valve before placing heater in operation.

VENT/COMBUSTION AIR SYSTEM MAINTENANCE

Check vent/combustion air system at least once a year. Inspect all joints, seams, and terminal caps. Replace any defective parts.

BURNER RACK MAINTENANCE

Remove, disassemble, clean, reassemble, and re-install burner rack as follows:

a. Remove burner rack

(1) Turn OFF gas and electric supply

(2) Remove control access side panel

(3) Disconnect ignition and ﬂame sensor leads

(4) Mark and disconnect electric valve leads

(5) Uncouple union in gas supply

(6) Remove sheet metal screws in top corners of burner rack assembly

(7) Pull drawer-type burner rack out of furnace

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Page 43

b. Disassemble burner rack

TOP VIEW

SIDE VIEW

NOTE: Natural gas burner racks manufactured before Series 6 may have a lighter tube carryover system. Break the lighter tube connection at the oriﬁce and remove the supply tubing, the drip shield, and the lighter tube.

(1) For natural gas burner rack, remove ﬂash carryover system from manifold end of burner rack.

(2) For propane gas burner rack, break lighter tube connection at regulator and remove lighter tube oriﬁce

supply tubing; remove retaining screws in drip shield and remove shield; remove retaining screws and slide out lighter tube

(3) Pull main burners horizontally away from injection opening and lift out

(4) Remove manifold bracket screws and remove manifold

(5) Remove burner oriﬁces

(6) Remove screws and lift out pilot burner

c. Clean burner rack in accordance with instructions in Cleaning Pilot and Burners

d. Re-assemble and re-install burner rack by reversing above steps, being careful not to create any unsafe

conditions

CLEANING PILOT AND BURNERS

⚠ WARNING ⚠

To prevent injury when cleaning pilot and burners, wearing eye protection is recommended.

⚠ CAUTION ⚠

To prevent damage to pilot oriﬁce, do not ream the oriﬁce.

• If the pilot ﬂame appears short and/or yellow, check the pilot oriﬁce for blockage caused by lint or dust accumulation.

• Remove the pilot oriﬁce and clean it using compressed air.

• Check and clean the aeration slot in the pilot burner.

• Clean the metal sensing probe and the pilot hood with an emery cloth and wipe off the ceramic insulator.

• Check the spark gap (see Figure 37), which should be maintained to 0.100 inch (2.5 mm).

Figure 37. Pilot Assembly Spark Gap

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CLEANING PILOT AND BURNERS—CONTINUED

IGNITION CONTROLLER WITH LOCKOUT FOR GAS CONTROL OPTION AH3, UTEC MODEL 1003-514 (PN 257010): REPLACE WITH REPLACEMENT KIT (PN 257473)

RECYCLING IGNITION CONTROLLER FOR GAS CONTROL OPTION AH2, UTEC MODEL 1003-638A (PN 257009): REPLACE WITH REPLACEMENT KIT (PN 257472)

• After the pilot is cleaned, blow away any dirt using compressed air.

• Clean the main burners and burner oriﬁces using compressed air.

⚠ CAUTION ⚠

When cleaning burner ports, do not use anything that might change the port size.

• Use an air nozzle to blow out scale and dust accumulation from the burner ports. Alternate with blowing compressed air through the burner ports and then through the venturi. Use a ﬁne wire to dislodge any stubborn particles from the burner ports.

• Clean the burner rack carryover systems with air pressure.

SPARK IGNITION SYSTEM MAINTENANCE

The ignition controller provides the high voltage spark to ignite the pilot service and also acts as the ﬂame safety device. After ignition of pilot gas, the controller electronically senses pilot ﬂame. A separate solid metal probe in the pilot burner assembly is used to sense the ﬂame. A low voltage DC electrical signal is imposed on the metal probe, which is electrically-insulated from ground. Proper operation of the electronic spark ignition system requires a minimum ﬂame signal of 0.2 microamps DC. When the pilot ﬂame impinges on the sensing probe, the ﬂame acts as a conduction path to ground. This completes the DC circuit; the ignition controller responds by energizing the main gas valve.

If no spark occurs, check the following:

⚠ WARNING ⚠

Due to high voltage on pilot spark wire and pilot electrode, do not touch when energized.

NOTE: When checking for spark with the pilot burner assembly removed from the burner rack, the pilot assembly must be grounded to the heater for proper spark.

a. Using microampmeter, measure voltage between blue and white terminals (non-lockout type pilot) and between

terminals 2 and 5 (lockout type pilot) on ignition controller. Voltage should be at least 20 volts and no higher than 32 volts. Refer to TROUBLESHOOTING if no voltage is observed.

b. Check for short to ground in high tension lead and/or ceramic insulator.

c. Verify that pilot spark gap (see Figure 37) is approximately 0.100 inch (2.5 mm).

If the above conditions are normal and no spark occurs, replace the ignition controller.

NOTE: If replacing an earlier model of ignition controller (see Figure 38), order a replacement kit (PN 257472 for a unit with recycling gas control option AH2 or PN 257473 for a unit with gas control with lockout option AH3). Option codes are listed on the unit wiring diagram.controllers.

Figure 38. Obsolete Ignition Controllers

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Page 45

If the main gas valve fails to open with a normal full-size pilot ﬂame established, check the following:

a. If voltage between black and brown leads on main gas valve is 20–32 VAC and there is no main gas ﬂow with

built-in manual valve in FULL OPEN position, main valve is defective.

b. If there is no voltage between black and brown leads on main gas valve, check for disconnected or shorted

ﬂame sensor lead or ﬂame sensor probe.

If the above conditions are normal and main gas ﬂow is still off, the ignition controller is probably defective. Do not attempt to service the ignition controller as it does not contain any replaceable components.

CLEANING HEAT EXCHANGER

• Remove the burner rack assembly in accordance with Burner Rack Maintenance to allow access to the inside of the heat exchanger tubes.

• Clean the heat exchanger tubes using a 1/2-inch diameter furnace brush.

• A mirror and ﬂashlight are helpful for examining the narrow section of each tube. Remove any accumulated dust and soot.

VENTER MOTOR MAINTENANCE

Power venter motors are permanently lubricated. No oiling is required.

AIR CIRCULATION SYSTEM MAINTENANCE

Check blower pulley and motor pulley to ensure that they are secured to the shaft. Check belt condition and belt tension (refer to Belts, Blowers, and Drives).

LIMIT CONTROL CHECK

With the heater on, completely block off distribution air. The limit control should open within a few minutes to shut off the gas supply to the main burners.

TROUBLESHOOTING

Refer to Table 21 to troubleshoot the unit.

NOTE: If the furnace is equipped with electronic modulation option AG39 or AG40, see Figure 29 for additional troubleshooting guidelines.

Table 21. Troubleshooting Table

SYMPTOM PROBABLE CAUSE REMEDY

Venter motor will not start

Pilot will not light with venter operating

1. No power to furnace Turn on power and check supply fuses or circuit breaker

2. No 24-volt power to venter relay Turn up thermostat and check control transformer output Check for loose or improper wire connections

3. Defective venter relay Replace defective part

4. Defective motor or capacitor Replace defective part

1. Manual valve not open Open manual valve

2. Air in gas line Bleed gas line

3. Dirt in pilot oriﬁce Remove pilot oriﬁce and clean with compressed air or solvent

4. Gas pressure too high or too low Adjust gas supply pressure (refer to Gas Piping and Pressures)

5. Kinked pilot tubing Replace tubing

6. Pilot valve does not open If 24-volt power is available at valve, replace valve

7. No spark

a. Loose wire connections Ensure that all wires connections are solid b. Transformer failure Ensure that 24-volt power is available c. Incorrect spark gap Maintain spark gap at 0.100 inch d. Spark cable shorted to ground Replace worn or grounded spark cable e. Spark electrode shorted to ground Replace pilot if ceramic spark electrode is cracked or grounded f. Drafts affecting pilot Ensure that all panels are in place and are tightly secured to prevent drafts at pilot g. Ignition control not grounded Ensure that ignition control is grounded to furnace chassis h. Faulty ignition controller If 24-volt power is available to ignition controller and all other causes have been

8. Optional lockout device interrupting

control circuit due to above causes

9. Faulty combustion air proving switch Replace combustion air proving switch

eliminated, replace ignition control Reset lockout by interrupting control at thermostat

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Page 46

TROUBLESHOOTING—CONTINUED

Table 21. Troubleshooting Table

SYMPTOM PROBABLE CAUSE REMEDY

Pilot lights, main valve will not open

Insufﬁcient heat with heater operating

Motor will not run

Motor turns on and off while operating

Motor cuts out on overload

1. Manual valve not open Open manual valve

2. Main valve not operating a. Defective valve If 24-volt power is measured at valve connections and valve remains closed, replace

b. Loose wire connections Check and tighten all wiring connections

3. Ignition control does not power main valve a. Loose wire connections Check and tighten all wiring connections b. Flame sensor grounded, pilot

lights, and spark continues c. Incorrect gas pressure Adjust gas pressure (refer to Gas Piping and Pressures) d. Cracked ceramic at sensor Replace sensor e. Faulty ignition controller If all checks listed in Spark Ignition System Maintenance indicate no other cause,

1. Dirty ﬁlters in blower system Clean or replace ﬁlters

2. Incorrect manifold pressure Check manifold pressure (refer to Gas Piping and Pressures)

3. Limit control cycling on Check air throughput

4. Improper thermostat location or adjustment

5. Belt slipping on blower Adjust belt tension (refer to Belts, Blowers, and Drives)

6. Fan control improperly wired Ensure that wiring connections are in accordance with wiring diagram

7. Defective fan control Replace fan control

8. Blower set for too low temperature rise

1. Circuit open Check wiring and connections

2. Inoperative fan control Replace fan control

3. Fan control improperly wired Ensure that wiring connections are in accordance with wiring diagram

4. Inoperative contactor Replace contactor

5. Defective motor Replace motor

1. Motor overload device cycling Verify motor load against motor rating plate

2. 3-phase motor rotating in opposite direction

1. Improper motor pulley adjustment Ensure that motor pulley is properly-adjusted (refer to Belts, Blowers, and Drives)

2. Improper static pressure on duct system

3. Low voltage Check power supply

valve

Ensure that ﬂame sensor lead is not grounded and that insulation or ceramic is not cracked; replace as required

replace ignition controller; do not attempt to repair ignition controller, which has no ﬁeld-replaceable parts

Refer to thermostat manufacturer’s instructions

Decrease blower speed (refer to Belts, Blowers, and Drives) or increase static pressure

Replace motor or overload device Interchange two legs of supply connections

Adjust dampers in duct system

—Continued

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INSTALLATION RECORD

NOTE: The following is to be completed by the installer.

Installer:

Name ________________________________________________________

Company ________________________________________________________

Address ________________________________________________________

________________________________________________________

Phone _________________________________

Distributor (company from which the unit was purchased):

Company ________________________________________________________

Contact ________________________________________________________

Address ________________________________________________________

________________________________________________________

Phone _________________________________

Model ________________ Serial No.______________________________Date of Installation ___________

SPECIFIC INSTALLATION NOTES: (i.e., Location, Amps, Gas Pressure, Temperature, Voltage, Adjustments, Warranty, etc.)

________________________________________________________________________________________

BUILDING OWNER OR MAINTENANCE PERSONNEL:

For service or repair

• Contact the installer listed above.

• If you need additional assistance, contact the Reznor

• For more information, contact your Reznor

Reznor

150 McKinley Avenue Mercer, PA 16137

Representative by calling 800-695-1901.

Distributor listed above.

I-SCE (09-18) PN207697R9

Page 48

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Speciﬁcations and illustrations subject to change without notice or incurring obligations.

Reznor SCE, SCE 150, SCE 125, SCE 175, SCE 250 Installation Operation & Maintenance

Specifications and Main Features

Frequently Asked Questions

User Manual

TABLE OF CONTENTS

IMPORTANT SAFETY INFORMATION

GENERAL INFORMATION

INSTALLATION CODES

SPECIAL INSTALLATIONS (AIRCRAFT HANGARS/GARAGES)

WARRANTY

INSTALLATION

DIMENSIONS

UNCRATING/UNPACKING

CLEARANCES

LOCATION

WEIGHTS

SUSPENSION

MOUNTING

DUCT CONNECTIONS

VENTING AND COMBUSTION AIR

VENTING OPTIONS

GAS PIPING AND PRESSURES

ELECTRICAL SUPPLY AND CONNECTIONS

CONTROL THERMOSTAT

COMBUSTION AIR PROVING SWITCH

BLOWER FAN CONTROL

LIMIT CONTROL

MOTOR LOAD AND AMPS

BELTS, BLOWERS, AND DRIVES

OPERATING VALVE

OPTIONAL TWO-STAGE OPERATION—HEATING ONLY APPLICATION

OPTIONAL TWO-STAGE OPERATION—MAKEUP AIR APPLICATION

OPTIONAL ELECTRONIC MODULATION

PILOT AND IGNITION SYSTEMS

BURNERS, BURNER ORIFICES, AND CARRYOVER SYSTEM

BURNER AIR SHUTTERS

OPTIONAL EQUIPMENT

OPTIONAL CONDENSATION DRAIN FOR DUCT FURNACES

OPTIONAL DAMPERS AND CONTROLS

OPTIONAL FILTER RACK AND FILTERS

OPTIONAL DIRTY FILTER SWITCH

INSTALLATION AND STARTUP CHECKLISTS

PRE-STARTUP CHECKLIST

STARTUP CHECKLIST

POST-STARTUP CHECKLIST

SERVICE AND MAINTENANCE

OPERATING GAS VALVE MAINTENANCE

VENT/COMBUSTION AIR SYSTEM MAINTENANCE

BURNER RACK MAINTENANCE

CLEANING PILOT AND BURNERS

SPARK IGNITION SYSTEM MAINTENANCE

CLEANING HEAT EXCHANGER

VENTER MOTOR MAINTENANCE

AIR CIRCULATION SYSTEM MAINTENANCE

LIMIT CONTROL CHECK

TROUBLESHOOTING

INSTALLATION RECORD