Reznor UEZ User manual

Revision: I-UEZ (04-21) 1034347-0
UNIT HEATER INSTALLATION/OPERATION/MAINTENANCE
Supersedes: — (Original Version)
MODEL UEZ: HIGH-EFFICIENCY, SEPARATED-COMBUSTION, LOW-STATIC
⚠ DANGER ⚠
FIRE OR EXPLOSION HAZARD
• Failure to follow safety warnings exactly could result in serious injury, death, or property
damage.
• Improper installation,adjustment,alteration, service,or maintenance can cause serious injury,
death, or property damage.
• Installation and service must be performed by a qualified installer, service agency, or the gas
supplier.
• 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 neighbor’s phone. Follow the gas supplier’s
instructions.
• If you cannot reach your gas supplier, call the fire department.
DO NOT DESTROY. PLEASE READ CAREFULLY. KEEP IN A SAFE PLACE FOR FUTURE REFERENCE.

2I-UEZ (04-21) 1034347-0
TABLE OF CONTENTS
GENERAL INFORMATION ................................................................... 4
References .............................................................................. 4
Important Safety Information................................................................. 4
Certification .............................................................................. 5
Warranty ................................................................................ 5
Installation Codes ......................................................................... 5
Unit Location ............................................................................. 5
Heater Throw............................................................................. 6
Mounting Height Requirements............................................................... 7
Hazards of Chlorine........................................................................ 7
Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Clearances .............................................................................. 8
Weights ................................................................................. 9
Venting and Combustion Air Requirements ..................................................... 9
Vent/Combustion Air System Piping Requirements ............................................. 9
Vent/Combustion Air System Piping Joints ..................................................11
Vent/Combustion Air System Piping Support.................................................12
Technical Data ..........................................................................13
INSTALLATION.......................................................................... 14
Unpacking and Inspection.................................................................. 14
Pre-Installation Checklist................................................................... 14
Heater Suspension .......................................................................15
Suspension of Heater with Downturn Nozzle ................................................. 15
Piping Connections ....................................................................... 16
Gas Supply Pressure ...................................................................16
Gas Supply Piping .....................................................................16
Supply Piping Connections .............................................................. 17
Concentric Adapter Box Connections ......................................................... 18
Vent Terminal Options.....................................................................20
Vertical Vent Terminal (Option CC2) Installation ..............................................20
Horizontal Vent Terminal (Option CC6) Installation ............................................24
Condensate Drain Installation ...............................................................28
Vent Condensate Drain Installation ........................................................29
Heat Exchanger Condensate Drain Installation ...............................................32
Electrical Connections..................................................................... 32
CONTROLS ..............................................................................33
Thermostat Options....................................................................... 34
Main Operating Gas Valve .................................................................35
Pressure Switch .........................................................................35
High Temperature Limit Control .............................................................35
Vent Temperature Limit Switch ..............................................................36
Interlock Door Switch .....................................................................36
Fan Motor ..............................................................................36
Circuit Board (DSI Control Module)........................................................... 36
Venter Motor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

3
I-UEZ (04-21) 1034347-0
TABLE OF CONTENTS—CONTINUED
OPERATION ............................................................................. 37
Pre-Startup Checklist .....................................................................37
Startup................................................................................. 38
Startup Procedure .....................................................................38
Operating Sequences...................................................................39
Vent System Testing ...................................................................41
Post-Startup Checklist ..................................................................42
ADJUSTMENTS........................................................................... 42
Pressure Switch Replacement ..............................................................42
Measure and Adjust Manifold (Outlet) Gas Pressure ............................................. 43
Measure and Adjust Manifold Gas Pressure—Elevation ≤2,000 Feet (≤610 Meters) .................. 43
For installations at high elevations, measure and adjust the manifold (outlet) gas pressure as follows: .... 45
Converting Unit from Natural Gas to Propane...................................................46
MAINTENANCE........................................................................... 47
Service Checklist......................................................................... 47
Maintenance Procedures .................................................................. 48
Burner Maintenance .................................................................... 48
Burner Orifice Maintenance ..............................................................50
Heat Exchanger Maintenance ............................................................50
Ignition System Maintenance ............................................................. 50
Maintenance of Fan Motor, Fan Blades, and Fan Guard ........................................ 51
Venter Motor, Wheel, and Pressure Sensing Tap Maintenance .................................. 52
Operating Gas Valve Maintenance ........................................................ 53
Pressure Switch Maintenance ............................................................53
High Temperature Limit Control Maintenance ................................................53
Interlock Door Switch Maintenance ........................................................53
Transformer Maintenance ...............................................................53
Vent Temperature Limit Switch Maintenance.................................................54
Disconnect Switch Replacement ..........................................................54
Vent or Vent/Combustion Air System Maintenance ............................................ 54
Condensate Drain System ...............................................................54
TROUBLESHOOTING ......................................................................54
Unit Troubleshooting Using DSI Control Module.................................................54
General Troubleshooting................................................................... 56
INSTALLATION RECORD (TO BE COMPLETED BY INSTALLER)................................... 60

4I-UEZ (04-21) 1034347-0
GENERAL INFORMATION
This unit heater has been tested for capacity and efficiency so as to provide many years of safe and dependable
comfort providing it is properly installed and maintained. With regular maintenance, this unit will operate satisfactorily
year after year. Abuse, improper use, and/or improper maintenance can shorten the life of the appliance and create
unsafe hazards.
To achieve optimum performance and minimize equipment failure, it is recommended that periodic maintenance
be performed on this unit. The ability to properly perform maintenance on this equipment requires certain tools and
mechanical skills.
This manual applies only to the models listed. Accessories referenced may not apply to all models.
Installation should be done by a qualified agency in accordance with these instructions. The qualified service agency
installing this heater is responsible for the installation.
References
NOTE: Both this installation/operation manual and the appropriate venting instructions are shipped
with the heater. Verify that the literature is correct for the heater being installed. If either manual is
missing or incorrect, contact your distributor before beginning installation.
Important Safety Information
Please read all information in this manual thoroughly and become familiar with the capabilities and use of your
appliance before attempting to operate or maintain this unit. 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.
DANGER: A danger statement describes a potentially hazardous situation that if not avoided, will result in severe
personal injury or death and/or property damage.
WARNING: A warning statement describes a potentially hazardous situation that if not avoided, can result in severe
personal injury and/or property damage.
CAUTION: A caution statement describes a potentially hazardous situation that if not avoided, can result in minor
or moderate personal injury and/or property damage.
NOTE: A note provides important information that should not be ignored.
⚠ 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.
• Should overheating occur, or the gas supply control system fail to shut off the flow of gas, shut
off the manual gas valve to the unit before shutting off the electrical supply.
• Do not use this appliance if any part has been under water. Immediately call a qualified service
technician to inspect the appliance and replace any gas control that has been under water.
• Installation should be done by a qualified agency in accordance with these instructions. The
qualified service agency installing this high efficiency separated-combustion system is responsible
for the installation.
Table 1. Related Technical Manuals Available from Factory Distributor
Type Form PN*
Replacement parts P-UEZ 1034348
Venting I-OPT-VC 205892
Vertical louver installation CP-UB-UD-UEZ-VL 1036173
*Also available at www.reznorhvac.com.

5
I-UEZ (04-21) 1034347-0
Certification
•These high-efficiency unit heaters are design-certified by Intertek for use in industrial and commercial installations
in the United States and in Canada.
•These unit heaters are available for use with either natural or propane gas. The type of gas, the input rate, and
the electrical supply requirement are shown on the heater rating plate. Check the rating plate to determine if the
heater is appropriate for the intended installation. All heaters are factory-equipped for use with natural gas and
include a conversion kit for field-conversion for use with propane.
•These unit heaters have a titanium stabilized primary heat exchanger with a MacroChannel® secondary heat
exchanger.
Warranty
Refer to the limited warranty form in the literature bag provided with the unit. The warranty is void if:
•Wiring is not in accordance with the diagram furnished with the heater.
•The unit is installed without proper clearance to combustible materials.
•A fan model is connected to a duct system or if the air delivery system is modified.
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, ANSI Z223.1. A Canadian
installation must be in accordance with the CSA B149 Installation Codes. These codes are 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.
•Installations in aircraft hangars should be in accordance with ANSI/NFPA No. 409 (latest edition), Standard for
Aircraft Hangars. Installations in public garages should be in accordance with ANSI/NFPA No. 88A (latest edition),
Standard for Parking Structures. Installations in repair garages should be in accordance with ANSI/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.
•If the heater is being installed in the Commonwealth of Massachusetts, installation must be performed by a licensed
plumber or licensed gas fitter.
Unit Location
⚠ CAUTION ⚠
• Unit heaters should not be used in an application where the heated space temperature is below
50°F. The combination of low space and combustion air temperatures may result in condensate
freezing in the secondary heat exchanger and/or condensate drain.
• Do not locate the heater where it may be exposed to water spray, rain, or dripping water.
•Refer to the venting instructions provided with the unit for venting requirements.
•Refer to the following sections of this manual to determine where to suspend the heater: Heater Throw, Mounting
Height Requirements, Hazards of Chlorine, Dimensions, Clearances, Weights, and Venting and Combustion
Air Requirements.

6I-UEZ (04-21) 1034347-0
GENERAL INFORMATION—CONTINUED
Heater Throw
Figure 1 shows throw patterns for fan model units. Table 2 and Table 3 list throw distances for standard, adjustable
horizontal louvers at the angles listed. The louver angles listed are relative to the top of the heater. The throw pattern
changes with the addition of optional vertical louvers and/or downturn nozzles.
Z = Distance at which air velocity drops below 50 feet (15.2 meters) per minute
Figure 1. Heater Throw Patterns (Refer to Table 2 and Table 3)
Table 2. Heater Throw Distances with Standard Horizontal Louvers at Mounting Heights of 8 to 18 Feet
Distance*Louver
Angle
Distance*Louver
Angle
Distance*Louver
Angle
Distance*Louver
Angle
H
X Y Z X Y Z X Y Z X Y Z
Unit Size
130 180 260 310
8 13 24 73 −26° 16 30 93 −20° 15 28 94 −24° 17 31 105 −20°
10 14 24 69 −32° 17 31 91 −25° 16 28 89 −29° 18 32 103 −25°
12 14 24 64 −39° 18 31 88 −30° 17 28 85 −34° 19 32 98 −30°
14 14 22 59 −45° 19 30 84 −34° 17 27 80 −40° 20 32 95 −34°
16 13 20 53 −51° 19 29 79 −39° 17 25 74 −45° 21 31 90 −38°
18 11 17 44 −58° 19 28 74 −44° 16 24 66 −51° 20 30 85 −43°
*Distance in feet (see Figure 1).
Table 3. Heater Throw Distances with Standard Horizontal Louvers at Mounting Heights of
2.4 to 5.5 Meters
Distance*Louver
Angle
Distance*Louver
Angle
Distance*Louver
Angle
Distance*Louver
Angle
H
X Y Z X Y Z X Y Z X Y Z
Unit Size
130 180 260 310
2.4 4 7 22 −26° 5 9 28 −20° 5 9 29 −24° 5 9 32 −20°
3.0 4 7 21 −32° 5 9 28 −25° 5 9 27 −29° 6 10 31 −25°
3.7 4 7 20 −39° 6 9 27 −30° 5 9 26 −34° 6 10 30 −30°
4.3 4 7 18 −45° 6 9 26 −34° 5 8 24 −40° 6 10 29 −34°
4.9 4 6 16 −51° 6 9 24 −39° 5 8 23 −45° 6 9 27 −38°
5.5 3 5 13 −58° 6 9 23 −44° 5 7 20 −51° 6 9 26 −43°
*Distance in meters (see Figure 1).

7
I-UEZ (04-21) 1034347-0
Mounting Height Requirements
⚠ WARNING ⚠
If touched, the vent pipe and internal heater surfaces that are accessible from outside the heater
will cause burns. Suspend the heater a minimum of 5 feet (1.5 meters) above the floor.
•For best results, the heater should be mounted with certain rules in mind. In general, a unit should be located 8 to
12 feet (2.4 to 3.7 meters) 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 for best results.
•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, care should be exercised to 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 (4.6 to 6.1 meters).
Hazards of Chlorine
The presence of chlorine vapors in the combustion air of gas-fired heating equipment presents a potential corrosion
hazard for separated-combustion heaters with regard to the combustion air inlet. Chlorine is usually found in the form
of freon or degreaser vapors. When chlorine is exposed to flame, it will precipitate from the compound and go into
solution with any condensation that is 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 and combustion air terminals
with regard to exhausters or prevailing wind directions. Chlorine is heavier than air. Keep these facts in mind when
determining installation location of the heater in relation to building exhaust systems.
Dimensions
Unit dimensions are shown in Figure 2 and listed in Table 4. All dimensions are in inches (mm).

8I-UEZ (04-21) 1034347-0
GENERAL INFORMATION—CONTINUED
Dimensions—Continued
Figure 2. Dimensions (Refer to Table 4)
Table 4. Dimensions
Unit
Size
Dimension (See Figure 2)
A B C E F G H J K M N P R S
Inches (±1/8) (mm (±3))
130,
180
20-1/8
(511)
39-3/16
( 995)
16-1/16
( 408)
11-31/32
( 304 )
2-3/8
( 60 )
25-11/16
( 652 )
55-13/32
(1407)
46-1/32
(1169)
15-19/32
(396)
8-5/16
( 211 )
4-5/16
( 110 )
5-1/16
( 129 )
6-9/32
(160)
1-3/4
( 45 )
260,
310
34-1/8
(867)
41
(1041)
30
(762)
13-31/32
(355)
1-13/32
(36)
27-11/16
(703)
58
(1473)
48-21/32
(1236)
16-15/32
(418)
9-3/32
( 231 )
5-3/32
( 129 )
18-13/16
( 478 )
7 1/32
(179)
1-3/8
( 35 )
A
C
23" (584 mm)
B
FRONT VIEW
25" (635 mm)
E
F
G
TOP VIEW
FOUR SUSPENSION POINTS
(3/8 - 16 FEMALE THREAD)
J
H
RIGHT SIDE VIEW
1 9
16
" (40 mm)
5 5
8
" (143 mm)
R
P
N
M
K
S
3 3
16
" (81 mm)
8 3
16
" (208 mm)
REAR VIEW
DISCONNECT SWITCH
LINE VOLTAGE ENTRANCE
(CONNECTS IN SEALED ELECTRICAL BOX)
EXTERNAL GAS CONNECTION
6" COMBUSTION
AIR CONNECTION
CONDENSATE DRAIN
4" VENT CONNECTION
THERMOSTAT
CONNECTION
Clearances
Units must be installed so that the clearances listed in Table 5 are provided for with regards to combustion air space,
inspection, and service and for proper spacing from combustible construction. Clearance to combustibles is defined
as the minimum distance from the heater to a surface or object for which it is necessary to ensure that a surface
temperature of 90°F (50°C) above the surrounding ambient temperature is not exceeded. Refer to the dimensions
listed in Table 4 and shown in Figure 2 when determining clearances to combustibles.

9
I-UEZ (04-21) 1034347-0
Table 5. Clearances to Combustibles
HeaterSurface Minimum Clearance (Inches (mm))
Top 4 (102)
Flue connector 6 (152)
Access panel 18 (457)
Non-access side 2 (51)
Bottom*1 (25)
Rear** 18 (457)
*Suspend the heater so that the bottom is a minimum of 5 feet (1.5 meters) above the floor.
**Measure rear clearance from the fan motor.
Weights
⚠ WARNING ⚠
Check the supporting structure to be used to verify that it has sufficient load carrying capacity to
support the weight of the unit. Suspend the heater only from the threaded nut retainers or with a
manufacturer-provided kit. Do NOT suspend from the heater cabinet.
NOTE: For unit shipping weight, contact an authorized Factory Distributor.
Before suspending the heater, ensure that the supporting structure to be used has sufficient load-carrying capacity
to support the weight (refer to Table 6) of the unit.
Venting and Combustion Air Requirements
•All separated-combustion units MUST BE equipped with both combustion air and exhaust piping to the outdoors.
The unique concentric adapter box required with this heater allows for both combustion air and exhaust piping
with only one horizontal or vertical penetration hole in the building.
•Concentric horizontal and vertical vent/combustion air systems (option CC6 or CC2) are the only venting/combustion
air systems approved for this heater.
•These units are certified as Category IV heaters. These heaters are very thermal efficient and will produce
condensate during operation.
Vent/Combustion Air System Piping Requirements
• Types of pipe: provide field-supplied pipe in the following types:
• Vent pipe: schedule 40 PVC or CPVC pipe—in Canada, all PVC vent pipe must be approved to ULC 636.
• Combustion air inlet pipe: sealed, single-wall galvanized pipe is recommended.
• Venter outlet and combustion air inlet: located at rear of heater (see Figure 3).
Table 6. Unit Weights
Unit Size
130 180 260 310
Pounds (kg)
230 (104) 245 (111) 360 (163) 395 (179)

DISCONNECT
SWITCH LINE VOLTAGE
ENTRANCE
COMBUSTION AIR
PIPE COLLAR
A
C
B
D
GAS CONNECTION
TERMINAL STRIP
CONDENSATE DRAIN
VENT PIPE
Figure 3. Connections at Rear of Unit (Refer to Table 7)
Table 7. Connection Sizes and Locations
Dimension (See Figure 3) or
Connection Description
Dimension/Diameter
Unit Size 130 or 180 Unit Size 260 or 310
Inches (mm)
A
—
8-1/4 (210) 8-1/4 (210)
B 3-1/4 (83) 3-1/4 (83)
C 8-5/16 (211) 9-3/32 (231)
D 4-5/16 (110) 5-1/16 (129)
Combustion air pipe Collar 6 (153) 6 (153)
Vent pipe PVC 4 (102) 4 (102)
Condensate drain PVC 1/2 (13) 1/2 (13)
• Pipe size requirements: size requirements are as follows:
• Vent piping: from heater to terminal end of vertical or horizontal vent (refer to Table 8)
• Combustion air piping: from heater to concentric adapter box and from concentric adapter box to outdoors
(refer to Table 9).
NOTE: The minimum/maximum requirements for the length of vent pipe that extends outdoors are different
for horizontal and vertical vent terminals (refer to Vent Terminal Options section).
Table 8. Vent Piping Size Requirements
Unit
Size
Diameter
(Inches (Millimeters))
Maximum Length
(Feet (Meters))
Equivalent Straight Length for Elbows
90-Degree Elbow*45-Degree Elbow
130, 180, 260, 310 4 (102) 50 ( 15.2) 8 ( 2.4) 4 ( 1.2 )
*All 90-degree elbows in the vent system must be sweep type.
10 I-UEZ (04-21) 1034347-0
GENERAL INFORMATION—CONTINUED
Venting and Combustion Air Requirements—Continued
Vent/Combustion Air System Piping Requirements—Continued

11
I-UEZ (04-21) 1034347-0
• Vent pipe clearance: do not install the vent piping near any high temperature steam lines, radiant heaters, or
other sources of heat.
• Condensate drain connections: during operation, condensate is produced both in the heater and in the venting
system. Therefore, the installation requires a condensate drain from the secondary heat exchanger and from the
vent pipe. For safe performance of the heater, each condensate drain must include a trap. Install the condensate
drains in accordance with the Condensate Drain Installation section.
Vent/Combustion Air System Piping Joints
• Piping joints: when ready to install the vent system, ensure that piping joints are in accordance with the following:
• Combustion air piping: secure slip-fit joints of single-wall combustion air pipe using sheet metal screws or
rivets. Seal joints and seams with aluminium tape or silicone sealant.
• Vent piping: the schedule 40 PVC or CPVC vent system should be installed in a manner consistent with normal
industry standards and in compliance with all local fire and building code requirements. Failure to follow proper
installation practices, procedures, or techniques can result in system failure, property damage, or personal injury.
The installer is responsible for the installation. Read the following procedure before beginning installation:
NOTE: Install piping joints one at a time. Pipe and fittings should be assembled quickly while ce-
ment is fluid.
1. Cut pipe square—angled cut may result in joint failure:
a. Remove all burrs from inside and outside diameter of cut end of pipe burrs using deburring tool, file, or knife
edge.
b. Chamfer (bevel) end of pipe 10 to 15 degrees.
c. Remove surface dirt, grease, and moisture from pipe sections and fittings using clean dry cloth.
2. Check for proper fit—test fit using light pressure:
a. Install dry pipe one-half to one-third of way into fitting hub.
b. Ensure that pipe and fittings are not too tight or too loose.
3. Apply primer to pipe and fitting surfaces using 2–3 applicator brush:
a. Ensure that primer conforms to ASTM F 656.
b. Ensure that primer does not puddle inside system.
4. Apply cement using 2–3 applicator brush, quickly assembling joint while cement is fluid:
a. Ensure that cement conforms to ASTM D 2564.
b. Apply full even layer of cement to pipe OD slightly greater than depth of socket on coupler (fitting).
c. Coat coupler (fitting) socket with medium layer of cement, ensuring that cement does not puddle inside system.
d. Apply second full even layer of cement to pipe OD.
5. Join pipe and coupler (fitting):
a. Working quickly while cement is fluid, insert pipe into coupler (fitting) until it touches socket bottom.
a. Turn pipe quarter turn and hold joint together until pipe will not pull out.
b. Clean excessive cement from exterior—properly made joint will have continuous bead of cement around
perimeter.
Table 9. Combustion Air Piping Size Requirements
Unit
Size
Pipe
Section
Diameter
(Inches (Millimeters))
Length (Feet (Meters))
Minimum Maximum
130, 180, 260, 310
Heater to concentric
adapter box 6 (152)
3 ( 914) Same as vent pipe
Concentric adapter box
to outdoors 8 (203) Refer to Vent Terminal Options section

Figure 4. Vent Pipe Support
• Combustion air pipe support: support a single-wall metal horizontal combustion air run every 6 feet (1.8 meters).
Support a vertical single-wall metal combustion air pipe in accordance with accepted industry practices. The heater
and concentric adapter box may be used to support a vertical combustion air pipe.
•This unit heater is a high-efficiency appliance designed to extract part of the latent heat from the products of
combustion.
Cradle Support
3 to 6 inches
(76 to 152 mm)
Maximum length 6 feet (1.8 M) for single support
3/8-inch threaded rod
attached to building
structural member
Vertical single-wall
combustion air pipe may be
supported by heater and
concentric adapter box
UNIT
Vertical Vent
Sweep-type
elbow only
Slope horizontal run downward slightly
toward vent condensate drain at heater
12 I-UEZ (04-21) 1034347-0
GENERAL INFORMATION—CONTINUED
Venting and Combustion Air Requirements—Continued
Vent/Combustion Air System Piping Support
⚠ CAUTION ⚠
DO NOT use the heater or concentric adapter box to provide vent pipe support.
• Vent pipe support: for continued safe operation, the vent system must be properly supported. A 10-foot (3-meter)
length of PVC pipe weighs 20 pounds (9 kg) and has an expansion rate of four times that of metal pipe.
• Horizontal CPVC or PVC vent: must be supported every 6 feet (1.8 meters). The hangers should provide as
much bearing surface as possible and must be free of sharp edges and burrs. Hangers must allow the pipe to
expand laterally. Consider pipe expansion when placing hangers. Changes in pipe direction will allow for expansion.
Hangers must be placed to allow for some direction movement. The slip joint at the concentric adapter box is
designed to permit some limited expansion.
• Vertical CPVC or PVC vent: it is recommended that an engineer design the vertical support system. An acceptable
field-supplied cradle-type support that allows for expansion for a simple vertical vent that is 30 feet (9.1 meters)
or less and rises closely from the heater is shown in Figure 4.

13
I-UEZ (04-21) 1034347-0
Technical Data
⚠ CAUTION ⚠
DO NOT use copper or copper-based alloys for condensate drains.
•The combustion process forms condensation, which is collected and directed to a drainage point inside the unit.
The heater is equipped with a 1/2-inch (12.7-mm) PVC pipe for connecting to a condensate drain. The water
condensed from the products of combustion will be acidic. The level of concentration is dependent upon the
environment where the appliance is installed and may be as high as 6 pH.
•The unit’s operating principle showing combustion airflow and supply airflow is shown in Figure 5. Related technical
data is listed in Table 10.
Figure 5. Combustion Airflow and Supply Airflow
Room Supply Air
Intake
Warm
Air
Discharge
Flue Gas Outlet
-
perature requires a
condensate drain in
the vent.
Condensate
drain connection from
the secondary heat exchanger
Outside
Combustion Air to
the Burner
Table 10. Technical Data
Parameter Unit Size Unit of
Measurement
130 180 260 310
Input heating capacity
131,000 175,000 260,000 305,000 BTUh
38.4 51.2 76.1 89.3 kWh
Thermal efficiency 93 91 92 91 %
Output heating capacity*121,830 159,250 239,200 277,550 BTUh
35.7 46.6 70.0 81.3 kWh
Gas connection, natural** 1/2 3/4
Inches
Gas connection, propane**
Vent connection diameter 4 4
Combustion air inlet diameter 6 6
Control, 24V 1.0 1.0 Amps
Full load amps, 115V 6.3 10.0
Maximum overcurrent protection, 115V*** 15.0 20.0 Amps
Normal power consumption 657 1020 Watts
Discharge air temperature rise 50 60 50 60 °F
Air volume 2256 2458 4430 4283 cfm
63.9 69.6 125.4 121.3 Meter3/minute
Discharge air opening area 2.56 4.79 Foot2
0.2 0.5 Meter2
*CSA ratings for elevations up to 2,000 feet.
**Size shown is for gas connection to a single-stage gas valve—not supply line size.
***MOCP = 2.25 × (largest motor FLA) + smallest motor FLA. Answer is rounded to the next lower standard circuit breaker size.

Table 10. Technical Data
Parameter Unit Size Unit of
Measurement
130 180 260 310
Output velocity 883 962 924 894 fpm
269 293 282 272 Meter/minute
Standard open fan motor size 1/4 1/2 Horsepower
Optional enclosed fan motor size
Fan motor speed 1050 1050 rpm
Fan diameter 18 24 Inches
Approximate condensate per hour 1 2 Gallons
3.8 7.6 Liters
INSTALLATION
Unpacking and Inspection
•The unit was test-operated and inspected at the factory prior to crating and was in operating condition.
•It is important to note when uncrating the unit that shipping brackets are attached with cabinet screws. When
removing shipping brackets, re-insert ALL screws into the cabinet.
•If, upon removing it from its crate, the unit has been found to have incurred any damage in shipment, document
the damage with the transporting agency and contact an authorized Factory Distributor. If you are an authorized
Distributor, follow the FOB freight policy procedures.
•A conversion kit is included with the heater for converting for use with propane (refer to Converting Unit from
Natural Gas to Propane. section).
Pre-Installation Checklist
Check the rating plate for the gas specifications and electrical characteristics of the heater to ensure that they
are compatible with the gas and electric supplies at the installation site.
Read this manual and become familiar with the installation requirements of your particular heater.
If you do not have knowledge of local requirements, check with the local gas company or any other local agencies
who might have requirements concerning this installation.
Before beginning, make preparations for necessary supplies, tools, and manpower.
Check to see if there are any field-installed options (refer to Table 11) that need to be assembled/installed
prior to unit installation. Ensure that all options ordered are at the installation site. Instructions are in this
manual or in the option package (option packages are shipped separately).
14 I-UEZ (04-21) 1034347-0
—Continued
GENERAL INFORMATION—CONTINUED
Technical Data—Continued
Table 11. Field-Installed Options
Name Code Description
Vent/combustion air inlet terminal kit CC2 Vertical roof vent
CC6 Horizontal through-wall vent
Vertical louvers CD1 —
Downturn nozzle
CD2 25- to 65-degree variable air deflection range
CD3 50- to 90-degree variable air deflection range
CD4 25- to 65-degree variable air deflection range nozzle with vertical louvers
Manual shutoff valve CE1 Natural gas or propane
Hanger kit CK10 Adapts 3/8-inch hangers for suspension from 1-inch threaded pipe

15
I-UEZ (04-21) 1034347-0
Figure 6. Heater Suspension
Suspension of Heater with Downturn Nozzle
Downturn nozzle kits (option CD2, CD3, or CD4) require four-point suspension. Follow the instructions provided
with the kit to install.
DETAIL A DETAIL B
Heater Suspension
⚠ WARNING ⚠
• Before suspending the heater, check the supporting structure to be used to verify that it has
sufficient load-carrying capacity to support the weight (refer to Weights section) of the unit.
• The heater must be level for proper operation. DO NOT place or add additional weight to a
suspended heater.
⚠ CAUTION ⚠
• Before lifting the heater, verify that any screws used for holding shipping brackets were re-
installed in the cabinet.
• When the heater is lifted for suspension, support the bottom of the heater with plywood or other
appropriately placed material. If the bottom is not supported, damage could occur.
The heater is designed to be suspended using four-point suspension by one of the following methods:
1. Suspending heater using field-supplied 3/8-inch threaded rods (see Figure 6, DETAIL A):
a. A 3/8-16 threaded nut retainer is located at each suspension point.
b. Install 3/8-inch nut and washer to lock heater to threaded rod at each suspension point. Ensure that threaded
rod does not extend into heater more than 1/2 inch (13 mm). Recommended rod length is 6 feet (1.8 meters).
2. Using swivel connectors to suspend heater from 1-inch pipes (see Figure 6, DETAIL B):
a. Lock threaded swivel connectors (option CK10) to heater at 3/8-16 threaded nut retainers.
b. Swivel connectors are threaded to suspend heater from 1-inch pipe.

16 I-UEZ (04-21) 1034347-0
INSTALLATION—CONTINUED
Piping Connections
Gas Supply Pressure
The unit is equipped for a maximum gas supply pressure of 1/2 psi, 3.5 kPa, or 14 IN WC.
NOTES:
Supply pressure higher than 1/2 psi requires the installation of an additional lockup-type service
regulator external to the unit.
PRESSURE TESTING SUPPLY PIPING
• Test pressures above 1/2 psi—disconnect the heater and manual valve from the gas supply line
to be tested. Cap or plug the supply line.
• Test pressures below 1/2 psi—before testing, close the manual valve on the heater.
Gas Supply Piping
⚠ DANGER ⚠
• All components of a gas supply system must be leak tested prior to placing equipment in service.
NEVER TEST FOR LEAKS WITH AN OPEN FLAME. Failure to comply could result in personal
injury, property damage, or death.
• 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.
•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 section).
•Gas supply piping installation shall conform with good practice and with local codes.
•Support gas piping with pipe hangers, metal strapping, or other suitable material. Do not rely on the heater to
support the gas pipe.
•The heater is orificed for operation with natural gas having a heating value of 1,000 (±50) BTU per cubic foot or
with propane gas having a heating value of 2,500 (±100) BTU per cubic foot. Sizing of gas supply lines depends
on piping capacity and is based on cubic feet per hour based on a 0.3 IN WC pressure drop, a 0.6 specific gravity
for natural gas at 1,000 BTU per cubic feet, and a 1.6 specific gravity for propane at 2,550 BTU per cubic feet. If
the gas at the installation does not meet this specification, consult the factory for proper orificing.
•Variables for sizing gas supply lines are listed in Table 12. When sizing supply lines, consider possibilities of future
expansion and increased requirements. Refer to National Fuel Gas Code for additional information on line sizing.

17
I-UEZ (04-21) 1034347-0
Table 12. Gas Supply Line Sizes
Length
of Pipe
(Feet)
Diameter of Pipe (Inches)
1/2 3/4 1 1-1/4 1-1/2 2
Natural
Gas Propane Natural Gas Propane Natural Gas Propane Natural Gas Propane Natural Gas Propane Natural Gas Propane
Cubic Feet per Hour
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
Supply Piping Connections
•Gas connection sizes are listed in Table 13.
•Install a ground joint union and manual shutoff valve upstream of the unit control system, as shown in Figure 7.
•The 1/8-inch plugged tapping in the manual shutoff valve in Figure 7 provides connection for a supply line pressure
test gauge.
•The National Fuel Gas Code requires the installation of a trap with a minimum 3-inch drip leg (see Figure 7). Local
codes may require a drip leg longer than 3 inches (typically 6 inches). To permit burner removal, this drip leg must
extend beyond the edge of the heater.
•Leak-test all connections by brushing on a leak-detecting solution. Bleed trapped air from gas lines as needed.
•The gas connection is made at the pipe nipple that extends outside the cabinet, as shown in Figure 7.
Table 13. Gas Connection Sizes
Unit Size Natural Gas Propane
Connection (Inches)*
130, 180 1/2 1/2
260, 310 3/4 3/4
*Connection size for a standard unit (not gas supply line size).
Figure 7. Gas Connections

INSTALLATION—CONTINUED
Concentric Adapter Box Connections
•All model UEZ installations require a concentric adapter box. The concentric adapter box is included in the vent/
combustion air kit, which is ordered with the heater.
•A horizontal terminal vent/combustion air kit is option CC6; a vertical terminal vent/combustion air kit is option CC2.
The concentric adapter box is included in both the horizontal and vertical vent/combustion air kits. Installation is
included in the instructions for options CC6 and CC2.
•The concentric adapter box is shown Figure 8. Dimensions and connections are shown in Figure 9.
Figure 8. Concentric Adapter Box
There is silicone ring around
this opening in box. Loosen
screws on pipe support bracket.
Adjust bracket to provide good
seal with ring and tighten screws.
HEATER SIDE VIEW
18 I-UEZ (04-21) 1034347-0

Figure 9. Concentric Adapter Box Dimensions and Connections
1-7/8”
(48mm)
6-3/16”
(157mm)
2”
(51mm)
9-11/32” (237mm)
5-11/23”
(136mm)
8” diameter Collar for
Combustion Air Pipe
6” diameter Collar for
Combustion Air Pipe
6” diameter Collar for
Combustion Air Pipe
14-3/8”
(365mm)
4-3/32”
(104mm)
5-9/32”
(134mm)
6-1/8”
(156mm)
6-1/8”
(156mm)
1-1/16” (27mm)
16” (406mm)
17” (432mm)
Opening for 4”
diameter Vent Pipe
Silicone
Ring
Top
View
Heater
Side
View
19
I-UEZ (04-21) 1034347-0

INSTALLATION—CONTINUED
Vent Terminal Options
Vent terminal options CC2 (vertical vent configuration) and CC6 (horizontal vent configuration) are shown in Figure 10.
Figure 10. Vent Terminal Options
Vertical Vent Terminal (Option CC2) Installation
•Field-supplied components required for installation of the vertical vent kit are as follows:
• Vent and combustion air piping—6- and 8-inch single-wall galvanized pipe
• 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 14 and shown in Figure 11.
VERTICAL (OPTION CC2) HORIZONTAL (OPTION CC6)
Table 14. Vertical Vent Terminal/Combustion Air Package (Option CC2) Components
PN Description Qty
221248 Kit package 1
221069 Concentric adapter box with silicone sealing ring (see Figure 8 and Figure 9) 1
221185 Rain collar (see Figure 11) 1
221250 Combustion air inlet (see Figure 11) 1
221091 Cap, condensate drain connection, 4-inch PVC 1
221215 Bird guard (see Figure 11) 1
37661 Screw, self-drilling, #10-16 × 1/2, bird guard 2
Figure 11. Option CC2 Components
RAIN COLLAR COMBUSTION AIR INLET BIRD GUARD
20 I-UEZ (04-21) 1034347-0