Reznor WS Installation and operating instructions

Revision: WS-IOM (12-22) 1042506-0
HYDRONIC UNIT HEATER INSTALLATION, OPERATION,
AND MAINTENANCE
Supersedes: — (Original Version)
MODEL WS
⚠ WARNING ⚠
• Be sure to read and understand the installation, operation, and service instructions in this
manual.
• 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.
• This appliance is not intended for use by persons with reduced physical, sensory, or mental
capabilities or lack of experience and knowledge, unless they have been given supervision
or instruction concerning use of the appliance by a person responsible for their safety.
• Children should be supervised to ensure that they do not play with the appliance.
• Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or
any other appliance.
• Do not remove the security labels. If they are unreadable contact an authorized distributor
for replacement labels.
• The heat exchanger coils must be protected against freezing.
DO NOT DESTROY. PLEASE READ CAREFULLY. KEEP IN A SAFE PLACE FOR FUTURE REFERENCE.

2WS-IOM (12-22) 1042506-0
TABLE OF CONTENTS
GENERAL INFORMATION ................................................................... 3
Important Safety Information................................................................. 3
Warranty ................................................................................ 3
Certification .............................................................................. 3
Installation Codes ......................................................................... 3
Heater Location........................................................................... 4
Mounting Height ........................................................................ 4
Heater Throw and Cover ................................................................. 4
Acoustical Considerations ................................................................ 5
Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Clearances .............................................................................. 6
Weights ................................................................................. 6
INSTALLATION ............................................................................ 7
Unpacking and Inspection................................................................... 7
Pre-Installation Checklist.................................................................... 7
Field-Installed Options...................................................................... 7
Installing Vertical Louvers (Option HL10) .................................................... 7
Installing Airflow Optimizer (Option HL11) .................................................... 8
Heater Mounting .......................................................................... 8
Wall-Mounting Heater for Horizontal Discharge ................................................ 8
Suspending Heater for Horizontal Discharge Using Threaded Rods or Eyebolts ...................... 9
Suspending Heater for Vertical Discharge Using Suspension Plates .............................. 10
Piping Connections ....................................................................... 10
Electrical Connections..................................................................... 12
Cleaning and Water Treatment .............................................................. 13
OPERATION ............................................................................. 13
Pre-Startup Checklist ..................................................................... 13
Startup................................................................................. 13
Fan Speed Adjustment .................................................................... 14
Louver Adjustment ....................................................................... 15
MAINTENANCE........................................................................... 15
Service Checklist......................................................................... 16
Heat Exchanger Maintenance............................................................... 16
Fan and Motor Maintenance ................................................................ 16
TROUBLESHOOTING ...................................................................... 17
INSTALLATION RECORD (TO BE COMPLETED BY INSTALLER)................................... 20

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WS-IOM (12-22) 1042506-0
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.
•Hydronic unit heaters can be operated with hot water or steam at a high pressure. Warm water, hot water, or
steam produced by a boiler flows through the heat exchanger. Standard hot water units are option HA11. Steam
units are option HA12.
•These hydronic unit heaters are designed and constructed for industrial, commercial, or sports facility heating.
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.
⚠ CAUTION ⚠
To prevent damage to the unit or to its internal components, it is recommended that two wrenches
be used when loosening or tightening nuts. Do not over tighten!
Warranty
NOTE: The standard unit heater warranty covers only original defects and does not cover the
repairs resulting from a water condition such as corrosion or scale. It is up to you and is your
sole responsibility to ensure that a proper water treatment and maintenance program is correctly
followed at all times.
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 air delivery system is modified.
•Improper water conditions result in excessive corrosion or leaks.
Certification
These unit heaters are listed by Intertek for use in the United States and in Canada.
Installation Codes
These units must be installed in accordance with local building codes. Local authorities having jurisdiction should
be consulted before installation is made to verify local codes and installation procedure requirements.

4WS-IOM (12-22) 1042506-0
GENERAL INFORMATION—CONTINUED
Heater Location
⚠ CAUTION ⚠
• Do not locate the heater where it may be exposed to water spray, rain, or dripping water.
• When installing the hydronic unit heater in applications where the heater can be subject to damage
from balls in gymnasiums and/or courts, it is necessary to fit the heater with a frame and a safety
net. The directional air louvers on the front of the unit should especially be protected.
For best results, the heater should be mounted with certain rules in mind:
•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.
Mounting Height
⚠ WARNING ⚠
If touched, the 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.
In general, a unit should be located 10–20 feet (3.5–6.1 meters) above the floor. 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 15–20 feet (4.6–6.1 meters).
Heater Throw and Cover
All units can be installed for either horizontal or vertical discharge. Table 1 lists throw and cover data for standard
adjustable horizontal louvers on heaters suspended at varying mounting heights.
Table 1. Heater Throw and Cover with Standard Horizontal Louvers
Unit Size
Fan Speed
Low High Low High Low High Low High
Horizontal Discharge Vertical Discharge
Dimension H*
(Feet (Meters))
Throw
(Feet (Meters))
Dimension H*
(Feet (Meters))
Cover
(Feet2(Meters2))
18/24 10 (3) 10 (3) 16 (5) 23 (7) 10 (3) 11 (3.5) 344 (32) 473 (44)
23/33 10 (3) 10 (3) 16 (5) 25 (7.5) 10 (3) 11 (3.5) 366 (34) 516 (48)
44/62 10 (3) 11 (3.5) 18 (5.5) 26 (8) 11 (3.5) 13 (4) 387 (36) 538 (50)
60/85 11 (3.5) 13 (4) 25 (7.5) 36 (11) 13 (4) 15 (4.5) 484 (45) 646 (60)
78/110 11 (3.5) 13 (4) 33 (10) 46 (14) 15 (4.5) 16 (5) 538 (50) 753 (70)
96/120 13 (4) 15 (4.5) 33 (10) 46 (14) 15 (4.5) 16 (5) 538 (50) 753 (70)
140/175 15 (4.5) 16 (5) 39 (12) 52 (16) 16 (5) 18 (5.5) 646 (60) 861 (80)
190/238 16 (5) 18 (5.5) 46 (14) 59 (18) 18 (5.5) 20 (6) 968 (90) 1184 (110)
300/350 18 (5.5) 20 (6) 66 (20) 85 (26) 23 (7) 30 (9) 1399 (130) 1722 (160)
*Maximum mounting height (see Figure 1).

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WS-IOM (12-22) 1042506-0
Figure 1. Heater Throw and Cover (Refer to Table 1)
Acoustical Considerations
Refer to sound level data listed in Table 2 when determining unit location based on acoustical considerations.
Table 2. Acoustical Data
Fan
Speed
Unit Size
18/24 23/33 44/62 60/85 78/110 96/120 140/175 190/238 300/350
Sound level (dBa) @ 16-1/2 feet
Low 45 46 49 54 57 47 49 52 61
High 52 54 58 63 65 52 55 60 67
THROW
COVER
H
H

6WS-IOM (12-22) 1042506-0
GENERAL INFORMATION—CONTINUED
Dimensions
Figure 2. Dimensions (Refer to Table 3)
Table 3. Dimensions
Dimension
(See Figure 2)
Unit Size
18/24, 23/33 44/62 60/85 78/110 96/120 140/175 190/238 300/350
Inches (mm)
A 16-7/16 (418) 18-9/16 (472) 20-11/16 (526) 22-13/16 (580) 24-15/16 (634) 27-1/16 (688) 29-3/16 (742) 35-7/16 (900)
B 11-1/8 (282) 13-1/4 (336) 15-3/8 (390) 17-1/2 (444) 19-5/8 (498) 21-3/4 (552) 23-7/8 (606) 30-1/16 (764)
C 18-5/16 (465) 19-3/16 (488) 20-3/16 (513) 22-5/8 (575)
D 12-5/8 (321) 14-3/4 (375) 16-7/8 (429) 19 (483) 21-1/8 (537) 23-1/4 (591) 25-3/8 (645) 31-5/8 (803)
E 8-11/16 (220) 8-1/4 (210)
F 5-1/8 (130) 5-1/2 (140)
G 3-15/16 (100) 4-3/4 (120) 5-1/8 (130)
Ø 3/4 (19) 1-1/4 (32) 1-1/2 (38)
Fan diameter 11-13/16 (300) 13-3/4 (350) 15-3/4 (400) 17-11/16 (450) 19-11/16 (500) 21-5/8 (550) 25-9/16 (650)
Clearances
Always maintain a minimum clearance of 6 inches (150 mm) behind the unit for maintenance of the motor and fan.
Weights
Table 4. Weights
Unit Size
18/24 23/33 44/62 60/85 78/110 96/120 140/175 190/238 300/350
Pounds (kg)
37 (17) 44 (20) 49 (22) 55 (25) 66 ( 30) 75 (34) 88 (40) 101 (46) 146 (66)
11-1/2
(290)
1-9/16
(40)
1-9/16
(40)
1-1/16 (26.5)
F
C
D
A
BA
G
E
B
NOTE: Inches (mm)

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WS-IOM (12-22) 1042506-0
INSTALLATION
⚠ WARNING ⚠
Always wear work gloves when installing or servicing the heater.
Unpacking and Inspection
•The unit was test-operated and inspected at the factory prior to crating and was in operating condition.
•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.
Pre-Installation Checklist
Check the rating plate for the water and electrical requirements of the heater to ensure that they are compatible
with the water 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 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 Field-Installed Options section) that need to be
assembled/installed prior to unit installation. Ensure that all options ordered are at the installation site.
Field-Installed Options
Table 5. Field-Installed Options
Option Name Description
HL10 Vertical louvers Direct discharge air to provide wider throw pattern
HL11 Airflow optimizer Greatly increases throw of horizontal discharge units
HT15 Thermostat
CM4 Guard/cover Thermostat
Installing Vertical Louvers (Option HL10)
NOTE: Vertical louvers can be used with either horizontal or vertical discharge installations, but
they are recommended for vertical discharge units to create a four-way discharge pattern.
1. Position vertical louver assembly (see Figure 3) on face of heater and align existing mounting holes.
2. Secure vertical louver assembly to heater using fasteners provided in option kit.
Figure 3. Vertical Louver Assembly

8WS-IOM (12-22) 1042506-0
Figure 4. Airflow Optimizer Assembly
Heater Mounting
⚠ WARNING ⚠
• Before mounting the heater, check the supporting structure to verify that it has sufficient load-
carrying capacity to support the weight (refer to Weights section) of the unit.
• Ensure that the heater is not supported by piping.
• The heater must be level for proper operation. DO NOT place or add additional weight to a wall-
mounted or suspended heater.
• DO NOT allow any foreign objections into the heat exchanger coil. Foreign objects can damage
the heat exchanger and can damage or destroy pumps and boilers.
Wall-Mounting Heater for Horizontal Discharge
1. Determine installation height and secure field-supplied brackets to wall as shown in Figure 5 using field-supplied
hardware.
2. Raise heater using suitable hoist or lift and secure heater to brackets as shown in Figure 5 using M8 metric
screws and flat washers provided.
INSTALLATION—CONTINUED
Field-Installed Options—Continued
Installing Airflow Optimizer (Option HL11)
NOTE: For horizontal discharge installations, the airflow optimizer increases air throw, which
results in energy savings and better environmental control.
1. Remove existing horizontal louvers by pushing each louver toward spring to release louver.
2. Position airflow optimizer assembly (see Figure 4) on face of heater and align existing mounting holes.
3. Secure airflow optimizer assembly to heater using fasteners provided in option kit.
4. Adjust wingnut on threaded rod as necessary to set optimizer louvers for desired airflow.

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WS-IOM (12-22) 1042506-0
Figure 5. Wall-Mounting Heater
Suspending Heater for Horizontal Discharge Using Threaded Rods or Eyebolts
1. Install field-supplied threaded rods or eyebolts as shown in Figure 6.
2. Determine installation height, raise heater using suitable hoist or lift, and suspend heater using threaded rods or
wire rope or chains connected to eyebolts.
Figure 6. Suspending Heater for Horizontal Discharge (Refer to Table 6)
Table 6. Suspension Point Dimensions
Unit Size
18/24, 23/33, 44/62, 60/85 78/110, 96/120, 140/175 190/238, 300/350
Dimension A*(Inches (mm))
4 (102) 4-3/4 (121) 5-1/8 (130)
*See Figure 6.
1/2 (13)
7/8 (22)
1-9/16
(40)
7/8 (22)
A
1-9/16
(40)
NOTE: Inches (mm)

10 WS-IOM (12-22) 1042506-0
INSTALLATION—CONTINUED
Heater Mounting—Continued
Suspending Heater for Vertical Discharge Using Suspension Plates
NOTE: The optional vertical louvers are recommended for vertical airflow units for four-way air
distribution.
1. Install suspension plates, M8 metric screws, and flat washers provided with unit as shown in Figure 7.
2. Determine installation height, raise heater using suitable hoist or lift, and suspend heater using bars, wire rope,
or chains connected to suspension plates.
Figure 7. Suspending Heater for Vertical Discharge
Piping Connections
⚠ WARNING ⚠
• Maximum operation pressure is 150 psi (10 bar).
• Flange seals must not be made with rubber or other material that melts easily. In the event of
overheated water, rubber seals may melt.
• Mount a thermostatic air vent if the distribution ring of the water or steam is in a lower position
than the heater.
•Connect inlet and outlet piping using a three-part joint union and ball valve (see Figure 8) sealed with pipe sealant.
•Connect hot water piping in accordance with piping diagram shown in Figure 9.
•Connect steam piping in accordance with piping diagram shown in Figure 10.
Figure 8. Three-Part Joint Union and Ball Valve

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WS-IOM (12-22) 1042506-0
Figure 9. Hot Water Piping Diagram
Figure 10. Steam Piping Diagram
HORIZONTAL DISCHARGE VERTICAL DISCHARGE
RETURN
RETURN
SUPPLY
SUPPLY
HORIZONTAL DISCHARGE VERTICAL DISCHARGE
RETURN
RETURN
SUPPLY
SUPPLY
CONDENSATE
CONDENSATE
FLOW TRAP
FLOW TRAP
DRIP LEG AND
CLEANOUT DRAIN
DRIP LEG
AND
CLEANOUT
DRAIN
STEAM
SLOPE
STEAM
SLOPE

INSTALLATION—CONTINUED
Electrical Connections
⚠ WARNING ⚠
• Before connecting the motor, ensure that the electrical power is OFF.
• A security disconnect switch must be mounted near the unit in an easily-accessible location.
• Ensure that the double-speed, single-phase 115V/60Hz motor (refer to Table 7) is grounded.
12 WS-IOM (12-22) 1042506-0
Figure 11. Wiring Diagram
Table 7. Motor Electrical Data
Parameter Speed
Setting
Unit Size
18/24 23/33 44/62 60/85 78/110 96/120 140/175 190/238 300/350
HP Low 0.014 0.020 0.027 0.048 0.090 0.041 0.070 0.110 0.500
High 0.040 0.055 0.082 0.150 0.260 0.090 0.160 0.250 1.140
Amp
rating
Low 0.3 0.4 0.6 1.1 1.7 0.9 1.1 2.2 6.5
High 0.6 0.9 1.2 1.9 3.0 1.8 2.6 3.4 13.0
BLK
WHT
GRN
L1
L2
G
FIELD-
SUPPLIED
OVER-
LOAD THERMOSTAT
CAPACITOR
MOTOR
HIGH SPEED
LOW SPEED
MANUAL STARTER U1 V1 W1
NOTE: Ignore terminals U2, V2, and W2.They are covered with plastic insulators and are not used.
In accordance with the wiring diagram shown in Figure 11, make the following electrical connections:
1. Remove cover from motor’s terminal board.
2. Connect hot wire from L1 to motor terminal U1.
3. Connect high speed neutral wire from L2 to motor terminal V1.
4. Connect low speed neutral wire from L2 to motor terminal W1.
5. Connect green ground wire.
6. Close terminal board cover and tighten fasteners.
NOTE: Internal motor wiring (for reference only): black wire from motor winding connects to U1,
red wire from motor winding connects to V1, and green wire from motor winding connects to W1.

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WS-IOM (12-22) 1042506-0
Cleaning and Water Treatment
⚠ CAUTION ⚠
• During installation, most systems become contaminated by pipe dope, thread-cutting oils,
soldering flux, rust preventives, or dirt in the pipe and fittings. Frequently, there are sufficient
quantities of these contaminates that chemically break down to cause gas formation and acid
in system water. Once the system is contaminated, deterioration continues, leaks develop, and
water losses increase that may cause serious damage due to scaling or corrosion of the unit.
To eliminate this potential hazard, the system must be cleaned and water must be conditioned
before operation.
• When installed in a hot water application,the heater(s) should be installed in a closed loop system.
Installing in an open hot water system can cause excessive buildup of chemicals and corrosion
and could cause premature failure.
•Every system should be properly cleaned when the installation is completed and before putting the system in
operation. This includes the boiler, the entire piping system, and the unit heater(s).
•Every steam or hot water system requires a proper water treatment program with regular water analyses (refer to
Table 8), adequate regulated drains, correct maintenance, periodic safety checks, and periodic inspection followup.
Table 8. Water Recommendations
Water Type pH Hardness Total Alkalinity Sodium Sulfite (SO3)
Supply water 7.5–9.5 5 mg/l CaCO3 —
Boiler water 10–11.5 250–700 ppm 40–100 ppm
Condensate return water 8–9 — —
OPERATION
Pre-Startup Checklist
Check the following before startup:
Check suspension—unit must be secure and at desired angle.
Check electrical wiring—ensure that all wire gauges are as recommended—verify that fusing or circuit breakers
are adequate for load use.
Check polarity—verify that line voltage exists between black L1 wire and earth ground.
Place literature bag that contains limited warranty form, this manual, and any control or optional information in
accessible location near unit.
Startup
Start up the heater as follows:
1. Set thermostat at lowest setting.
2. Turn ON electric power to heater.
3. Open hot water or steam supply valve.
4. Set thermostat to desired setting. Refer to Table 9 for operational sequence.

14 WS-IOM (12-22) 1042506-0
Fan Speed Adjustment
⚠ WARNING ⚠
When setting the rotation speed of the motor, keep away from the fan.
•After making the electrical connection, set the rotation speed of the motor. Table 10 lists fan speed settings with
an entering water temperature of 20°F (93°C) and an entering air temperature of 60° (16°C).
Table 9. Operational Sequences
Operation Type Operational Sequence when Thermostat Calls for Heat
lntermittent fan operation—hot
Fan motor is energized
Hot water or steam is continuously supplied to heater even when fan motor is not running
When thermostat is satisfied, fan motor is de-energized
Continuous fan operation—intermittent
hot/cold (requires field-supplied
electronically-controlled supply valve)
Fan runs continuously
Supply valve is opened to allow steam or hot water to enter heater
When thermostat is satisfied, supply valve is closed
lntermittent fan operation—intermittent
hot/cold (requires field-supplied
electronically-controlled supply valve)
Fan motor is energized*
Supply valve is opened to allow steam or hot water to enter heater
When thermostat is satisfied, supply valve is closed and fan motor is de-energized
*To avoid cold air delivery, an field-supplied aquastat may be installed in the supply or return piping to prevent fan operation until the heat
exchanger is adequately heated.
OPERATION—CONTINUED
Startup—Continued
Table 10. Fan Speed Settings
Parameter Heat
Source
Fan
Speed
Unit Size
18/24 23/33 44/62 60/85 78/110 96/120 140/175 190/238 300/350
Fan rpm
(approximate)
Hot water
or steam
Low 1050 850 750
High 1550 1600 1100
Leaving air
temperature
(°F (°C))
Hot water Low 104 (40) 107 (42) 113 (45) 112 (44) 109 (43) 115 (46) 119 (48) 116 (47)
High 104 (40) 108 (42) 107 (42) 106 (41) 113 (45) 112 (45) 117 (47) 114 (45)
Steam Low 121 (49) 124 (51) 132 (56) 129 (54) 125 (52) 134 (57) 134 (57) 140 (62) 133 (56)
High 115 (46) 121 (49) 126 (52) 123 (51) 121 (49) 131 (55) 130 (54) 137 (58) 128 (53)
Air volume
(cfm (m3/hr)
Hot water
or steam
Low 270
(459)
330
(561)
560
(952)
800
(1359)
1100
(1869)
1200
(2039)
1750
(2973)
2200
(3738)
3800
(6457)
High 400
(680)
500
(850)
860
(1461)
1250
(2124)
1650
(2804)
1550
(2634)
2300
(3908)
2850
(4842)
4750
(8071)
Maximum
heating capacity
(MBH)
Hot water Low 13 17 32 45 58 72 105 141 230
High 19 24 45 64 82 89 131 177 276
Steam Low 18 23 44 60 78 96 140 190 300
High 24 33 62 85 110 120 175 238 350

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WS-IOM (12-22) 1042506-0
Louver Adjustment
⚠ WARNING ⚠
To avoid burns, adjust louvers while heater is not in operation. If louvers must be adjusted while
heater is operating, wear protective gloves.
⚠ CAUTION ⚠
Units are shipped from the factory with the air louvers closed. Failure to open the louvers and
direct the air could cause damage to the unit.
After installing the unit, the air louvers must be set to direct heated air where it is needed.
MAINTENANCE
⚠ WARNING ⚠
• Only qualified trained maintenance personnel should work on the heater.
• Before cleaning or servicing the heater, disconnect the power source.
• Eye protection is recommended when cleaning unit.
⚠ CAUTION ⚠
• When any service is completed, ensure that the unit is reassembled correctly so that no unsafe
conditions are created.
• If replacement parts are required, use only factory-authorized parts.
NOTE: To ensure long life and satisfactory performance, a heater that is operated under normal
conditions should be inspected and cleaned at the start of each heating season. If the heater is
operating in an area where an unusual amount of dust or soot or other impurities are present in
the air, more frequent maintenance is recommended.
The unit is designed to operate with a minimum of maintenance. However, to ensure long life and satisfactory
performance, routine service is recommended. When servicing, follow standard safety procedures and those specific
instructions and warnings in this manual.

16 WS-IOM (12-22) 1042506-0
MAINTENANCE—CONTINUED
Service Checklist
The following section is designed to aid a qualified service person in maintaining and servicing this equipment. At a
minimum, perform the following annually:
Clean all dirt, lint, and grease from fan blade, fan guard, and motor.
Replace any parts that do not appear sound.
Check for any damaged wiring and replace as necessary.
Heat Exchanger Maintenance
⚠ CAUTION ⚠
• Failure to maintain an unobstructed airflow could cause damage to the heat exchanger.
• When cleaning the fins with a pressure washer, be careful not to get the motor wet.
The heat exchanger should be checked about every 6 months for dirt or other debris caught in the fins. Clean the
fins using a low-pressure air blower or pressure washer.
Fan and Motor Maintenance
⚠ WARNING ⚠
DO NOT place your hands or any foreign objects in the fan. Do not wear loose clothing when
servicing the fan.
•The fan is composed of three or six blades, depending on the size of the heater. Fans have been statically-balanced
for reduced noise levels. The blades can reach a speed of 1,650 rpm. The finger-proof fan guard is made of
galvanized steel wire and is secured using anti-vibration fasteners. If you notice noise or vibrations caused by the
fan, check to ensure that the mounting bolts on the motor, the support, and the fan are well-secured.
•Closed motors have self-lubricating bearings and are maintenance-free. If the motor is replaced, don’t forget to
check fan rotation.

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WS-IOM (12-22) 1042506-0
TROUBLESHOOTING
Table 11. Troubleshooting
Symptom Probable Cause Remedy
A. Unit will not
start
1. No power to unit Turn ON power and check supply fuses or circuit breaker
2. No 24V power to thermostat Turn up thermostat
Check control transformer output
3. No power to fan motor Tighten connections at motor terminals
4. Defective fan motor Replace fan motor
5. Improper thermostat location or adjustment Refer to thermostat manufacturer's instructions
B. No heat
(heater operating)
1. Insufficient hot water/steam supply Provide adequate hot water/steam supply
2. Improper thermostat location or adjustment Refer to thermostat manufacturer's instructions
C. Fan motor will
not run
1. Circuit open Check wiring and connections
2. Defective capacitor Replace capacitor
3. Defective starter Replace starter
4. Defective overload Replace overload
5. Defective fan motor Replace motor
D. Fan motor cuts
out on overload
1. Low or high voltage supply Correct electric supply
2. Defective capacitor Replace capacitor
3. Defective starter Replace starter
4. Defective overload Replace overload
5. Defective fan motor Replace motor
6. Poor airflow Clean motor, fan, and fan guard
Clean heat exchanger
Adjust louvers

NOTES
18 WS-IOM (12-22) 1042506-0

NOTES
19
WS-IOM (12-22) 1042506-0

INSTALLATION RECORD (TO BE COMPLETED BY INSTALLER)
Installer:
Name ________________________________________________________
Company ________________________________________________________
Address ________________________________________________________
________________________________________________________
Phone ________________________________________________________
Distributor (company from which the unit was purchased):
Company ________________________________________________________
Contact ________________________________________________________
Address ________________________________________________________
________________________________________________________
Phone ________________________________________________________
Model ________________ Serial No.______________________________ Date of Installation ____________
Specic 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 Distributor listed above.
For more information, contact your Factory Representative.
Specifications and illustrations subject to change without notice or incurring obligations.
Latest version of this manual is available at www.reznorhvac.com.
©2022 Nortek Global HVAC LLC, O’Fallon, MO. All rights reserved.
WS-IOM (12-22) 1042506-0