Reznor AS3 User manual

DO NOT DESTROY. PLEASE READ CAREFULLY. KEEP IN A SAFE PLACE FOR FUTURE REFERENCE.
GENERAL INFORMATION
•The optional evaporative cooling module for packaged indirect-fired system models RGBL, RPBL, SSCBL, PGBL,
blower cabinet model RBL, and direct-fired makeup air models ADF/ADFH 700/1200 is factory-assembled but
requires field-installation.
•The evaporative cooling module is available in the following options:
Option AS3: includes 6-inch rigid cellulose media
Option AS4: includes 12-inch rigid cellulose media
Option AS5: includes 6-inch rigid glass fiber media
Option AS8: includes 12-inch rigid glass fiber media
•The base parts for supporting the evaporative cooling module and the transition duct for connecting it to the unit
are shipped with the module for field-assembly and installation. If optional moisture elimination pads, a drain and
fill kit, and/or a water hammer arrestor are to be included in the installation, they also require field-installation.
•All evaporative cooling modules require outside air.
TABLE OF CONTENTS
GENERAL INFORMATION .............................................................................1
Dimensions ........................................................................................2
Weights...........................................................................................2
INSTALLATION ...................................................................................... 3
Pre-Installation Checklist .............................................................................3
Assemble Base.....................................................................................3
Install Evaporative Cooling Module on Base ..............................................................4
Assemble Transition Duct.............................................................................4
Connect Transition Duct to Blower Cabinet ............................................................... 5
Connect Transition Duct to Evaporative Cooling Module .....................................................5
Installation/Replacement of Media Pads.................................................................. 6
Pump/Junction Box Assembly Installation ................................................................7
Electrical Connections ...............................................................................8
Piping Connections..................................................................................9
Float Valve Connection ............................................................................9
Optional Fill and Drain Kit Installation ................................................................10
AquaSaver Timed Metering Control System Connections ................................................11
Shutoff and Drain Connections .....................................................................11
Bleed Line Connection ...........................................................................11
MAINTENANCE.....................................................................................12
Filling and Adjusting Water Level in Reservoir ............................................................12
Adjusting Water Flow ...............................................................................12
Adjust Water Flow with Float and Pump Control System .................................................12
Adjust Water Flow with AquaSaver Timed Metering Control System ........................................13
Media Maintenance.................................................................................14
Flushing Water Lines ...............................................................................14
Water Pump Maintenance ...........................................................................14
TROUBLESHOOTING ................................................................................15
Revision: OPT-AS3,4,5,8 (07-22) 160202-B
OPTION AS3, AS4, AS5, OR AS8 FOR MODELS ADF, ADFH, PGBL, RBL,
RGBL, RPB, RPBL, AND SSCBL
EVAPORATIVE COOLING MODULE INSTALLATION,
MAINTENANCE, AND TROUBLESHOOTING
Supersedes: OPT-AS3,4,5,8 (06-22) 160202-A

2OPT-AS3,4,5,8 (07-22) 160202-B
GENERAL INFORMATION—CONTINUED
NOTE: INDOOR INSTALLATIONS: DO NOT suspend the evaporative cooling module—it must be
mounted on a platform. If the installation location does not have a suitable platform that allows
the module to be installed directly to the cabinet, install the module on a separate platform with a
compatible field-fabricated transition duct between the module and the cabinet.
•Ensure that all components listed in Table 1 are available before beginning installation. These components are
shipped with the evaporative cooling module.
Figure 1. Dimensions
Weights
Table 1. Evaporative Cooling Module Installation Components
Item No. Component PN (Quantity) Application
1 End rail 107235 (2)
Base assembly2 Side rail 107227 (2)
3 Two-piece leg 107236 (4)
4 Front top cover 107228 (1) Cooling module
5 Duct top 107229 (1)
Transition duct
6 Duct side 107231 (2)
7 Duct bottom 107230 (1)
8 Screw, #10 × 1/2 11813 (AR)
9 Hex head bolt, 1/4-20 16246 (AR)
10 Nut, 1/4-20 16050 (AR)
11 Duct extension 107233 (2) BL models, unit sizes 500 and 600
12 107234 (2) BL models, unit sizes 700 and 1050
13 Bleed line fitting, 1-1/4 hose ID × 1/2 NPT*105945 (1) Cooling module connections
14 Bushing (Heyco #SR-7W-2) 16835 (2)
NOTE: AR = as required.
*Not used with optional timed metering AquaSaver® system.
Dimensions
Table 2. Weights
Option
AS3 AS4 AS5 AS8
Net Weight (Pounds (kg))*
379 (172) 431 (195) 420 (191) 514 (233)
*With wet media and full reservoir.

3
OPT-AS3,4,5,8 (07-22) 160202-B
INSTALLATION
Install the evaporative cooling module as follows. Item numbers in parentheses refer to Table 1.
⚠ CAUTION ⚠
• DO NOT mount the cooling module directly on soft tar roofs where the legs could sink and tilt
the cooling module. Provide a weather-resistant solid wood or metal base under the cooling
module support base.
• DO NOT install the cooling module and connecting duct while blowers are in operation.
NOTE: Before installation,make preparations for necessary supplies,tools,and manpower.
Pre-Installation Checklist
Ensure that installation complies with all local, utility, and federal building and safety codes and regulations.
Check module for shipping damage. If damage is found, document it with transporting agency and immediately
contact Distributor.
If module is being installed indoors (model SSCBL, PGBL, or ADF/ADFH 700/1200), outside makeup air must
be provided.
If optional shipped-separate equipment is required (i.e., drain and fill kit, freeze protection kit, moisture elimination
pads, and/or water hammer arrestor), check to ensure that these parts are available for installation.
Ensure that there is adequate clearance between bottom of reservoir and roof or platform to allow for drain and
overflow pipe connections (refer to Dimensions section).
Ensure that roof or platform is capable of handling additional load of cooling module with full reservoir (refer to
Weights section).
Ensure that mounting surface for cooling module is level and free of debris.
Assemble Base
Refer to Figure 2.
1. Assemble all four legs:
a. Secure each two-piece leg (3) together using four bolts (9) and nuts (10).
b. Top flange of assembled legs should be level with bottom of system cabinet. Adjust legs to proper height and
securely tighten bolts and nuts. Leg height is adjustable from 9–16 inches (229–406 mm).
c. Position four assembled legs approximately 2 feet (610 mm) from air inlet side of cabinet in rectangular
pattern corresponding to size of cooling module. Check again to ensure that top of legs are level with bottom
of makeup air system cabinet.
Figure 2. Base Assembly (Refer to Table 1)
3
2
1

4OPT-AS3,4,5,8 (07-22) 160202-B
INSTALLATION—CONTINUED
Assemble Base—Continued
2. Connect base rails to legs:
a. Position side rails (2) on inside of top flanges on assembled legs (3). Secure rails to top three holes on legs
located just below top flange using bolts (9) and nuts (10). Repeat on three remaining legs. Tighten nuts securely.
b. Position end rails (1) on inside of top flanges on assembled legs (3). Secure rails to top three holes on legs
located just below top flange using bolts (9) and nuts (10). Repeat on three remaining legs. Tighten nuts securely.
Install Evaporative Cooling Module on Base
Refer to Figure 3.
1. Carefully lift cooling module with both ends supported and place it on base assembly. Ensure that module is level
and that all base assembly bolts are secure.
2. Install top front cover (4) and secure using 13 screws (8)—three per side and seven across top.
Assemble Transition Duct
Refer to Figure 3.
1. Secure duct top (5) to duct sides (6) using eight screws (8)—four per side.
2. Secure duct bottom (7) to duct sides (6) using eight screws (8)—four per side.
NOTE: If the packaged heating system is a unit size 500, 600, 700, or 1050 BL model, duct exten-
sions (11 or 12) must be installed on the transition duct.
3. Secure duct extensions (11 for unit size 500 or 600 or 12 for unit size 700 or 1050) to transition duct assembly
using fourteen screws (8).
Figure 3. Evaporative Cooling Module and Transition Duct (Refer to Table 1)
COOLING MODULE
4
5
6
7
11
OR
12

5
OPT-AS3,4,5,8 (07-22) 160202-B
Connect Transition Duct to Blower Cabinet
Refer to Figure 4.
1. Remove and save screws from along top rear lip of blower cabinet panel.
2. Slide transition duct flange underneath blower cabinet top edge and loosely insert two existing screws through
top edge, through transition duct flange, and into cabinet end panel.
3. If transition duct has duct extensions (11 or 12), insert duct extension mounting flanges into slots on blower
cabinet end panel.
Figure 4. Evaporative Cooling Module, Transition Duct, and Blower Cabinet (Refer to Table 1)
Connect Transition Duct to Evaporative Cooling Module
Refer to Figure 4.
1. With transition duct connected to blower cabinet, carefully tilt transition duct upwards to clear cooling module
reservoir pan and slide cooling module underneath catch pad mounting trough.
2. Squeeze cooling module and transition duct assembly into blower cabinet until tight fit is obtained.
3. Align holes in cooling module corner leg (3) with holes in transition duct sides and secure transition duct sides to
cooling module using screws (8)—five per side.
4. Secure transition duct flange to front top cover (4) using seven screws (8).
5. With cooling module and transition duct properly positioned on blower cabinet, tighten two screws that have been
loosely inserted. Re-insert and tighten existing screws in remaining holes along top edge of cabinet.
NOTE: It may be easier to connect the transition duct to the blower cabinet with the media pads
removed. If optional moisture elimination pads are included, media pads will have to be removed
to complete the installation (refer to Installation/Replacement of Media Pads section).
6. If there are no duct extensions (11 or 12) on transition duct, reach inside cooling module and secure module to
back of blower cabinet end panel using six screws (8). If there are duct extensions, reach inside cooling module
and secure duct extensions to back of blower cabinet end panel using four screws (8).
7. Secure bottom of transition duct to blower cabinet end panel using seven screws (8).
8. Ensure that all screws are in place and seal all corners of transition duct assembly using waterproof silicone
sealant to prevent moisture from entering cabinet.
COOLING MODULE
TRANSITION DUCT
FLANGE
BLOWER CABINET
11
OR
12
CATCH PAD
MOUNTING TROUGH
4

6OPT-AS3,4,5,8 (07-22) 160202-B
INSTALLATION—CONTINUED
Installation/Replacement of Media Pads
NOTE: Option ASA1 moisture elimination pads are shipped separately for field-installation.
Install/replace media pads and/or moisture elimination pads as follows:
1. Remove media pads (see Figure 5):
a. Remove three screws that secure top pad retainer and release top pad retainer from cooling module.
b. Remove three screws that secure bottom pad retainer and release bottom pad retainer from cooling module.
c. Disengage screen retainers from sides of media pads.
d. Disengage inlet screen from media pads and remove media pads from cooling module.
e. Slide all media pads horizontally away from cooling module until clear of bottom reservoir pan.
Figure 5. Media Pad Assembly
2. Install moisture elimination pads if required (see Figure 6):
a. Install two catch pad clamps to one side of cooling module’s front legs and secure clamps through legs into
clamp using four screws (8).
b. Assemble catch pads together using three screws (8).
NOTE: The screen part of the catch pad assembly should always be facing the attached air mover.
c. Guide catch pad assembly through inlet of cooling module and place bottom of lower pad into catch pad mounting
trough (see Figure 4). Slide catch pad assembly into two slots located in catch pad clamps installed in step 2a.
d. With pads in place, slide one of two remaining clamps over middle seam where assembled catch pads meet.
Slide other clamp over top catch pad frame and secure both clamps to cooling module leg using screws (8).
⚠ CAUTION ⚠
IMPORTANT: Cooling media is made up of two different sheets of cooling material, each with
its own unique angle. When replacing the cooing media, BE CERTAIN that the 45° angle slopes
downward toward the incoming outside air. If the media is not installed properly, water blowoff
from the media pads will occur.

7
OPT-AS3,4,5,8 (07-22) 160202-B
Figure 6. Elimination Catch Pad Assembly
3. Reverse procedure in step 1 to replace media pads. Media must be installed in orientation shown in Figure 7.
Figure 7. Airflow Direction Through Media Pads
Pump/Junction Box Assembly Installation
NOTE: To avoid damage during shipping, the pump/junction box assembly is secured to the top
of the side panel.
1. Support pump/junction box assembly and remove and save four screws that secure assembly in its shipping
location.
2. Install pump/junction box assembly in its operating location (see Figure 8) and secure using existing screws.

8OPT-AS3,4,5,8 (07-22) 160202-B
INSTALLATION—CONTINUED
Pump/Junction Box Assembly Installation—Continued
Figure 8. Pump/Junction Box Assembly
Electrical Connections
PUMP/JUNCTION
BOX ASSEMBLY
OPERATING
LOCATION
Figure 9. Evaporative Cooling Module Factory-Installed Wiring
BL MODELS WITH
115/230/1/60 OR
230/460/575/3/60
(HEATER OPTIONS
AK3, AK6, AK7, OR
AK8) AND MODELS
ADF/ADFH 700/1200
SYSTEMS WITH
208/1-3/60 (HEATER
OPTION AK2 OR AK5)

9
OPT-AS3,4,5,8 (07-22) 160202-B
⚠ WARNING ⚠
Disconnect power to the unit.
NOTES:
• Line voltage wiring must be field-installed between the blower junction box and the evaporative
cooling module junction box. The tubing-encased wires are factory-connected in the cooling
module junction box.
• Models ADF/ADFH have optional 115V evaporative cooling module pumps. A transformer is
included on the unit.
• The two snap strain relief bushings, which must be used to prevent water from leaking into the
cabinet, are shipped in the bottom pan of the cooling module.
1. Remove compartment door panels, electrical compartment cover, and service panel in line with hole in cooling
module.
2. Drill 7/8-inch hole in cabinet end panel in line with hole in cooling module junction box.
3. Pull tubing-encased wires through hole in blower cabinet. Place one strain relief bushing around tubing and insert
bushing into hole.
4. Route wires across cabinet bottom. If there are any filters, run wires through slot in bottom filter rack. If there are
inlet dampers, take care to ensure that wires do not interfere with damper controls.
5. Run wires up to electrical compartment, remove plug from one bottom entrance hole, and push tubing-encased
wires into electrical compartment. Place other strain relief bushing around tubing and insert bushing into hole in
electrical compartment.
6. Connect wires to terminal blocks in accordance with wiring diagram provided with heater. If there is excess tubing
and/or wiring, trim before making connections.
7. Before unit is operated, replace all door panels and fasten all latches.
Piping Connections
⚠ CAUTION ⚠
On outdoor systems, the water reservoir must be drained and the pump motor must be turned off
when the outside temperature falls below 32°F. The pump must never be operated without water
in the reservoir.
Float Valve Connection
•In a cooling module with pump and float controls, a float valve (see Figure 10) maintains the appropriate water
level in the reservoir.
•Connect the fresh water supply to the float valve inlet using a field-supplied 1/4-inch diameter tubing with compression
nut and tubing ferrule. Place the nut and ferrule over the tubing and insert the tubing into the float valve stem.
Tighten the nut securely.
Figure 10. Float Valve Connection
COMPRESSION NUT AND
TUBING FERRULE
1/4-INCH TUBING
CABINET SIDE PANEL
FLOAT VALVE ROD

10 OPT-AS3,4,5,8 (07-22) 160202-B
INSTALLATION—CONTINUED
Piping Connections—Continued
Optional Fill and Drain Kit Installation
An optional automatic fill and drain kit will automatically release supply water to the cooling module when a call
for cooling is made and will drain all water from the reservoir when the cooling switch is deactivated or a cooling
thermostat is satisfied. Install the optional fill and drain kit as follows:
NOTE: Follow instructions included in the valve packages for connecting valves to the water line
only. The remainder of the installation instructions with the valves do not apply to this type of ap-
plication.
1. Connect water line (see Figure 11):
a. For supply (three-way valve) connections, connect water supply line to B (normally closed), connect water
drain line to A (normally open), and connect middle outlet to supply water to cooling module reservoir.
b. For drain (two-way valve) connections, connect drain pipe from reservoir to A and connect outlet side to B and
connect into drain lines from cooling reservoir and supply valve.
2. Connect wiring (requires black and white 14-gauge wire):
⚠ WARNING ⚠
Risk of electrical shock. Disconnect the power.
NOTE: Refer to the wiring diagram provided with the furnace. If the kit is not ordered with the
system, connections will not be shown on the diagram.Terminal connections are specific to each
system. Contact the factory for terminal connections. Be prepared to provide all model information.
a. Run field-supplied black wire from electrical compartment (terminal on wiring diagram) of evaporative cooling
module and connect to black wire on three-way and two-way valves.
b. Run field-supplied white wire from electrical compartment (terminal on wiring diagram) of evaporative cooling
module and connect to white wire on three-way and two-way valves.
Figure 11. Fill and Drain Kit Connections

11
OPT-AS3,4,5,8 (07-22) 160202-B
AquaSaver Timed Metering Control System Connections
•If the cooling module is equipped with a timed metering system, connect a 1/2-inch water line to the fitting on the
side of the cooling module.
•Due to various water pressures and installation conditions, the water supply line may bang abruptly when the solenoid
valve in the AquaSaver system closes. This banging can be minimized by installing a water hammer arrestor in
the supply line. If installing an optional water hammer arrestor, select an indoor (>32°F) location, either horizontal
or vertical, in line with and as close to the solenoid valve as possible. Follow the manufacturer’s instructions to
install and maintain the water hammer arrestor.
•A freeze protection kit is available for a module with a timed control system. It includes a two-way valve and is
shipped separately for field-installation.
Shutoff and Drain Connections
•To allow the water supply to be turned on and off, a manual water shutoff should be installed upstream of the inlet
at a convenient non-freezing location. If necessary, install a bleed line between the manual valve and the cooling
module inlet to allow drainage of the line between the shutoff valve and the cooling module.
•All cooling modules are equipped with an overflow and drain fitting. The fittings are in the cabinet bottom and come
complete with a locknut and a sealing gasket. Check these fittings for tightness before installing the overflow and
drain piping. The drain and overflow fitting will accommodate a 3/4-inch garden hose thread and is tapped with a
1/2-inch female pipe thread for iron pipe.
Bleed Line Connection
NOTE: Adequate bleed-off is important to maintaining an efficiently-operating evaporative cooling
system. Discharging a quantity of water by bleed-off will limit undesirable minerals in the water
from being circulated through the cooling module. Mineral buildup occurs because evaporation
releases only pure water vapor, which causes the concentration of contaminants in the water to
increase as the evaporation process continues.The minerals accumulate on the media, in the water
lines, on the pump, and in the reservoir.
•Install a bleed line on cooling modules equipped with pump and float controls only—does not apply to modules
with AquaSaver timed controls.
•Thread the 1/4 ID × 1/2 NPT nylon bleed line fitting (shipped in the cooling module’s bottom pan) into the female
adapter on the distribution pipe. The hose barb protrudes from the air inlet side of the module cabinet (see Figure
12). Connect a 1/4 ID hose to the barb and run to the nearest drain.
Figure 12. Bleed Line Connection
BLEED LINE
CONNECTION

12 OPT-AS3,4,5,8 (07-22) 160202-B
MAINTENANCE
Filling and Adjusting Water Level in Reservoir
Fill and adjust the reservoir water level on cooling modules equipped with pump and float controls only—does not
apply to modules with AquaSaver timed controls.
1. Turn on water supply and check for good flow.
2. When float valve shuts OFF water supply, measure water depth—should be approximately 3 inches.
3. If it is necessary to adjust float valve to obtain proper water level or to free float valve from obstructions, carefully
bend float valve rod (see Figure 10) upward to raise water level or downward to lower water level.
4. While reservoir is full, check for any water leaks. Reservoir was tested, but if any small leaks are present, drain
reservoir and apply waterproof silicone sealer around corners and welds.
Adjusting Water Flow
⚠ DANGER ⚠
Adjust the ball valve only when power is disconnected from the unit. Failure to do so can cause
electrical shock, personal injury, or death.
⚠ CAUTION ⚠
Do not flood the media pads with extreme quantities of water for long periods as this will cause
premature breakdown of the media. An even flow from top to bottom of the media with the least
amount of water is all that is required to assure maximum efficiency and media life span. More
water does not provide more evaporation or more cooling. Proper water flow over the evaporative
cooling media is critical to extend the life and maintain the efficiency of the pads.
Adjust Water Flow with Float and Pump Control System
1. Adjust ball valve (see Figure 13) located in water line from pump to sprinkler pipe inlet to allow water flow to
completely dampen media pads from top to bottom.
2. Operate unit and observe water flow. After 15 minutes with blower in operation, water should have completely
dampened pads but should not be flowing off entering side of media.
3. If water is flowing off entering side of media, turn system off, disconnect power, and adjust ball valve to reduce
entering water flow.
Figure 13. Ball Valve
BALL
VALVE

13
OPT-AS3,4,5,8 (07-22) 160202-B
Adjust Water Flow with AquaSaver Timed Metering Control System
NOTE: Water flow and pad wetting time should be adjusted at maximum airflow and wet bulb de-
pression to ensure complete wetting of the media at the extreme operating conditions.
In addition to adjusting water flow, the timing of the water ON/OFF cycle can be adjusted. Adjustments are correct
when:
•Water rises from holes in sprinkler pipe consistently along entire pipe length
•Media pads wet evenly after few ON cycles (no dry spots or dry streaks)
•Slight amount of excess water collects at drain at completion of ON cycle
1. Adjust AquaSaver water flow:
a. Adjust ball valve (see Figure 13) to allow water flow to rise above distribution (sprinkler) pipe shown in Figure 14.
b. Adjust rise from distribution (sprinkler) pipe in accordance with Table 3.
Table 3. Water Rise from Distribution (Sprinkler) Pipe
Pad Height Dimension A*
Inches (mm)
24 (610 mm) 1/8–1/2 (3–13 mm)
48 (1219 mm) 1/4–1/2 (6–13 mm)
*See Figure 14.
Figure 14. Distribution (Sprinkler) Pipe
2. Adjust AquaSaver timer (see Figure 15):
NOTE: At any given temperature, the media pads should completely wet from top to bottom dur-
ing the ON cycle.The AquaSaver microprocessor has three preset timing settings based on media
size. The appropriate setting is selected by changing the position of the suitcase jumper at J2 on
the microprocessor. On units manufactured before 2003 the AquaSaver timed cycle was controlled
by a mechanical timer. Turn the adjustment screw clockwise to increase the ON time or counter-
clockwise to decrease the ON time. One complete turn will adjust the cycle by 12 to 14 seconds.
a. Remove cover to check setting.
b. If jumper is at correct location, replace cover. If jumper needs to be adjusted, move it to correct setting—setting
will go into effect when power is restored.
c. Check ON timing—media pads should be wet from top to bottom during ON cycle.
d. If preset timing is not suitable for application, follow instructions provided with microprocessor to change
calibration of ON and/or OFF cycle.
MEDIA HEIGHT
12–36 INCHES
(305–914 mm)
37–48 INCHES
(940–1219 mm)
49–72 INCHES
(1245–1829 mm)
Figure 15. AquaSaver Microprocessor
3. Check reservoir for any water leaks. Reservoir was tested, but if any small leaks are present, drain reservoir and
apply waterproof silicone sealer around corners and welds.

14 OPT-AS3,4,5,8 (07-22) 160202-B
MAINTENANCE—CONTINUED
Media Maintenance
•Over time, excessive amounts of mineral deposits will begin to build up on the media. Annually, scale and dirt
should be washed off the entering surface of the media.
•Remove the pad retainers and screen. Clean the media using a garden hose, mild soap, and a soft bristled brush.
•When the media becomes too clogged with mineral deposits and dirt that it cannot be cleaned, the pads should
be replaced (refer to Installation/Replacement of Media Pads section). The average pad life is approximately
three cooling seasons. Select the correct replacement part numbers (refer to Table 4) and order replacement
media pads through your Distributor.
Table 4. Evaporative Cooling Module Media Pads
Size (Inches) Cellulose Glass Fiber Quantity
PN
48 × 12 × 6 107190 107199 4
48 × 12 × 12 107194 107201
48 × 8-5/8 × 6 107191 107200 1
48 × 8-5/8 × 12 107195 107202
Flushing Water Lines
•Annually, the water supply line, the PVC water distribution pipe, and the bleed line should be flushed of debris
and contaminants.
•Remove (and replace) the media pads in accordance with the Installation/Replacement of Media Pads section.
Remove the water feed line from the downstream side of the ball valve and unscrew the water bleed line barbed
hose fitting.
•Force a fresh water supply up through the water inlet hose and thoroughly flush the distribution pipe.
Water Pump Maintenance
⚠ DANGER ⚠
• Disconnect all power to the unit before doing any maintenance. Failure to do so may cause
electrical shock, personal injury, or death.
• Do not expose pump motor or any part of the electrical box to water. Evaporative cooling pump
is NOT submersible.
Annually, the water pump and inlet basket screen should be removed, disassembled, and cleaned as follows:
1. Disconnect power supply to unit.
2. Remove junction box door and disconnect two power supply wires from terminal block inside junction box (see
Figure 16).
3. Disconnect water feed line hose from upstream side of ball valve.
4. Remove four sheet metal screws that secure junction box to cooling module and remove junction box/pump/float
switch assembly (see Figure 16).
5. Dislodge inlet basket screen from pump and clean any buildup of debris and dirt.
6. Carefully remove basket and snap-on base cover plate from bottom of pump and wash all deposits from inside
pump using mild soap solution.
7. Remove all debris from impeller.
8. Reassemble pump, replacing parts in exact reverse order and ensuring that everything is returned to its proper
position.

15
OPT-AS3,4,5,8 (07-22) 160202-B
Figure 16. Water Pump
TROUBLESHOOTING
⚠ DANGER ⚠
Disconnect the power before servicing the cooling module. Failure to do so can cause electrical
shock, personal injury, or death.
Float
Switch
Pump
Motor
Pump
Junction Box
NOTE: Only 208V unit has
transformer in
junction box.
Table 5. Troubleshooting
Symptom Probable Cause Remedy
A. Pump doesn’t
run (pump and
float system)—unit
calling for cooling
and reservoir
1. Electrical connections (low voltage) Verify all electrical connections
Verify correct voltage at pump terminal H
2. Electric float switch Check position of actuators on electric float switch
3. Dirty pump Clean pump (refer to Water Pump Maintenance section)
4. Defective pump Replace pump
B. Required water
level (3 inches) not
being maintained
(pump and float
control system)
1. Float valve Adjust float valve (refer to Filling and Adjusting Water Level in
Reservoir section)
2. Drain and fill valves not working properly Check valves for proper operation
3. Incorrect overflow pipe nipple Replace pipe nipple with 3-1/2-inch nipple
4. Drain leaking Tighten drain fittings
C. Water running
off media pads
1. Excessive water flow Adjust ball valve in distribution line (refer to Adjusting Water Flow
section)
2. Dirty media pads Clean or replace media pads (refer to Installation/Replacement of
Media Pads section)
D. Water not
distributing evenly
1. Distribution line clogged Flush distribution line (refer to Flushing Water Lines section)
2. Holes in distribution line turned Check position of distribution line—holes should be spraying upward
toward diffuser
Adjust position of line if not positioned with holes toward top
3. Pump not running on correct voltage Check voltage at pump terminal in cooling module junction box
E. Media pads
becoming clogged
and discolored
(scale and salt
deposits) quickly
1. Bleed line clogged or inadequate bleed-off
(pump and float control system)
Clean bleed line (refer to Flushing Water Lines section)
Uniform buildup of minerals on entering air face of media indicates
insufficient bleed-off—increase rate until mineral deposits dissipate
2. Excessive water flow Adjust ball valve in distribution line (refer to Adjusting Water Flow
section)
F. Water blow-
off from media
pads or water
being pulled from
reservoir
1. Media pads installed incorrectly Install media pads correctly (refer to Installation/Replacement of
Media Pads section)
2. Requires moisture elimination pad Install moisture elimination (over 600 FPM) pad (refer to Installation/
Replacement of Media Pads section)
3. Water level not 3 inches
(pump and float control system)
Refer to probable causes and remedies for symptom B above

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.
OPT-AS3,4,5,8 (07-22) 160202-B