Installed by: _________________________________ Installer Phone: _______________________ Date Installed: _______________
ON/ OFF button
used to turn
dehumidifier on
and off
MODE button
used for optional
ventilation feature
Up/ Down
buttons used to
change humidity
setting
Dehumidifer Control
InletFilter Access
Door
Outlet
DrainPower
Switch
90-2309
CRAWL SPACE DEHUMIDIFICATION
The Aprilaire® dehumidifier controls the humidity level in your crawl space. A powerful blower inside the dehumidifier draws air into the
cabinet, filters the air and removes moisture, then discharges the dry air into the crawl space. Inside the cabinet, a sealed refrigeration system
removes moisture by moving the air through a series of tubes and fins that are kept colder than the dew point of the incoming air. The dew
point is the temperature at which moisture in the air will condense, much like what occurs on the outside of a cold glass on a hot summer
day. The condensed moisture drips into the dehumidifier drain pan to a drain tube routed to the nearest floor drain or condensate pump. After
the moisture is removed, the air moves through a second coil where it is reheated before being sent back into the space. The air leaving the
dehumidifier will be warmer and drier than the air entering the dehumidifier.
Page 2
SETTING THE DESIRED HUMIDITY LEVEL
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The dehumidifier on-board control will display the humidity setting when not running, and displays
the measured humidity when running.
The UP and DOWN arrow buttons allow the humidity level to be set from 40% to 80% relative
humidity. Use the ON/OFF button to turn the dehumidifier ON or OFF.
Set the control at 59%RH when first installed. Allow the dehumidifier to run until it reaches the
setting before deciding if you want to change the setting.
• If you prefer the air to be more dry, decrease the humidity setting.
• If you prefer the air to be less dry, increase the humidity setting.
HOW DOES THE DEHUMIDIFIER WORK?
Once per hour the dehumidifier will measure the humidity level of the air and compare it to the humidity setting. If the humidity in your crawl
space is higher than the setting, the dehumidifier will dehumidify the air until the humidity level drops 3%RH below the setting.
When the dehumidifier turns on, the blower circulates the air for 3 minutes before measuring the
humidity level of the air. The on-board control will display AIR SAMPLING, along with the measured
humidity on the control screen.
If the humidity of the air is higher than the setting, the compressor turns on and the control will display
DEHUMIDIFYING, along with the measured humidity on the control screen.
90-1853
EXTERNAL CONTROL OPTIONS
Your Aprilaire dehumidifier can be controlled with an optional Aprilaire Model 76 Control. Install the
Model 76 in your living space and make changes to the dehumidifier setting or find out what the humidity
level is in the crawl space from the comfort and convenience of the living space. Refer to the Model 76
Owner’s Manual for operating instructions. Aprilaire owner’s manuals are available at www.aprilaire.com.
If you are interested in having an external control installed, please consult your installing contractor.
2
Model 76 Control
Page 3
MAINTENANCE
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90-1854
CLEAN OR REPLACE THE AIR FILTER
After initial installation the air filter should be checked and cleaned every 6 months. The CLEAN
FILTER service reminder will display on the on-board control screen every 6 months. To clear the
service message, press the UP and DOWN arrows simultaneously for 3 seconds.
Filter Cleaning Procedure
1. Turn the ON/OFF switch OFF.
2. Remove the filter access door from either side of the dehumidifier.
3. Slide the filter out of the dehumidifier.
4. Flush the filter with warm water and a mild detergent solution.
5. Shake off the excess water from the filter.
6. Replace the filter, making sure the filter is secured in both the top and bottom filter rails.
7. Replace the filter access door.
8. Turn the ON/OFF switch ON.
9. Press the UP and DOWN buttons simultaneously for 3 seconds to clear the service message.
CHECK THE DRAIN
The drain should be checked annually to ensure there are no blockages or air lock in the drain system. If the unit is not draining properly, have it
checked by a qualified service professional.
CAUTION
Do not use spray solvents or cleaners on or near the inlet side of the dehumidifier.
If desired, apply cleaner to a cloth and use to clean the cabinet.
TROUBLESHOOTING
DIAGNOSTIC CODES
The on-board control will display a diagnostic code if an error should occur and service is required.
Contact your installing contractor if E1– E7 or E9 is displayed on the on-board control screen. E8 will be
displayed if the incoming air temperature is below 50°F, above 104°F, or when the dew point is below
40°F. When the incoming air is within the acceptable range, the dehumidifier will resume operation.
If the error persists, contact your installing contractor.
3
Page 4
LIMITED WARRANTY
Your Research Products Corporation Aprilaire® Dehumidifier is expressly warranted for five (5) years from date of installation to be free from defects in materials or workmanship.
Research Products Corporation’s exclusive obligation under this warranty shall be to supply, without charge, a replacement for any component which is found to be defective within such
five (5) year period and which is returned not later than thirty (30) days after said five (5) year period by you to either your original supplier or to Research Products Corporation, Madison,
Wisconsin 53701, together with the model number and installation date of the dehumidifier.
THIS WARRANTY SHALL NOT OBLIGATE RESEARCH PRODUCTS CORPORATION FOR ANY LABOR COSTS AND SHALL NOT APPLY TO DEFECTS IN WORKMANSHIP OR MATERIALS
FURNISHED BY YOUR INSTALLER AS CONTRASTED TO DEFECTS IN THE DEHUMIDIFIER ITSELF.
IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE SHALL BE LIMITED IN DURATION TO THE AFORESAID FIVE YEAR PERIOD. RESEARCH
PRODUCTS CORPORATION’S LIABILITY FOR INCIDENTAL OR CONSEQUENTIAL DAMAGES, OTHER THAN DAMAGES FOR PERSONAL INJURIES, RESULTING FROM ANY BREACH OF THE
AFORESAID IMPLIED WARRANTIES OR THE ABOVE LIMITED WARRANTY IS EXPRESSLY EXCLUDED. THIS LIMITED WARRANTY IS VOID IF DEFECT(S) RESULT FROM FAILURE TO HAVE
THIS UNIT INSTALLED BY A QUALIFIED HEATING AND AIR CONDITIONING CONTRACTOR. IF THE LIMITED WARRANTY IS VOID DUE TO FAILURE TO USE A QUALIFIED CONTRACTOR,
ALL DISCLAIMERS OF IMPLIED WARRANTIES SHALL BE EFFECTIVE UPON INSTALLATION.
Some states do not allow limitations on how long an implied warranty lasts or the exclusion or limitation of incidental or consequential damages so the above exclusion or limitations
may not apply to you.
This warranty gives you specific legal rights and you may also have other rights which vary from state to state.
WARRANTY REGISTRATION
Visit us on-line at www.aprilaire.com to register your Aprilaire product. If you do not have on-line access, please mail a postcard with your
name, address, phone number, email address, product purchased, model number, date of purchase and dealer name and address to:
Research Products Corporation, P.O. Box 1467, Madison, WI 53701
Your Warranty Registration information will not be sold or shared outside of this company.
1. 120 Volts may cause serious injury from electric shock. Disconnect electrical power before starting installation or servicing.
Leave power disconnected until installation/service is completed.
2. Sharp edges may cause serious injury from cuts. Use care when cutting plenum openings and handling duct work.
3. Dropping may cause personal injury or equipment damage. Handle with care and follow installation instructions.
CAUTION
1. Read all instructions before beginning installation.
2. Improper installation may cause property damage or injury. Installation, service, and maintenance must be performed by a
qualified service technician.
3. Do not use in pool applications. Pool chemicals can damage the dehumidifier.
4. Do not use solvents or cleaners on or near the circuit board. Chemicals can damage circuit board components.
5. Wait 24 hours before running the unit if it was not shipped or stored in the upright position
shipping support bracket and remove the strap and shipping bracket.
See Figure 1.
PACKAGING CONTENT
1. Dehumidifier
2. Inlet/Outlet Collars
FIGURE 1 – Remove Shipping Bracket
3. Literature
a. Installation Instructions
b. Owner’s Manual
4. Parts Bag
a. #10 x 1/2 Screws (9)
b. Threaded Barbed Fitting for Drain
Connections
c. Torx Bit
5. 10 foot, 3/4” Drain Tube
DUCT COLLARS
Use the screws in the parts bag to attach the duct
collars to the inlet and outlet of the dehumidifier.
See Figure 2.
PLASTIC
STRAP
90-2302
FIGURE 2 – Install Duct Collars
DUCT
2
90-2308
Page 7
LOCATION CONSIDERATIONS
FOR PROPER
AIR FLOW
2.00" MAX
3/4" FNPT DRAIN
• Allow sufficient clearance for filter removal and
to prevent airflow obstruction
• Electrical service access will require the removal
of the side panel shown. Allow sufficient space
for service on this side of the unit.
FIGURE 3 – Filter Access Clearance
ELECTRICAL
SERVICE ACCESS
THIS SIDE
8 FT. POWER CORD
90-2304
TOP VIEW
FILTER
MINIMUM
13"
CLEARANCE
FOR FILTER
MINIMUM
CLEARANCE
6"
INSTALLATION
LEVELING
The feet can be adjusted to level the unit, and
if required, to accommodate drain fittings and a
secondary condensate pan. Leveling is required
to ensure proper drainage from the dehumidifier.
See Figure 4.
DUCTWORK INSTALLATION
Adding 5-10 feet of insulated ductwork to the inlet and outlet of the dehumidifier will ensure dehumidified air is circulated throughout the crawl
space and will reduce the noise level of the dehumidifier. Point the inlet and outlet ducts in opposite directions to minimize recirculation of
dehumidified air.
FIGURE 4 – Level the Unit
0.38" MIN
90-2305
• Maximum recommended total duct length is 100 feet.
• To avoid pulling in dirt and other particles, do not lay intake duct on the floor of the crawl space.
NOTE: This dehumidifier is designed for crawl space and stand-alone applications only. Do not duct to HVAC system.
3
Page 8
INSTALLATION (CONTINUED)
3/4" CLEAR PVC TUBING
(INCLUDED)
CONDENSATE PUMP
FLOAT SWITCH
WIRE
3/4" MNPT x 3/4"
BARB FITTING
(INCLUDED)
DRAIN TUBING AND CONDENSATE PUMP
INSTALLATION
The drain outlet on the dehumidifier can be plumbed
directly to a condensate pump (see Figure 5) using
the provided 3/4” MNPT x 3/4” hose barb fitting
and 3/4” clear PVC tubing. Always maintain a
constant downward slope from the dehumidifier to
the condensate pump. NOTE: PTFE thread seal tape
is recommended for the threaded connection. Hand tighten only. The 4856 condensate pump is capable
of lifting water up to 22 feet. The dehumidifier can
be elevated (while remaining level) to increase
downward slope for proper draining. Wire the float
switch terminals to the normally closed contacts on
the condensate pump (see Figure 6).
FIGURE 5 – Drain and Condensate Pump Installation
8" DIAMETER
INSULATED
FLEX DUCT
FIGURE 6 – Float Switch Wiring
DH DH
FLOAT
Switch
LOW VOLTAGE NORMALLY CLOSED
CONTACTS ON CONDENSATE PUMP
90-2306
90-1857
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Page 9
MODEL 76 – CRAWL SPACE CONTROL AND WIRING
NOTE: Use 18-22 AWG wire for control wiring.
Used as a crawl space control (or remote control),
the Model 76 is mounted in the living space while
the dehumidifier is located in the crawl space.
When the dehumidifier is powered, the display on
the dehumidifier control will show “REMOTE” to
indicate that a remote control is being used. The
RH shown on the Model 76 is the RH measured at
the dehumidifier.
NOTE: Air Cycling is not an option when using a
Model 76 as a remote control.
FIGURE 7 – Model 76 Crawl Space/Sealed Attic (Remote) Wiring
+ -ABODT
SensorRemote
Gh Rf Cf Gs YW
HVAC EQUIP.
MODEL 76 CONTROL
C/R/+
DH
DH
A
B
90-1860
AIR CYCLING
The dehumidifier has an optional ventilation feature that can be used to circulate air through the dehumidifier, to promote uniform humidity
levels throughout the space. When this feature is enabled, the dehumidifier fan can be set to run from 0 minutes (no air cycling) to 60 minutes
(continuous) per hour. See VENTILATION / AIR CYCLING in the SYSTEM SET-UP, CHECK & START-UP section on page 7.
NOTE: The on-board control must be used when Air Cycling.
5
Page 10
SYSTEM SET-UP, CHECK & START-UP
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90-1854
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90-1854
If using a Model 76 Remote Control and/or the Air Cycling feature,
proceed to Step 1 below. If not using either feature, proceed to
SYSTEM CHECK on page 7.
1. Check all wiring.
2. Make sure the wire access cover has been snapped back onto the
on-board control.
3. Plug unit in and turn power switch to ON. The power switch is
located on the dehumidifier outlet next to the power cord.
4. The on-board control screen should display OFF.
NOTE: If the display backlight is not on, the first button press (any
button) will only turn on the backlight. Press the button a second time
to achieve function.
5. Hold the MODE button on the on-board control for 3 seconds to
enter the Installer Set-up Menu.
6. Navigate through the following screens to set up the dehumidifier
for the installed application.
REMOTE CONTROL – CRAWL SPACE
If not installing in a crawl space
with Model 76 remote control,
press MODE to go to VENT screen
selections
If installing in a crawl space with
remote control, Enable and press
MODE. The installer set-up is
complete, proceed to SYSTEM
CHECK on page 7.
NOTE: Air Cycling is not an
option when Remote is enabled.
Use the UP or DOWN arrows to select items and use MODE to
switch to the next set-up option. To exit installer set-up, all options
must be scrolled through using the MODE button.
7. After the installer set up options have been completed, DONE will
blink for 3 seconds and the control will return to the OFF screen.
6
Page 11
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SYSTEM SET-UP, CHECK & START-UP (CONTINUED)
90-1854
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90-1854
90-1854
VENTILATION / AIR CYCLING
If not using the dehumidifier to
periodically cycle air in the crawl
space, press MODE to go to ZONE
screen selections.
If using the dehumidifier for air
cycling, Enable and press MODE.
Press MODE at the VENT TIMED
screen to go to ventilation time
selection screen.
Press the UP or DOWN arrows
to adjust the ventilation time
per hour from 0 to 60 minutes.
After selecting time, press
MODE. Press MODE through the
ZONE, EXTERNAL, DEH w/AC,
and RH offset screens. DONE
will be displayed on the screen
and Installer Set-up is complete.
Proceed to SYSTEM CHECK. on
page 7.
SYSTEM CHECK
Press and hold the ON/OFF button
and MODE buttons for 3 seconds.
The measured humidity, AIR
SAMPLING and TEST will show on
the display.
After three (3) minutes the
dehumidifier compressor will
turn on and DEHUMIDIFYING will
replace AIR SAMPLING on the
control screen.
After one minute of compressor
operation, all outputs will turn off
and DONE will blink for 3 seconds
and then return to the OFF screen.
7
Page 12
SYSTEM SET-UP, CHECK & START-UP (CONTINUED)
CRAWL SPACE USING THE DEHUMIDIFIER CONTROL
1. Press the ON/OFF button to turn the dehumidifier control ON. The display will show the current setting, and the dehumidifier blower and HVAC
blower (if wired to the HVAC system) will turn on to start sampling the air.
The setting will be replaced by the measured humidity and “AIR SAMPLING” will show on the display.
2. Use the UP or DOWN button to adjust the humidity setting as desired. The recommended initial setting is 59%.
3. After three (3) minutes of sampling, the measured humidity will be compared to the setting:
a. If the humidity is above the setting, the dehumidifier compressor turns on and “AIR SAMPLING” will be replaced by “DEHUMIDIFYING”. The
compressor remains on until the measured humidity falls 3% RH below the setting.
b. If the measured humidity is below the setting, the blowers turn off and the display returns to showing the RH setting.
4. The dehumidifier will sample again every 60 minutes, or at any time if the humidity setting is lowered.
CRAWL SPACE REMOTE CONTROL USING MODEL 76
1. Press the ON/OFF button to turn the dehumidifier control ON. “REMOTE” will show on the display to indicate that a remote control is wired to
the dehumidifier.
2. At the Model 76, press the ON button; the Model 76 will display the RH measured at the dehumidifier, and the dehumidifier blower will turn
on to start sampling the air.
3. Use the UP or DOWN button on the Model 76 to adjust the dryness level as desired. The dryness levels are from 1 to 7, with 1 being least dry
and 7 being most dry; the recommended initial setting is 3.
4. After three (3) minutes of sampling, the measured humidity will be compared to the setting:
a. If the humidity is above the setting, the dehumidifier compressor turns on and “ON” flashes on the Model 76 display.
b. If the measured humidity is below the setting, the dehumidifier blower turns off.
5. The dehumidifier will sample again every 60 minutes, or at any time if the dryness level is increased.
START-UP
Your dehumidifier is equipped with two features that protect against unwanted energy consumption. Defrost is a normal operating mode that
helps to prevent significant ice formation on the refrigeration system coil. The dehumidifier display will show “DEFROSTING” when operating
in this mode. This mode can occur when there is not enough air moving through the dehumidifier or if the temperature and/or humidity of
the incoming air is too low. The second protection feature is the E8 code. E8 on the dehumidifier display indicates that the air entering the
dehumidifier is below 50°F or above 104°F, or the dew point of the incoming air is below 40°F. There would be a significant reduction in
dehumidifier efficiency if the dehumidifier operated outside of these conditions. Low dew point conditions can be seen in some basements
or crawl spaces and usually occur in the Winter and Spring months. The dehumidifier continues to monitor the incoming air and when the
conditions are within the operating range, E8 will be removed from the display and dehumidification will begin as needed.
8
Page 13
TROUBLESHOOTING
Technical Support is available Monday through Friday, 7:00 a.m. to 5:00 p.m. CST, at (800) 334-6011. Use the guides on the following pages to
identify and correct system faults. Contact Technical Support before replacing the unit or any components and for additional troubleshooting.
DIAGNOSTIC CODES
When an error occurs, the Diagnostic Code along with SERVICE REQUIRED
will be displayed on the control screen.
90-1854
TABLE 1 – Diagnostic Codes
Diagnostic
CodeFailure ModeActionReset
E1Internal Humidity or
Temperature Sensor
Open or Shorted
E2High Refrigeration
Pressure
E3Model 76
Remote Control
Communication Loss
E4Insufficient Capacity1. Check the frost sensor connection at the power board. Terminal should be fully seated on the
1. Check the connection between the sensor board and control board.
2. If connection okay, replace sensor board, Part No. 5460.
1. Verify that the fan works and there is no blocked or restricted ductwork.
2. If the fault persists, call Technical Support.
1. Check connections between Model 76 and dehumidifier control board. Terminals should be fully
inserted and secured in the control board and Model 76 control terminals.
2. If connections are correct and secure, turn off the dehumidifier and remove the Model 76.
Use a short section of 4-wire cable to reconnect the Model 76 to the control board. Turn the
dehumidifier back on and increase the dryness level setting on the Model 76. If the dehumidifier
turns on, the problem is with the wiring between the dehumidifier and control.
3. If the dehumidifier does not turn on, call Technical Support.
power board pins.
2. Remove the side access panel and verify that the sensor is secured to the suction line.
3. If the sensor is connected and secured to the refrigeration line proceed to the next step.
4. Reset the fault by cycling power to the dehumidifier.
5. Turn the humidity setting down (below room/home humidity level) to make a dehumidification call.
6. Allow the fan and compressor to run for approximately 10-15 minutes and then enter diagnostic
test mode by simultaneously pressing the UP ARROW and MODE buttons for 3 seconds. The
LCD will display the temperature measured by the internal sensor while also displaying AIR
SAMPLING and ON, the humidity measured by the internal sensor while also displaying %RH
and ON, and the frost sensor temperature while also displaying ON. Scroll through these values
and by using the UP/DOWN arrow buttons.
7. Record values and call Technical Support.
Cycle Power
Cycle Power
Self-Correcting
Cycle Power
E5High Temperature
Thermistor Failure
E6Low Temperature
Thermistor Failure
E7Float Switch Open1. Empty the condensate pan.
E8Inlet Air Temperature
Out of Range
50°F – 104°F or dew
point below 40°F
1. Check the high temperature sensor connection at the power board. Terminal should be fully
seated on the power board pins.
2. Remove the side access panel and verify the sensor is not damaged and connected to the
refrigeration line coming from the compressor.
3. If the sensor is connected and secured to the refrigeration line, contact Technical Support.
1. Check the low temperature sensor connection at the power board.
2. Remove the side access panel and verify the sensor is not damaged and connected to the
suction line.
3. If the sensor is connected and secured to the refrigeration line, contact Technical Support.
2. Check the float switch connection at the control board.
3. If not using a float switch, verify jumper is between float switch terminals on dehumidifier
control board.
4. If the problem persists, replace the float switch.
1. Verify all ductwork is properly sealed.
2. If no signs of leak points, contact Technical Support.
Cycle Power
Cycle Power
Self-Correcting
Self-Correcting
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Page 14
TROUBLESHOOTING (CONTINUED)
TABLE 2 – Troubleshooting Guide
SymptomPossible ReasonTroubleshooting Procedure
Dehumidifier does not
turn on/run.
Dehumidifier blower is
running but with little or
no airflow.
Dehumidifier blower is
running but compressor
is not.
Dehumidifier is not
draining properly.
Dehumidifier is
producing hot air.
No power to unit.• Check that the dehumidifier is plugged in.
• Check that the power switch is turned ON.
• Check that the control is turned ON.
• Check that the circuit breaker has not tripped.
Pressure drop across
dehumidifier is higher
than 0.4”w.c.
Float switch open.• If float switch installed, check connections at control board and empty condensate pan.
Coil frosting.• Lack of or reduced airflow. Check dehumidifier air filter and wash or replace.
Inlet air temperature is
outside of the 50°F –
104°F range or the dew
point is below 40°F and
there is a demand for
dehumidification.
Drain line blocked or unit
not level.
Normal function.• Air is reheated across the condenser coil, resulting in a temperature rise between inlet and outlet,
• Check dehumidifier air filter and wash or replace.
• Check for blocked duct work and clear.
• If no float switch installed check that the jumper is installed at the float switch terminals on the
control board.
• Check for blocked duct work.
• Inlet air conditions below 60°F. Increase the humidity setting.
• Verify all ductwork is properly sealed.
• Verify that the unit is level.
• Check the drain line blockages and for a continuous downward slope.