AprilAire Dehumidifier

Introduction to Low-Profile Dehumidification

The AprilAire Dehumidifier controls the humidity level in your crawl space or other small spaces. A powerful blower draws air into the cabinet, where it is filtered before moisture is removed. A sealed refrigeration system removes moisture by moving the air through a series of tubes and fins kept colder than the dew point of the incoming air. The dew point is the temperature at which moisture condenses, similar to condensation on a cold glass. Condensed moisture drips into the drain pan and then to a floor drain or condensate pump. After moisture removal, the air is reheated before being returned to the space, making it warmer and drier than when it entered.

To reduce indoor humidity, close windows and doors when outdoor humidity is high, and dry clothes outside. For humidity from cooking or showers, direct exhaust from kitchen and bath fans is recommended. This dehumidifier is not designed to prevent window condensation in winter; use ventilation for that purpose.

Specifications

NOTE: Rated capacity and current draw measured at 80°F/60% RH inlet conditions at 0.0 external static pressure.

Safety Instructions

WARNING

ATTENTION INSTALLER:

• Read this manual before installing. Improper installation or maintenance may cause property damage or injury. Installation, service, and maintenance should be performed by a trained service technician. Comply with all local, state, and federal codes.
• Follow all safety precautions.
• Dispose of properly according to federal or local regulations.

ELECTRIC SHOCK HAZARD:

• 120 volts can cause serious injury. Disconnect electrical power before installation or servicing. Leave power disconnected until installation/service is completed.
• To reduce electrical shock risk, this equipment has a grounding-type (three-prong) plug. Use only in a grounding-type power outlet. Contact a qualified person to install the proper outlet if needed. Do not alter the plug.
• Position the product so the power cord can be plugged into an electrical outlet without an extension cord.

RISK OF FIRE OR EXPLOSION:

• Flammable refrigerant is used. Do not puncture refrigerant tubing.
• Store in a well-ventilated room away from continuously operating flames or other potential ignition sources.
• Auxiliary devices that could be ignition sources shall not be installed in ductwork.

CAUTION

• SHARP EDGES MAY CAUSE INJURY FROM CUTS. Use care when cutting plenum openings and handling ductwork. Always wear safety glasses/goggles and gloves.
• This unit is not intended for use by persons with reduced physical, sensory, or mental capabilities, or lack of experience/knowledge, unless supervised or instructed by a responsible person.
• Supervise children to ensure they do not play with the unit.
• Replace damaged supply cords with a special cord or assembly from the manufacturer or service agent.
• Never operate electrical equipment in standing water.
• Do not insert fingers or objects through safety grills.
• Do not sit or stand on the unit, or use it as a table or shelf.
• The unit is designed for indoor installation only.
• Always place in a well-ventilated area to prevent refrigerant accumulation in case of a leak or system failure.

NOTICE

EQUIPMENT DAMAGE MAY OCCUR IF INSTALLATION INSTRUCTIONS ARE NOT FOLLOWED.

• Do not use in pool applications; pool chemicals can damage the dehumidifier.
• Do not use solvents or cleaners on or near the display and circuit board, as chemicals can cause damage.
• Wait 24 hours before running the unit if it was not shipped or stored upright.
• Do not use dehumidification to prevent window condensation in winter. Use ventilation to lower indoor humidity in winter.

ELECTRICAL INTERFERENCE CAN CAUSE OUTDOOR TEMPERATURE SENSOR INACCURACY.

• Do not run the Outdoor Temperature Sensor alongside wires carrying high voltage (120 VAC or higher).
• Do not run Outdoor Temperature Sensor wire lengths greater than 300 feet.

Operating the Dehumidifier

Exterior Components: The dehumidifier has a user interface (A), an ON/OFF power switch (B) near the power cord, a filter tab (C), a filter (D), and a drain (E).

1. Apply power to the dehumidifier using the ON/OFF power switch (B) by the power cord. (Note: The unit can remain plugged in with the switch ON unless stored for extended periods. Use the ON/OFF button on the user interface for short durations. Idle units use less than 3W.)

2. Press the ON/OFF button on the user interface (A) to turn the unit ON. The first press may only illuminate the display. Press again if needed. The display will show the current humidity setting.

3. The dehumidifier blower will turn on, 'SETTING' disappears, and 'AIR SAMPLING' appears, indicating the unit is measuring humidity (See FIGURE 3: AIR SAMPLING). If the control is already ON, lowering the setting initiates air sampling.

4. After 3 minutes of sampling, if the Relative Humidity (RH) is above the set point, the compressor turns on, and 'DEHUMIDIFYING' appears (See FIGURE 4: DEHUMIDIFYING).

Energy Savings Tips

• Tip #1: Set the humidity as high as comfortable to reduce run time. If it feels clammy or musty, lower the setting. Turn the unit OFF when opening windows.
• Tip #2: When vacating your home for an extended summer period, set RH to 55% and your thermostat to a comfortable cooling setting. This maintains humidity control while minimizing cooling energy use.

Maintenance

Cleaning the Filter

Check and clean the air filter and drain every 6 months after initial installation.

1. Press the ON/OFF button on the user interface to turn the unit OFF.
2. Lift the bottom filter tab and slide the filter out of the dehumidifier (See FIGURE 1).
3. Rinse the filter with water to remove dust and particles.
4. Shake off excess water.
5. Clean the drain as described in 'Cleaning the Drain'.
6. Reinstall the filter, ensuring the airflow arrow points into the dehumidifier.
7. Press the ON/OFF button to turn the unit back ON.

The 'CLEAN FILTER' service reminder (See FIGURE 5: CLEAN FILTER SERVICE REMINDER) will appear every 6 months. To clear it, press the ▲ and ▼ buttons simultaneously for 3 seconds.

Cleaning the Drain

1. Clean the accessible portion of the drain pan with a mild detergent.
2. If the drain has a capped tee or elbow, remove the cap and pour approximately one cup of white vinegar into the tube (See FIGURE 6: CAPPED DRAIN ACCESS FOR CLEANING). If no external access is available, pour vinegar into the drain pan.
3. For clear flexible drain tubing, check for buildup that might impede flow and replace if necessary. 3/4" Inside Diameter (ID) clear, smooth, flexible drain tubing is available at hardware stores.

Installation

Installing the Duct Collars (Sold Separately)

Duct collars are not included. Separate inlet/outlet duct collar accessories are available:

• Inlet/Outlet Duct Kit: Part #70000047
• Inlet Duct Kit: Part #70000041
• Outlet Duct Kit: Part #70000040

Use the provided screws to attach duct collars to the dehumidifier's inlet and outlet (See FIGURE 7: INSTALL DUCT COLLARS). Ensure at least 4 inches of straight ductwork off the outlet to maintain proper airflow.

Installing the Dehumidifier

Dehumidifier Location

CAUTION: For ducted Whole-home applications, install in an air-conditioned space to prevent external condensate. Avoid attics, basements, or unconditioned spaces.

• Allow sufficient space for service on the electrical service side panel (for access and drain cleaning).
• Ensure sufficient clearance for airflow obstruction.
• For hard-to-reach locations (crawl spaces, attics, basements), consider a remote control like the Model 76.
• For attic installations, suspending the dehumidifier is recommended to reduce noise.
• Always install in or above a condensate pan when locating above a finished space.

Leveling and Raising the Dehumidifier

Adjust the feet to level the unit front-to-back and side-to-side for proper drainage (See FIGURE 8: LEVELING THE UNIT). If using a condensate pump, risers (Part #5879) or hanging kits (Part #5822) may be needed for additional elevation.

Installing a Condensate Pan Under the Dehumidifier

Install the dehumidifier in or above a condensate pan when locating it above a finished space. Adhere to local codes for draining. If a condensate pump is needed, place it in the pan. Install a float switch in the pan or use the pump's overflow wires to stop the dehumidifier if overflow occurs. See 'Wiring to a Float Switch' on page 8.

Installing the Drain

Using Hard Pipe

• Install a 3/4" PVC slip x 3/4" MNPT PVC fitting to the dehumidifier. Use 3/4" nominal PVC Schedule 40 pipe to run the condensate line to a floor drain or outside location, sloping away from the building.
• Maintain a constant downward slope in the drain piping. Ensure tubing does not interfere with panel or filter door removal.
• Do not use metal fittings; hand-tighten threaded fittings. Use PTFE thread seal tape.
• Install a tee or three-way elbow at the outlet with a small, capped vertical tube (do not cement cap) for cleaner access (See FIGURE 6).
• Use PVC primer and cement for slip-fit connections (do not cement threaded connections).

Using Flexible Tubing

• Install the provided 3/4" NPT x 3/4" hose barb fitting and use 3/4" I.D. flexible drain tubing. Hand-tighten the fitting. Use PTFE thread seal tape.
• Maintain a constant downward slope to the drain or pump. Avoid soft tubing curling up, which can cause air locks.

Installing the Condensate Pump

The AprilAire Model 4856 condensate pump can lift water up to 22 feet (See FIGURE 9: DRAIN AND CONDENSATE PUMP INSTALLATION). The dehumidifier can be elevated for increased slope.

• Wire the float switch terminals to the normally closed contacts on the condensate pump (See FIGURE 12).

Installing Ductwork (Optional)

Add ductwork to the inlet and outlet to circulate dehumidified air and reduce noise. Point ducts in opposite directions to minimize recirculation. Maximum recommended total duct length is 100 feet. Do not lay intake duct on the floor to avoid picking up dirt.

NOTE: Maximum allowable static pressure for this unit is 0.4" w.c.

CAUTION: If installing for a ducted Whole-home application, ensure the dehumidifier is located in an air-conditioned space to prevent condensate from developing on the exterior. Avoid attics, basements, or other unconditioned spaces.

Wiring

Additional wiring is only needed for a separate remote control (dehumidistat) or a float switch (integral to a condensate pump or mounted to the condensate pan).

Use 18-22 AWG wire. Access wiring terminals by pulling off the wiring access cover (B) near the user interface (A) (See FIGURE 10: WIRING ACCESS COVER LOCATION). Replace the cover after wiring.

Wiring to a Remote Control

The Model 76 remote control allows viewing and adjusting humidity settings remotely. This is useful for hard-to-reach locations like crawl spaces or basements. Wire the remote control as shown in FIGURE 11: MODEL 76 CRAWL SPACE/SEALED ATTIC (REMOTE) WIRING. If using the AprilAire Model 76, wire to the {+ - A B} terminals. Refer to the control's installation instructions for details.

NOTE: Air cycling is not an option when using a Model 76 as a remote control.

Wiring to a Float Switch

Use if the installation includes a float switch or condensate pump. The dehumidifier ships with a jumper wire in the float switch terminals. Remove the jumper and wire the float switch terminals to the float switch or condensate pump overflow switch as shown in FIGURE 12: FLOAT SWITCH WIRING.

Air Cycling

The dehumidifier has an optional ventilation feature to circulate air and promote uniform humidity. The fan can be set to run from 0 to 60 minutes per hour (See page 9 for setup). The on-board control must be used when Air Cycling.

Installer Set-Up

Proceed to Step 1 if using a Model 76 Remote Control, the Air Cycling feature, or applying an RH Offset. Otherwise, proceed to 'Starting Up the Unit' on page 10.

1. Plug in the unit and turn the power switch ON (if equipped).
2. The onboard control screen should display 'OFF'. If not, press ON/OFF to turn it OFF. (Note: The first button press may only turn on the backlight; press a second time for function.)
3. Hold the MODE button for 3 seconds to enter the Installer Set-Up menu.
4. Press MODE to navigate through screens for application setup. Press ▲ or ▼ to select items. To exit, navigate through all options using MODE.
5. After completing Installer Set-Up options, 'DONE' will blink for 3 seconds, and the control returns to the OFF screen.
6. Not all set-up options are covered here; default settings are recommended for most applications.

Setting Up Remote Control – Crawl Space/Sealed Attic

If wiring to a Model 76 for remote control (see page 8), press ▲ or ▼ to select 'ENABLED'. Then press MODE to advance.

Setting Up Ventilation / Air Cycling

1. If using air cycling (see page 8), press ▲ or ▼ to select 'ENABLED'. Then press MODE to advance.
2. Press MODE at the 'VENT TIMED' screen to go to ventilation time selection.
3. Press ▲ or ▼ to adjust ventilation time per hour from 0 to 60 minutes.

Applying an RH Offset

An offset can be applied to the onboard humidity reading to correct discrepancies with other home humidity devices. Use ▲ or ▼ to select an offset from -5% to 5%. Press MODE to exit Installer Set-Up screens. 'DONE' will display, and setup is complete.

Starting Up the Unit and Sequence of Operation

Ensure the unit is plugged in and, if equipped, use the ON/OFF power switch near the power cord to apply power.

Using the Dehumidifier Control Only

1. Press the ON/OFF button to turn the control ON. The display shows the current humidity setting, and the blower starts sampling. The setting is replaced by the measured humidity, and 'AIR SAMPLING' appears.
2. Use ▲ or ▼ to adjust the humidity setting. The recommended initial setting is 55%–59% RH.
3. After 3 minutes of sampling, the measured humidity is compared to the setting:
   • If humidity is above the setting, the compressor turns on, 'AIR SAMPLING' changes to 'DEHUMIDIFYING', and the compressor stays on until humidity falls 3% RH below the setting.
   • If humidity is below the setting, the blowers turn off, and the display returns to the RH setting.
4. The dehumidifier will sample again every 60 minutes, or anytime the humidity setting is lowered.

Using a Model 76 as a Remote Control

1. Press the ON/OFF button to turn the dehumidifier control ON. The display shows 'REMOTE' to indicate a remote control is in use.
2. At the Model 76, press ON. The Model 76 displays the RH measured at the dehumidifier, and the blower starts sampling.
3. Use ▲ or ▼ on the Model 76 to adjust the dryness level (1=least dry, 7=most dry). The recommended initial setting is 3.
4. After 3 minutes of sampling, measured humidity is compared to the setting:
   • If humidity is above the setting, the compressor turns on, and 'ON' flashes on the Model 76 display.
   • If humidity is below the setting, the blower turns off.
5. The dehumidifier will sample again every 60 minutes, or anytime the dryness level is increased.

Service Instructions

Symbols

• Symbol ISO 7010-W021 (2011-05): ⚠️ Warning: Flammable materials
• Symbol ISO 7000-1659 (2004-01): ? Service indicator: Read technical manual
• Symbol ISO 7000-1659 (2004-01): ? Operator's manual: Operating instructions

Safety Instructions

WARNING

• Sealed Refrigeration System is not field serviceable! This appliance contains a mildly flammable A2L refrigerant.
• Do not use methods other than those recommended by the manufacturer to accelerate defrosting or cleaning.
• Store the appliance (when not in use) in a room without continuously operating ignition sources (e.g., open flames, operating gas appliances, or electric heaters).
• Do not pierce or burn the sealed system.
• Be aware that refrigerants may not contain odor.

CAUTION

When connected via air ducts to one or more rooms, the appliance shall be directly ducted to the space. Open areas like false ceilings shall not be used as a return air duct.

Service Procedures

Approved auxiliary devices must be approved by the manufacturer. A Fresh Air Ventilator (Stock # 8190FF) is an example.

Checks for installations using FLAMMABLE REFRIGERANTS:

• Ensure ventilation machinery and outlets are adequate and unobstructed.
• Markings on equipment must be visible and legible; correct illegible markings.
• When opening the enclosure for electrical component repair, check for refrigerant leaks with a certified flammable refrigerant leak detector.

Repair Initial Safety Checks:

• Electrical system servicing must be done by a qualified and licensed electrician.
• Disconnect power (unplug) before attempting service or repair.
• Discharge capacitors safely to avoid sparking; ensure no live electrical components or wiring are exposed in case of a leak.
• Verify continuity of earth bonding.
• Sealed electrical components must be replaced, not repaired.
• Do not apply permanent inductive or capacitance loads that exceed permitted voltage and current.
• Replace intrinsically safe components if tripped.
• Replace components only with manufacturer-specified parts to avoid refrigerant ignition risk.
• Before working on systems with FLAMMABLE REFRIGERANTS, perform safety checks to minimize ignition risk.
• Ensure the work area is open or adequately ventilated before removing panels or performing hot work near the unit. Maintain ventilation to disperse any released refrigerant.

Refrigeration System:

• The refrigeration system is factory sealed; puncturing refrigerant tubing is prohibited.
• Refrigeration system repair must be done at the manufacturing facility by trained personnel.
• Check cabling for wear, corrosion, excessive pressure, vibration, sharp edges, or other adverse environmental effects, including aging or continual vibration from sources like compressors or fans.
• If a leak is suspected, extinguish all naked flames.

Leak Detection Methods:

• Do not use potential ignition sources for leak detection. Halide torches (or any naked flame detector) are prohibited.
• Electronic leak detectors are acceptable but must be calibrated for Flammable Refrigerants in a refrigerant-free area. Ensure the detector is not an ignition source and is suitable for the refrigerant.
• Leak detection equipment must be set to a percentage of the Lower Flammability Limit (LFL) of the refrigerant and calibrated accordingly (25% maximum).
• Leak detection fluids are suitable but avoid chlorine-containing detergents, as chlorine can react with refrigerant and corrode copper pipework. Examples include bubble method and fluorescent method agents.
• NOTE: Silicon sealant can inhibit some leak detection equipment.

FOR ADDITIONAL ASSISTANCE: Technical Support is available Monday through Friday (see TROUBLESHOOTING).

Troubleshooting

NOTICE

Troubleshooting and repairs must be performed by a qualified HVAC service technician, following all safety procedures. Technical support is available Monday–Friday, 7:00 a.m.–5:00 p.m. CST at 800.334.6011. Use the guides below to identify and correct faults. Contact Technical Support before replacing units or components.

Diagnostic Codes

When an error occurs, the Diagnostic Code and 'SERVICE REQUIRED' display on the user interface.

Troubleshooting Guide

Service Parts

E050 Service Parts Diagram: The diagram shows numbered components of the dehumidifier.

Limited Warranty

Terms of Coverage

Your AprilAire® Dehumidifier is warranted free from defects in materials or workmanship for five (5) years from the date of purchase.

What Is Covered

AprilAire's sole obligation is to supply, without charge, a replacement for any defective component or product. A defective part will be replaced with a genuine AprilAire part. A defective product will be replaced with a new AprilAire product of equal or similar features if the original is discontinued.

Not Covered by the Limited Warranty

• Consumable or maintenance products (e.g., Air Filters, Water Panels, Steam Canisters, Electrode Wires).
• Products purchased used (e.g., from eBay, auction sites).
• Labor charges, shipping costs, removal fees, service fees, or reinstallation costs.
• Materials furnished by the installer.
• Damage caused by misuse, abuse, improper installation, or failure to install, use, or maintain per instructions.
• Damage to HVAC equipment from improper installation or misapplication.
• Modifications, changes, repurposing, or alterations to the AprilAire product.
• Extended warranties or satisfaction guarantees from third parties.
• Cosmetic damage or normal wear and tear (scratches, peeling finish, dents that don't impede function).
• Damage from acts of nature (fire, flood, wind, power surge, lightning, mold).
• Damage during transit.
• Damage during installation due to failure to follow local, state, or federal laws/codes.
• Damage caused by installer-furnished defects.

Limit of Liability

IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE ARE LIMITED TO THE EXPRESS WARRANTY PERIOD. APRILAIRE IS NOT LIABLE FOR INCIDENTAL OR CONSEQUENTIAL DAMAGES (OTHER THAN FOR PERSONAL INJURIES) RESULTING FROM BREACH OF IMPLIED WARRANTIES OR THE LIMITED WARRANTY. THIS WARRANTY IS VOID IF DEFECT(S) RESULT FROM FAILURE TO INSTALL ACCORDING TO APRILAIRE INSTALLATION INSTRUCTIONS. IF VOID DUE TO MISAPPLICATION OR IMPROPER INSTALLATION, ALL DISCLAIMERS OF IMPLIED WARRANTIES ARE EFFECTIVE UPON INSTALLATION.

Some states limit implied warranty duration or exclude incidental/consequential damages. This warranty provides specific legal rights, and you may have others varying by state.

Register Your AprilAire® Product

Register your product at aprilaire.com/warranty for updates, notifications, and streamlined claims. Warranty information is not sold or shared externally.

Make a Warranty Claim

For warranty questions or claims, contact AprilAire Customer Service at 1.800.334.6011 (Monday–Friday, 7:00 a.m.–5:00 p.m. Central Time). AprilAire may require product return, contractor service, product testing, or submission of photos with serial number for claim review or replacement.

AprilAire® is a registered trademark and division of Research Products Corporation, P.O. Box 1467, Madison, WI 53701-1467 USA.

Manufacturing Use Only

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AprilAire reserves the right to change specifications without notice.