Aprilaire Automatic & Manual Humidifier Control 4655 Introduction

Aprilaire Humidifier Control Models 60, 62, and 4655 are designed to help maintain the optimal humidity levels in your home, enhancing comfort while also protecting your health and the structural integrity of your property. These digital humidifier controls are compatible with Aprilaire's whole-house humidifiers and have an estimated price range of $36.95, depending on the model and retailer.

Detailed Specifications

Some key features of Aprilaire Automatic & Manual Humidifier Control 4655 include:

Digital display and controls
Automatic humidity control
Outdoor temperature sensor compatibility
Dual-sensor technology: temperature and relative humidity
Sleep mode to minimize operation during nighttime
User-friendly interface
Low-voltage transformer included
Five-year limited warranty
Energy-efficient operation
Dimensions: 4.5" x 3.25" x 1"

Your Aprilaire Automatic & Manual Humidifier Control 4655

Your humidifier is controlled by either an Automatic Digital Humidifier Control, or a Manual Humidifier Control.
The Automatic Digital Humidifier Control offers two modes of operation, Automatic or Manual. When in the Automatic Mode, this system offers the following benefits:

You will receive the optimum amount of humidity so that your home and its furnishings are protected from the damaging effects of excess condensation or low humidity during the heating season. The Control automatically adjusts your home’s RH based on the outdoor temperature, increasing the time maximum comfort is maintained
Simple operation with few adjustments. The Control eliminates the need to manually adjust the control when outdoor temperature changes. It also eliminates the need to turn the dial setting to “OFF” during the summer season.

Digital Humidifier Control Indicator Lights
Call Dealer for Service: The red light indicates that the humidifier is not operating normally and that service is required. Change Water Panel: The yellow light indicates that it is time to change the Water Panel in the humidifier. (Model 60 only. The Model 62 is used for steam applications that do not require this feature.)
Humidifier On: The green light indicates that the humidifier is operating normally.

Description

The Aprilaire Automatic & Manual Humidifier Control 4655 models provide an easy-to-use and precise method of controlling the humidity levels in your house, avoiding dry air that can lead to skin dryness, respiratory problems, and damage to wooden furniture and flooring. These controls make it simple to maintain the optimal humidity range of 40–60% for your house thanks to their digital displays, automated humidity management, and dual-sensor technology. For optimal comfort and energy efficiency, the integrated outdoor temperature sensor assists in adjusting humidity levels in response to variations in the outside temperature. Furthermore, the sleep mode feature lowers noise levels at night to maintain a quiet atmosphere while controlling humidity levels.

OPERATING INSTRUCTIONS

Blower Activation

Set the Blower Activation Switch to “ON” to allow the Humidifier Control to activate the furnace fan for additional humidification. Refer to TABLE 3 – Operation Guide. This may be required if the humidifier is mounted on a heat pump or a furnace with short run cycles. The humidifier should be plumbed to hot water when using the Blower Activation feature.
When the Blower Activation switch is “ON”, the Humidifier Control will turn on the HVAC blower when humidity is required. In the “OFF” position, the humidifier will only operate if humidity is required and the HVAC system is operating.
When the Blower Activation switch is “ON”, the Humidifier Control will periodically turn the HVAC blower on for 3 minutes to sample the RH of the air.

Automatic Digital Humidifier Control

Your Automatic Digital Humidifier Control works in conjunction with your heating, ventilating, air conditioning equipment (HVAC) to control the operation of the humidifier. The control senses indoor humidity and outdoor temperature and automatically adjusts the operation of the humidifier to provide the optimum humidity level in the home.
The digital readout on the automatic control displays the humidity level inside the cold air return duct. This reading will accurately indicate the humidity in the living space when the HVAC blower is operating.

AUTOMATIC MODE

Your Aprilaire Humidifier Control is installed in the cold air return duct. During the first heating season, your Humidifier Control needs to be set initially to match your home’s condition. Please follow these steps when adjusting your control (refer to Figure A).

Turn the dial setting knob to “5”, which is within the normal range. During the next 24-48 hours it may be necessary to adjust the dial for more or less humidity, depending on your personal comfort and home’s requirements. Refer to TABLE 3 –Operation Guide.
During the coldest portion of the first heating season, minor adjustments may be necessary. This is dependent upon your home’s construction. Refer to TABLE 3 – Operation Guide.

The humidity in your home will now be accurately controlled to meet your needs and should not need further adjustment during future heating seasons. Make note of the dial setting in the event you temporarily move the knob to “OFF” when performing annual maintenance of your Aprilaire humidifier.

MANUAL MODE

When installed in the Manual Mode (see Figure B – internal switch in “MAN” position and “M” in the display), it is important to anticipate a drop in outdoor temperature and reduce the setting accordingly to avoid excessive condensation. For example, with an outdoor temperature of 20°F the correct setting will be 35%. If the temperature is expected to fall to 0°F, then merely reduce the setting to 25% several hours prior to the temperature change.

See Table 1 for the recommended settings. These settings, which are based on years of research, represent a compromise between humidity levels that would be most desirable for comfort and humidity levels that are suitable for protection of your home and to avoid condensation on your windows. For example, a wintertime indoor humidity of 50% may be considered ideal for comfort, but unfortunately, it probably would result in condensation, which can cause damage to your home. Observing the recommended humidity levels on your Humidifier Control is an important safeguard. Condensation of water on the inside surface of windows in the form of fogging or frost is usually an indication of too much humidity. This same condensation can occur in other areas in your home, possibly resulting in damage.

TABLE 1 – Outdoor Temperature/ Indoor Relative Humidity
Outside Temperature	Recommended RH
+40°F	45%
+30°F	40%
+20°F	35%
+10°F	30%
0°F	25%
-10°F	20%
-20°F	15%

WATER PANEL CHANGE INDICATOR (MODEL 60 ONLY)

The control keeps track of humidifier operation time. The yellow “Change Water Panel” light flashes after a preset amount of running time has elapsed. This running time is preset by the installer based on the humidifier model and water hardness.
Refer to the Annual Maintenance section for instructions on changing the Water Panel or call your heating and air conditioning dealer for service. After the Water Panel is replaced, turn the Control knob to the “Test/Reset” position until the green “Humidifier ON” light flashes, to reset the Water Panel change timer.
TEST/RESET

The Test/Reset feature allows the humidifier operation to be checked even if there is no call for humidity.

ADDITIONAL INFORMATION

Your humidifier is a precision system that will accurately maintain the humidity in your home. For every 2°F change in outdoor temperature, the Digital Humidifier Control will automatically adjust the indoor RH by 1%. The Digital Humidifier Control will accurately control the humidity in your home to a maximum of 45%.
The humidity values in Table 2 are targets based on the outdoor temperature and the Digital Humidifier Control setting. The actual humidity may vary due to conditions in the home (cooking, showering, etc.).

TABLE 2 – % Relative Humidity Guide
		Outdoor Temperature (°F)
		-10°F	0°F	10°F	20°F	30°F	40°F
Dial Setting	1	10%	10%	10%	15%	20%	25%	Relative Humidity (%)
	2	10%	10%	15%	20%	25%	30%
	3	10%	15%	20%	25%	30%	35%
	4	15%	20%	25%	30%	35%	40%
	5	20%	25%	30%	35%	40%	45%
	6	25%	30%	35%	40%	45%	45%
	7	30%	35%	40%	45%	45%	45%

TABLE 3 – Operation Guide
Condition	Solution
Condensation on windows.	Reduce the setting on the control dial by 1 increment.
Lack of humidity.	Increase the setting on thecontrol dial by 1 increment. Ifthe Humidifier Control is already at the maximum setting of “7”, set the Blower Activation Switch to “ON”. Thehumidifier should be plumbed to hot water when using the Blower Activation feature.
Humidifier does not operate.	Turn dial to “Test/Reset”. Make certain HVAC blower is operating. If unit still does not operate, consult a heating contractor.
Humidifier won’t shut off.	Turn dial to “Off”. If unitcontinues to operate, consult a heating contractor.
Test mode.	System operation is checked bysetting the knob to “Test/Reset”. Make certain HVAC blower is operating. Humidifier will operate for one minute. NOTE: Placing the knob in “Test/Reset” resets the Water Panel change timer.
Red “Call Dealer for Service” light flashes (Figure A).	Note theerror code on the display (E1, E2, E3 or E4) and call your heatingand air conditioning dealer.
Model 60 only: Yellow “Change Water Panel” light flashes (Figure A).	Refer to the Humidifier Owner’s manual for instructions on changing the Water Panel or call your heating and air conditioning dealerfor service. After the Water Panelis replaced, turn the Control knob to the “Test/Reset” position until the green “Humidifier On” light flashes, to reset the Water Panel change timer.

Manual Humidifier Control

Your Aprilaire humidifier is controlled by a Manual Humidifier Control (see Figure C). The Manual Humidifier Control is installed either in the cold air return duct or on an interior wall of the home. With the Manual Humidifier Control, it is important to anticipate a drop in outdoor temperature and reduce the setting accordingly to avoid excessive condensation, just as with the Digital Humidifier Control installed in Manual Mode (see page 5).
To determine the indoor RH, slowly turn the knob clockwise and counterclockwise and listen for 2 clicks. The indoor RH is within the range of the 2 clicks.

Check the Humidifier Operation

DIGITAL HUMIDIFIER CONTROL

Set the knob to “Test/Reset”, and make sure that the water saddle valve is open and that there is electricity to the humidifier. The HVAC fan must be running for the humidifier to function. NOTE: Turning the knob to “Test/Reset” resets the “Change Water Panel” timer. The humidifier will only operate for 1 minute in test mode. (Model 400 and 400M: Floats must be down for the solenoid valve to allow water flow.) Reduce the Humidifier Control setting to the recommended inside humidity, depending on the outside temperature. DO NOT LEAVE IN TEST MODE AS THE HUMIDIFIER WILL NOT OPERATE.
MANUAL HUMIDIFIER CONTROL

Set the knob to the highest setting, make sure that the water saddle valve is open and that there is electricity to the humidifier. The HVAC system must be operating for the humidifier to function. Confirm that the solenoid valve is energized and water is flowing into the humidifier. Return the control knob to the desired setting.

Annual Summer Shutdown

Digital Humidifier Control in Automatic Mode (see Figure A) and the Blower Activation switch is in the ”OFF” position: No adjustment is necessary.
Digital Humidifier Control in Automatic Mode (see Figure A) and the Blower Activation switch is in the ”ON” position: Set the knob to the “OFF” position. Digital Humidifier Control in Manual Mode (see Figure B): Set the knob to the “OFF” position.
Manual Humidifier Control (see Figure C): Set the knob to the “OFF” position.

Aprilaire Automatic & Manual Humidifier Control 4655 Troubleshooting

Common problems and solutions for Aprilaire Automatic & Manual Humidifier Control 4655:

Problem: Humidity levels are not being maintained as expected.
Solution: Ensure the outdoor temperature sensor is properly installed and functioning. Also, verify that the humidifier is set up correctly and the filters are clean and in good condition.
Problem: Control is not responding to button inputs.
Solution: Make sure the power source is connected and functioning. If the power is on, try resetting the control by disconnecting and reconnecting the power source or by pressing and holding the "Reset" button (if applicable).
Problem: Error messages or alerts appear on the display.
Solution: Refer to the user manual or contact Aprilaire customer support. They can guide troubleshooting specific error messages or alerts.

Pros & Cons

Pros

Automatic humidity control
Dual-sensor technology
Outdoor temperature sensor compatibility
Easy-to-use digital interface
Energy efficient

Cons

May require professional installation for optimal performance
Limited to compatibility with Aprilaire humidifiers
May have a learning curve for those unfamiliar with digital controls

Customer Reviews

Customers have praised Aprilaire Automatic & Manual Humidifier Control 4655 for their accuracy, user-friendly interface, and effectiveness in maintaining ideal humidity levels. The automatic humidity control and dual-sensor technology are particularly popular features. However, some users have noted that the controls may be challenging to set up for those unfamiliar with digital interfaces, and professional installation might be necessary for optimal performance.

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