Aprilaire 8444, 8446, 8448, 8463, 8465, 8466 - Thermostat Manual

THERMOSTAT FEATURES
ALL 8400 SERIES THERMOSTATS

• Large, clear, backlit display is easy to read – even in the dark
• Displays room temperature, temperature setting, and optional outdoor temperature
• Front battery door access for fast, easy replacement
• Built in compressor protection
• Circulation fan mode for air cleaning
• Air filter, humidifier, dehumidifier, and HVAC service reminders
• Auto backlight (activated with first button press).

PROGRAMMABLE MODELS ONLY (8463, 8465, 8466)

• Separately programmable weekday/weekend schedules
• Easy to use temperature control can override program schedule at any time
• Progressive recovery

HOW TO IDENTIFY YOUR THERMOSTAT'S MODEL NUMBER
To locate the model number, remove the battery cover

QUICK REFERENCE TO CONTROLS & DISPLAY

NON-PROGRAMMABLE MODELS (8444, 8446, 8448)

NOTE: BACKLIGHT IS ACTIVATED WITH FIRST BUTTON PRESS AND AUTOMATICALLY TURNS OFF.

PROGRAMMABLE MODELS (8463, 8465, 8466)

NOTE: BACKLIGHT IS ACTIVATED WITH FIRST BUTTON PRESS AND AUTOMATICALLY TURNS OFF.

OPERATION (ALL MODELS)

SELECT SYSTEM MODE (AUTO/OFF/HEAT/COOL/EM-HEAT)
Press to select:
AUTO: Thermostat automatically selects heating or cooling depending on the indoor temperature
OFF: Heating and cooling systems are off
HEAT: Thermostat controls only the heating system
COOL: Thermostat controls only the cooling system
EM-HEAT: Thermostat controls emergency/ auxiliary heat Heat pump will not operate (Only for heat pumps with auxiliary heat on models 8446, 8465, 8448HP and 8466HP)

CHANGE TEMPERATURE SETTING
Applies to programmable models (8463, 8465, 8466) when in HOLD mode and to non-programmable models (8444, 8846, 8448)
Press or to adjust the current setting. In AUTO use to switch between the HEAT and COOL setting.

SELECT FAN SETTING (ON/AUTO/CIRC)
Press to select:
ON: Fan runs continuously Use this mode for maximum air circulation/air cleaning
AUTO: Fan runs only when the heating or cooling system is on
CIRC: Same as AUTO, but ensures the fan is on for at least 20 minutes per hour Use this mode for a balance of energy savings and air circulation/cleaning

RESET SERVICE REMINDER MESSAGES
Press and hold and simultaneously for three seconds to reset a service reminder message

OPERATION & PROGRAMMING (PROGRAMMABLE MODELS ONLY 8463, 8465, 8466)

SET TIME AND DAY

1. Press to enter time setting mode. Hour and AM/PM are flashing.
2. Press or to adjust the hour.
3. Press , the minutes flash. Press or to adjust the minutes.
4. Press , the day flashes. Press or to adjust day.
5. Press to end. DONE will display.

The thermostat will save changes and return to Normal mode if no key is pressed in 20 seconds.

UNDERSTANDING PROGRAM SCHEDULES
The daily schedule is split into four sections:

The times shown are the defaults The start time and temperature of each section can be changed to fit your schedule.

PROGRESSIVE RECOVERY
The Progressive Recovery feature, if enabled by the installer, allows the thermostat to activate the heating and cooling equipment PRIOR to a scheduled event in order to reach the desired temperature at the start of that scheduled event. When a heating or cooling call is active for Progressive Recovery, the current event schedule will flash.
EXAMPLE: Set the WAKE time to 6:00 am, and the temperature to 70°. The heat will come on before 6:00 am, so the temperature is 70° by the time you wake at 6:00 am

CHANGING PROGRAM SCHEDULES

1. Press twice to enter program setting mode. If the backlight is not already active the first button press will activate the backlight and two additional button presses are required. Start time of the WAKE event is flashing.
   
2. Press or to adjust the start time
3. Press , HEAT setting flashes. Press or to adjust the heat setting.
   

4. Press , COOL setting flashes. Press or to adjust the cool setting.
5. Press to advance the next event, and repeat steps 2-5 for LEAVE, RETURN and SLEEP events.
6. Press to change to weekend program. Repeat steps 2-5 for the weekend program.
7. Press to end. DONE will display.

The thermostat will save changes and return to Normal mode if no key is pressed in 20 seconds.

PROGRAM SCHEDULE OVERRIDES (TEMPORARY, PERMANENT)
TEMPORARY PROGRAM OVERRIDE

Press or to immediately adjust the temperature. This will temporarily override the temperature setting for the current programmed time period. The new temperature setting will be maintained until the next time period of the programmed schedule. To cancel the temporary override, adjust the temperature setting back to the programmed temperature, or press twice. If the backlight is not already active the first button press will activate the backlight and two additional button presses are required.

PERMANENT PROGRAM OVERRIDE

Press to permanently hold the temperature at its current setting. This will override the temperature settings for all time periods of the programmed schedule. With the thermostat in permanent override, the thermostat temperature can be manually adjusted and will stay at that setting until the override is cancelled. To cancel the permanent override press .