Settings Tables; Humidifier System Settings - Aprilaire 8840 Safety & Installation Instructions

TABLE 2 – THERMOSTAT SYSTEM SETTINGS
System setting Description
Second Stage
Second stage differential
Differential
Third Stage Differential Third stage differential
Fourth Stage
Fourth stage differential
Differential
The period for displaying the HVAC
Service HVAC Reminder
Service reminder message
Number of Months for Select number of months for displaying
Recurrence reminder
INDOOR AIR QUALITY SYSTEM SETTINGS TABLES
The following tables contain the Indoor Air Quality system settings and their details Default
settings are shown in bold Some settings are only present dependent upon the value of
other settings
The use of an outdoor temperature sensor (recommended) enables additional Indoor Air
Quality functionality
Please refer to the Model 8840 Owner's Manual for further information about thermostat
features
NOTE: Refer to manuals for humidifier, dehumidifier, air cleaner, and ventilation products for
recommended installation and operation
TABLE 3 – HUMIDIFIER SYSTEM SETTINGS
System setting Description
Selects if a humidifier is installed. Yes/On
HVAC is used for applications where the
humidifier is installed on the HVAC duct.
Yes/Standalone is used for application
Humidifier Installed?
where the humidifier is independent of
the HVAC system (If set to No, no other
humidifier settings will be available.)
NOTE: Only available if Humidifier Installed
Display Button?
is set to No
Outdoor Temperature
Select if outdoor sensor is attached or not
Sensor Installed?
Selects auto or manual mode Auto
mode controls humidity based on the
humidity setting and outdoor temperature
Humidifier Mode Manual mode controls humidity based
on the %RH setpoint (Auto mode is only
available if Outdoor Sensor is set to Yes or
Automation)
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Factory default setting
(bold) and setting range
1°F (0.5°C)
1 to 9°F (05 to 45°C)
1°F (0.5°C)
1 to 9°F (05 to 45°C)
1°F (0.5°C)
1 to 9°F (05 to 45°C)
Disabled
Enabled
12 Months
1 to 12 Months
Factory default setting
(bold) and setting range
No
Yes/On HVAC
Yes/Standalone
Yes
No
No
Yes
Auto
Manual
TABLE 3 – HUMIDIFIER SYSTEM SETTINGS
System setting Description
Selects when humidification is allowed to
occur relative to heating and fan operation
Without Fan allows humidification to
occur without the HVAC fan This option
Allowed Humidifier
should only be used when the humidifier
Operation
is independent of the HVAC system
NOTE: Without Fan is only available
when Humidifier Installed is set to Yes/
Standalone
CAUTION: When Humidifier Operation is set to Without Fan the thermostat will turn on
humidification without energizing the HVAC fan. Do not select this option when the humidifier
is installed on the HVAC duct. Without airflow moisture can accumulate in the duct resulting in
significant damage.
Select the minimum difference between
the humidifier and dehumidifier setpoints.
Humidity Deadband
(Only available if both a humidifier and
dehumidifier are installed.)
Selects when the Change Water Panel
Humidifier Reminder
message is displayed
Single or First Determines the month the first (or only)
Reminder Appears Change Water Panel message is displayed
Second Reminder Determines the month the second Change
Water Panel message is displayed
Appears
Factory default setting
(bold) and setting range
Heat Only
Heat or Fan
Forces Fan
Without Fan
10%
10 to 20%
Off
300h Valve
600h Valve
1 per season
2 per season
October
November
December
January
February
March
April
May
June
July
August
September
October
November
December
January
February
March
April
May
June
July
August
September
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