Advanced Thermostat Operations
40 ENV-VST-C - Operation / Reference Guide
The thermostat automatically defaults to One Stage Furnace for the HVAC System setting when you install it. You can
change the type of HVAC system you are using, which activates certain features depending on which type of system you
have. This option should be set when the thermostat is installed for the first time, and should not need to be changed after
that. Perform the following steps to change the type of HVAC system you are using:
1. From the Main screen, press Mode/Select to access the Thermostat Mode screen.
2. Use the navigation buttons to select Settings, and press Mode/Select. The Settings screen appears.
3. Use the navigation buttons to select Advanced Settings. Press Mode/Select to access the Security Code screen.
4. Enter the security code, and select Enter to access the User Preferences screen. See the Entering the Security Code
on page30 for more information.
5. Use the navigation buttons to highlight More, and press Mode/Select to access the second User Preferences screen.
6. On the second User Preferences screen, use the navigation buttons to highlight More, and press Mode/Select to
access the third User Preferences screen.
7. Use the navigation buttons to highlight Advanced Setup, and press Mode/Select to access the Advanced Setup
screen (FIG.43).
Advanced Setup Screen Options (Cont.)
Year Enables you to set the current year.
Hour Enables you to set the current hour. You can enter a value between 0-23.
Minute Enables you to set the current minute. You can enter a value between 0-59.
Cycle Rate Enables you to set the number of times per hour your HVAC system can turn on and off. You can
choose from 3, 4, 5, or 6. The default value is 4.
AxLink Setup Enables you to access the AxLink Setup screen. See the AxLink Communications Screen on
page45 for more information.
Thermostat Setup Enables you to access the Thermostat Setup screen. See the Thermostat Setup Screen on
page47 for more information.
Diagnostic Mode Enables you to activate a mode during which you can test the functionality of the thermostat. With
Diagnostic Mode turned on, the cycle rate no longer applies and you can enter the Advanced
Settings sections without entering a security code. Text appears on the Main screen notifying you
when Diagnostic Mode is active.
Humidification
System Enables you to activate the humidification system to add humidity to the air. You can set the
humidify setpoint on the Program Mode or Away Mode screens.
See the Program Screensection on page 24 and the Away Mode Screen section on page 26 for
more information.
Dehumidification
System Enables you to activate the dehumidification system to remove humidity from the air. You can set
the dehumidify setpoint on the Program Mode or Away Mode screens.
See the Program Screensection on page 24 and the Away Mode Screen section on page 26 for
more information.
Comfort Recovery Enables you to indicate whether the heating/cooling system recovers gradually from an energy-
saving setpoint temperature to a comfort setpoint temperature. By incrementing the setpoints
gradually, the heating/cooling system activates in advance of the actual set program time so the
area is at the desired temperature at the start of the program time.
If this option is disabled, heating/cooling setpoints are changed at the exact start time of the
program period.
Help Mode Enables a help screen that you can access by pressing Mode/Select on the Main screen. See the
Help Screensection on page 21 for more information.
Exit Returns you to the User Preferences screen.