Filter Reminder; Service Indicator; Thermostat Reset; Default Thermostat Settings - Lennox ComfortSense 3000 Series Operation Manual

If auto fan mode is selected, the fan will only run when the
heating or cooling equipment is running. In this case, AUTO
will be displayed in the FAN box as shown in figure 10.
Figure 10. Fan AUTO with Icon
To change from continuous to auto fan mode and vice versa,
press the FAN button. Also note the presence of a fan icon
in the FAN box. This icon indicates that the fan is running.

Filter Reminder

The L3021H thermostat includes a filter reminder feature.
the filter reminder can be set for 1, 3, 6, or 12-month
intervals. The SETTINGS button, located behind the door
on the right-hand side of the thermostat is used to set the
filter reminder interval. See figure 3. Press the SETTINGS
button from the HOME screen to display the Filter Reminder
Settings screen as shown in figure 12.
Figure 11. Filter Reminder Settings
The default setting for the filter reminder is 0, which disables
the function. Use the UP arrow while in the Filter Reminder
Settings screen to select the desired interval between
reminders. It may be necessary to press the UP arrow
several times to access the desired setting. The HOME
screen will reappear about 10 seconds after the arrow key
has been pressed for the final time.
After the programmed interval has elapsed, the FILTER
reminder will be displayed as shown in figure 13. After the
filter has been changed, reset the filter reminder by pressing
the SETTINGS button for 4 seconds. The screen will blink
for a few moments to indicate that the timer has been reset.
Figure 12. Display of Filter Reminder

Service Indicator

When abnormal equipment operation is detected, the
SERVICE indicator will flash on the upper-right corner of the
screen. This indicates that the equipment requires service
from a qualified service technician. The SERVICE indicator
is shown in figure 13.
Figure 13. Service Indicator Flashing

Thermostat RESET

Under some abnormal conditions, it may be desirable to
reset the thermostat to its default condition. The RESET
button can be used to return the unit to normal operation
after an occurrence such as an electrical storm or power
outage.
The RESET button is an unlabeled, recessed button located
behind the door on the right-hand side of the thermostat,
just below the SETTINGS button. The RESET button is
visible in figure 3. Use a paper clip or small pencil to press
the RESET button. After the RESET button is pressed, the
thermostat settings will return to the defaults listed in the
Default Settings section.

Default Thermostat Settings

Default Thermostat settings are in table 1.
Table 1. Default Thermostat Settings
Mode
Setpoint
Fan
Filter Reminder
Equipment Protection Timers
4
Heat (Permanent Hold)
70°F (or 21°C)
Auto
OFF (reminder setting = 0)
Reset Back to Zero