Thermostat Operation; Dip Switch Settings - Lennox ComfortSense L3021H Installation Instructions Manual

Table 2. L3021H Terminal Designations
Terminal Description
O Reversing valve, cool active
B Reversing valve, heat active
R 24VAC
G Fan control
Y1 First-stage cooling/heating, compressor-
generated
W1 Auxiliary heating, furnace-generated
L Service Indicator
C 24VAC common
E Emergency heat
T Outdoor temperature sensor connection 1
T Outdoor temperature sensor connection 2
Figure 1. L3011C Terminal Strip

Thermostat Operation

NOTE: The thermostat heating mode will not operate if the
thermostat has been stored or is being used at ambient
temperatures that are above 93°F. The heating function
will be enabled after the thermostat is exposed to ambient
temperatures below 93°F for about 30 minutes.

DIP Switch Settings

DIP Switch Settings
L3011C and L3021H thermostats include five DIP
switches located on the back side of the thermostat body.
These switches may be used to re−calibrate the thermostat
(Wired)
(Cal 1, Cal 2 and Cal±) and to select the thermostat display
(Fahrenheit or Celsius). Thermostats L3011C also include
a DIP switch used to select fan operation for either electric
heat or gas heat applications.
Thermostat L3021H includes a DIP switch used to indicate
whether electric or gas back−up heat will be used. Refer to
table 3 for DIP switch function descriptions.
Page 3
Figure 2. L3021H Terminal Strip
(Wired)
L3011C/L3021H THERMOSTATS