8
Table 2. O/B Terminal Relationship States
State
O/B Terminal Control
Power ON
O terminal : ON (If O terminal selected)
B terminal : OFF (If B terminal selected
Heat only or
emergency
heat mode
O terminal : always OFF
B terminal : always ON
Cool mode
only
O terminal : always ON
B terminal : always OFF
Heat/Cool
mode
During heating
O terminal : OFF
B terminal : ON
During cooling
O terminal : ON
B terminal : OFF
No Demand
The terminal continues the previous ON / OFF
state
Off mode
The terminal state continues the state before en-
tering off mode
System Wiring Diagrams
For system diagrams, see the included fold-out
iComfort
®
M30 Smart Thermostat System Diagrams
sheet.
Connecting Thermostat Wiring
Use “Table 1. Terminal Designations” on page 7
for connecting the thermostat wiring to the back
plate terminals.
If this is a replacement thermostat, connect
to terminals as noted when removing the old
thermostat. If terminals were different on old
thermostat, use “Table 1. Terminal Designations” on
page 7 and wiring diagrams provided in the kit.
NOTE:
Remember to seal the hole in the wall with
a suitable material to prevent drafts from
entering the thermostat case. Not doing
so could affect the thermostat’s internal
temperature sensor.
Supported Configurations
See “Table 3. Supported Configurations” on page
9.
