Honeywell RTH7400 series - About Your New Thermostat; Thermostat Features

4
Do not remove wallplate yet
3 Label Wires with Tags
Label the wires using the supplied wire labels as you disconnect them.
Wire Labels
M28100
C
C
MCR33823
Terminal
designation
If you have an older thermostat with a
sealed mercury tube, turn to page 2
for proper disposal instructions.
Terminal designation
C
C
MCR31537
2 Remove Old Thermostat
Remove old thermostat but leave wallplate with wires attached.
4 Separate Wallplate from New Thermostat
Remove wallplate from the new thermostat
and mount onto wall.
Wallplate
M28073