SmartCommand Thermostat
Installation Manual
20

Installation overview

Before you remove an existing thermostat and install the SmartCommand thermostat, follow these guidelines:
Record existing wiring information.
Do the be nch test.
Ch eck WDU wiring before applying power to the control unit.
Be sure to install a freez e protection de vice as required.
Figure 14 shows the standard thermostat wiring versus retrofit applications.
Figure 14. Wiring over view
75
XHeating and cooling
system
Heating and cooling
system
Old system
New system
SmartCommand WDU SmartCommand
control unit
Replace existing thermostat
with SmartCommand WDU
Insert control unit
into existing wiring
4, 5, or 6 wires
as original installation
4, 5, or 6 wires
18 Ga thermostat wiring
4 wires