User Guide

On this thermostat, the labels for conventional systems are on the inside of the connectors and
the labels for heat pump systems are on the outside of the connectors.
If you know what kind of system you have, use the labels for that system.
If you're unsure, the color of the wires can be a clue. For example, in the photo above, the
connector labeled O/B for heat pumps is also labeled W for conventional systems.
The color of the wire that has been inserted into the O/B and/or W connector in the photo above
is orange. Therefore, you might guess that this system is a heat pump. However, the colors of the
wires don't always correspond to their labels, so it’s best to consult the user guide for your
thermostat to be sure.
If the same connector label lists a second letter
in addition to O or B then that connector can be used for heat pump or conventional systems. In
the example below the connector labeled W/B is actually a W wire, not a B wire in this case,
because the heating system is a conventional heating system not a heat pump. The white color of
the wire is another clue.