3. With all wires labeled, remove them from the old unit. Make sure the wires do
not fall back inside the wall. You can wind them around a pencil to keep them
from falling.
4. Loosen all screws on the old thermostat and remove it from the wall.
Figure 2: Labeling wires
Wiring
Make sure your wires are labeled. This may require you to find the other end
connection for each wire on your heating or air conditioning equipment and read
the label there. See “Wire reference chart” on page 16 for more information on
wire labels from different HVAC system makers.
Note:
The thermostat runs on three AA alkaline batteries and/or the C wire if
available. If you do not have a C wire, you can run a new wire from the HVAC or
use a standard 12 to 24 VAC or VDC wall transformer. An external power source
is required when using a radio module.
Note:
If you have both RH and RC you need to remove the jumper wire between
these two terminals (see Figure 3 on page 5).
Prepare the wires
Follow these guidelines for safe and secure wire connections:
• You will need at least 2.6 in. of wire for each connection to the thermostat. If
you do not have enough wire, splice additional wire to allow enough slack.
• Terminals accept 16 to 22 AWG wire.
• Fan out wires below the mounting hole (see Figure 3 on page 5).
• Remove insulation 1/8 in. from the tip of each wire (see Figure 3 on page 5).
• When handling, take care not to damage the labels for each wire.
4
IS-ZW-TSTAT-300 Advanced Thermostat Installation Guide
