51
Installation Instructions
The T5900 Thermostat Backplate
W3/AUX
3rd stage heat circuit/2nd stage
aux heat/humidification/dehumidication
W2
2nd stage heat circuit/1st stage aux heat
W1/O/B
1st stage heat circuit/reversing valve
Y2
2nd stage compressor relay
Y1
1st stage compressor relay
G
fan relay
R
24 VAC return
C
24 VAC common
SENSOR
remote/outdoor/supply/return sensor connections
IMPORTANT: This thermostat requires both R (24 VAC Return) and
C (24 VAC Common) be connected to the backplate terminals.
To remove the thermostat backplate:
Using the Finger Pull Areas, pull the
front housing away from the backplate.
Look for these tabs to locate
the pull areas
Pull out with thumbs in these areas
Backplate
Front Housing
W3/A
UX
W2
W1/O/B
Y2
Y1
SENSOR
NOTE:
The backplate does not fully
cover a full size vertical junction
box. The ACC-WPLWH ColorTouch
Wallplate or a single-gang,
horizontally mounted junction box
would be needed for that type of
installation
