Wiring conventional systems: forced air and hydronics
Shaded areas below apply only to TH6320U/TH6220U or as otherwise noted.
1H/1C System (1 transformer)
R
Power [1]
Rc
[R+Rc joined by Slider Tab] [2]
Y
Compressor contactor
C
24VAC common [3]
W
Heat relay
G
Fan relay
Heat-only System
R
Power [1]
Rc
[R+Rc joined by Slider Tab] [2]
C
24VAC common [3]
W
Heat relay
Heat-only System (Series 20) [5]
R
Series 20 valve terminal "R" [1]
Rc
[R+Rc joined by Slider Tab] [2]
Y
Series 20 valve terminal "W"
C
24VAC common [3]
W
Series 20 valve terminal "B"
Heat-only System
(power open zone valve) [5]
R
Power [1]
Rc
[R+Rc joined by Slider Tab] [2]
W
Valve
C
24VAC common [3]
NOTES
Wire specifications: Use 18- to 22-gauge thermostat wire. Shielded cable is not required.
[1] Power supply. Provide disconnect means and
overload protection as required.
[2] Move R-Slider Tab on UWP to the R setting.
For more information, see "Setting Slider Tabs"
on page 3
[3] Optional 24VAC common connection.
1H/1C System (2 transformers)
R Power (heating transformer) [1]
Rc Power (cooling transformer) [1]
Y
Compressor contactor
C
24VAC common [3, 4]
W
Heat relay
G
Fan relay
Heat-only System with Fan
R
Power [1]
Rc [R+Rc joined by Slider Tab] [2]
C
24VAC common [3]
W
Heat relay
G
Fan relay
Cool-only System
R
Power [1]
Rc [R+Rc joined by Slider Tab] [2]
Y Compressor contactor
C
24VAC common [3]
G
Fan relay
2H/2C System (1 transformer) [6]
R
Power [1]
Rc
[R+Rc joined by Slider Tab] [2]
Y
Compressor contactor (stage 1)
C
24VAC common [3]
W
Heat relay (stage 1)
G
Fan relay
W2 Heat relay (stage 2)
Y2
Compressor contactor (stage 2)
[4] Common connection must come from cooling
transformer.
[5] In ISU set Heat system type to Radiant Heat.
Set number of cool stages to 0.
[6] In Installer Setup, set system type to
2Heat/2Cool Conventional.
4