Honeywell Heat/1Cool - T841A1563 Premier 2 Stage Thermostat User Manual page 81

IMPORTANT: Replace separate indoor/outdoor transformers with single 75 VA transformer. See diagram on page 78.
Existing
Function Terminals
Common
Power Indoor
Common Outside
Common Outside
Compressor Stage 1
Compressor Stage 2
Auxiliary Heat
Fan
C/O Valve
Cool
C/O Valve
Heat
System Monitor/
System Defrost
Em. Heat
Thermistor
1st Stage Heat
LED Indication
IMPORTANT: When subbase system is in AUTO position, equipment will
operate in COOL mode only (Q674F1022).
For emergency heat indication, jumper E and X2. For auxiliary heat
indication, jumper W2 and X2. For any X2 functions, X1 must be connected to
transformer common.
For proper operation of auxiliary heat connect Y to W3 or AUX terminal.
Terminal must be connected to the transformer common.
W1 to Y1 jumper required.
TYPICAL THERMOSTATS AND SUBBASES — HONEYWELL MODEL NUMBER
T872G1323/Q672L1201
T874D1207/Q674L1199
Electromechanical
X X1
VR R
X –
V
M Y1
M2 Y2
Y W2
F G
R O
– B
L X2
E E
A –
– W1
– –
T874D1033
T874D1207/Q674L1389
Electronic Replacement or Upgrade
Chronotherm ® III
C C
R R
– –
Y Y1
Y2 Y2
W2 –
W3 W3
G G
O O/B
B O/B
L L
E E
– –
– –
X1 X2 –
Optional LED indication activated with completed circuit on X1 and
X2 terminals.
Replace separate indoor and outdoor transformers with one 75 VA
transformer. See page 78 for wiring diagram.
Configure O/B (select models) in Installer Setup.
LED is energized when terminal is powered.
L terminal is powered continuously when thermostat is in Em. Ht. position.
LENNOX
HP11
Chronotherm IV
C C
R R
– –
Y1 Y1/W1
Y2 Y2
– W2
W3 Aux.
G G
O/B O/B
O/B O/B
L L
E E
– –
– –
X1 X2 –
T874D1199
70-6627 • 79
M13156