Honeywell Heat/1Cool - T841A1563 Premier 2 Stage Thermostat User Manual page 79

IMPORTANT: Replace separate indoor/outdoor transformers with single 75 VA transformer. See diagram on page 78.
Existing
Function
Terminals
Common X
Indoor
Common X3
Outside
Power VR
Indoor
Power V
Outside
Compressor M
1st Stage –
Heat
or
Auxiliary W1 Y
Heat
Fan F
C/O Valve –
Heat
C/O Valve R
Cool
System Monitor/ L
System Defrost
Em. Heat E
Thermistor A
Multiple Aux. –
Heat Loads
LED Indication –
Configure O/B (select models) in Installer Setup.
Tape off. Not used.
R8222B1067 Relay required to operate system monitor light (emergency
heat LED) on TRADELINE replacement thermostats. See page 10.
Terminal X (C) must be connected to transformer common.
Do not remove factory-installed jumper.
Optional Check LED on T8611G1004. See Fig. 26.
TYPICAL THERMOSTATS AND SUBBASES — HONEYWELL MODEL NUMBER (CUSTOMER PART NUMBER)
T872G1067/Q672L1029 (P-8-11222)
T872R1024/Q672L1003
T872R1040/Q672L1029 (P-8-11221)
T872R1131/Q672L1144
Electromechanical
X X X
– – –
R R R
– – –
Y Y Y1
– W1 W1
W2 W2 W2
G G G
B B B
O O O
L
E E E
– – –
W3 W3 W3
– X2 X1 X2
Electronic Replacement or Upgrade
Chronotherm ®
III
C C
– –
R R
– –
or
Y1 Y Y
W1 W1
W2 W2
G G
B B
O O O
L L
E E
– –
– –
X1 X2 –
Field-installed X2 to X jumper (provided).
Use Aux terminal for Auxiliary heat and configure W2 cycle rate to NC.
If separate transformers are used, replace with one 75 VA transformer, as
shown on page 78.
LED is energized when terminal is powered.
L terminal is powered continuously when thermostat is in Em. Ht. position.
T874C1448/Q674L12165 (24F5101/24F5901)
T874R1020/Q674L1025 (24F5401/24F6101)
T874R1178/Q674L1165 (24F5601/24F5901)
Chronotherm
IV
C C C
– – –
R R R
– – –
Y1 Y Y1
W1 W1 W1
W2 W2 W2
G G G
or or
B O/B B B
or or
O/B O O
L L L
E E E
– – –
– – –
– – X1 X2
LENNOX
HP9, HP10
C
–
R
–
Y1/W1
–
Aux.
G
O/B O/B
O/B O/B
L
E
–
–
–
M13163
70-6627 • 77