Honeywell Heat/1Cool - T841A1563 Premier 2 Stage Thermostat User Manual page 87

Existing
Function
Terminals
or
Common
C X
or
Power
R R1
Power Reset
R2
or
1st Stage
Y1 Y
Comp.
2nd Stage
Y2
Comp.
1st Stage
–
Heat
Aux. Heat
W2
Fan
G
C/O Valve
B
Heat
C/O Valve
O
Cool
or
System Monitor/
X L
System Defrost
EM. Heat
–
Multiple Aux.
–
Heat Loads
LED Indication
–
Filter
F
2nd Stage
Compressor
–
Configure O/B (select models) in Installer Setup.
Both first stage heat and cool are connected to Y terminal.
Terminal is for multiple auxiliary heat loads such as contactors, sequencers,
or relays.
If provided on original equipment.
Relay (typically R8222B1067) required if outdoor section has reset shunt
relay and malfunction light indication is desired on thermostat. See page 11.
Terminal X (C) must be connected to transformer common.
T834C2135 T841B1042
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
– – –
– – –
TYPICAL THERMOSTATS AND SUBBASES — HONEYWELL MODEL NUMBER
T874G1659/Q674C1330
Electronic Replacement or Upgrade
Chronotherm ®
III
C C
R R
– –
or
Y1 Y Y
– –
W1 W1
W2 W2
G G
B B
O O
L L
E E
– –
X1 X2 –
– –
– –
Do not remove factory-installed jumper.
Optional CHECK LED on T8611G1004. See Fig. 26.
Field-installed X2 to X jumper (provided).
When W2 is not used, configure W2 cycle rate to NC.
Optional LED indication activated with completed circuit on X1 and
X2 terminals.
LED is energized when terminal is powered.
L terminal is powered continuously in Emergency Heat Position.
T874H1096/Q674C1330
MAMMOTH
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 O/B O O
L L L
E E E
– – –
– – X1
– – –
– – –
T874Y1005/Q674E1353
C
R
–
Y1/W1
– Y2
–
Aux.
G
O/B O/B
O/B O/B
L
E
–
X2 –
–
W2
M13169
70-6627 • 85