TRADELINE
The T874G Thermostats and Q674F,J Subbases pro-
vide 24 to 30 Vac control of 2-stage heating and 1-stage cool-
ing heat pump systems with automatic changeover. Stage 1
Thermostat/
Thermostat/
Subbase
Subbase
Model
Package
Numbers
Y594G1252
T874G1246/
Q674F1212
—
T874G1246/
Q674F1410
Y594G1419
T874G1642/
Q674F1444
c
Y594G1476
T874G1741/
Q674F1477
d
Y594G1534
T874G1824/
Q674F1477
Y594G1526
T874G1626/
Q674F1436
—
T874D1165
or
T874E1016/
Q674F1543
Y594G1567
T874G1865/
Q674J1209
c
Y594G1575
T874G1873/
Q674J1225
Y594G1633
T874G1972/
Q674F1584
a
EM.HT. also shows compressor malfunction.
b
When switch is in EM. HT. position, the emergency heat will operate continuously until system switch is moved to another position.
c
Thermostat is white and subbase is gray.
d
Sold only in Australia; degrees C.
e
LED indicator is not labeled but may be connected per user's requirements. See Fig. 9.
®
for Heat Pump Systems
Installation Instructions for the Trained Service Technician.
TABLE 1—THERMOSTAT/SUBBASE SPECIFICATIONS.
LED
Indication
AUX.HT.,
EM.HT.-OFF-
a
EM.HT.
HEAT-AUTO-
AUX.HT.,
EM.HT.
a
EM.HT.
HEAT-AUTO-
AUX.HT.,
OFF-EM.HT.-
EM.HT.,
HEAT-AUTO-
CHECK
AUX.HT.,
OFF-EM.HT.-
EM.HT.
HEAT-AUTO-
e
(RED)
OFF-EM.HT.-
HEAT-AUTO-
EM.HT.
EM.HT.-
AUTO-OFF
EM.HT.
EM.HT.-
AUTO-OFF
AUX.HT.,
OFF-EM.HT.-
EM.HT.
HEAT-AUTO-
J.H. • Rev. 7-94 •
T874G Thermostats
and Q674F,J Subbases
heat and cool anticipation is fixed voltage type; stage 2 heat
anticipation is adjustable (except as noted). See Table 1 for
specific T874G/Q674F,J combinations and specifications.
Switching
System
Fan
Changeover
AUTO-
ON
COOL
b
-OFF-
AUTO-
ON
COOL
AUTO-
ON
COOL
AUTO-
ON
COOL
AUTO-
ON
COOL
AUTO-
ON
AUTO-
ON
AUTO-
ON
COOL
• ©Honeywell Inc. 1994 • Form Number 69-0435—10
M3375
Comments
AUTO,
TRADELINE
COOL
AUTO,
Separate W1 and Y1
COOL
terminals; TRADELINE
subbase.
AUTO,
SUPER TRADELINE
HEAT OR
includes factory-installed
COOL
jumper across W1 and Y1;
fixed stage 2 heat anticipation.
Isolated CHECK LED
includes jumper for connecting
X2 terminal to X or R for
power.
AUTO,
TRADELINE
HEAT
AUTO
TRADELINE
replacement for York model
no. 2TB04700524. Thermostat
not included; order separately.
AUTO,
TRADELINE
COOL
replacement for York model
nos. 2TH11702424 and
6TH11702424.
AUTO,
TRADELINE
COOL
replacement for York model
nos. 2TH11702424 and
6TH11702424.
AUTO,
TRADELINE
HEAT OR
COOL
Application
See
Fig.
®
5
6
®
7
®
;
®
8
®
subbase; exact
9
®
; exact
10
®
; exact
10
®
11