T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
60-2485872
B1240 234 Obsolete. Northrup heat pump; AUX HEAT LED; used
with T874G1139. Y594G1252aWirin
g
differences
(
old=new
)
:
Y1=Y2, W1=W2; EM HT
s
y
stem switch position is not
operational.
B1257 56 Obsolete. LSI-Mammoth; RESET LED; automatic fan
operation in heat and cool modes; used with
T874C1471; used in Y594C1314.
Q674B1075 Replacement has no LED.
B1273 57 Obsolete. McQua
y
part no. 860-442727B-00; S
y
stem:
OVERRIDE-HEAT-OFF-COOL; used with T874P1006. T874A1036/
Q674B1075a
Wirin
g
differences
(
old=new
)
:
Y=Y1, L=R, W=O;
j
umper Y1-
W1; no ni
g
ht setback.
T8600D2028
(
pro
g
rammable
)
Wirin
g
differences
(
old=new
)
:
L=R, W=O; W-Y
j
umper
re
q
uired; ni
g
ht setback.
B1281 191 Obsolete. Carrier no. 42QH400103; S
y
stem: HEAT-
OFF-COOL; Fan: LOW-HI-CONT; international
s
y
mbols on switches; used with T874R1319.
See OEM for
replacement.
B1299 46 Obsolete. Heil Quaker part no. HQ521714HW. Q674B1075
B1307 62 Obsolete. Includes two LEDs; used with T874F1122. T874F1015/
Q674D1040a
Replacement has no LEDs.
B1315 68 Obsolete. Friedrich part no. AQ5215; OVERRIDE and
SERVICE LEDs; used with T874P1022, P1030. T8600D2028
(
pro
g
rammable
)
Wirin
g
differences
(
old=new
)
:
L=R, W=O; W-Y
j
umper
re
q
uired; set dual fuel switch
to electric heat; ni
g
ht setback.
B1331 65 Obsolete. Includes two LEDs; used with T874A1002. Q674B1034 Replacement has no LEDs.
B1349 67 Obsolete. Goettl part no. 372072; used with
T874R1541. Y594R1300a
B1356 138 Obsolete. Carrier part no. HH93AZ192; used with
T874L1018
(
HH07AT178
)
.See OEM for
replacement.
B1372 44 Obsolete. Trane part no. BAS-0427; used with T874A-D. Q674B1018
B1380 46 Obsolete. Trane part no. BAS-0426; used with T874A-D. Q674B1075
B1398 48 Obsolete. Trane part no. BAS-0431; FILTER LED;
used with T874A-D. Q674B1034 Replacement has no LEDs.
B1406 172 Obsolete. Carrier part no. HH93AZ200; FAULT and
CHECK FILTER LEDs; used with T874H1070
(
HH07AT166
)
, T874H1088
(
HH07AT167
)
or
T874H1153
(
HH07AT167
)
; used in Y594H1046.
T874A1150/
Q674B1075a
Wirin
g
differences
(
old=new
)
:
Y=Y1;
j
umper W1-Y1;
replacement has no LEDs.
B1414 51 American Standard
(
Trane
)
part no. ASYSTAT1617. Q674B1075
B1448 215 Obsolete. Carrier part no. HH93A2202; Fan: Lo-Med-
Hi
g
h-On; used with T874L1059. See OEM for
replacement.
B1455 214 Obsolete. Carrier part no. HH93AZ208; Fan: Lo-Med-
Hi
g
h-On; used with T874A1424
(
HH07AT194
)
.See OEM for
replacement.
B1463 45 Trol-A-Temp; used with T874D1801. None See Trol-A-Temp.
B1471 45 Trol-A-Temp; used with T874D1827. None See Trol-A-Temp.
B1513 53 Obsolete. TRADELINE; exact replacement for
Q674B1125
(
York part no. 2TB04700324
)
.Q674B1075 Jumper RC-RH; replacement
has no LOCKOUT LED.
B1521 53 Obsolete. Carrier Canada part no. HH93AZ179-W;
g
ra
y
color; includes LOCKOUT LED and removable
j
umpers between RC and RH terminals.
Q674B1075 Jumper RC-RH; replacement
has no LOCKOUT LED; bei
g
e
color.
B1539 45 Obsolete. Carrier part no. HH93AZ139; used with
T874D2049; used in Y594D1370. Q674B1034
B1547 237 Obsolete. TRADELINE;
g
ra
y
color; used with
T874C1810; used in Y594C1389. Y594C1389
Table 9. Q674 Subbase Cross Reference.
Model
Number Fig.
No. Description Q674 Trade
Replacement Remarks
aBoth the thermostat and subbase must be repl aced.