T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
60-2485—874
C1207 78 Obsolete. Friedrich; S
y
stem: OVERRIDE-AUTO-OFF;
used with T874P1014.
T8600D2028
(
pro
g
rammable
)
Wirin
g
differences
(
old=new
)
:
L=R, W=O; W-Y
j
umper
re
q
uired; ni
g
ht setback.
C1215 97 Obsolete. Friedrich part no. AQ5315; S
y
stem:
OVERRIDE-AUTO-OFF; 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; ni
g
ht setback.
C1223 73 Obsolete
. Friedrich part no. AQ5323; used on s
y
stems
re
q
uirin
g
ni
g
ht setback contacts; used with
T874G1584.
Y594H1012
a
Wirin
g
differences
(
old=new
)
:
Y1=O, Y2=Y, L=R, R=none; R-
L
j
umper re
q
uired; 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.
C1249 164 Includes MALFUNCTION LED; used with T874H1062;
used in Y594H1012.
Y594H1012
a
C1256 73 Obsolete. Used with T874G1618.
Y594H1012
a
Wirin
g
differences
(
old=new
)
:
Y1=O, Y2=Y, L=R, R=none; R-
L
j
umper re
q
uired; 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.
C1264 165 Obsolete. Carrier part no. HH93AZ193; used with
T874L1018
(
HH07AT178
)
.
See OEM for
replacement.
C1280 181,
203
Obsolete. McQua
y
heat pump; part no. 60687401;
COMP FAULT LED; used with T874K1019, L1034.
T8600D2028 See thermostat description for
replacement information.
C1298 76,
225
Obsolete
. McQua
y
part no. 60684801; SERVICE LED;
used with T874A1523, A1549, D1918.
See OEM for
replacement.
C1306 75 Obsolete
. McQua
y
part no. 60685001; SERVICE LED;
sprin
g
return momentar
y
s
y
stem switch position; used
with T874A1325.
See OEM for
replacement.
C1314 72 Obsolete
. Trane part no. BAS-0429; used with T874A-F. Q674C1058
C1322 173 Obsolete. Carrier part no. HH93AZ199; FAULT and CK
FILTER LEDs; used with T874H1070
(
HH07AT166
)
,
T874H1088
(
HH07AT167
)
or T874H1153
(
HH07AT167
)
; used in Y594H1053.
Y594H1012
a
Wirin
g
differences
(
old=new
)
:
2=X.
C1330 177 Obsolete
. LSI-Mammoth part no. 71115201; RESET
LED; used on s
y
stems with ni
g
ht setback contacts;
used with T874G1659, H1096; used in Y594G1427,
H1020.
Y594H1012
a
Wirin
g
differences
(
old=new
)
:
R1=R; R2=L.
C1355 74 Friedrich part no. AQ355; SERVICE LED; used with
T874H1112.
Y594H1012
a
Wirin
g
differences
(
old=new
)
:
Y1=O, Y2=Y; L-R
j
umper
re
q
uired.
C1363 99 Obsolete. McQua
y
part no. 61202601; SERVICE LED;
auto fan in heat and cool mode; used with T874C.
T874C1125/
Q674B1075
a
Replacement has HEAT-OFF-
COOL.
219 Obsolete. Used with T874C. See OEM for
replacement.
220 Obsolete
. Used with T874W. See OEM for
replacement.
100 Obsolete
. Used with T874W. T8611M2025
(
pro
g
rammable
)
Includes ni
g
ht setback.
C1371 72 American Standard part no. ASYSTAT616. Q674C1058
Table 9. Q674 Subbase Cross Reference.
Model
Number
Fig.
No. Description
Q674 Trade
Replacement Remarks
a
Both the thermostat and subbase must be replaced.