Honeywell T874 Product Data page 74

T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
Model Fig.
Number No.
C1207 78 Obsolete. Friedrich; System: OVERRIDE-AUTO-OFF;
used with T874P1014.
C1215 97 Obsolete. Friedrich part no. AQ5315; System:
OVERRIDE-AUTO-OFF; OVERRIDE and SERVICE
LEDs; used with T874P1022, P1030.
C1223 73 Obsolete. Friedrich part no. AQ5323; used on systems
requiring night setback contacts; used with
T874G1584.
C1249 164 Includes MALFUNCTION LED; used with T874H1062;
used in Y594H1012.
C1256 73 Obsolete. Used with T874G1618.
C1264 165 Obsolete. Carrier part no. HH93AZ193; used with
T874L1018 (HH07AT178).
C1280 181, Obsolete. McQuay heat pump; part no. 60687401;
203 COMP FAULT LED; used with T874K1019, L1034.
C1298 76, Obsolete. McQuay part no. 60684801; SERVICE LED;
225 used with T874A1523, A1549, D1918.
C1306 75 Obsolete. McQuay part no. 60685001; SERVICE LED;
spring return momentary system switch position; used
with T874A1325.
C1314 72 Obsolete. Trane part no. BAS-0429; used with T874A-F.
C1322 173 Obsolete. Carrier part no. HH93AZ199; FAULT and CK
FILTER LEDs; used with T874H1070 (HH07AT166),
T874H1088 (HH07AT167) or T874H1153
(HH07AT167); used in Y594H1053.
C1330 177 Obsolete. LSI-Mammoth part no. 71115201; RESET
LED; used on systems with night setback contacts;
used with T874G1659, H1096; used in Y594G1427,
H1020.
C1355 74 Friedrich part no. AQ355; SERVICE LED; used with
T874H1112.
C1363 99 Obsolete. McQuay part no. 61202601; SERVICE LED;
auto fan in heat and cool mode; used with T874C.
219 Obsolete. Used with T874C.
220 Obsolete. Used with T874W.
100 Obsolete. Used with T874W.
C1371 72 American Standard part no. ASYSTAT616.
Both the thermostat and subbase must be replaced.
a
60-2485—8
Table 9. Q674 Subbase Cross Reference.
Description
74
Q674 Trade
Replacement
T8600D2028 Wiring differences (old=new):
(programmable) L=R, W=O; W-Y jumper
required; night setback.
T8600D2028 Wiring differences (old=new):
(programmable) L=R, W=O; W-Y jumper
required; night setback.
Wiring differences (old=new):
Y594H1012
a
Y1=O, Y2=Y, L=R, R=none; R-
L jumper required; no night
setback.
T8600D2028 Wiring differences (old=new):
(programmable) L=R, W=O; W-Y jumper
required; night setback.
Y594H1012
a
Wiring differences (old=new):
Y594H1012 a
Y1=O, Y2=Y, L=R, R=none; R-
L jumper required; no night
setback.
T8600D2028 Wiring differences (old=new):
(programmable) L=R, W=O; W-Y jumper
required; night setback.
See OEM for
replacement.
T8600D2028 See thermostat description for
replacement information.
See OEM for
replacement.
See OEM for
replacement.
Q674C1058
Wiring differences (old=new):
Y594H1012 a
2=X.
Wiring differences (old=new):
Y594H1012 a
R1=R; R2=L.
Wiring differences (old=new):
Y594H1012 a
Y1=O, Y2=Y; L-R jumper
required.
T874C1125/ Replacement has HEAT-OFF-
COOL.
Q674B1075 a
See OEM for
replacement.
See OEM for
replacement.
T8611M2025 Includes night setback.
(programmable)
Q674C1058
Remarks