T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
60-2485—8 84
L1405 106 Obsolete. BDP heat pump; part no. HH641501; used
with T874R1335; used in Y594R1201.
Y594R1243a
L1413 133 Obsolete. Fedders heat pump; used with T874R1343;
used in Y594R1219.
Y594R1425aWiring differences (old=new):
K=E, C=X, Z=L; remove
W1-Y jumper.
L1421 125 Obsolete. Coleman heat pump; used with T874R1368;
used in Y594R1235.
Y594R1797a
L1439 131 Obsolete. Carrier part no. HH93AZ187; SUPL HEAT
LED; System: SUPL HT-HEAT- COOL; used with
T874R1384 (HH07AQ170).
Q674L1207 or
Y594G1393a
Wiring differences (old=new):
C=X.
L1447 128 Obsolete. Williamson heat pump; three LEDs; used
with T874R1392; used in Y594R1250.
Y594R1425aWiring differences (old=new):
A=L.
L1454 131 Obsolete. Carrier part no. HH93AZ197; SUPL HEAT
LED; used with T874R1384 (HH07AQ170).
Y594R1393aWiring differences (old=new):
C=X.
L1462 113 Obsolete. LSI heat pump; part no. 104710002; used
with T874R1400.
Y594R1243aWiring differences (old=new):
X1=X.
L1496 136 Obsolete. Trane heat pump; used with T874R1426;
used in Y594R1284.
Y594R1763a
L1504 134 Rheem part no. 41-20796-24; used with T874R1442,
R1434, R1459; used in Y594R1631, R1649, R1854.
Y594R1300a
L1512 108 Includes two LEDs; used with T874R1467; used in
Y594R1292.
Y594R1292a
L1520 123 Includes EM HEAT and AUX HEAT LEDs; used with
T874R1475; used in Y594R1300.
Y594R1300a
L1538 130 Obsolete. Snyder General heat pump; used with
T874R1483, R1517, R1566 and C815A1005; used in
Y594R1318, R1342, R1375.
Y594R1763aWiring differences (old=new):
C=B, W1=W, E=X2, X=F.
132 Obsolete. Used with T874R1574, R1582; used in
Y594R1383, R1391.
Y594R1243aWiring differences (old=new):
C=X, X=L, W=W2.
L1546 140 Obsolete. Rheem part no. 41-20797-21; three LEDs;
used with T874W1031 and C815A1005; used in
Y594W1022.
T8611M2025
(programmable)
Includes night setback.
L1553 137 Obsolete. Includes three LEDs; used with T874R1491;
used in Y594R1326.
Y594R1615a
L1561 121 Obsolete. Used with T874C1638; used in Y594C1322. Y594C1322aUse Y594C1322 when T874C
is used.
123 Obsolete. Used with T874R. Y594R1243aUse Y594R1243 when T874R
is used.
L1579 135 Obsolete. Carrier heat pump; part no. HH93AZ198;
SUPL HEAT LED; used with T874R1384
(HH07AQ170).
Y594R1243aWiring differences (old=new):
C=X.
L1587 168 Used with T874R1616; used in Y594R1425. Y594R1425a
L1595 200,
201
Obsolete. Miller heat pump; used with T874R1624 or
T874R1202; used in Y594R1433.
Y594R1243a or
Y594R1763a
L1603 134 Obsolete. Used with T874R1632. Y594R1243a
L1611 136 Obsolete. American Standard heat pump; part no.
WY28X235; used with T874R1657; used in
Y594R1441.
Y594R1763a
L1637 207 Obsolete. Carrier heat pump; part no. HH93AZ195;
used with T874J1002 (HH07AT175) or T874J1010
(HH07AT165).
Y594J1001a
Table 9. Q674 Subbase Cross Reference.
Model
Number
Fig.
No. Description
Q674 Trade
Replacement Remarks
aBoth the thermostat and subbase must be replaced.