Q672-Q674 Subbase Cross Reference - Honeywell T874 Product Data

Model Number
Q672A System: HEAT-AUTO-COOL, Fan: AUTO-ON
A1005 Standard OEM
A1013 TRADELINE
A1021 RC-RH jumper
A1039 RC-RH jumper; Chek Lite
Q672B System: HEAT-OFF-COOL, Fan: AUTO-ON
B1004 Standard OEM
B1012 Isolated G terminal.
B1020 System: HEAT-OFF-RESET-COOL
B1038 TRADELINE
B1046 Heat pump circuit; used with T872R1008.
B1053 RC-RH jumper
B1061 Chek Lite
B1079 Auto fan operation in heat and cool.
B1087 Carrier no. HH93AZ078; RC-RH jumper.
B1095 Carrier no. HH93AZ084; RC-RH jumper.
B1103 Addison; heat pump circuit; used with
T872R1016.
B1111 Carrier no. HH93AZ080; isolated G terminal.
B1129 Trane special circuit; used with T872T1004.
B1137 RC-RH jumper; isolated G terminal.
B1145 Fedders special
B1152 Fedders special; auto fan operation in heat
and cool.
B1160 Lennox; heat pump circuit; used with
T872R1024; includes compressor lockout in
EM. HT.
B1178 General Electric no. AY28X107; auto fan
operation in heat and cool.
B1186 Trane; isolated G terminal; Filter LED.
B1194 General Electric no. AY28X124; auto fan
operation in heat and cool.
B1202 Lennox no. P-8-11223; heat pump circuit; used
with T872R1040.
B1210
B1228 General Electric no. BAY28X137; isolated
G terminal.
B1236 Carrier no. HH-93AZ079; RC-RH jumper;
LOCKOUT LED indicates compressor lockout
switch activated.
B1244 Friedrich; heat mode changeover; used with
T872R1115.
B1251 Used with T872W1035 and C815A1043.
a
When replacing a T872 Thermostat and Q672 Subbase, always replace both the thermostat and subbase.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
Table 7. Q672-Q674 Subbase Cross Reference.
Description
39
Q674 Trade
Replacement
a
Q674A1019
Q674A1019
Q674A1019 RC-RH jumper required.
Q674A1019 RC-RH jumper required.
Q674B1034
Q674B1018
Q674B1034 Used system off as reset position.
Q674B1034
Y594R1425 Wiring differences (old=new):
W1=Y1, W=W2.
Q674B1034 RC-RH jumper required.
Q674B1034
Q674B1075
Q674B1075
Q674B1034
Y594R1425 Wiring differences (old=new):
W=W2; W1-Y1 jumper required.
Q674B1018
None
Q674B1018 RC-RH jumper required.
Q674B1034 RC-RH jumper required.
Q674B1075
Y594R1243 Wiring differences (old=new):
V-VR=R, M=Y, Y=W2, F=G, R=O.
Q674B1075
Q674B1018
Q674B1075 Set T874 stage-1 anticipator for
combined load of heat relay and fan
relay.
Y594R1243 Wiring differences (old=new):
V-VR=R, M=Y, Y=W2, F=G, R=O.
None
Q674B1018
Q674B1034 RC-RH jumper; LED cannot be
provided in TRADELINE model.
T874C1018/ Wiring differences (old=new): C=no
Q674B1034 connection; RC-RH and W1-Y1
jumpers required.
Y594W1014
Remarks
60-2485—8