Honeywell Heat Pump T8611M User Manual

T8611M  
(7-Day Programming)  
Chronotherm III™  
Heat Pump Thermostats  
The T8611M Chronotherm III Programmable  
Thermostat provides automatic control of multi-  
stage heat pump systems and offers users the  
highest standard of comfort and convenience  
available with energy savings.  
Fullseven-dayprogramcapability;differentsched-  
stat indicates system is energized.  
ules may be selected for every day.  
AUX. HT., EM. HT., CHECK LEDs available on  
Can be programmed in hand (with batteries in-  
stalled) or on the wall to provide up to four tem-  
perature periods per day.  
select models.  
Automatic heat/cool changeover.  
Batteriesincludedprovidepowertomaintainclock  
Large digital clock (liquid crystal display) indi-  
cates continuous time-of-day, day-of-week, cur-  
rent period and room temperature.  
and memory during power failures.  
Switchingsubbasewithwiringterminalsincluded.  
Powered directly from control transformer.  
Model available with separate sensor for remote  
AdaptiveIntelligentRecoverybringsroomtem-  
perature to programmed temperature at program-  
med time, maximizing comfort and energy sav-  
ings.  
Temperature control program maintains tempera-  
ture within 1° F of setpoint.  
CONTENTS  
Specifications ................................................. 2  
Ordering Information ..................................... 2  
Selection/Application ..................................... 5  
Installation ................................................... 12  
Checkout....................................................... 18  
Programming The Thermostat ..................... 20  
Operating The Thermostat ........................... 25  
Operation ..................................................... 27  
Troubleshooting ........................................... 29  
Glossary ....................................................... 30  
Table of Contents ......................................... 32  
Temporaryprogramoverrideavailablebyusing—  
—WARMER and COOLER keys.  
—SKIP next period key.  
—CHANGE to last period key.  
HOLDTEMPkeyprovidedforindefiniteprogram  
override (vacation/holiday).  
Installer self-test with time delay override saves  
installation time.  
SYSTEM light-emitting diode (LED) on thermo-  
temperature sensing.  
 
C. H. • Rev. 10-92 • ©Honeywell Inc. 1992 • Form Number 68-0076—1  
T8611M  
SPECIFICATIONS  
Fig. 1—T8611 Subbase mounting dimensions in in. [mm].  
31  
32  
1
[50]  
13  
1
16  
[46]  
3
32  
4
[104]  
5
5
16  
[135]  
5
16  
3
[83]  
3
4
4
[121]  
7 [179]  
M5181A  
Fig. 2—202905AA Remote Sensor dimensions in in. [mm].  
FRONT  
SIDE  
BACK  
2
31  
1
[51]  
32  
[50]  
31  
32  
[50]  
1
19  
[8]  
64  
3
32  
4
41  
64  
[16]  
9
64  
[104]  
[4]  
1
3
8
1
[35]  
DIA.  
2
[13]  
[25]  
1
M5244  
3
68-0076—1  
 
T8611M  
SPECIFICATIONS  
Fig. 3—Typical thermostat keypad.  
SYSTEM  
AM  
ROOM  
WED  
HEAT ON  
MIDDAY  
TEMPERATURE  
PRESENT  
SETTING  
RUN  
PROGRAM  
TIME  
SKIP  
SET  
COPY  
FROM  
NEXT  
PRESENT  
DAY/TIME  
PERIOD  
WARMER  
COOLER  
DAY  
AHEAD  
PERIOD  
CHANGE  
TO LAST  
PERIOD  
BACK  
SET  
HEAT/COOL  
HOLD  
TEMP  
CANCEL  
PERIOD  
COPY  
TO  
FAN  
COOL  
HEAT  
OFF  
ON  
AUTO  
M5360  
4
 
T8611M  
SELECTION/APPLICATION  
Selection/Application  
The T8611 Thermostat uses the latest microelectronic  
design and control technology to provide home and build-  
ing owners with the highest level of comfort available and  
optimal energy savings in a package that is easy to use and  
easy to live with.  
The following section is a guide to selection and appli-  
cation of the best thermostat to meet individual customer  
needs.  
IF RETROFIT/REPLACEMENT APPLICATION,  
CONSIDER  
• equipment requirements  
— systemswitching(manual:EM.HT.-HEAT-OFF-  
COOL,automatic:EM.HT.-HEAT-OFF-AUTO-  
COOL).  
— unique heat pump functions of emergency or  
supplemental heat, changeover on heat or cool,  
and status indication.  
PROGRAMMING  
— Table 3 lists typical applications by manufac-  
turer.  
Does the thermostat selected accommodate the  
customer’s daily schedule, lifestyle or work schedule?  
Refer to choices below.  
• existing wiring  
— Arethereenoughconductorstooperatetheequip-  
ment and the thermostat? Can a new cable be  
pulled?  
TRADELINE  
Device  
Daily Temperature  
Selection  
Programming  
T8611G,R*  
Weekday,  
Sat, Sun.  
4 heat and  
4 cool  
• existing thermostat  
— Table3isaguideforreplacingpopularHoneywell  
standard nonprogrammable thermostats with a  
T8611.  
T8611M  
7-day  
(each day  
different)  
4 heat and  
4 cool  
SECURITY  
Does the thermostat selected provide access to pro-  
gramming and the override features that will best suit the  
application? Refer to choices below.  
Typical  
Application  
Access  
Device  
*Specifications form 68-0057 for information.  
Free access to  
programming  
and adjustment/ commercial  
Home or  
owner-occupied  
T8611  
IF NEW CONSTRUCTION APPLICATION,  
CONSIDER  
override.  
building.  
• equipment type (see manufacturer’s specifications)  
— system switching required  
— status indication provided  
• control wiring—number of conductors required to  
operate equipment and thermostat.  
Restricted  
access to  
device.  
Public building. T8611 with TG512  
Locking Cover;  
T8611 with remote  
temperature  
sensing.  
IMPORTANT: The T8611 requires a conductor to trans-  
former common to provide continuous 24V power  
for thermostat operation. This feature is commonly  
specified and provided by equipment manufacturer.  
5
68-0076—1  
 
T8611M  
SELECTION/APPLICATION  
Table 2 lists features and wiring terminal functions of the TRADELINE T8611M thermostat.  
TABLE 2—T8611M FEATURES AND TERMINALS.  
T8611M  
FEATURES  
COMMENTS  
Heating Stages  
Cooling Stages  
3
2
May be applied to 2-stage heat pump systems; see wiring  
diagrams Figs. 6 and 7.  
Changeover  
Auto  
7-day  
Yes  
Programming  
SYSTEM LED  
Lights on call for heat or cool.  
EM. HEAT LED (red)  
AUX. HEAT LED (green)  
CHECK LED (yellow)  
Yes  
Lights continuously in EM. HEAT mode.  
Lights during call for final auxiliary heat stage.  
Field wired option; indicates equipment malfunction.  
Yes  
Yes  
Remote Temperature  
Sensing  
Yes  
Available on T8611M7040 only. (202905A Remote Sensor  
included).  
WIRING TERMINAL  
FUNCTION  
24 Vac Common  
C
Must be connected to control transformer to operate  
thermostat.  
24 Vac Power  
R
Y
Compressor, Stage 1  
heat and cool.  
Compressor,  
Stage 2 cool  
Y2  
If applying T8611M to 1-stage cooling system, leave Y2  
unconnected.  
Second Stage Heat  
Auxiliary (Resistive)  
Third Stage Heat  
W2  
W3  
If applying T8611M to 2-stage heat systems in which the  
second stage is compressorized, connect stage 2 to W2;  
leave W3 unconnected.  
If 2-stage heat system in which the second stage is auxillary  
(electric resistive), connect auxiliary stage to W3; leave  
W2 unconnected.  
Fan  
G
B
Changeover Heat Mode  
O/B changeover terminals are energized continuously  
following first call for cool or heat, respectively.  
Changeover Cool Mode  
O
L
System Monitor,  
Energizes EM. HEAT LED when externally powered.  
continuously energized  
in EM. HEAT mode.  
Emergency Heat  
energized on call for  
stage 1 heat in  
E
EM. HEAT mode  
Check LED terminals  
to indicate equipment  
malfunction  
X1  
S1  
X2  
S3  
See wiring diagrams for hookup alternatives.  
Remote Temperature  
Sensing  
S2  
Available on T8611M7040 only. Must be connected to  
202905A Remote Sensor for proper thermostat operation.  
6
 
T8611M  
SELECTION/APPLICATION  
TABLE 3—T8611 GUIDE FOR REPLACING POPULAR T874 AND T872 THERMOSTATS,  
BY EQUIPMENT MANUFACTURER.  
(NOTE: Also see form 70-6627, Heat Pump Thermostat Cross Reference Guide, for wiring hookup illustrations.)  
Thermostat (Subbase Included)  
Auto  
Manual  
Changeover  
Weekday,  
Sat, Sun  
Changeover  
Weekday,  
Sat, Sun  
Auto  
Changeover  
7-day  
T8611G1004  
T8611R1000  
T8611G1012 (° C) T8611R1042 (° C)  
T8611G1103 T8611R1141  
T8611M7008  
c
(Premier White) (Premier White) T8611M7040 Thermostat Subbase Thermostat Subbase  
(also see form 68-0057, Specifications)  
T874  
Q674  
T872  
Q672  
Comments  
Amana  
D1009  
D1017  
D1165  
F1022  
D1003  
D1011  
D1300  
F1026 Separate first stage  
heat/cool terminals W1, Y1.  
Arco/Comfort Maker  
a
na na  
na  
na  
na  
na  
Check LED optional;  
X = X1, jump X2 to C.  
Arco/Friedrich  
na na  
a
Changeover on heat,  
check LED optional.  
Bard  
a
N1024  
R1129  
F1261  
L1181  
N1036  
R1146  
F1299 Changeover on heat (typical),  
L1185 checkLEDoptional,equipment  
terminal W1 to thermostat B.  
Bryant, Day-Night, Payne  
G1451 F1113b G1166  
b
a,b  
a
b
F1125 Check LED optional; F = X1,  
jump X2 to C. Note: P terminal  
G1261  
J1010  
F1253  
L1371  
a
G1174  
available  
on  
manual  
changeover  
a
R1335  
Carrier  
L1405  
(T8611R) models only.  
a
G1055  
G1071  
G1121  
J1035  
L1041  
L1397  
P1005  
G1075  
G1158  
G1182  
G1273  
G1307  
G1257  
J1054 Check LED optional (typical)  
L1052  
L1169  
J1002  
J1028  
D1074  
L1371  
L1074  
F1059  
F1030  
F1063  
E1114  
E1042  
L1116  
Multistage heat pump  
No Supl. Ht. function  
No Supl. Ht. function  
Multistage heat pump  
D1264  
Command Aire  
H1005 C1041  
G1352 C1066  
H1009 C1086 No AUX. HEAT or EM.  
HEAT required; Y1 = 0  
a No CHECK LED.  
b Dual transformer requires conversion to single transformer.  
c Model includes separate sensor for remote temperature sensing.  
(continued)  
68-0076—1  
7
 
T8611M  
SELECTION/APPLICATION  
TABLE 3—T8611 GUIDE FOR REPLACING POPULAR T874 AND T872 THERMOSTATS,  
BY EQUIPMENT MANUFACTURER (Continued).  
(NOTE: Also see form 70-6627, Heat Pump Thermostat Cross Reference Guide, for wiring hookup illustrations.)  
Thermostat (Subbase Included)  
Auto  
Manual  
Changeover  
Weekday,  
Sat, Sun  
Changeover  
Weekday,  
Sat, Sun  
Auto  
Changeover  
7-day  
T8611G1004  
T8611R1000  
T8611G1012 (° C) T8611R1042 (° C)  
T8611G1103 T8611R1141  
T8611M7008  
c
(Premier White) (Premier White) T8611M7040 Thermostat Subbase Thermostat Subbase  
(also see form 68-0057, Specifications)  
T874  
Q674  
T872  
Q672  
Comments  
Coleman  
a
R1368  
L1421  
na  
na  
Late models optional check  
LED. Z = X2, jump X1 and C,  
K = L.  
Earlier T.H.E. models with  
reverse-acting EM. HT.  
require relay isolation.  
na  
na  
na  
na  
Crispaire/Marvair  
G1089  
F1162  
F1204  
L1215  
G1208  
R1156  
F1166  
F1323  
L1094  
R1111  
Fedders/Airtemp/Climatrol  
a
C1398  
C1406  
C1414  
L1090  
C1509  
C1517  
C1541  
L1102 Separate first stage heat/cool  
terminals required; check LED  
optional; equipment terminal  
K to thermostat E.  
a
a
Florida Heat Pump  
na na  
a
na  
na  
Optional check LED;  
X = X1, jump X2 to C.  
Heatwave/Southwest Mfg.  
G1105 F1170 G1232  
Heil Quaker/Whirlpool/Tempstar  
F1224  
R1137  
L1132  
R1172  
L1193 Equipment terminal B  
to thermostat C.  
Honeywell  
A-D (typ.) F1006 A-D (typ.) F1000 Separate first stage  
F1022  
F1048  
F1089  
F1026 heat/cool terminals.  
F1042  
F1075  
C1000  
C1018  
C1117  
C1240  
G1246  
G1444  
C1004  
C1038  
C1350  
C1566  
G1224  
G1000  
G1018  
G1083  
°C  
°C  
F1212  
F1238  
F1208 TRADELINE  
F1018  
°C  
F1158  
G1212  
G1139  
a No CHECK LED.  
b Dual transformer requires conversion to single transformer.  
c Model includes separate sensor for remote temperature sensing.  
(continued)  
8
 
T8611M  
SELECTION/APPLICATION  
TABLE 3—T8611 GUIDE FOR REPLACING POPULAR T874 AND T872 THERMOSTATS,  
BY EQUIPMENT MANUFACTURER (Continued).  
(NOTE: Also see form 70-6627, Heat Pump Thermostat Cross Reference Guide, for wiring hookup illustrations.)  
Thermostat (Subbase Included)  
Auto  
Manual  
Changeover  
Weekday,  
Sat, Sun  
Changeover  
Weekday,  
Sat, Sun  
Auto  
Changeover  
7-day  
T8611G1004  
T8611R1000  
T8611G1012 (° C)T8611R1042 (° C)  
T8611G1103 T8611R1141  
T8611M7008  
c
(Premier White) (Premier White) T8611M7040 Thermostat Subbase Thermostat Subbase  
(also see form 68-0057, Specifications) T874 Q674 T872 Q672  
Comments  
Honeywell (continued)  
N1016  
N1040  
R1004  
F1220  
F1261  
B1042  
B1109  
L1207  
L1157  
L1181  
N1002  
N1028  
R1008  
R1057  
R1198  
F1133 Changeover on heat; equip-  
F1216 ment terminal C to thermostat  
B1046 Y, W1 to B, K to E.  
L1037  
R1152  
R1285  
R1350  
L1227  
Janitrol/Tappan  
G1147  
F1139  
G1109  
F1117 Equipment terminal C to  
thermostat C.  
Lennox  
NOTE: Rewire for single 75  
VA  
transformer if two-transformer  
system.  
F1067  
E1019 °C  
DoD specs—use guard.  
L1201  
G1014  
G1022  
G1162  
G1154  
R1024  
R1040  
R1178  
F1113  
E1148  
G1026  
G1125  
G1091  
G1323  
F1105  
B1160  
B1202  
L1355  
L1165  
L1165  
L1199  
L1389  
C1148  
D1207  
Two-speedunit;optionalcheck  
LED; thermistor A not used.  
minal Conversion  
Ter-  
Guide:  
Lennox Standard  
Transformer  
Common  
Transformer  
Power  
X
C
VR (in)  
R
V (out)  
Compressor  
M
M2  
Y
F
R
L
E
Y
Y2  
W2  
G
O
L,X1,X2  
E
Aux. Heating  
Fan  
Changeover  
System Monitor  
Em.Heat (cycling)  
Thermistor  
A
T (not  
required)  
(continued)  
a
No CHECK LED.  
b Dual transformer requires conversion to single transformer.  
9
68-0076—1  
c Model includes separate sensor for remote temperature sensing.  
 
T8611M  
SELECTION/APPLICATION  
TABLE 3—T8611 GUIDE FOR REPLACING POPULAR T874 AND T872 THERMOSTATS,  
BY EQUIPMENT MANUFACTURER (Continued).  
(NOTE: Also see form 70-6627, Heat Pump Thermostat Cross Reference Guide, for wiring hookup illustrations.)  
Thermostat (Subbase Included)  
Auto  
Manual  
Changeover  
Weekday,  
Sat, Sun  
Changeover  
Weekday,  
Sat, Sun  
Auto  
Changeover  
7-day  
T8611G1004  
T8611R1000  
T8611G1012 (° C)T8611R1042 (° C)  
T8611G1103 T8611R1141  
T8611M7008  
c
(Premier White) (Premier White) T8611M7040 Thermostat Subbase Thermostat Subbase  
(also see form 68-0057, Specifications)  
T874  
Q674  
T872  
Q672  
Comments  
Luxaire  
G (Borg F1188  
Warner)  
Magic Chef  
G1315  
F1281  
na  
na  
na  
na  
na  
na  
na  
Earlier PB series, separate first  
stage heat/cool.  
Late PE series, optional check  
LED; X1 = X1, jump X2 to R.  
a
na  
Rheem/Ruud  
G1097  
G1238  
F1238  
G1133  
G1141  
R1081  
R1107  
F1158  
L1157  
L1045  
L1136  
G1220  
R1079  
R1095  
Square D/Sun Dial  
a
C1224 F1071  
C1525  
F1182 Separate first stage heat/cool  
required; optional check LED;  
X = X1, jump X2 to R.  
Trane/General Electric  
G1204 J1043  
a
G1059  
J1039 Optional check LED; F = X1,  
jump X2 to C; T not used;  
equipment terminal B to ther-  
mostat C, R to R, Y to Y (Y1 +  
W1), W to W2, G to G, 0 to 0,  
X2 to E.  
Weather King  
na na  
G1265  
F1265 Optional check LED; X = X1,  
jump X2 to R; equipment ter-  
minal C to thermostat C, W1  
to Y (W1 + Y1), E to W2,  
Y1 to 0.  
a
No CHECK LED.  
b Dual transformer requires conversion to single transformer.  
c Model includes separate sensor for remote temperature sensing.  
(continued)  
10  
 
T8611M  
SELECTION/APPLICATION  
TABLE 3—T8611 GUIDE FOR REPLACING POPULAR T874 AND T872 THERMOSTATS,  
BY EQUIPMENT MANUFACTURER (Continued).  
(NOTE: Also see form 70-6627, Heat Pump Thermostat Cross Reference Guide, for wiring hookup illustrations.)  
Thermostat (Subbase Included)  
Auto  
Manual  
Changeover  
Weekday,  
Sat, Sun  
Changeover  
Weekday,  
Sat, Sun  
Auto  
Changeover  
7-day  
T8611G1004  
T8611R1000  
T8611G1012 (° C)T8611R1042 (° C)  
T8611G1103 T8611R1141  
T8611M7008  
c
(Premier White) (Premier White) T8611M7040 Thermostat Subbase Thermostat Subbase  
(also see form 68-0057, Specifications)  
T874  
Q674  
T872  
Q672  
Comments  
Wesco/Addison  
G1287  
F1253  
EquipmentterminalC1tother-  
mostat C, W1 to Y (W1 + Y1),  
R1012  
B1109  
R1016  
G1265  
G1281  
B1103 Y1to0. Commontothermostat  
F1265 directfromcontroltransformer.  
Westinghouse  
G1048  
F1121  
G1034  
F1141  
F1091  
F1257  
J1013  
J1062  
L1110  
L1128  
L1151  
F1246  
F1279  
J1019  
J1050  
L1108  
L1173  
R1103  
R1149  
na  
na  
na  
na  
Separate first stage heat/cool  
minals required.  
ter-  
D1108  
L1223  
G1356  
L1219 2-speed heat pump; optional  
check LED; L = X1, jump  
X2 to C.  
White Rodgers  
na  
na  
na  
na  
1F58-910/S28 series.  
Williamson  
R1236  
N1008  
L1348  
F1196  
na  
na  
na  
na  
Changeover on heat; W1 = B.  
York/Borg Warner  
a
G1170  
G1295  
G1345  
J1027  
F1311  
L1363  
G1042  
G1299  
J1021 Optional check LED; X = X1,  
L1177 jump X2 to C; equipment ter-  
G1331 D1077 minal B to thermostat C,  
G1402 D1032 G1364  
W to W2, H to B, T not re-  
quired.  
G1410  
G1428  
G1436  
R1046  
R1169  
R1251  
G1398  
L1017  
L1330  
L1272  
R1032  
L1011  
Zone Aire  
N1040  
R1350  
F1261  
L1181  
Changeover on heat;  
W1 = B.  
a
No CHECK LED.  
b Dual transformer requires conversion to single transformer.  
c Model includes separate sensor for remote temperature sensing.  
11  
68-0076—1  
 
T8611M  
INSTALLATION  
Installation  
COMPATIBILITY  
This thermostat requires a single transformer. A two-  
transformer system may require turning off two switches  
or disconnects, and rewiring to run the thermostat from a  
single transformer. Make sure the transformer has ad-  
equatepower(VA)fortheheating/coolingcontrolsystem.  
Add current ratings of the system components (such as  
auxiliaryheatrelay, changeoverrelay, fanrelay). Multiply  
this total by 24V to determine transformer VA required.  
Remove any existing wallplate or subbase from wall.  
Label or write down each wire color with the letter or  
number on the wiring terminal as the wire is removed to  
avoid miswiring later.  
The T8611 Thermostats will replace most heat pump  
system thermostats. As long as ac power is continuously  
available to the thermostat, the thermostat will be compat-  
ible with almost any low-volt control system.  
WHEN INSTALLING THIS PRODUCT…  
1. Read these instructions carefully. Failure to follow  
them could damage the product or cause a hazardous  
condition.  
2. Check the ratings given on the product to make sure  
the product is suitable for your application.  
3. Installer must be a trained, experienced service tech-  
nician.  
IF NEW INSTALLATION  
4. Allow thermostat to warm to room temperature  
before operating.  
5. After installation is complete, check out product  
operation as provided in these instructions.  
Run cable to a hole at the selected wall location for  
thermostat and remote sensor, and pull about 3 in. [76 mm]  
of wire through the opening. Color-coded, 18-gauge ther-  
mostat cable with at least one conductor for each wiring  
terminal is recommended. Good service practice recom-  
mends selecting cable with one or two more conductors  
than the immediate application requires.  
If using thermostat model with remote temperature  
sensing, run 3-wire, 18-gauge thermostat cable from the  
thermostat location to the sensor location (200 ft. [61 m]  
maximum). Route cable away from sources of electrical  
noise.  
CAUTION  
!
Disconnect power supply to prevent electrical  
shock or equipment damage.  
LOCATION  
Thermostat with Integral Sensor  
Install thermostat and subbase about 5 ft. [1.5 m] above  
the floor in an area with good air circulation at room  
temperature.  
Do not install the thermostat where it may be affected  
by—  
MOUNTING SUBBASE  
IMPORTANT:Set the subbase system switch in the OFF  
position before mounting.  
Thesubbasedoesnotrequirelevelingforoperation, but  
— draftsordeadspotsbehinddoors, incornersorunder  
cabinets.  
— hot or cold air from ducts.  
— radiant heat from sun or appliances.  
— concealed pipes and chimneys.  
— unheated (uncooled) areas behind the thermostat,  
such as an outside wall.  
for appearance only.  
Remove thermostat from subbase (Fig. 4).  
Thermostat with Remote-Mounted Sensor  
Installthermostatinanareathatisaccessibleforsetting  
and adjusting the temperature and settings.  
Install remote temperature sensor in an area with good  
air circulation at average temperature.  
Do not install the sensor where it may be affected by—  
— drafts or dead spots behind doors, in corners, or  
under cabinets.  
— hot or cold air from ducts.  
— radiant heat from sun or appliances.  
— concealed pipes and chimneys.  
— unheated (uncooled) areas behind the sensor, such  
as an outside wall.  
IF REPLACING AN EXISTING THERMOSTAT  
Turn thermostat power off at furnace or heat pump.  
12  
 
T8611M  
INSTALLATION  
Fig. 4—Removing thermostat from subbase.  
Use a 3/16 in. bit to drill the required holes. Gently tap  
The subbase mounts directly onto the wall with the  
screws and anchors included. Instead, the subbase can be  
mounted on a vertical or horizontal outlet box. If you must  
mount the subbase on a vertical outlet box, order 193121A  
Adapter Assembly. The assembly includes an adapter  
ring, two screws and a cover plate to cover marks on the  
wall. Install the ring and cover plate on the vertical outlet  
box as instructed.  
anchors into holes until they are flush with the wall  
WALL  
REMOTE SENSOR  
COVER  
WIRES  
THROUGH  
WALL  
OPENING  
Use the subbase as a template, and with a pencil, mark  
the two mounting screw positions (Fig. 5).  
If drywall construction, plastic anchors must be used;  
use 3/16 in. bit to drill holes for anchors. Gently tap  
anchors into holes until they are flush with the wall  
surface.  
WALL  
ANCHORS (2)  
MOUNTING HOLES  
WIRING  
HOLE  
REMOTE  
SENSOR BASE  
MOUNTING  
SCREWS (2)  
M1549B  
Thread wires through the center opening of the sub-  
base.  
surface. Thread wires through the opening in the base.  
Mount remote sensor base using the screws provided. See  
Fig. 6. Make sure base looks level before tightening  
screws.  
Fig. 6—Mounting remote sensor base on wall.  
WIRING  
All wiring must comply with local electrical codes and  
ordinances.  
Disconnect power before wiring to prevent electrical  
shock or equipment damage.  
The shape of the terminal barrier permits insertion of  
straight or conventional wraparound wiring connections.  
Either method is acceptable.  
Push excess wire back into the hole, and plug hole with  
nonhardening caulk, putty or insulation to prevent drafts  
from affecting operation of thermostat and remote sensor,  
if applicable.  
Refer to Figs. 8-10 for typical hookups of subbase and  
thermostat.  
After wiring remote sensor, replace cover.  
NOTE: Restrict all wiring to recessed area surrounding  
Mount the subbase using two screws provided. Gently  
tighten screws, level top surface of subbase, and securely  
tighten screws.  
Fig. 5—Mounting subbase on wall.  
MOUNTING REMOTE TEMPERATURE SENSOR  
(IF APPLICABLE)  
The remote sensor mounts directly on the wall with  
screws and anchors included. Remove cover from remote  
sensor (Fig. 6). Use the remote sensor base as a template,  
and with a pencil, mark holes for mounting screws.  
13  
68-0076—1  
 
T8611M  
INSTALLATION  
terminals (Fig. 7) to assure thermostat/subbase contact.  
1
7
L1  
R
C
(HOT)  
4
POWER  
SUPPLY  
HIGH  
LIMIT  
L2  
3
FAN  
SWITCH  
AUX. HEAT  
LED (GRN)  
MONITOR  
EM. HEAT  
LED (RED)  
ON  
L
AUTO  
AUXILIARY  
HEAT RELAY  
W3  
HEAT 3  
STAGE 2  
HEAT RELAY  
W2  
HEAT 2  
EMERGENCY  
HEAT RELAY  
SUBBASE  
LOGIC/  
CONTROL  
CIRCUIT  
THERMOSTAT  
LOGIC  
CIRCUIT  
E
FAN RELAY  
SYSTEM  
SWITCH  
G
CHANGEOVER  
RELAY (COOL)  
EM. HT.  
HEAT  
O
C.O.  
CHANGEOVER  
RELAY (HEAT)  
OFF  
AUTO  
COOL  
B
COOL 1  
C.O.  
STAGE 1 COMPRESSOR  
CONTACTOR  
Y
HEAT 1  
STAGE 2 COMPRESSOR  
CONTACTOR  
HIGH  
LIMIT  
Y2  
COOL 2  
6
S1  
S2  
S1  
S2  
X2  
2
CHECK LED  
(YELLOW)  
S3  
S3  
X1  
5
202905 REMOTE  
SENSOR  
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.  
POSSIBLE CHECK LED CIRCUITS:  
1
2
TO R  
TO R  
L1  
(HOT)  
X2  
CHECK  
LED  
X2  
CHECK  
LED  
X2  
CHECK  
LED  
FAULT DETECTION  
SWITCH  
FAULT DETECTION  
SWITCH  
SWITCHING  
DEVICE  
1
(YELLOW)  
(YELLOW)  
(YELLOW)  
24 Vac  
TO C  
TO C  
L2  
X1  
X1  
X1  
SWITCH TO R (POWER) SIDE OF  
SYSTEM TRANSFORMER  
SWITCH IN SECONDARY OF  
SEPARATE TRANSFORMER  
SWITCH TO C (COMMON) SIDE  
OF SYSTEM TRANSFORMER  
3
4
5
SOME OLDER HEAT PUMP THERMOSTATS USE X FOR COMMON TERMINAL.  
NOMINAL 24 Vac POWER MUST BE PRESENT BETWEEN R AND C TERMINALS FOR THERMOSTAT OPERATION.  
RECOMMENDED INTERCONNECT CABLE: 18-GAUGE THERMOSTAT CABLE, 200 ft. [61 m] MAXIMUM LENGTH. ROUTE INTERCONNECT  
CABLE AWAY FROM SOURCES OF ELECTRICAL NOISE.  
APPLICABLE ONLY ON MODEL WITH REMOTE SENSOR.  
DENOTES THERMOSTAT TO SUBBASE INTERCONNECT.  
6
7
M1017D  
14  
 
T8611M  
INSTALLATION  
Fig. 7—Restrict wiring to recessed area surrounding terminals.  
1
6
L1  
R
C
(HOT)  
4
POWER  
SUPPLY  
HIGH  
LIMIT  
L2  
3
FAN  
SWITCH  
EM. HEAT  
LED (RED)  
AUX. HEAT  
LED (GRN)  
MONITOR  
L
ON  
AUTO  
W3  
STAGE 2  
HEAT 3  
HEAT RELAY  
W2  
HEAT 2  
EMERGENCY  
HEAT RELAY  
SUBBASE  
LOGIC/  
CONTROL  
CIRCUIT  
THERMOSTAT  
LOGIC  
CIRCUIT  
E
FAN RELAY  
SYSTEM  
SWITCH  
G
CHANGEOVER  
RELAY (COOL)  
EM. HT.  
O
B
HEAT  
OFF  
C.O.  
C.O.  
CHANGEOVER  
RELAY (HEAT)  
AUTO  
COOL  
COOL 1  
STAGE 1 COMPRESSOR  
CONTACTOR  
Y
HEAT 1  
STAGE 2 COMPRESSOR  
CONTACTOR  
HIGH  
LIMIT  
Y2  
COOL 2  
7
X2  
2
S1  
S1  
CHECK LED  
(YELLOW)  
S2  
S3  
S2  
S3  
X1  
5
202905 REMOTE  
SENSOR  
1
2
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.  
POSSIBLE CHECK LED CIRCUITS:  
TO R  
TO R  
L1  
(HOT)  
X2  
CHECK  
LED  
X2  
CHECK  
LED  
X2  
CHECK  
LED  
FAULT DETECTION  
SWITCH  
SWITCHING  
DEVICE  
FAULT DETECTION  
SWITCH  
1
(YELLOW)  
(YELLOW)  
(YELLOW)  
24 Vac  
TO C  
TO C  
X1  
L2  
X1  
X1  
SWITCH TO R (POWER) SIDE OF  
SYSTEM TRANSFORMER  
SWITCH IN SECONDARY OF  
SEPARATE TRANSFORMER  
SWITCH TO C (COMMON) SIDE  
OF SYSTEM TRANSFORMER  
3
SOME OLDER HEAT PUMP THERMOSTATS USE X FOR COMMON TERMINAL.  
NOMINAL 24 Vac POWER MUST BE PRESENT BETWEEN R AND C TERMINALS FOR THERMOSTAT OPERATION.  
4
5
RECOMMENDED INTERCONNECT CABLE: 18-GAUGE THERMOSTAT CABLE, 200 ft. [61 m] MAXIMUM LENGTH. ROUTE  
INTERCONNECT CABLE AWAY FROM SOURCES OF ELECTRICAL NOISE.  
6
DENOTES THERMOSTAT TO SUBBASE INTERCONNECT.  
APPLICABLE ONLY ON MODEL WITH REMOTE SENSOR.  
7
M1018D  
15  
68-0076—1  
 
T8611M  
INSTALLATION  
Fig. 8—T8611M Thermostat with EM.HT.-HEAT-OFF-AUTO-COOL system and ON-AUTO fan switching;  
EM.HT., CHECK, and AUX. HT. LEDS. Applied to 3-stage heat/2-stage cool system.  
Fig. 9—T8611M Thermostat with EM.HT.-HEAT-OFF-AUTO-COOL system and ON-AUTO fan switching,  
1
7
L1  
(HOT)  
R
4
HIGH  
LIMIT  
POWER  
SUPPLY  
L2  
3
C
FAN  
SWITCH  
AUX. HEAT  
LED (GRN)  
MONITOR  
EM. HEAT  
LED (RED)  
ON  
L
AUXILIARY  
HEAT RELAY  
AUTO  
W3  
W2  
HEAT 3  
HEAT 2  
EMERGENCY  
HEAT RELAY  
SUBBASE  
LOGIC/  
CONTROL  
CIRCUIT  
E
THERMOSTAT  
LOGIC  
CIRCUIT  
FAN RELAY  
SYSTEM  
SWITCH  
G
CHANGEOVER  
RELAY (COOL)  
EM. HT.  
HEAT  
OFF  
O
C.O.  
CHANGEOVER  
RELAY (HEAT)  
AUTO  
COOL  
B
COOL 1  
C.O.  
STAGE 1 COMPRESSOR  
CONTACTOR  
Y
HEAT 1  
COOL 2  
HIGH  
LIMIT  
Y2  
X2  
2
6
S1  
S1  
S2  
S3  
CHECK LED  
(YELLOW)  
S2  
S3  
X1  
5
202905 REMOTE  
SENSOR  
1
2
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.  
POSSIBLE CHECK LED CIRCUITS:  
TO R  
TO R  
X2  
CHECK  
LED  
X2  
CHECK  
LED  
X2  
CHECK  
LED  
(YELLOW)  
X1  
L1  
(HOT)  
FAULT DETECTION  
SWITCH  
SWITCHING  
DEVICE  
24 Vac  
FAULT DETECTION  
SWITCH  
1
(YELLOW)  
(YELLOW)  
X1  
TO C  
TO C  
X1  
L2  
SWITCH TO R (POWER) SIDE OF  
SYSTEM TRANSFORMER  
SWITCH IN SECONDARY OF  
SEPARATE TRANSFORMER  
SWITCH TO C (COMMON) SIDE  
OF SYSTEM TRANSFORMER  
SOME OLDER HEAT PUMP THERMOSTATS USE X FOR COMMON TERMINAL.  
NOMINAL 24 Vac POWER MUST BE PRESENT BETWEEN R AND C TERMINALS FOR THERMOSTAT OPERATION.  
3
4
5
RECOMMENDED INTERCONNECT CABLE: 18-GAUGE THERMOSTAT CABLE, 200 ft. [61 m] MAXIMUM LENGTH. ROUTE  
INTERCONNECT CABLE AWAY FROM SOURCES OF ELECTRICAL NOISE.  
6
7
APPLICABLE ONLY ON MODEL WITH REMOTE SENSOR.  
DENOTES THERMOSTAT TO SUBBASE INTERCONNECT.  
M1019D  
16  
 
T8611M  
INSTALLATION  
EM.HT. and CHECK LEDs. Applies to 2-stage  
heat/2-stage cool system in which both heating  
stages are compressorized.  
Fig.10—T8611M Thermostat with EM.HT.-HEAT-  
OFF-AUTO-COOL system and ON-AUTO fan  
switching; EM.HT., CHECK, and AUX. HT. LEDs.  
Applied to 2-stage heat/1-stage cool system.  
The Stage 1 cycle rate of this thermostat is factory-set  
for heat pumps and cannot be adjusted. The auxiliary heat  
cycle rate can be adjusted by turning the cycle rate adjust-  
ment screw on the back of the thermostat. See Fig. 11.  
Increasing the cycle rate will reduce room temperature  
swings when auxiliary heat is being used.  
INSTALLING BATTERIES  
ADJUSTING CYCLE RATE  
Three AAA alkaline batteries are included to provide  
backup to prevent program loss in case of power outage.  
Install batteries in back of thermostat as shown in Fig. 12.  
Without battery backup, the program will remain about  
20 seconds in event of power loss.  
To customize the thermostat last heating stage cycling  
performance to various types of auxiliary heating equip-  
ment, a cycle rate adjustment screw is provided on the back  
ofthethermostattoprovideoptimumsavingsandoccupant  
comfort.  
IMPORTANT: When batteries are first installed, the  
display will flash 1:00 PM and 32°. After a brief  
delay, the display will flash 1:00 PM and room  
temperature.  
NOTE: MOST APPLICATIONS WILL NOT REQUIRE  
A CHANGE IN CYCLE RATE.  
The room air temperature normally will vary slightly  
from the comfort temperature setting with the cycling of  
the heat pump or auxiliary heater.  
When the batteries are low, the display will flash REPL  
BAT. Homeowner will have 20-30 seconds to install new  
batteriesafterremovingoldbatteriesfrombackofthermo-  
stat. After 20-30 seconds, it will be necessary to repro-  
gram. REPL BAT indication will disappear within 5-10  
minutes when thermostat is remounted on the powered  
subbase.  
Fig. 11—Cycle rate adjustment.  
IMPORTANT:Forproperthermostatoperation, always  
replace dead batteries with new alkaline batteries.  
If batteries are completely dead, the display will go  
blank when the thermostat is removed from subbase.After  
replacing the batteries, reprogramming will be necessary.  
POWER OUTAGES  
Backup batteries will hold the programming and keep  
the display on during most power outages. Once the power  
is restored, the system will resume normal operation.  
If the display goes off when power is lost, either the  
backup batteries need to be replaced or are not installed.  
When power is restored, the display will flash 1:00 PM to  
remind you to reprogram.  
Fig. 12—Battery placement.  
MOUNTING THE THERMOSTAT  
With sys Tm switch set to OFF, hang the thermostat on  
S
t
E
e
PRESENT  
DAY/TIME  
the tabs at the top of the subbase (Fig. 13A). Swing down  
and press on lower edge until thermostat snaps in place  
DAY  
(Fig. 13B). pen cover and tighten the captive mounting  
screws (Fig. 13C).  
BACK  
AHEAD  
SETTING DAY D TIME  
Restore 24V power to the thermostat. Set present day  
and time.  
Press  
.
Press  
to set the current day. (Each press of the  
DAY key advances the display one day.)  
Press TIME or tosetthecurrenttime.  
If the display will not come on—  
— check mounting of thermostat to subbase. If loose or  
misaligned, remove thermostat and reinstall on the  
17  
68-0076—1  
subbase, making sure it is firmly attached.  
— check to see that batteries are installed properly.  
 
T8611M  
INSTALLATION • CHECKOUT  
Fig. 13—Mounting thermostat on subbase.  
Checkout  
COOLING  
CAUTION  
!
CAUTION  
!
During cold weather, some heat pumps will re-  
quire that crankcase heater be energized several  
hours before operating heat pump. Refer to  
manufacturer’s recommendations.  
Do not operate cooling if outdoor temperature is  
below 50° F [10° C]. Refer to manufacturer’s  
recommendations.  
NOTE: When cooling setting is changed, thermostat will  
wait up to five minutes before turning on the cooling  
equipment. This delay protects the compressor.  
HEATING  
NOTE: When heating setting is changed, thermostat will  
wait up to 5 minutes before turning on the heating  
equipment. This delay protects the compressor.  
Move the system switch to COOL and the fan switch to  
AUTO. Press COOLER key until the setting is about 10°  
F [6° C] below room temperature. The cooling equipment  
and fan should start. Press WARMER key until the setting  
is about 10° F [6° C] above room temperature. The cooling  
equipment and fan should stop.  
Move the system switch to HEAT and the fan switch to  
AUTO. Press WARMER key until the setting is about 10°  
F [6° C] above room temperature. Heating should start and  
the fan should run (there may be a delay of 5-10 minutes  
before heat turns on). Press COOLER key until the setting  
is about 10° F [6° C] below room temperature. The heating  
equipment should shut off, followed by the fan.  
NOTE: On an AUTO changeover thermostat, the heating  
temperature must be set at least 3° F [2° C] below the  
cooling temperature, or display will flash.  
NOTE: On an AUTO changeover thermostat, the cooling  
temperature must be set at least 3° F [2° C] above the  
heating temperature, or display will flash.  
18  
 
T8611M  
CHECKOUT  
FAN  
Move the system switch to OFF, and the fan switch to  
ON. Thefanshouldruncontinuously. Whenthefanswitch  
is in the AUTO position, fan cycles with the heating or  
cooling system.  
System  
Switch  
Position  
Press  
This  
Key  
CHANGE  
TO LAST  
PERIOD  
Look For This Response  
Key  
Down  
03 Blank  
Key Released  
OFF  
SKIP  
NEXT  
PERIOD  
07 Blank  
15 Blank  
INSTALLER SELF-TEST (OPTIONAL)  
PRESENT  
SETTING  
IMPORTANT:  
• Thermostat must have ac power to perform self-test.  
• Five-minute time delay on compressor does not  
function during self-test.  
PRESENT  
SETTING  
AUTO  
COOL or  
15 1st stage cooling, fan and  
SYSTEM LED on.  
15 2nd stage cooling also on.  
(with fan  
in AUTO)  
PRESENT  
SETTING  
Perform the following test as a check of all thermostat  
functions. If thermostat does not respond as indicated,  
thermostat and subbase must be replaced.  
PRESENT  
SETTING  
15 2nd stage cooling off.  
15 1st stage cooling, fan and  
SYSTEM LED on.  
PRESENT  
SETTING  
1. Press AHEAD and BACK keys at the same time.  
While holding keys down, all segments of the display  
should be on (see Fig. 14).  
OFF  
06 Blank  
02 Blank  
05 Blank  
04 Blank  
WARMER  
COOLER  
AHEAD  
BACK  
Fig. 14—All segments on display.  
01 Control microprocessor  
mask no. and revision no.  
COPY  
FROM  
REPL  
AM  
SET  
BAT  
PT  
PM  
COPY  
TO  
00 Blank  
ROOM  
OUTDOOR  
SUN MON TUE WED THU FRI SAT TEMPORARY  
(CHECK  
EACH )  
POSITION)  
12 See note A .  
MORNING MIDDAY EVENING NIGHT  
COOL ON HEAT ON  
M 525A  
PERIOD  
OFF  
08 Blank  
CANCEL  
PERIOD  
13 Interface microprocessor  
mask no. and revision  
2. SetsystemswitchtoOFF.PressandreleaseAHEAD,  
BACK, and PRESENT SETTING keys at the same time to  
enter self-test.  
DAY  
no.  
SET  
HEAT/COOL  
09 Blank  
14 Blank  
SET  
PRESENT  
DAY/TIME  
3. Press each key as listed below, and look for re-  
sponses listed as key is held down and released. Keys may  
be pressed in any order except RUN PROGRAM should  
be pressed last because it ends self-test.  
SET  
PRESENT  
DAY/TIME  
HEAT or  
AUTO  
(with fan  
in auto)  
14 1st stage heating, fan  
and SYSTEM LED on.  
14 2nd stage heating also on.  
SET  
PRESENT  
DAY/TIME  
SET  
PRESENT  
DAY/TIME  
14 3rd stage heating and AUX.  
HT. LED also on.  
SET  
PRESENT  
DAY/TIME  
14 3rd stage heating and AUX.  
HT. LED off.  
SET  
PRESENT  
DAY/TIME  
14 2nd stage heating also off.  
SET  
PRESENT  
DAY/TIME  
14 1st stage heating, fan and  
SYSTEMLEDalsooff.  
HOLD  
TEMP  
OFF  
10 Blank  
RUN  
PROGRAM  
11 Normal operating display  
A HEAT displayed when system switch is in HEAT, COOL  
when in COOL, HEAT and COOL when in AUTO, neither  
when in OFF. Also, a four-digit code is displayed. Expla-  
nation for each digit is following.  
19  
68-0076—1  
 
T8611M  
CHECKOUT • PROGRAMMING THE THERMOSTAT  
First Digit  
Degrees  
Clock (Hrs.)  
Third  
Digit  
System Switch  
Position  
Sensor  
Location  
0
1
2
3
F
F
12  
24  
12  
24  
0
1
4
5
COOL, AUTO or OFF  
HEAT or EM.HT.  
Local  
Local  
C
C
COOL, AUTO or COOL  
HEAT or EM. HT.  
Remote  
Remote  
M5346  
Second Digit  
System Switch Position  
EM. HT., HEAT or OFF  
AUTO  
Nominal Cycle Rate  
(cph at 50% load  
for 3rd stage heat)  
Fourth  
Digit  
0
1
2
4
5
6
3
COOL  
Programming The Thermostat  
STEP 1  
SET  
PRESENT  
DAY/TIME  
Press and release. The display shows  
1:00 PM Mon.  
PM  
SETTING THE CURRENT DAY  
AND TIME  
MON  
M2701  
This thermostat can be programmed  
either on the wall or in the hand. See  
page 12 to remove the thermostat from  
the subbase.  
Press and hold until the current day ap-  
pears in the display.  
PM  
DAY  
TUE  
M2702  
TIME  
Alwayspressthekeyswithfingertipor  
similar blunt tool. Sharp instruments  
like a pen or pencil point can damage  
the keyboard.  
Press and hold until the current time ap-  
pears in the display. Be sure AM or PM  
appears as desired.  
PM  
AHEAD  
TUE  
M2703  
BACK  
NOTE: Check the glossary, page 30,  
for definitions of unfamiliar words.  
This completes setting the current day and  
time. Go on to Step 2.  
STEP 2  
Press and release. Note that the display  
showsMORNINGandthepreprogrammed  
time and temperature.  
AM  
SET  
PT  
SETTING THE PROGRAM  
TIMES AND TEMPERATURES  
FOR ONE DAY  
PERIOD  
MON  
MORNING  
HEAT  
M2704  
AM  
AM  
Chooseadaytoprogramfirst. Monday  
is used in the examples. Start by pro-  
gramming the MORNING time and  
temperatures. The thermostat requires  
a MORNING program every day. Set  
additional programs as desired.  
If the display reads COOL, press and re-  
lease to switch to HEAT.  
SET  
PT  
SET  
HEAT/COOL  
MON  
MORNING  
HEAT  
M2704  
Press and hold until MONDAY (or the  
desired day) appears in the display.  
SET  
PT  
DAY  
MON  
MORNING  
HEAT  
M2704  
20  
 
T8611M  
PROGRAMMING THE THERMOSTAT  
Press and hold until the display shows the  
time that the temperature should be at the  
comfort setting.  
AM  
SET  
PT  
AHEAD  
BACK  
MON  
MORNING  
HEAT  
M2705  
Press and hold until the display shows the  
desired heating temperature.  
AM  
SET  
PT  
WARMER  
COOLER  
MON  
MORNING  
HEAT  
M2706  
If the display flashes while holding down  
TEMPERATURE  
WARMER  
or  
COOLER, the setting limit has been  
reached.Ifthermostatisanautochangeover  
model, the heating temperature must be at  
least 3 degrees below the air conditioning  
temperature. For example, if the cooling  
setting is 75° F, the maximum heating set-  
ting is 72° F. To set a higher heating tem-  
perature, first raise the cooling setting.  
Program the MIDDAY time and heat-  
ing temperature if desired.  
Press and release. The display shows MID-  
DAY, but no time or temperature.  
SET  
PT  
MON  
MON  
PERIOD  
MIDDAY  
MIDDAY  
HEAT  
HEAT  
Press and hold until the display shows the  
time to start the energy saving period.  
AM  
SET  
PT  
AHEAD  
BACK  
M2708  
Press and hold until the display shows the  
desired temperature.  
AM  
SET  
PT  
WARMER  
COOLER  
MON  
MIDDAY  
HEAT  
M2709  
NOTE: It is possible to cancel any  
period showing on the display ex-  
cept MORNING by pushing the  
CANCEL PERIOD key. To move  
to the next period while program-  
ming, simply press the PERIOD  
key again.  
SET  
PT  
Program the EVENING time and tem-  
perature, if desired.  
Press and release. The display shows  
EVENING, but no time or temperature.  
MON  
MON  
PERIOD  
EVENING  
HEAT  
SET  
PT  
PM  
AHEAD  
BACK  
Press and hold until the display shows the  
time the temperature should be at the com-  
fort setting.  
EVENING  
HEAT  
M2711  
SET  
PT  
PM  
WARMER  
COOLER  
Press and hold until the display shows the  
desired heating temperature.  
MON  
EVENING  
HEAT  
M2712  
21  
68-0076—1  
 
T8611M  
PROGRAMMING THE THERMOSTAT  
SET  
PT  
PM  
PERIOD  
Program the NIGHT time and tem-  
perature, if desired.  
Press and release. The display shows  
NIGHT and the preprogrammed time and  
temp-erature.  
MON  
NIGHT  
HEAT  
M2713  
SET  
PT  
PM  
AHEAD  
BACK  
Press and hold until the display shows the  
time to start the energy saving period.  
MON  
NIGHT  
HEAT  
M2714  
SET  
PT  
PM  
WARMER  
COOLER  
Press and hold until the display shows the  
desired heating temperature.  
MON  
NIGHT  
HEAT  
M2715  
heating.  
SET  
HEAT/COOL  
SET  
PT  
PM  
Set the cooling temperatures for all the  
periods programmed. The program  
times are the same for both heating and  
cooling.Onlythecoolingtemperatures  
need to be programmed if program-  
ming has been completed for heating.  
If you change program times for cool-  
ing, youarealsochangingthetimesfor  
MON  
NIGHT COOL  
Press and release. The display shows  
COOL, the preprogrammed cooling tem-  
perature and the programmed start time for  
NIGHT.  
M2716  
SET  
PT  
PM  
WARMER  
COOLER  
MON  
NIGHT COOL  
M2717  
Press and hold until the display shows the  
desired cooling temperature for NIGHT.  
If the display blinks while holding down  
TEMPERATURE  
WARMER  
or  
COOLER, the setting limit has been  
reached. If thermostat can switch auto-  
matically between heating and cooling, the  
heating temperature must be at least 3 de-  
grees F below the air conditioning tem-  
perature. For example, if the heating set-  
ting is 72° F, the minimum cooling setting  
is 75° F. To set the cooling temperature  
lower, first lower the heating setting.  
AM  
AM  
SET  
PT  
PERIOD  
MON  
MORNING  
COOL  
M2718  
Press and release. The display shows the  
preprogrammed cooling temperature and  
theprogrammedstarttimeforMORNING.  
SET  
PT  
WARMER  
COOLER  
MON  
MORNING  
COOL  
M2719  
Press and hold until the display shows the  
desired cooling temperature for MORN-  
ING.  
AM  
AM  
SET  
PT  
PERIOD  
MON  
MIDDAY  
COOL  
M2720  
SET  
PT  
WARMER  
COOLER  
Press and release. The display shows the  
preprogrammed cooling temperature and  
the programmed start time for MIDDAY.  
MON  
MIDDAY  
COOL  
M2721  
Press and hold until the display shows the  
desiredcoolingtemperatureforMIDDAY.  
SET  
PT  
PM  
ROOM  
PERIOD  
MON  
EVENING  
COOL  
M2722  
SET  
PT  
PM  
WARMER  
COOLER  
ROOM  
Press and release. The display shows the  
preprogrammed cooling temperature and  
the programmed start time for EVENING.  
MON  
EVENING  
COOL  
M2723  
Press and hold until the display shows the  
desiredcoolingtemperatureforEVENING.  
22  
This completes the program schedule for  
Download from Www.Somanuoalns.ecodmay. A. lGl MoatnouaSltseSpe3artcoh cAonpdyDothwinslopardo.gram  
T8611M  
PROGRAMMING THE THERMOSTAT  
If necessary, press and release to enter the  
programming mode.  
STEP 3  
SET  
PT  
PM  
COPYING THE PROGRAM TO  
THE DESIRED DAYS  
PERIOD  
DAY  
MON  
NIGHT  
HEAT  
M2724  
Press and hold until the day containing the  
program to be copied shows in the display.  
It is possible to copy the program for  
one day to any other day or combina-  
tion of days. The new program will  
replace any program already set in the  
day selected.  
SET  
PT  
PM  
MON  
NIGHT  
HEAT  
M2724  
Press and release. The day to be copied will  
show, and the next day will flash, in the  
display.  
COPY  
FROM  
MON TUE  
M2725  
Press and release to copy the program into  
the day that is flashing in the display. Note  
that the next day now starts to flash.  
COPY  
TO  
MON TUE WED  
M2726  
M2727  
Press and release if it is not desired to copy  
into the day that is flashing. Note that the  
next day now starts to flash.  
DAY  
MON  
WED  
Press and release the COPY TO key again  
to select the day that is flashing, or the  
DAY key to bypass it.  
COPY  
TO  
MON  
WED THU  
M2728  
M2729  
Continue until all desired days are showing  
in the display and are not flashing.  
PM  
TUE  
MIDDAY  
If an error is made in copying, start over by  
pressing COPY TO key repeatedly until all  
days are shown (not flashing); press COPY  
TO key once more.  
Press and release to copy the program into  
all the days selected.  
RUN  
PROGRAM  
Press and release to enter the programming  
mode.  
STEP 4  
AM  
SET  
PT  
PERIOD  
SETTING THE SCHEDULES  
AND TEMPERATURES FOR  
THE REMAINING DAYS  
TUE  
MIDDAY  
HEAT  
M2730  
Press and hold until the day desired to  
program shows on the display.  
Use the procedures described in Steps  
2 and 3 and summarized in this step to  
program the remaining days.  
SET  
PT  
DAY  
FRI  
FRI  
MIDDAY  
MIDDAY  
HEAT  
M2731  
If COOL shows on the display, press and  
release to switch to HEAT.  
SET  
HEAT/COOL  
SET  
PT  
HEAT  
M2731  
Use the AHEAD/BACK keys to set the  
time and the WARMER/COOLER keys to  
set the heating temperature.  
AHEAD  
BACK  
WARMER  
COOLER  
Press and release the PERIOD key to step  
throughtheremainingtimeperiods.Usethe  
AHEAD/BACKkeystosetthetimeandthe  
WARMER/COOLER keys to set the heat-  
ing temperature for each time period.  
PERIOD  
AHEAD  
BACK  
WARMER  
COOLER  
23  
68-0076—1  
 
T8611M  
PROGRAMMING THE THERMOSTAT  
Press and release so COOL shows on the  
display.  
AM  
SET  
HEAT/COOL  
SET  
PT  
FRI  
MORNING  
COOL  
M2732  
PressandreleasethePERIODkeytostep  
through the time periods, and use the  
WARMER/COOLER keys to set the  
cooling temperature for each period.  
WARMER  
COOLER  
PERIOD  
This completes the time and temperature  
program for another day. Copy it into  
additional days if desired.  
Press and release COPY FROM to enter  
the copy mode. The next day flashes on  
the display.  
COPY  
FROM  
FRI SAT  
M2733  
M2734  
Press and release the COPY TO key to  
selectthedaythatisflashing, ortheDAY  
key to bypass it.  
COPY  
TO  
SUN  
FRI  
DAY  
Continue, using the COPY TO key to  
bringupthenextday, followedbyCOPY  
TO to select, orDAY to bypasstheDAY,  
until all desired days are selected.  
COPY  
TO  
COPY  
TO  
DAY  
Press and release RUN PROGRAM to  
complete the copy.  
RUN  
PROGRAM  
PM  
TUE  
MIDDAY  
M2735  
Repeat Step 4 as needed until all days are  
programmed.  
STEP 5  
FAN ON: The fan runs continuously.  
Use for improved air circulation during  
special occasions or for more efficient  
electronic air cleaning.  
FAN  
SETTING THE SYSTEM AND  
FAN SWITCHES ON THE  
SUBBASE.  
ON AUTO  
M2757  
Depending on thermostat model, some  
of the switch positions shown may not  
be available. Note the positions pro-  
videdonsubbase,thensettheswitch(es)  
as desired.  
FAN AUTO: Normal setting for most  
homes and businesses. The fan starts and  
stops with the compressor in heat pump  
systems when the system switch is set to  
HEAT, AUTO or COOL. When system  
switch is set to EM. HT., the fan operates  
withtheauxiliaryheat(onsomemodels).  
FAN  
ON AUTO  
M2758  
First set the fan switch.  
Then set the system switch.  
EM. HT: The thermostat controls only  
the backup heat. The heat pump is off.  
EM. HT. HEAT OFF  
EM. HT. HEAT OFF  
AUTO COOL  
M2752  
HEAT:Thethermostatcontrolstheheat-  
ing system.  
AUTO COOL  
M2753  
OFF: Both the heating and cooling sys-  
tems are off.  
EM. HT. HEAT OFF  
AUTO COOL  
M2754  
24  
 
T8611M  
PROGRAMMING THE THERMOSTAT • OPERATING THE THERMOSTAT  
Then set the system switch. (contin-  
ued)  
AUTO (select models only): The ther-  
mostatcontrolseithertheheatingorcool-  
EM. HT. HEAT OFF  
AUTO COOL  
M2755  
ing system, depending on room tempera-  
ture.  
COOL:Thethermostatcontrolsthecool-  
ing system.  
EM. HT. HEAT OFF  
AUTO COOL  
M2756  
Now, read on to learn about the oper-  
ating flexibility that makes this ther-  
mostat THE SMART CHOICE.  
This completes the programming of the  
thermostat.  
If thermostat was removed from the wall  
to program, replace it following the pro-  
cedure on page 20.  
Operating The Thermostat  
TEMPORARILY CHANGING  
THE PROGRAM  
These features allow customizing the  
program for those times when some-  
one comes home early, is working late  
or planning to be out for the evening.  
Changes made with these keys are ac-  
tive for one program period and then  
are canceled.  
To keep the current temperature  
through the next program period:  
Press and release. The name of the period  
SKIP  
NEXT  
PERIOD  
SET  
PT  
PM  
to be skipped will flash in the display  
until the start time of the skipped period.  
During the skipped period, the display  
will flash “temporary” to show that the  
programmed temperature for this period  
is not being used.  
TUE  
MIDDAY EVENING  
M2736  
To go back to the temperature of the  
previous program period:  
Press and release. The display will show  
the name of the previous period and flash  
“temporary” until the next regularly  
scheduled period starts.  
CHANGE  
TO LAST  
PERIOD  
SET  
PT  
PM  
TUE  
TEMPORARY  
MORNING  
M2737  
IMPORTANT: The CHANGE feature will be operable the day after the thermostat has been  
programmed and operating. The thermostat requires this time to learn the programmed  
schedule.  
To temporarily raise or lower the tem-  
perature for the current period only:  
Press and hold until the desired tempera-  
ture is reached. The display will flash  
“tem-porary” until the next programmed  
time period starts.  
SET  
PT  
WARMER  
COOLER  
TEMPORARY  
HEAT  
M2738  
To change back:  
Press and release to cancel any of the  
temporary settings.  
RUN  
PROGRAM  
PM  
TUE  
MIDDAY  
M2739  
25  
68-0076—1  
 
T8611M  
OPERATING THE THERMOSTAT  
REPROGRAMMING THE  
THERMOSTAT  
PERIOD  
DAY  
Press and hold until the desired time period  
shows on the display.  
If schedule changes or a different tem-  
perature is desired, update any setting  
without affecting the rest of the pro-  
gram.  
Press and hold until the desired schedule  
day shows on the display.  
Press and hold the Time or Temperature  
keys until the display shows the desired  
new program.  
WARMER  
COOLER  
AHEAD  
BACK  
are copied.  
COPY  
FROM  
COPY  
TO  
Press and release. The next day will flash  
on the display. Press COPY TO to copy  
into, or DAY to bypass, the day. Continue  
until the program has been copied into all  
desired days.  
Copy the new program into other days,  
if desired. When copying a program, all  
the times and temperatures for that day  
DAY  
RUN  
PROGRAM  
Press and release to return to normal opera-  
tion.  
gram.  
SET  
PT  
HOLD  
TEMP  
HOLDING A TEMPERATURE  
FOR EXTENDED ABSENCE  
HEAT  
Press and release.  
M2740  
SET  
PT  
WARMER  
COOLER  
This feature is particularly useful when  
going on vacation or other extended  
absence. It does not cancel the pro-  
HEAT  
Press and hold to change the temperature  
setting. After a few seconds, the display  
will show the current temperature.  
M2741  
PRESENT  
SETTING  
SET  
PT  
HEAT  
Press and release to check the temperature  
setting.  
M2742  
RUN  
PROGRAM  
PM  
TUE  
MIDDAY  
M2743  
Pressandreleasetocancelmanualcon-  
trol.  
others can be canceled. Each time period  
for each day must be canceled separately.  
SET  
PT  
PM  
PERIOD  
MON  
NIGHT  
HEAT  
M2744  
CANCELING PROGRAM  
SETTINGS  
Press and hold until the desired time period  
shows on the display.  
The thermostat requires time and tem-  
peraturesettingsintheMORNINGtime  
period for each day, but any of the  
SET  
PT  
PM  
WED  
DAY  
NIGHT  
HEAT  
M2745  
Press and hold until the desired day shows  
on the display.  
SET  
PT  
CANCEL  
PERIOD  
WED  
NIGHT  
HEAT  
M2746  
Press and release to cancel the time and  
temperature settings for that time period.  
ber: all the programs will be copied, not  
just the cancellation.  
Both the heating and cooling tempera-  
tures will be canceled.  
RUN  
PROGRAM  
PM  
WED  
EVENING  
HEAT  
M2747  
Use the copy function to cancel the  
program from other days, but remem-  
26  
 
T8611M  
OPERATING THE THERMOSTAT • OPERATION  
Press and release to return to normal  
operation.  
without affecting the permanent program.  
SET  
PT  
PM  
PERIOD  
FRI  
NIGHT  
HEAT  
Pressandholduntilthedesiredperiodshows  
on the display. The start time and tempera-  
ture setting will appear on the display.  
M2748  
CHECKING THE PROGRAM  
TIMES AND TEMPERATURES  
If desired, check all the stored settings  
SET  
PT  
PM  
SAT  
NIGHT  
DAY  
HEAT  
Press and release to display the next day  
time and temperature for that period.  
M2749  
SET  
PT  
RUN  
PROGRAM  
PM  
FRI  
EVENING  
Press and release to return to normal opera-  
time.  
M2750  
tion.  
PRESENT  
SETTING  
SET  
PT  
HEAT  
CHECKING THE CURRENT  
TEMPERATURE SETTING  
Press and release. The display will show  
the current temperature setting for several  
seconds, then revert to the room tempera-  
ture.  
M2751  
Press a single key to compare actual  
room temperature to the setting at any  
During recovery from energy savings, the  
setting displayed will not match the pro-  
grammed setting. This is because the ther-  
mostat gradually changes the temperature  
setting during recovery to provide maxi-  
mum comfort combined with most effi-  
cient use of the heating or cooling equip-  
Operation  
ment.  
TheT8611MThermostatprovidesautomaticcontrolof  
multistage heat pump systems with up to three stages of  
heat and up to two stages of cool. The first heat stage is the  
heat pump and the last stage is electric, gas, or oil auxiliary  
heat. T8611M provides automatic changeover from heat  
to cool or cool to heat.  
the weather conditions and the building heating/cooling  
system.  
The advantages are:  
• The comfort setting is achieved at the programmed  
time and maintained regardless of weather condi-  
tions; occupants come home and wake up to com-  
fort.  
ADAPTIVE INTELLIGENT RECOVERY™  
OPERATION  
• Drafts from low temperature discharge air are mini-  
mized during occupied periods.  
AdaptiveIntelligentRecoveryistheHoneywelltrade-  
mark for the way the T8611 controls the heating and  
cooling equipment during recovery from an energy sav-  
ings setting to a comfort setting. During recovery, the  
control point changes gradually rather than jumping from  
theenergysavingssettingtothecomfortsettingallatonce.  
This provides additional energy savings.  
• The thermostat automatically uses the more eco-  
nomical heat pump as the primary heat source dur-  
ing heat mode recovery, avoiding the use of the  
expensive auxiliary heat.  
• Comfort and energy savings can be achieved in both  
heating and cooling.  
When Adaptive Intelligent Recovery™ is used in the  
heatingmode, thecontrolpointraisesgradually, maximiz-  
ing the use of the more economical heat pump to bring the  
sensed temperature to the desired comfort setpoint. This  
minimizes the use of the typically more expensive auxil-  
iary heat.  
In both heating and cooling, the thermostat monitors  
recovery each day and adjusts the next day recovery start  
time. This ensures that the building is at the desired  
temperature at the programmed time, regardless of the  
outdoor temperature. Recovery time varies depending on  
• Reduces heat pump compressor cycling, extending  
equipment life.  
Use of Outdoor Thermostats  
BecauseAdaptiveIntelligentRecoverycallsforaux-  
iliary heat only when it is truly needed, it eliminates the  
need for outdoor thermostat(s). If an outdoor thermostat is  
used with T8611 and it is set close to the balance point, the  
recovery time from energy savings will be prolonged  
because the outdoor thermostat will prevent operation of  
27  
68-0076—1  
 
T8611M  
OPERATION  
the auxiliary heat even when the T8611 is calling for it.  
cycles even during the energy savings period. When re-  
covery from energy savings begins, the heat pump will  
stay on and auxiliary heat will cycle. During recovery, the  
auxiliary heat ON times will be long, and the OFF times  
will be short. The ON times will shorten as the control  
point approaches the comfort setpoint. During the comfort  
period,theheatpumpisoncontinuouslyandauxiliaryheat  
cycles until the next energy savings period. When energy  
saving begins, the heat pump cycles off until the sensed  
temperature falls below the control point. Although the  
heat pump comes on when the sensed temperature falls  
below the control point, the sensed temperature may lag 2°  
or3° Fbelowthecontrolpointbecauseofthetimerequired  
to warm up the walls and furniture. Auxiliary heat will  
cycle as necessary during the energy savings period.  
(Balance point is the outdoor temperature below which the  
heat pump must call on auxiliary heat to help handle the  
load.) The resulting unnecessarily long recovery times  
reduce building energy savings.  
When Adaptive Intelligent Recovery™ Is Used  
Adaptive Intelligent Recovery™ is used during recov-  
ery from energy savings. It is bypassed when the setpoint  
is changed, and when the CHANGE TO LAST PERIOD,  
SKIP NEXT PERIOD or HOLD TEMP key is pressed. If  
Adaptive Intelligent Recovery™ is bypassed, the system  
operates the stages of equipment like a conventional ther-  
mostat.  
WHAT TO EXPECT DURING RECOVERY  
FROM ENERGY SAVINGS IN HEATING  
The T8611 controls the heating equipment based on the  
indoor sensed temperature, which is a combination of air  
temperature and wall temperature.  
THERMAL PERFORMANCE WITH T8611  
During severe weather, the T8611 actually controls  
closer to the setpoint than a conventional thermostat. This  
is because the heat anticipator is replaced by two elec-  
tronic control strategies—cycling by heat anticipation and  
proportional plus integral control.  
In Mild Weather  
When the outdoor temperature is mild, say 50°F [10°  
C], the recovery from energy savings will be handled  
completely by the heat pump, without using the more  
costly auxiliary heat. The heat pump starts only after the  
control point has risen above the sensed temperature and  
is locked on until the comfort setpoint is reached. During  
the comfort period, the heat pump will cycle on and off as  
needed to maintain the sensed temperature within +/-1° F  
of the setpoint. During energy savings periods, the T8611  
will call the heat pump on only if the sensed temperature  
falls below the control point.  
Electronic cycling by heat anticipation acts like a tradi-  
tional heat anticipator, except that never needs adjustment  
for various control circuit load currents. It cycles the heat  
pump off slightly before the room temperature reaches the  
setpoint to keep heat remaining in the ductwork from  
overheating the room.  
In severe weather, a conventional thermostat with a  
heat anticipator tends to turn off the thermostat too soon,  
so the effective control point is somewhat below the  
setpoint. In very cold weather, the difference between  
setpoint and effective control point may be 5° or 6° F [2°  
or3° C]withaconventionalthermostat. Thisphenomenon  
is called droop.  
In Moderate Weather  
When outdoor temperature is below the balance point  
of the heat pump, the heat pump will run continuously  
duringtherecoveryperiodandtheauxiliaryheatwillcycle  
as necessary. During the comfort period, the heat pump  
runs continuously and auxiliary heat cycles until the next  
energy savings period begins. During energy savings, the  
heat pump cycles on only when the sensed temperature  
falls below the control point. Under these conditions,  
auxiliary heat is typically not needed during the energy  
savings period.  
Proportional plus integral action eliminates droop by  
adjusting the on-time of the stage that is cycling longer or  
shorter until the control point matches the setpoint. The  
T8611 controls space temperature within one degree of  
setpoint, when the temperature has stabilized after an  
energy savings period.  
This zero droop performance of the T8611 provides  
improved occupant comfort and energy savings. Occu-  
pants do not need to continually adjust thermostat setting  
to maintain desired temperature, even during severe  
weather.  
In Severe Weather  
When the outdoor temperature is severe, say 0° F [-18°  
C], the heat pump is on continuously and auxiliary heat  
MINIMUM-OFF TIMING  
A minimum-off timer in the T8611 ensures that the  
compressorwill not come on again forat least five minutes  
after it turns off. The minimum-off timer is triggered when  
the compressor goes off, or when the system switch is  
moved. If the compressor turns off when the setpoint is  
changed or the CHANGE TO LAST PERIOD key is  
pressed, then the minimum-off timer is triggered. The  
minimum-off timer operates during the first stage of both  
heating and cooling.  
28  
 
T8611M  
TROUBLESHOOTING  
Troubleshooting  
Start the system by setting the thermostat and observing system response. If problem occurs, establish symptom and use  
the following troubleshooting chart to check for possible cause and action.  
SYMPTOM  
POSSIBLE CAUSE  
ACTION  
HEAT PUMP OR AUXILIARY HEAT  
WON'T OPERATE  
CHECK POWER TO HEAT PUMP OR  
AUXILIARY HEATING SYSTEM  
–ON-OFF SWITCH  
NO ac POWER TO THERMOSTAT  
–FUSE OR CIRCUIT BREAKER  
–LOOSE 24 V CONNECTION  
-AT THERMOSTAT  
-AT HEAT PUMP OR AUXILIARY HEATING SYSTEM  
–INCORRECT WIRING  
-CHECK WIRING DIAGRAM  
THERMOSTAT INOPERATIVE  
CONDUCT SELF-TEST; SEE CHECKOUT.  
ADJUST TEMPERATURE BY PUSHING WARMER/COOLER  
KEYS.  
PRESENT SETTING TOO LOW/HIGH  
SYSTEM SWITCH ON THERMOSTAT IN  
WRONG POSITION  
RESET THERMOSTAT SYSTEM SWITCH.  
MINIMUM-OFF TIMES IN THERMOSTAT IN  
OPERATION ON COOLING OR HEATING  
WAIT 5-10 MIN. OR USE SELF-TEST IN THERMOSTAT.  
SEE CHECKOUT.  
INCORRECT WIRING  
CHECK CIRCUIT DIAGRAM.  
HEAT PUMP OR AUXILIARY HEAT SYSTEM  
INOPERATIVE  
CONSULT HEAT PUMP/AUXILIARY HEAT SYSTEM  
INSTRUCTIONS.  
PARTIAL DISPLAY  
NO DISPLAY  
REPLACE THERMOSTAT.  
INOPERATIVE THERMOSTAT  
CHECK THAT HEAT OR COOL SYSTEM POWER IS ON.  
PRESS RUN PROGRAM KEY TWICE.  
NO POWER TO THERMOSTAT  
THERMOSTAT IN SELF-TEST MODE  
THERMOSTAT MOUNTED INCORRECTLY  
ON BASE  
SEE INSTALLATION INSTRUCTIONS FOR CORRECT  
MOUNTING.  
PRESENT SETTING APPEARS  
INACCURATE  
NORMAL OPERATION THERMOSTAT TURNS ON  
HEATING/COOLING EARLY TO MEET TEMPERATURE  
SETTING AT PROGRAMMED TIMES.  
RECOVERY CAN BE ENDED BY PUSHING  
WARMER/COOLER KEYS.  
THERMOSTAT IS IN RECOVERY MODE  
ROOM TEMPERATURE DISPLAY  
APPEARS INACCURATE  
THERMOSTAT HAS SEPARATE REMOTE-  
MOUNTED SENSOR  
THERMOSTAT IS CONTROLLED BY TEMPERATURE SENSED  
AT REMOTE SENSOR LOCATION.  
CHECK TEMPERATURE AT REMOTE SENSOR LOCATION.  
MAKE SURE WIRING FROM THERMOSTAT LOCATION TO  
REMOTE SENSOR LOCATION IS IN GOOD CONDITION.  
ROOM TEMPERATURE IS NOT WHAT  
IS EXPECTED ON WEEKENDS  
THERMOSTAT NOT PROGRAMMED FOR  
WEEKENDS  
REPROGRAM FOR WEEKENDS PER INSTRUCTIONS.  
THERMOSTAT TEMPERATURE  
NEEDS TO BE ADJUSTED ON A  
REGULAR BASIS  
REPROGRAM THERMOSTAT TO MAKE PERMANENT  
CHANGE IN PROGRAM. WARMER/ COOLER KEYS ARE  
TEMPORARY UNLESS PERIOD KEY IS PRESSED FIRST.  
WARMER/COOLER KEYS BEING USED  
TO ADJUST TEMPERATURE  
PROGRAM IS LOST DUE TO POWER  
OUTAGE OR DISPLAY GOES BLANK  
WHEN POWER IS TURNED OFF  
BATTERIES ARE INCORRECTLY INSTALLED  
BATTERIES ARE DEAD  
REMOVE AND REPLACE PER MARKINGS ON THERMOSTAT.  
REPLACE BATTERIES.  
DISPLAY FLASHES WHILE  
PROGRAMMING  
CHECK HOMEOWNERS MANUAL FOR CORRECT PROGRAM  
SEQUENCE.  
IMPROPER PROGRAM SEQUENCE  
AUTOMATIC CHANGEOVER THERMOSTAT  
HEATING OR COOLING TEMPERATURES  
CAN NOT BE SET CLOSER THAN 3°F  
SET HEATING AND COOLING TEMPERATURES 3°F OR  
MORE APART.  
DISPLAY FLASHES DURING  
OPERATION  
PROGRAMMING HAS BEEN LOST BECAUSE OF  
A POWER OUTAGE  
REPROGRAM ACCORDING TO PROGRAMMING  
INSTRUCTIONS (MAKE SURE BATTERIES ARE INSTALLED).  
M1020A  
29  
68-0076—1  
 
T8611M  
GLOSSARY  
Glossary  
AUX. HT. light (green)  
conditioning equipment to return the building from the  
energy saving temperature to the comfort temperature.  
The thermostat starts the recovery period early so the  
building will be at the comfort setting by the time the  
owner has chosen.  
This light glows whenever the thermostat is calling for  
operation of the backup heater. Backup (auxiliary) heat is  
more expensive to operate than the heat pump, and typi-  
cally is used only when the heat pump is unable to handle  
the load (located on subbase).  
Setback  
CHECK light (yellow)  
Consult heat pump literature to determine its meaning  
(located on subbase).  
Reducing the temperature in the building for a set period  
inheatingforenergysavings. Thelowertemperatureisthe  
energy savings temperature.  
Comfort temperature  
The temperature desired when active and occupying the  
building.  
Setup  
Raising the temperature in the building for a set period in  
cooling for energy savings. The higher temperature is the  
energy savings temperature.  
EM. HT. light (red)  
This light glows whenever the thermostat system switch is  
in the EM. HT. position (located on subbase). On some  
systems, itmayalsoindicatetheneedtoswitchtoEM. HT.  
because of a heat pump problem.  
Setpoint  
The thermostat temperature setting the owner selects. The  
thermostat turns the heating or cooling equipment on and  
off to maintain this temperature at the thermostat location  
until another temperature setting (setpoint) goes into ef-  
fect.  
Energy-saving temperature  
The lower (heating) or higher (cooling) temperature that  
allows savings on heating and cooling costs when asleep  
or away. Also called the setback (heating) or setup (cool-  
ing) temperature.  
SYSTEM light (yellow)  
This light glows whenever the thermostat is calling for  
heating or cooling (located on thermostat).  
Preprogrammed schedule  
Time period  
This is the schedule programmed into the thermostat at the  
factory. It sets a night program that provides energy  
savings if owner does not set his/her own program, or if  
personal program is lost for any reason. The program,  
which is the same for all days of the week, is:  
One of four program periods: MORNING, MIDDAY,  
EVENING, and NIGHT; available with the Chrono-  
therm III™ Thermostat. One period begins when the  
previous program period ends.  
MORNING—The time period when the owner brings  
the building to a comfortable temperature to begin the  
day. This is the only period that must contain a time and  
temperature for every day.  
Start  
Time  
Temperature  
Period  
Heating  
Cooling  
MORNING 6:00 AM  
70° F  
78° F  
MIDDAY—The time period when the owner can set  
back (heating) or set up (cooling) the temperature for  
daytime energy savings if the building is unoccupied.  
MIDDAY  
EVENING  
NIGHT  
- - - - - -No program - - - - - - - - - -  
- - - - - -No program - - - - - - - - - -  
10:00 PM 60° F  
78° F  
EVENING—The time period when the owner wants  
the building at a comfortable temperature for evening  
activities after daytime energy savings.  
Program  
The times and temperatures the owner sets to define the  
comfort and energy saving periods for each day’s sched-  
ule.  
NIGHT—The time period when the owner can set  
back (heating ) or set up (cooling) the temperature for  
energy savings because family members are asleep or  
the building is unoccupied. Often a NIGHT energy  
savingstemperatureissetonlyfortheheatingseasonso  
family members can sleep cool in summer.  
Recovery  
The time when the thermostat operates the heating or air  
30  
 
T8611M  
TABLE OF CONTENTS  
Table of Contents  
Page  
Specifications .................................................................................................................................................................... 2  
Ordering Information ...................................................................................................................................................... 2  
Selection/Application ....................................................................................................................................................... 5  
Installation ...................................................................................................................................................................... 12  
Compatibility ............................................................................................................................................................. 12  
Location ...................................................................................................................................................................... 12  
Mounting Subbase ..................................................................................................................................................... 12  
Mounting Remote Temperature Sensor ................................................................................................................. 13  
Wiring ......................................................................................................................................................................... 13  
Adjusting Cycle Rate ................................................................................................................................................ 17  
Installing Batteries .................................................................................................................................................... 17  
Power Outages ........................................................................................................................................................... 17  
Mounting the Thermostat......................................................................................................................................... 17  
Setting Day and Time................................................................................................................................................ 17  
Checkout.......................................................................................................................................................................... 18  
Heating........................................................................................................................................................................ 18  
Cooling ........................................................................................................................................................................ 18  
Fan............................................................................................................................................................................... 19  
Installer Self-Test ...................................................................................................................................................... 19  
Programming The Thermostat ..................................................................................................................................... 20  
Setting the Current Day and Time .......................................................................................................................... 20  
Setting the Program Times and Temperatures for One Day ............................................................................... 20  
Copying the Program to the Desired Days ............................................................................................................. 23  
Setting the Schedules and Temperatures For the Remaining Days..................................................................... 23  
Setting the System and Fan Switches on the Subbase ........................................................................................... 24  
Operating The Thermostat ........................................................................................................................................... 25  
Temporarily Changing the Program....................................................................................................................... 25  
Reprogramming the Thermostat ............................................................................................................................. 26  
Holding a Temperature for Extended Absence ..................................................................................................... 26  
Canceling Program Settings ..................................................................................................................................... 26  
Checking the Program Times and Temperatures ................................................................................................. 27  
Checking the Current Temperature Setting .......................................................................................................... 27  
Operation ........................................................................................................................................................................ 27  
Adaptive Intelligent Recovery™ Operation ........................................................................................................... 27  
What To Expect During Recovery From Energy Savings Heating ..................................................................... 28  
Thermal Performance With T8611 ......................................................................................................................... 28  
Minimum-Off Timing ............................................................................................................................................... 28  
Troubleshooting.............................................................................................................................................................. 29  
Glossary ........................................................................................................................................................................... 30  
31  
68-0076—1  
 
Home and Building Control  
Honeywell Inc.  
1985 Douglas Drive North  
Golden Valley, MN 55422  
Home and Building Control  
Honeywell Limited—Honeywell Limitée  
740 Ellesmere Road  
Helping You Control Your World  
Scarborough, Ontario  
M1P 2V9  
QUALITY IS  
KEY  
Printed in U.S.A.  
 

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