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T8621A,C,D, CHRONOTHERM III  
FUEL SAVER THERMOSTATS  
APPLICATION  
These thermostats provide energy saving control for a  
4 Vac heating/cooling system as indicated in Table 1, and  
necessary. Cycle rates are adjustable for highest stage of  
heating.  
2
are powered direct from the control transformer.  
Fan operation option switch is included on SUPER  
TRADELINE model to select fan operation for electric heat  
application.  
12/24 hour clock conversion and °C/°F conversion is  
available on some models only.  
As long as thermostat is continuously powered, the  
thermostat will be compatible with any control system.  
These models include a SYSTEM LED, which is on  
whenthethermostatissignalingforheatingorcooling.Heat  
and cool anticipation is fixed in all models; no adjustment is  
TABLE 1—THERMOSTAT MODELS.  
SWITCHING  
SYSTEM  
STAGES  
THERMOSTAT  
T8621A  
T8621C  
T8621D  
T8621Da  
HEAT  
COOL  
FAN  
APPLICATION  
Single Stage  
Multistage  
Multistage  
Multistage  
1
2
2
2
1
1
2
2
HEAT-AUTO-COOL-OFF ON-AUTO  
HEAT-AUTO-COOL-OFF ON-AUTO  
HEAT-AUTO-COOL-OFF ON-AUTO  
HEAT-OFF-COOL  
ON-AUTO  
aSUPER TRADELINE model.  
INSTALLATION  
WHEN INSTALLING THIS PRODUCT…  
. Read these instructions carefully. Failure to follow  
them could damage the product or cause a hazardous  
condition.  
IF NEW INSTALLATION  
1
Run cable to a hole at the selected wall location, and pull  
about 3 in. [76 mm] of wire through the opening. Color-  
coded, 18 gauge thermostat cable with one conductor for  
each wiring terminal is recommended. Good service prac-  
tice recommends selecting cable with one or two more  
conductors than the immediate application requires.  
2
. Check the ratings on the product to make sure the  
product is suitable for your application.  
. Installer must be a trained, experienced service tech-  
nician.  
3
4
. Allow thermostat to warm to room temperature before  
MOUNTING SUBBASE  
IMPORTANT  
operating.  
5
. After installation is complete, check out product op-  
The T8621 requires an additional conductor to  
transformer common to provide continuous 24 V  
power for thermostat operation.  
eration as provided in these instructions.  
Set the system switch in the OFF position before  
mounting the subbase.  
CAUTION  
Disconnect power supply to prevent electrical shock  
or equipment damage.  
The subbase does not require leveling for proper opera-  
tion, but for appearance only.  
Remove thermostat from subbase (Fig. 1).  
IMPORTANT  
After wiring is complete, push excess wire back into  
the hole, and plug hole with nonhardening caulk,  
putty, or insulation to prevent drafts from affecting  
thermostat operation.  
The subbase mounts directly onto the wall with the  
screws and anchors included in the package. If drywall  
construction, plastic anchors must be used; use the sub-  
base as a template, and with a pencil, mark the two  
mounting screw positions (Fig. 2). Use 3/16 in. bit to drill  
holes for anchors. Gently tap anchors into holes until they  
are flush to the wall surface. Thread wires through the  
center opening of the subbase. Then, mount the subbase  
using two screws provided. Gently tighten screws, level top  
surface of subbase, then securely tighten screws.  
LOCATION  
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—  
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 thermostat,  
such as an outside wall.  
IF REPLACING AN EXISTING THERMOSTAT  
Turn power to thermostat off at furnace or boiler. A two  
transformer system may require turning off two switches or  
disconnects. 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.  
HEAT AUTO COOL OFF  
F
AN  
ON  
AUTO  
M844  
Fig. 1—Removing thermostat from subbase.  
C. H.  
Rev. 12-90  
Form Number 69-0330—3  
©Honeywell Inc. 1990  
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RefertoFigs.4-9fortypicalhookupsofsubbasethermo-  
stat.  
NOTE: Restrict all wiring to recessed area surrounding  
terminals (Fig.3) to assure thermostat/subbase contact.  
WALL  
WIRES THROUGH  
WALL OPENING  
ADJUSTING CYCLE RATE  
To custom-tailor the thermostats cycling performance  
to different types of heating equipment, cycle rate adjust-  
ment screws are provided on the back of the thermostat.  
Correct setting of these screws will provide optimum room  
temperature control.  
NOTE: MOST APPLICATIONS WILL NOT REQUIRE A  
CHANGE IN CYCLE RATE.  
WALL  
ANCHORS  
(
2)  
MOUNTING  
HOLES  
HEATING  
TRANSFORMER  
MOUNTING  
SCREWS (2)  
1
SUBBASE  
L1  
R
M846  
(HOT)  
2
L2  
3
HIGH  
LIMIT  
POWER  
SUPPLY  
C
Fig. 2—Mounting subbase on wall.  
H
HEAT RELAY  
W1  
SYSTEM  
SWITCH  
FOR STRAIGHT  
INSERTION –  
STRIP 5/16 in. (8 mm)  
HEAT  
FOR WRAPAROUND –  
STRIP 7/16 in. (11 mm)  
AUTO  
COOL  
RESTRICT  
WIRING TO  
THIS AREA  
OFF  
C
Y1  
G
FRONT VIEW OF  
TERMINAL AREA  
FAN  
SWITCH  
COOLING  
CONTACTOR  
AUTO  
ON  
KEEP WIRING BELOW  
THIS SURFACE  
TOP SURFACE  
OF SUBBASE  
FAN RELAY  
2
L1  
HOT)  
L2  
RC  
(
CROSS-SECTIONAL VIEW OF  
TERMINAL AREA  
1
COOLING  
TRANSFORMER  
M847  
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD  
PROTECTION AS REQUIRED.  
Fig. 3—Restrict wiring to recessed area surrounding  
terminals.  
2
3
FOR SINGLE TRANSFORMER SYSTEM JUMPER R AND RC.  
WIRING  
NOMINAL 24 Vac POWER MUST BE PRESENT BETWEEN R AND C FOR  
THERMOSTAT OPERATION.  
All wiring must comply with local electrical codes and  
ordinances.  
M1574  
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 thermostat operation.  
Fig. 4—T8621A 1-stage heat/1-stage cool thermostat  
with HEAT-AUTO-COOL-OFF system and  
AUTO-ON fan switching.  
2
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HEATING  
TRANSFORMER  
L1  
1
(HOT) L2  
L1  
HOT)  
L2  
R
3
1
(
2
HIGH  
LIMIT  
SYSTEM  
TRANSFORMER  
POWER  
SUPPLY  
C
R
HIGH  
LIMIT  
POWER  
SUPPLY  
H1  
HEAT RELAY 1  
HEAT RELAY 2  
HIGH  
LIMIT  
W1  
W2  
C
2
HIGH  
LIMIT  
H2  
H1  
H2  
K
RELAY K  
COOLING  
CHANGE-  
OVER  
SYSTEM  
SWITCH  
W1  
W2  
SYSTEM  
SWITCH  
HEAT  
HEAT  
AUTO  
COOL  
OFF  
AUTO  
COOL  
OFF  
COMPRESSOR  
CONTACTOR  
3
C2  
C2  
C1  
Y2  
Y1  
G
Y2  
Y1  
G
COOLING  
CONTACTOR 2  
C1  
FAN  
SWITCH  
COOLING  
CONTACTOR 1  
FAN RELAY  
FAN  
SWITCH  
AUTO  
AUTO  
ON  
ON  
FAN RELAY  
2
L1  
HOT)  
L2  
RC  
RC  
(
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD  
PROTECTION AS REQUIRED.  
1
COOLING  
TRANSFORMER  
2
3
ADD RELAY (SPDT) TO ACCOMMODATE COOLING CHANGEOVER.  
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD  
PROTECTION AS REQUIRED.  
T8621D ONLY.  
NOTE: SET CYCLE RATE TO HOT WATER SETTING (3 cph).  
THERMOSTAT DOES NOT PROVIDE MINIMUM OFF TIME  
2
3
FOR SINGLE TRANSFORMER SYSTEM JUMPER R AND RC.  
IN HEATING.  
M1575  
NOMINAL 24 Vac POWER MUST BE PRESENT BETWEEN R AND C FOR  
THERMOSTAT OPERATION.  
M1573  
Fig. 5T8621C,D 2-stage heat/2-stage cool thermostat  
with HEAT-AUTO-COOL-OFF system and  
AUTO-ON fan switching. For T8621C, delete  
second cooling stage.  
Fig. 6T8621C,D single-stage heat pump thermostats  
with cooling changeover. HEAT-AUTO-COOL-  
OFF system and AUTO-ON fan switching.  
3
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L1  
HOT) L2  
(
1
HEATING  
TRANSFORMER  
R
L1  
4
(
HOT) L2  
1
POWER  
SUPPLY  
C
SYSTEM  
TRANSFORMER  
HIGH  
LIMIT  
HIGH  
LIMIT  
R
C
FAN  
OPERATION  
SWITCH  
W1  
POWER  
SUPPLY  
3
HIGH  
LIMIT  
STAGE 1  
HEAT RELAY  
ELECTRIC  
HEAT 1  
W2  
HEAT 2  
2
NON-  
HIGH  
LIMIT  
ELECTRIC  
HEATING  
CHANGEOVER  
STAGE 2  
HEAT RELAY  
H1  
H2  
SYSTEM  
SWITCH  
W1  
W2  
HEAT  
B
SYSTEM  
SWITCH  
COMPRESSOR  
CONTACTOR  
OFF  
HEATING DAMPER OR  
CHANGEOVER RELAY  
HEAT  
COOL  
AUTO  
COOLING DAMPER OR  
CHANGEOVER RELAY  
COOL  
OFF  
O
2
C2  
STAGE 2  
COOLING RELAY  
Y2  
Y1  
G
Y2  
COOL 1  
COOL 2  
C1  
STAGE 1  
COOLING RELAY  
Y1  
G
FAN  
SWITCH  
AUTO  
FAN  
SWITCH  
FAN RELAY  
FAN RELAY  
AUTO  
ON  
ON  
RC  
3
RC  
1
2
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD  
PROTECTION AS REQUIRED.  
COOLING  
TRANSFORMER  
T8621D ONLY.  
1
NOTE: SET CYCLE RATE TO HOT WATER SETTING (3 cph).  
THERMOSTAT DOES NOT PROVIDE MINIMUM OFF TIME  
L1 L2  
(HOT)  
1
2
POWER SUPPLY. PROVIDE DISCONNECT MEANS  
AND OVERLOAD PROTECTION AS REQUIRED.  
IN HEATING.  
M1576  
FOR GAS OR OIL APPLICATIONS OR ELECTRIC HEAT  
APPLICATIONS WHERE THE FAN OPERATION IS CONTROLLED  
INDEPENDENTLY OF THE THERMOSTAT (AUTO FAN OPERATES  
WITH Y1 ONLY). TWO TRANSFORMERS MAY BE USED. SET  
SWITCH TO NONELECTRIC POSITION.  
3
4
FOR ELECTRIC HEAT APPLICATIONS (AUTO FAN OPERATES  
WITH W1 AND Y1), USE ONLY ONE TRANSFORMER; JUMPER  
R AND RC. SET SWITCH TO ELECTRIC POSITION.  
NOMINAL 24 VAC POWER MUST BE PRESENT BETWEEN  
R AND C FOR THERMOSTAT OPERATION.  
M13444  
Fig. 7T8621C,D single-stage heat pump thermostats  
with heating changeover. HEAT-AUTO-COOL-  
OFF system and AUTO-ON fan switching.  
Fig. 8T8621D 2-stage heat/2-stage cool manual  
changeover thermostat with auto fan on heat  
and cool; convertible to auto fan on cool only.  
HEAT-OFF-COOL system and AUTO-ON fan  
switching.  
4
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FAN OPERATION OPTION SWITCH  
The SUPER TRADELINE model includes a fan opera-  
tion option switch on the subbase, visible before the ther-  
mostat is mounted on the subbase. The switch should be in  
electricheatpositionforelectricheatingsystemsthatdonot  
have independent fan control.  
L1  
HOT) L2  
(
1
SYSTEM  
TRANSFORMER  
INSTALLING BATTERIES  
R
C
Three AAA alkaline batteries are provided as backup to  
preventprogramlossincaseofpoweroutage.Batteriesare  
includedwiththermostat.Installbatteriesinbackofthermo-  
stat as shown in Fig. 11.  
3
HIGH  
LIMIT  
POWER  
SUPPLY  
Without battery backup, the program will remain about  
3
0 seconds in event of power loss.  
HIGH  
LIMIT  
FAN  
OPERATION  
SWITCH  
IMPORTANT  
Whenbatteriesarefirstinstalled,thedisplaywillflash  
W1  
2
1
:00 PM and 32° or 0°. The temperature display will  
ELECTRIC  
HEAT 1  
W2  
HEAT 2  
stay at 32° or 0° until the thermostat is powered from  
the system wiring.  
NON-ELECTRIC  
SYSTEM  
SWITCH  
HEATING  
CHANGEOVER  
RELAY  
HEAT  
OFF  
B
COOL  
COOLING  
CHANGEOVER  
RELAY  
O
1
A
1B  
2B  
2
A
1
Y2  
COOL 1  
COOL 2  
COMPRESSOR  
CONTACTOR  
Y1  
G
FAN  
SWITCH  
FAN RELAY  
CYCLES  
PER HOUR  
TIME/TEMP  
DISPLAY  
AUTO  
SYSTEM  
GRAVITY  
1A  
1B  
2A  
IN  
2B  
OUT 1/2  
OUT 1/2  
ON  
AIR/WATER TO 1 TURN TO 1 TURN  
1
3
24 HR  
12 HR  
HOT  
WATER  
OUT 1/2  
TO 1 TURN  
OUT 1/2  
TO 1 TURN  
IN  
GAS/OIL  
IN  
IN  
RC  
WARM AIR (FACTORY SETTING)  
6
9
o
C
IN  
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND  
OVERLOAD PROTECTION AS REQUIRED.  
ELECTRIC  
WARM AIR  
IN  
OUT 1/2  
TO 1 TURN  
oF  
OUT 1/2  
TO 1 TURN  
2
3
FAN OPERATION SWITCH MAY BE IN EITHER POSITION.  
1
SCREWS 2A, 2B ONLY AVAILABLE ON SOME MODELS.  
M311A  
NOMINAL 24 VAC POWER MUST BE PRESENT BETWEEN R AND C  
FOR THERMOSTAT OPERATION.  
M1546A  
Fig. 10Cycle rate adjustment.  
Fig. 9T8621D single-stage manual changeover heat  
pump thermostat. HEAT-OFF-COOL system  
and AUTO-ON fan switching.  
The room air temperature will normally vary slightly from  
the comfort temperature setting with the cycling of the  
furnace or air conditioner.  
Theheatingcyclerateofthisthermostatisfactory-setfor  
gas/oil warm air heating. The cooling cycle rate cannot be  
adjusted. The heating cycle rate can be adjusted by turning  
one or both cycle rate adjustment screws located on the  
back of the thermostat. In multistage heat systems, the  
cycle rate adjustment applies to stage 2 only; stage 1 is  
fixed. See Fig. 10.  
BATTERY PLACEMENT  
(
NOTE CORRECT PLUS  
AND MINUS DIRECTION) M372A  
TIME/TEMPERATURECONVERSION(SOMEMODELS)  
The display readout may be converted between 12 and  
4 hour clock or °C and °F using screws 2A and 2B as  
2
indicated in Fig. 10.  
Fig. 11Battery placement.  
5
69-03303  
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When the batteries are low, the display will flash  
REPL BAT. The building owner will have 20-30 seconds to  
install new batteries after removing old batteries from  
thermostat. After 20-30 seconds, it will be necessary to  
reprogram. REPL BAT indication will disappear when ther-  
mostat is mounted back on the subbase.  
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.  
If batteries are completely dead, the display will go  
blank. After replacing the battery in this case, reprogram-  
ming will be necessary.  
MOUNTING THE THERMOSTAT  
Hang the thermostat on the tabs at the top of the base  
(
Fig. 12a). Swing down and press on lower edge until  
POWER OUTAGES  
Backup batteries will hold the programming and keep  
thermostat snaps in place (Fig. 12b). Open cover, and  
tighten the captive mounting screws (Fig. 12c).  
A.  
B.  
SYSTEM  
AM  
MORNIM  
MO  
G
N
HEAT  
R
OOM  
ON  
FAN  
AUTO  
ON AUTO  
HEAT AUTO COOL  
OFF  
SYSTEM  
C.  
A
M
ROOM  
HEAT ON  
MORN  
M
IM  
O
G
N
TEMPERATURE  
PR OR GU NR AM  
PRESENT  
SETTING  
TIME  
PD R SE ES TE NT  
AY/TIME  
FC  
O
OP MY  
P NES ERK XII OPT D  
DAY  
PERIOD  
R
AHEAD  
WARMER  
COOLER  
HT OLD  
EMP  
SET  
HEAT/COOL  
CANCEL  
PERIOD  
COPY  
TO  
BACK  
CHANGE  
TO LAST  
PERIOD  
M843  
Fig. 12Mounting thermostat on subbase.  
If the display will not come on—  
SETTING DAY AND TIME  
Restore 24 V power to the thermostat. When power is  
applied to the thermostat, the display will read 1:00 PM and  
roomtemperature.Itwillgooffforafewseconds,thenbegin  
to flash on and off. Set present day and time.  
 check mounting of thermostat to subbase. If loose or  
misaligned, remove thermostat and reinstall on the  
subbase, making sure it is firmly attached.  
 check to see that heat or cool system power is on.  
 check voltage between R and C; should be 24 to 30  
Vac.  
SET  
PRESENT  
Press DAY/TIME  
.
Press  
DAY  
to set the current day. Each press of the  
DAY key advances the display one day.  
BACK  
Press TIME AHEAD or  
tosetthecurrenttime.  
CHECKOUT  
HEATING  
delay on gas or oil forced air systems). Press COOLER key  
until the setting is about 10° F [6° C] below room tempera-  
ture.Theheatingequipmentshouldshutoff,followedbythe  
fan.  
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 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 (both  
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.  
[
stagesifmultistage), andthefanshouldrun(maybeashort  
6
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COOLING  
SYSTEM  
SWITCH  
POSITION  
PRESS LOOK FOR THIS RESPONSE  
CAUTION  
THIS  
KEY  
KEY  
KEY  
DOWN RELEASED  
Do not operate cooling if outdoor temperature is  
below 50° F [10° C]. Refer to manufacturers recom-  
mendations.  
OFF  
CHANGE  
TO LAST  
PERIOD  
03  
07  
15  
15  
Blank  
Blank  
Blank  
SKIP  
NEXT  
PERIOD  
NOTE: When cooling setting is changed, thermostat will  
wait up to 5 minutes before turning on the cooling  
equipment. This delay protects the compressor.  
PRESENT  
SETTING  
Move the system switch to COOL and the fan switch to  
AUTO. Press COOLER key until the setting is about 10° F  
COOL or  
AUTO (with  
fan in AUTO)  
1st stage cooling,  
fan and SYSTEM  
LED on.  
PRESENT  
SETTING  
[
6° C]belowroomtemperature. Thecoolingequipmentand  
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.  
15  
15  
2nd stage cooling  
also on.  
2nd stage cooling off.  
PRESENT  
SETTING  
PRESENT  
SETTING  
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.  
PRESENT  
SETTING  
15  
1st stage cooling, fan  
andSYSTEMLEDoff.  
NOTE: If single-stage cooling system, press key twice  
instead of 4 times; once to turn cooling, fan and SYS-  
TEM LED on, second time to turn off.  
FAN  
Move the system switch to OFF, and the fan switch to  
ON. The fan should run continuously. When the fan switch  
is in the AUTO position, fan operates directly with the  
cooling system, and also with heating system on some  
models.  
OFF  
06  
02  
Blank  
Blank  
Blank  
Blank  
Blank  
Blank  
See note  
WARMER  
COOLER  
05  
AHEAD  
BACK  
INSTALLER SELF-TEST (optional)  
IMPORTANT  
04  
AC power must be present on thermostat to con-  
duct self-test. Relays will not toggle, codes will not  
be present and thermostat will not manually exit  
self-test without ac power.  
01  
COPY  
FROM  
COPY  
TO  
00  
12  
Five-minute time delay on cooling does not func-  
tion during self-test.  
(CHECK  
A
EACH  
PERIOD  
POSITION)  
OFF  
Perform the following test as a check of all thermostat  
functions. If thermostat does not respond as indicated,  
thermostat must be replaced.  
CANCEL  
PERIOD  
08  
Blank  
13  
Microprocessormask  
no. and revision no.  
DAY  
1. Press AHEAD and BACK keys at the same time.  
Whileholdingkeysdown,allsegmentsofthedisplayshould  
be on (Fig. 13).  
SET  
HEAT/COOL  
09  
14  
Blank  
SET  
PRESENT  
DAY/TIME  
Blank  
HEAT or  
1
SET  
14  
14  
14  
1st stage heating and  
SYSTEM LED on.  
2nd stage heating  
also on.  
PRESENT  
DAY/TIME  
REPL  
AM  
AUTO  
SET  
PT  
BAT  
SET  
PRESENT  
DAY/TIME  
PM  
ROOM  
SUN MON TUE WED THU FRI SAT TEMPORARY  
OUTDOOR  
SET  
PRESENT  
DAY/TIME  
2nd stage heating off.  
MORNING MIDDAY EVENING NIGHT COOL ON HEAT ON  
M525A  
SET  
PRESENT  
DAY/TIME  
14  
1st stage heating and  
SYSTEM LED off.  
Fig. 13All segments on display.  
NOTE: If single-stage heating system, press key twice  
instead of 4 times; once to turn heating and SYSTEM  
LED on, second time to turn off.  
2
. Set system switch to OFF. Press AHEAD and BACK  
and PRESENT SETTING keys at the same time to enter  
self-test.  
OFF  
HOLD  
TEMP  
10  
11  
Blank  
3
. Press each key as listed below, and look for response  
listed as key is held down and released.  
RUN  
PROGRAM  
Normal operating  
display.  
1
For electric heat fan operationThe fan will operate  
with the heating system when fan switch is in AUTO.  
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, with each digit explained below.  
A
7
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CYCLE RATE SETTING  
CPH at 50% on time for  
stage 1 on 1-heat models,  
SYSTEM  
SWITCH  
POSITION  
(
THIRD  
DIGIT  
MANUAL OR AUTO  
CHANGEOVER  
FIRST  
DIGIT  
0
1
2
3
stage 2 on 2-heat models)  
0
1
3
4
5
Manual  
Auto  
Auto  
Manual  
Auto  
HEAT or OFF  
HEAT or OFF  
AUTO  
1
3
9
6
COOL  
COOL  
M13443  
SECOND  
DIGIT  
STAGES OF  
SYSTEM  
SWITCH  
POSITION  
COOL, AUTO  
or OFF  
COOL, AUTO  
or OFF  
HEAT  
HEAT  
HEAT  
COOL  
FOURTH  
DIGIT  
CLOCK  
(HRS)  
12  
DEGREES  
F
0
1
2
3
4
5
6
2
2
1
1
0
1
2
1
2
1
2
2
0
0
0
1
F
24  
2
3
4
F
F
C
12  
24  
12  
COOL, AUTO  
or OFF  
5
C
24  
COOL, AUTO  
or OFF  
6
7
C
C
12  
24  
HEAT  
HEAT  
This equipment is a Class B digital apparatus which complies with Canadian Radio Interference Regulations, CRC c. 1374.  
Honeywell Inc. International Sales Offices in all principal cities of the world. Manufacturing in  
U.S.A.: 1885 Douglas Drive N. Australia, Canada, Finland, France, Germany, Japan, Mexico, Netherlands,  
Golden Valley, MN 55422-4386 Spain, Taiwan, United Kingdom, U.S.A.  
CANADA: 740 Ellesmere Road  
Scarborough, Ontario M1P 2V9  
QUALITY IS KEY  
PRINTED IN TAIWAN R.O.C.