Honeywell T8602C User Manual

T8602C Chronotherm

Deluxe Programmable Thermostats

INSTALLATION INSTRUCTIONS

APPLICATION

The T8602 Chronotherm® IV Deluxe Programmable
Thermostat provides electronic control of 24 Vac single­stage heating and cooling systems. Refer to Table 1 for

Table 1. Description of T8602 Thermostats.

T8602 System Changeover

C Heat-Cool Manual Heat-Off-Cool On-Auto System and fan selections are done by

System

Selection

a general description of the thermostat. All T8602
thermostats are powered by batteries.

Fan

Selection Comments

keyboard.

®

IV

MERCURY NOTICE

If this control is replacing a control that contains
mercury in a sealed tube, do not place your old
control in the trash. Dispose of properly.

Contact your local waste management authority
for instructions regarding recycling and the
proper disposal of the old thermostat.

INSTALLATION

When Installing this Product...

1. Read these instructions carefully. Failure to follow
the instructions can damage the product or cause
a hazardous condition.

2. Check the ratings given in the instructions and on
the product to make sure the product is suitable
for your application.

3. Installer must be a trained, experienced service
technician.

4. After completing installation, use these instruc­tions to check out the product operation.

Location

Install the thermostat about 1.5m (5 ft) above the floor in
an area with good air circulation at average temperature.
See Fig. 1.

Do not install the thermostat where it can be affected by:
— drafts, or dead spots behind doors and in corners.
— hot or cold air from ducts.
— radiant heat from sun or appliances.
— concealed pipes and chimneys.
— unheated (uncooled) areas such as an outside wall

behind the thermostat.

Wallplate Installation

The thermostat can be mounted horizontally on the wall
or on a 50.8 mm x 101.6 mm (2 in. x 4 in.) wiring box.
Position wallplate horizontally on the wall or on a

50.8 mm x 101.6 mm (2 in. x 4 in.) wiring box.

1. Position and level the wallplate (for appearance

only). The thermostat will function properly even
when not level.

®U.S. Registered Trademark
Copyright © 2001 Honeywell • • All Rights Reserved

69-1567

T8602C CHRONOTHERM® IV DELUXE PROGRAMMABLE THERMOSTATS

NO

WIRES
THROUGH WALL

WALL
ANCHORS
(2)

Fig. 2. Mounting the wallplate.

YES

NO

1.5 METERS
(5 FEET)

Fig. 1. Typical location of thermostat.

2. Use a pencil to mark the mounting holes. See Fig. 2.

WALL

3. Remove the wallplate from the wall and drill two

4.76 mm (3/16 inch) holes in the wall (if drywall)
as marked. For firmer material such as plaster,
drill two 5.56 mm (7/32 inch) holes. Gently tap
anchors (provided) into the drilled holes until flush
with the wall.

4. Position the wallplate over the holes, pulling wires

through the wiring opening.

5. Loosely insert the mounting screws into the holes.

6. Tighten mounting screws.

WIRING

All wiring must comply with local electrical codes and
ordinances. Refer to Fig. 3 for typical hookup. A letter

MOUNTING
HOLES

MOUNTING
SCREWS

M15044

code is located near each terminal for identification.

CAUTION

Disconnect power before wiring to prevent
electrical shock or equipment damage.

1. Loosen the terminal screws on the wallplate and

connect the system wires. See Fig. 4.

IMPORTANT

2. Securely tighten each terminal screw.

3. Push excess wire back into the hole.

4. Plug the hole with nonflammable insulation to

prevent drafts from affecting the thermostat.

NO

M10856

Use 18 gauge, color-coded thermostat cable
for proper wiring.

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T8602C CHRONOTHERM® IV DELUXE PROGRAMMABLE THERMOSTATS

THERMOSTAT

YG

RC

2

COMPRESSOR
CONTACTOR

FAN
RELAY

L1
(HOT)

L2

1

COOLING
TRANSFORMER

1

POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD
PROTECTION AS REQUIRED.

JUMPER RC TERMINAL TO R TERMINAL WHEN INSTALLED ON A

2

ONE TRANSFORMER SYSTEM.

3

AVAILABLE ON SELECT MODELS. OT WIRES MUST HAVE A
SEPARATE CABLE FROM THE THERMOSTAT CABLE.

Fig. 3. Typical hookup in heat and cool

system with two transformers.

FOR WRAPAROUND
INSERTION STRIP
7/16 IN. (11 MM).

HEAT
RELAY

FOR STRAIGHT
INSERTION STRIP
5/16 IN. (8 MM).

RW

Fig. 4. Proper wiring technique.

OTOT

3

OUTDOOR
TEMPERATURE
SENSOR

1

HEATING
TRANSFORMER

M10855

M4826

Mounting Thermostat

1. Engage tabs at the top of the thermostat and

wallplate. See Fig. 5.

2. Press lower edge of case to close and latch.

NOTE: To remove the thermostat from the wall, first

pull out at the bottom of the thermostat;
remove top last.

L1
(HOT)

L2

A.

ENGAGE TABS
AT TOP OF
THERMOSTAT
AND WALLPLATE.

B.

PRESS LOWER
EDGE OF CASE
TO LATCH.

Fig. 5. Mounting thermostat on wallplate.

Using Thermostat Keys

The thermostat keys are used to:

• set current day and time,

• program times and setpoints for heating and cooling,

• temporarily override program temperatures,

• display present setting,

• configure Installer Setup,

• check Self-Test,

• display outdoor temperature (select models),

• set the system operation,

• set the fan operation.

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T8602C CHRONOTHERM® IV DELUXE PROGRAMMABLE THERMOSTATS

See Fig. 6 for the location of the keys.

INCREASE TIME SETTING
OR SCROLL FORWARD
THROUGH INSTALLER SETUP
AND SYSTEM TEST

SET CURRENT
DAY AND TIME

RETURN TO
NORMAL
OPERATIONS

ENTER
INDEFINITE
OR TIMED
HOLD MODE

SET CURRENT OR
PROGRAM DAY

CHANGE BETWEEN
DAYLIGHT SAVINGS
AND STANDARD TIME

SET WAKE TIMES
AND SETPOINTS

Set Current

Run

Day/Time

Program

Hold Temp

Day

Daylight

Time

COPY ONE PROGRAMMED
DAY TO ANOTHER DAY

SET LEAVE TIMES
AND SETPOINTS

Time Set Program

Wake

Heat/Cool

Settings

Copy

DECREASE TIME SETTING OR
SCROLL BACKWARD THROUGH
INSTALLER SETUP AND SYSTEM TEST

SET RETURN TIMES
AND SETPOINTS

Leave

Return Sleep

System Fan

Fig. 6. T8602C key locations and descriptions.

SETTINGS

System and Fan Settings

The system default setting is Heat and the fan default
setting is Auto. Use the System and Fan keys to change
the settings. See Fig. 7. The fan settings can be set for
each program period individually. The system selection
is for all the program periods.

System settings control the thermostat operation as
follows:

Heat: The thermostat controls the heating.
Off: Both the heating and cooling are off.
Cool: The thermostat controls the cooling.

Fan settings control the system fan as follows:

On: Fan operates continuously.
Auto: Fan operates with equipment.

Program

Hold Temp

Fig. 7. Thermostat System and Fan key locations.

NOTE: Always press the keys with your fingertip or

Time Set Program

Run

Set Current

Day/Time

Day

Daylight

Copy

Time

similar blunt tool. Sharp instruments like a pen
or pencil point can damage the keyboard.

INCREASE TEMPERATURE
SETTING OR SCROLL
FORWARD THROUGH
INSTALLER SETUP OPTIONS

DECREASE TEMPERATURE
SETTING OR SCROLL
BACKWARD THROUGH
INSTALLER SETUP OPTIONS

DISPLAY INFORMATION
SUCH AS PRESENT
SETTINGS AND OUTDOOR
TEMPERATURE

SET SLEEP TIMES
AND SETPOINTS

SELECT FAN
OPERATION

SELECT SYSTEM
OPERATION

CHANGE BETWEEN
HEATING AND COOLING
SETPOINTS

Leave

Wake

Return

Heat/Cool

System Fan

Settings

Sleep

M14625

M14624

System

Fan

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T8602C CHRONOTHERM® IV DELUXE PROGRAMMABLE THERMOSTATS

Temperature Settings

Refer to Table 2 for the default program. If the daytime
energy savings period is not used, press the period key
(Leave or Return) until the time is blank. The fan setting
feature is available on select thermostat models. See
Owners Guide, form number 69-0940, for complete
instructions on changing the program.

Table 2. Default Program Settings.

Period Time

Heat

Setpoint

Cool

Setpoint

Fan

Setting

Wake 6:45 AM 20°C25°C Auto
Leave 8:45 AM 4.5°C37°C Auto
Return 5:00 PM 20°C25°C Auto
Sleep 10:00 PM 4.5°C37°C Auto

INSTALLER SETUP

NOTE: For most applications, the thermostat factory-

settings will not need to be changed. Review
the factory settings in Table 2 and if no
changes are necessary, go to the Installer Self­Test section.

The Installer Setup is used to customize the thermostat
to specific systems. Some of the options include
temperature display, system changeover and outdoor
temperature display. Installer Setup numbers are listed
in Table 3. The table includes all the configuration
options and the factory-settings for the T8602.

A combination of key presses are required to use the
Installer Setup feature.
— To enter the installer setup, press and hold the

information i key with the increase ▲ and
decrease ▼ keys until the first number is displayed.
All display segments appear for approximately
three seconds before the number is displayed. See
Fig. 8 and 9.

— To advance to the next Installer Setup, press the

Time ▲ key.

— To change a setting, use the increase ▲ or

decrease ▼ key.

— To scroll the Installer Setup numbers backwards,

press the Time ▼ key.

— To exit the Installer Setup, press Run Program.

Wait
Recovery

Hold for

Filter

Em Ht

Mon

Tue WedThu Fri Sat Sun

Wake Leave Return Sleep

Set Day/TimeSet Program

Aux Ht

Days

Temporary Setting

AM
PM

Repl Batt

DST

Heat

OutdoorRoom

Cool

System

Em Heat

Fan

Fig. 8. Display of all the segments of the LCD.

INSTALLER SETUP
NUMBER DISPLAY
(COLUMN 2 OF TABLE 3)

FACTORY SETTING OR OTHER
CHOICE DISPLAY (COLUMN 3
OR 5 OF TABLE 3)

Fig. 9. Display of Installer Setup number and setting.

CAUTION

Electric heat systems must be configured to 1 in
Installer Setup number 2 to prevent equipment
damage caused by the system running without
the fan.

IMPORTANT

Only configurable numbers are shown on the
device. Example: If thermostat does not have a
system key, Installer Setup Number 12 will not
be displayed. Review Table 3 factory-settings
and mark any desired changes in the Actual
Setting column. When Installer Setup is
complete, review the settings to confirm that
they match the system.

Off
Cool
Auto

On
Auto

M14559

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T8602C CHRONOTHERM® IV DELUXE PROGRAMMABLE THERMOSTATS

Table 3. Thermostat Installer Setup Options.

Installer Setup

Select

Number (Press

Time ▲

change)

key to

Factory-Setting

Display Description Display Description

Not used. 1 —————

Fan operation

a

2 0 Conventional applica-

.

tions where equipment
controls fan operation

in heat mode.
Not used. 3 —————
Heating cycle

rate.

466—6 cph used for

conventional heat.

1, 3 or
9

Not used. 5 thru 12 ———
Adaptive

Intelligent
Recovery™
control.

13 1 Conventional recovery

(system starts

recovery at

programmed time).

Not used. 14 and 15 —————
Clock format. 16 0 12-hour clock format. 1 24-hour clock format.
Not used. 17 thru 23 —————
Outdoor

temperature
display (select
models).

24 0 No outdoor

temperature is

displayed.

Not used. 25 thru 32 —————
Minimum off

time for the
compressor.

Temperature
range stops in
heating.

Temperature
range stops in
cooling.

33 5 5 minute minimum off

34 32.0 Highest setting for

35 7.0 Lowest setting for

time for the

compressor.

heating setpoint.

cooling setpoint.

0 thru 4 Minimum number of minutes

4.5 to

31.5

7.5 to

37.0

Not used. 36 —————
Temperature

display
adjustment.

a

Number 2 must be set to 1 to extend fan operation.

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37 0 No difference in

displayed temperature

and actual room

temperature.

6

1.5 thru

-1.5

Other Choices

(Press ▲ or ▼ key to change)

1 Heat pump or electric heat

applications where thermostat
controls fan operation in heat
mode.

1—1 cph used for radiant floor

heat, gravity system.

3—3 cph used for hot water

systems or high efficiency
furnaces.

9—9 cph used for electric

heat systems.

—

0 Adaptive Intelligent

Recovery™ control is
activated (system starts early
so setpoint is reached by start
of program period).

1 Outdoor temperature is

displayed. Needs a
C7089B1000 Outdoor Sensor
to operate.

(0 thru 5) the compressor will
be off between calls for the
compressor.

Temperature range (0.5°C
increments) heating setpoint
can be set to.

Temperature range (0.5°C
increments) cooling setpoint
can be set to.

.5—Display adjusts to 0.5°C

higher than actual room
temperature.

1.0—Display adjusts to 1.0°C
higher than actual room
temperature.

1.5—Display adjusts to 1.5°C
higher than actual room
temperature.

-.5—Display adjusts to -0.5°C
lower than actual room
temperature.

-1.0—Display adjusts to -1.0°C
lower than actual room
temperature.

-1.5—Display adjusts to -1.5°C
lower than actual room
temperature.

Actual

Setting

—
—

T8602C CHRONOTHERM® IV DELUXE PROGRAMMABLE THERMOSTATS

IMPORTANT

Review the settings to confirm that they match
the system. Press Run Program to exit the
Installer Setup. The thermostat has saved the
Installer Setup changes and initiated a reset in
order to operate using the new settings. Be sure
to set the current day and time immediately.

Setting Current Day and Time

1. Press Set Current Day/Time.

NOTE: On initial powerup or after an extended

power loss, 1:00 pm flashes on the
display until a key is pressed.

Set Day/Time

Time Set Program

Set Current

Run

Leave

Wake

Set Current

Day/Time

Program

Hold Temp

Return Sleep

Day/Time

Heat/Cool

System Fan

Day

Settings

Daylight

Copy

Time

2. Press Day until the current day is displayed.

NOTE: Sun=Sunday, Mon=Monday,

Tue=Tuesday, Wed=Wednesday,
Thu=Thursday, Fri=Friday, Sat=Saturday.

Time Set Program

Set Current

Run

Leave

Wake

Return Sleep

Day/Time

Day

Program

Heat/Cool

Hold Temp

3. Press Time ▲ or Time ▼ until the current time is
displayed.

NOTE: Tapping the Set Current Day/Time

System Fan

Day

Settings

Daylight

Copy

Time

changes the time in one hour increments.

Time

Time Set Program

Set Current

Run

Leave

Wake

Return Sleep

Day/Time

Program

Heat/Cool

Hold Temp

NOTE: If the current time is Daylight Savings

Run
Program

Daylight

Hold Temp

Time

System Fan

Day

Settings

Daylight

Copy

Time

Time, press Daylight Time until DST is
displayed.

Time Set Program

Set Current

Leave

Wake

Return Sleep

Day/Time

Heat/Cool

System Fan

Day

Settings

Daylight

Copy

Time

PM

Mon

Set Day/Time

PM

Tue

Set Day/Time

AM

Tue

Set Day/Time

AM

Tue

DST

M14619

M14620

M14621

M14622

INSTALLER SYSTEM TEST

Use the Installer System Test to check the thermostat
operation. Refer to Table 4 for a list of the available
system tests.

To start the system test:

CAUTION

The minimum off time for compressors is
bypassed during the Installer System Test.
Equipment damage can occur if the compressor
is cycled too quickly.

Press and hold the increase ▲ and decrease ▼ keys at
the same time until 10 appears. All segments of the
display will be displayed before the 10 appears. See
Fig. 10 and 11.

Table 4. Tests Available In The Installer System Test.

Test

Number System Test Description

10-19 Heating equipment can be turned on

30-39 Cooling equipment can be turned on

40-49 Fan equipment can be turned on and off.

60 0 to
60 19

70-79 Thermostat information including date

Wait
Recovery

Hold for

Filter

Mon
Wake Leave Return Sleep

and off.

and off.

Keyboard keys test.

code and software versions are displayed.

Days

AM
PM

Repl Batt

Temporary Setting

OutdoorRoom

Cool

Heat

DST

Set Day/TimeSet Program

Em Ht

Aux Ht

Tue WedThu Fri Sat Sun

Fig. 10. Display of all LCD segments.

System

Em Heat

Cool
Auto

Fan

Auto

M14559

Off

On

4. Press Run Program.

Time Set Program

Set Current

Run

Leave

Wake

Day/Time

Program

Run

Program

Heat/Cool

Hold Temp

Day

Settings

Daylight

Copy

Time

Return Sleep

System Fan

System

AM

Tue

Wake

DST

Heat

Fan

Room

Auto

M14623

Fig. 11. Display of test number.

7

M14612

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T8602C CHRONOTHERM® IV DELUXE PROGRAMMABLE THERMOSTATS

Refer to Table 5 for the directions and results of the
specific tests.

NOTE: Press Time ▲ to advance to the next test and

Time ▼ to go back to the previous test. Press
Run Program to exit the system test.

Table 5. Installer System Test Options.

Key to
Press

Test

Number Description

Heating Equipment System Test

Time ▲ 10 Enter heating equipment system test.

▲ 11 Heat comes on. When Installer Setup number 2 is 1, the system fan is also energized.
▼ 10 Heat and system fan turn off.

Cooling Equipment System Test

Time ▲ 30 Change from heating to cooling equipment system test.

▲ 31 Cool and system fan come on.
▼ 30 Cool and system fan turn off.

Fan Equipment System Test

Time ▲ 40 Change from cooling to fan equipment system test.

▲ 41 Fan comes on.
▼ 40 Fan turns off.

Key Operation System Test

Time ▲

NOTE: Press any key and the displayed numbers will change. Press Time ▼ to go to the previous test and Time ▲

THERMOSTAT INFORMATION

1. Press the Time ▲ key to access the thermostat

60 2 Change from fan to key operation system test.

to go to the next test. The Run Program key will not exit this test. Press Time ▲ or Time ▼ and then the
Run Program key to exit.

4. Press the increase ▲ key again to display the

software revision number (Example: 001 =
Revision number 1).

information.

2. Press the increase s key to display the production
date code. The first two large digits are the month
and the third digit is the last digit of the year
(Example: 027 = February 1997).

3. Press the increase ▲ key again to display the

software identification code. (Example: 02 =
software ID code 2)

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M14613

M14614

M14615

5. Press the increase ▲ key again to display the

EEPROM identification code. (Example: 314 =
EEPROM ID 314)

6. Press the Run Program key to exit the system

test. The system test times out after four minutes
without any key presses.

8

M14616

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T8602C CHRONOTHERM® IV DELUXE PROGRAMMABLE THERMOSTATS

CHECKOUT

Outdoor Temperature Sensor
(Select Models)

Allow the outdoor temperature sensor to soak in the
outdoor air for a minimum of five minutes before taking
a reading.

TROUBLESHOOTING GUIDE

Symptom Possible Cause Action

Display will not
come on.

Temperature
display is incorrect.

Temperature
settings will not
change. (Example:
Cannot set the
heating higher or
the cooling lower.)

Heating will not
come on.

Thermostat is not being
powered.

Room temperature display has
been reconfigured.

Thermostat is configured for °F
or °C display.

Bad thermostat location. Relocate the thermostat.
The upper or lower temperature

limits were reached.

The setpoint temperature range
stops were configured.

No power to the thermostat. • Check for 24 Vac between R and W terminals.

Thermostat minimum off time is
activated.

System selection is not set to
Heat.

Heating setpoint is below room
temperature.

• Check if batteries are present and installed correctly.
— If batteries are present and installed correctly, replace

thermostat.

Enter Installer Setup number 37 and reconfigure the display.

Enter Installer Setup number 14 and reconfigure the display.

Check the temperature setpoints:

• Heating limits are 4.5 to 32°C

• Cooling limits are 7 to 37°C

Check Installer Setup numbers 34 and 35 and reconfigure the
setpoint stops.

— If missing 24 Vac:

— check if the circuit breaker is tripped—reset the

circuit breaker.

— check if the system fuse is blown—replace the

fuse.

— check if the power switch on the HVAC equipment

is in the Off position—set to the On position.

— check wiring between thermostat and HVAC

equipment—replace any broken wires and tighten
any loose connections.

— If 24 Vac is present, proceed with troubleshooting.

Wait up to five minutes for the system to respond.

Set system selection to Heat.

Check heating setpoint. Set heating setpoint to desired
temperature.

(continued)

9

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T8602C CHRONOTHERM® IV DELUXE PROGRAMMABLE THERMOSTATS

Troubleshooting Guide (continued)

Symptom Possible Cause Action

Cooling will not
come on.

Heating or cooling
come on momen­tarily and shut off

System on indicator
(flame=heat,
snowflake=cool) is
displayed, but no
warm or cool air is
coming from the
registers.

Outdoor tempera­ture not displayed

Outdoor
temperature
display is incorrect

Thermostat
backlight appears
dim.

a

Select models.

No power to the thermostat. • Check for 24 Vac between R or RC and Y terminals

— If missing 24 Vac:

— check if the circuit breaker is tripped—reset the

circuit breaker.

— check if the system fuse is blown—replace the

fuse.

— check if the power switch on the HVAC equipment

is in the Off position—set to the On position.

— check wiring between thermostat and HVAC

equipment—replace any broken wires and tighten
any loose connections.

— If 24 Vac is present, proceed with troubleshooting.

Thermostat minimum off time is
activated.

System selection is not set to
Cool.

Cool setpoint is above room
temperature.

Heat or cool circuit is opening
up or becoming high
impedance.

Fan operation set for 0 (con­ventional heat) when it should
be set for 1 (electric heat).

Conventional heating
equipment turns on the fan
when the furnace has
warmed up to a setpoint.

Heating or cooling equipment is
not operating.

Option not activated. Enter Installer Setup number 24 and set to 1. Thermostat must

a

Outdoor sensor is connected
incorrectly.

a

Wrong sensor. Replace sensor with C7089B1000 sensor.
Backlight may fade over the life

of the batteries.

• Wait up to five minutes for the system to respond.

• Enter Installer Setup number 33. Reconfigure minimum off

time (if required).

Set system selection to Cool.

Check cooling setpoint. Set cooling setpoint to desired
temperature.

Add resistor in parallel with load or install interface relay.

Enter Installer Setup number 2 and reconfigure the fan
operation.

Wait a minute after seeing the on indicator and then check the
registers.

Verify operation of heating or cooling equipment in self-test.

have OT terminals and a C7089B1000 installed.
Refer to C7089B1000 installation instructions and check wiring

between the thermostat and sensor.

• Wait unit Replace Battery indicator is illuminated and
replace batteries.

• Replace batteries now.

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T8602C CHRONOTHERM® IV DELUXE PROGRAMMABLE THERMOSTATS

11

69-1567

Home and Building Control

Honeywell
1985 Douglas Drive North
Golden Valley, MN 55422

Home and Building Control

Honeywell Limited-Honeywell Limitée
35 Dynamic Drive
Scarborough, Ontario
M1V 4Z9

69-1567 G.H. 8-01 Printed in Taiwan R.O.C.

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