Honeywell T8624D User Manual

Page 1

T8624D Chronotherm

Programmable Thermostat

APPLICATION

The T8624D Chronotherm® IV Deluxe Programmable Thermostat provides electronic control of 24 Vac multistage heating and cooling systems.

IV Deluxe

PRODUCT DATA

• Models available with outdoor temperature sensor capability for homeowner convenience. The sensor is also more accurate than a thermometer.

• Configurable features allows one model to be used to replace many different models (less inventory, no longer need to carry separate models to get these features). — °F or °C temperature display; — automatic or manual changeover; — electric or conventional heat fan operation; — adjustable heating cycle rate.

• Minimum off time for cooling compressors and heat pumps protects the equipment and extends the equipment life.

• Easy installation, setup and system test saves installer time and increases productivity.

• System test simplifies troubleshooting and saves time by overriding the time delays.

• Adaptive Intelligent Recovery® control brings the room temperature to temperature setpoint at the programmed time, maximizing comfort and energy savings.

• Setpoints are permanently held in memory (no batteries used) and retained during power outages for increased installer and homeowner convenience.

• Universal Versaguard™ Thermostat guards available for added security.

FEATURES

• Full seven-day program capability; different schedules and temperature setpoints may be selected for everyday to match the homeowner’s flexible schedule.

• Copy key makes programming easier and faster for the installer and homeowner.

• Daylight Savings Time (DST) key for quick change in and out of Daylight Savings Time.

• Models available with programmable fan operation for added homeowner comfort.

• Easy temporary temperature setpoint changes for current period, vacation hold (1 to 255 days) or indefinite hold adds to the homeowner comfort and energy savings.

• Most frequently used keys are located by the Liquid Crystal Display (LCD) for quick and easy access to information.

• Attractive styling complements any decor to the homeowner’s delight.

• Back lighting the large display makes the LCD very easy to read.

Contents

General ............................................................................... 1

Features .............................................................................. 1

Specifications ...................................................................... 2

Ordering Information ........................................................... 2

Installation ........................................................................... 3

Wiring .................................................................................. 4

Settings ............................................................................... 6

Installer Setup ..................................................................... 7

Installer System Test ........................................................... 10

Programming....................................................................... 12

Operation ............................................................................ 16

Troubleshooting Guide ........................................................ 18

Cross Reference ................................................................. 19

Wiring Diagram ................................................................... 20

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T8624D CHRONOTHERM® IV DELUXE PROGRAMMABLE THERMOSTAT

SPECIFICATIONS

Important

Thermostat Model

T8624D Thermostats provide features listed in Table 1.

Changeover

Electrical Rating (Nominal Range):

Batteries:

No batteries required.

Loss of Power:

The thermostat will maintain programmed times and temperatures for the life of the product. The clock and day information is retained for a minimum of thirty minutes.

The specifications given in this publication do not include normal manufacturing tolerances. Therefore, this unit might not exactly match the listed specifications. This product is tested and calibrated under closely controlled conditions, and some minor differences in performance can be expected if those conditions are changed.

Table 1. Thermostat Features.

System

Selection

Automatic Heat-Off-

Cool-Auto

24 Vac, 50/60 Hz. 20 to 30 Vac, 50/60 Hz.

Fan

Selection Comments

On-Auto System and fan

selections are done by keyboard.

Temperature:

Ratings:

Operating Ambient: 40°F to 110°F (4°C to 43°C). Shipping: -30°F to +150°F (-34°C to +65°C).

Display Accuracy:

±1°F (±0.5°C).

Setpoint:

Range:

Heating: 40°F to 90°F (7°C to 31°C)

Cooling: 48°F to 99°F (9°C to 37°C). Differential: 3°F (1.5°C). Default Settings: see Table 3.

Table 3. Default Setpoints.

Period Time

Wake 6:00 AM 70°F

Leave 8:00 AM 62°F

Return 6:00 PM 70°F

Sleep 10:00 PM 62°F

Minimum Stage Operation Time:

Minimum On (Heat and Cool) (select models): factory

setting 2 minutes; option 0 minutes. Minimum Off (Cool and Heat Pump): factory setting

2 minutes; option 0 minutes.

Heat

Setpoint

(21°C)

(16.5°C)

(21°C)

(16.5°C)

Cool

Setpoint

78°F

(25.5°C)

85°F

(29.5°C)

78°F

(25.5°C)

82°F

(28°C)

Fan

Setting

Auto

System Current Load Ratings:

6 VA maximum at 30 Vac, 50/60 Hz.

Output Relay Draw:

See Table 2.

Table 2. Maximum Amps at 30 Vac.

Relay Running (A) Inrush (A)

Fan 0.5 2.5 Heat (all stages) 1.5 3.5 Cool (all stages) 1.5 7.5

Humidity Ratings:

5% to 90% RH, noncondensing.

Clock Accuracy:

+1 minute per month.

Finish:

Taupe or Premier White® color.

ORDERING INFORMATION

When purchasing replacement and modernization products from your TRADELINE® wholesaler or distributor, refer to the TRADELINE® Catalog or price sheets for complete ordering number.

If you have additional questions, need further information, or would like to comment on our products or services, please write or phone:

1. Your local Home and Building Control Sales Office (check white pages of your phone directory).

2. Home and Building Control Customer Relations Honeywell, 1885 Douglas Drive North Minneapolis, Minnesota 55422-4386

In Canada—Honeywell Limited/Honeywell Limitée, 35 Dynamic Drive, Scarborough, Ontario M1V 4Z9. International Sales and Service Offices in all principal cities of the world. Manufacturing in Australia, Canada, Finland, France, Germany, Japan, Mexico, Netherlands, Spain, Taiwan, United Kingdom, U.S.A.

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T8624D CHRONOTHERM® IV DELUXE PROGRAMMABLE THERMOSTAT

Dimensions:

See Fig. 1.

3-5/8 (92)

6-1/16 (154)

2-3/4 (70)

3/8 (10)

1-13/16

(46)

3-3/4

(95)

3-1/2

(89)

1-9/16

1/2 (13)

(40)

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 5 ft (1.5m) above the floor in an area with good air circulation at average temperature. See Fig. 2.

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.

M10359

Fig. 1. Dimensions of thermostat in in. (mm).

Mounting Means:

The thermostat mounts on a wallplate. The wallplate mounts horizontally on a wall or outlet box with two no. 6 x 32 screws (included).

Accessories:

C7089B Outdoor Temperature Sensors (69-1020). Universal Versaguard™ Thermostat guards.

RECYCLING NOTICE

If this control is replacing a control that contains mercury in a sealed tube, do control in the trash.

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

not

place your old

Wallplate Installation

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

2. Use a pencil to mark the mounting holes. See Fig. 3.

3. Remove the wallplate from the wall and drill two

3/16 inch holes in the wall (if drywall) as marked. For firmer material such as plaster, drill two 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.

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T8624D CHRONOTHERM® IV DELUXE PROGRAMMABLE THERMOSTAT

YES

5 FEET

[1.5 METERS]

Fig. 2. Typical location of thermostat.

M10106

WALL ANCHORS (2)

WALL

WIRES THROUGH WALL

Fig. 3. Mounting the wallplate.

MOUNTING HOLES

MOUNTING SCREWS

M10822

WIRING

All wiring must comply with local electrical codes and ordinances. Follow equipment manufacturer wiring instructions when available. Refer to Fig. 14 for typical hookup. A letter code is located near each terminal for identification. Refer to Table 4 for terminal designations.

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

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

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.

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T8624D CHRONOTHERM® IV DELUXE PROGRAMMABLE THERMOSTAT

Table 4. Terminal Designations and Descriptions.

Standard

Terminal

Designations

Alternate

Terminal

Designations Typical Connection Function Terminal Type

B—Heat damper or changeover valve Output 24V powered contact CB

, C, X1, X2 Common Input GF Fan relay Output 24V powered contact ORCool damper or changeover valve Output 24V powered contact OT, OT — Outdoor temperature sensor (C7089B) Input — RV24V system or heating transformer Input — RC — 24V cooling transformer Input — W1 H1, R3 Stage 1 heating relay Output 24V powered contact W2 H2, R4, W3, Y Stage 2 heating relay Output 24V powered contact Y1 C1, M, Y Stage 1 compressor contactor Output 24V powered contact Y2 C2, M, Y Stage 2 compressor contactor Output 24V powered contact

Some OEM models label the terminal for transformer common B.

ENGAGE TABS AT TOP OF THERMOSTAT AND WALLPLATE.

FOR STRAIGHT

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

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

M4826

Fig. 4. Proper wiring technique.

Mounting Thermostat Wallplate

The thermostat mounts on the wallplate after they are installed.

1. Engage tabs at the top of thermostat and wallplate.

See Fig. 5.

2. Press lower edge of case to latch.

NOTE: To remove the thermostat from the wall, first pull out

at the bottom of the thermostat; then remove the top.

PRESS LOWER EDGE OF CASE TO LATCH.

M15043

Fig. 5. Mounting thermostat on wallplate.

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T8624D CHRONOTHERM® IV DELUXE PROGRAMMABLE THERMOSTAT

SETTINGS

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 System Test,

• display outdoor temperature (select models),

• set the system operation,

• set the fan operation.

See Fig. 6 for the location of the keys.

System and Fan Settings

The system default setting is Heat and the fan default setting is Auto. Use the System and Fan keys or switches 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. Auto: The thermostat automatically changes between

heating and cooling operation, depending on the indoor temperature.

Fan settings control the system fan as follows:

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

Run

Program

Hold Temp

Time Set Program

Set Current

Day/Time

Day

Daylight

Copy

Time

Heat/Cool

Settings

Leave

Wake

Return

System Fan

Sleep

M15042

System

Fan

Fig. 7. T8624D System and Fan key locations.

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

COPY ONE PROGRAMMED DAY TO ANOTHER DAY

SET WAKE TIMES AND SETPOINTS

Run

Program

Hold Temp

Fig. 6. T8624D key locations and descriptions.

Set Current

Day/Time

Day

Daylight

Time

SET LEAVE TIMES AND SETPOINTS

Time Set Program

Copy

Wake

Heat/Cool

Settings

SET RETURN TIMES AND SETPOINTS

Leave

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

INCREASE TEMPERATURE SETTING OR SCROLL FORWARD THROUGH INSTALLER SETUP OPTIONS

Return Sleep

System Fan

CHANGE BETWEEN HEATING AND COOLING SETPOINTS

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

M10405A

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T8624D CHRONOTHERM® IV DELUXE PROGRAMMABLE THERMOSTAT

NOTE: Always press the keys with your fingertip or similar

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

Temperature Settings

Refer to Table 5 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 Programming Section for complete instructions on changing the program.

Table 5. Default Program Settings.

Heat

Period Time

Setpoint

Wake 6:00 AM 70°F

(21°C)

Leave 8:00 AM 62°F

(16.5°C)

Return 6:00 PM 70°F

(21°C)

Sleep 10:00 PM 62°F

(16.5°C)

Cool

Setpoint

78°F

(25.5°C)

85°F

(29.5°C)

78°F

(25.5°C)

82°F

(28°C)

Fan

Setting

Auto

INSTALLER SETUP

NOTE: For most applications, the thermostat factory

settings will not need to be changed. Review the factory settings in Table 6 and if no changes are necessary, go to the Installer System Test section.

—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.

Set Program

Hold for

Em Ht Aux Ht

Mon

Wake

System Fan

Start Time

TueWedThuFriSatSun

LeaveReturnSleep

Off Auto

Heat

Cool

Set Day/Time

Temporary Setting Enrg

Heat

Recovery

DST

Wait

Cool

Auto

Sav

Room

%Humid

Outdoor

Repl Batt

Auto

M10345

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

INSTALLER SETUP NUMBER DISPLAY (COLUMN 2 OF TABLE 6)

FACTORY SETTING OR OTHER CHOICE DISPLAY (COLUMN 3 OR 5 OF TABLE 6)

M10404

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

The Installer Setup is used to customize the thermostat to specific systems. Some of the options include temperature display, changeover and outdoor temperature display. Installer Setup numbers are listed in Table 6. The table includes all the configuration options and the factory settings for the thermostat.

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.

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 6 factory settings and mark any desired changes in the Actual Settings column. When Installer Setup is complete, review the settings to confirm that they match the system.

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T8624D CHRONOTHERM® IV DELUXE PROGRAMMABLE THERMOSTAT

Table 6. Thermostat Installer Setup Options.

Installer Setup

Other Choices

Actual

Setting

Select

Number (Press

Time ▲ key to

change)

Factory-Setting

(Press ▲ or ▼ key to change)

Display Description Display Description

Not used 1 thru 3 — — — — —

Heating cycle

rate

46Stage 1 3 or 9 5 Stage 2

3—3 cph used for steam

systems

6—6 cph factory setting for all

stages of system

9— 9 cph used for electric

heat

Not used 6 thru 11 — — — — — System setting

adjustment

Adaptive Intelligent Recovery™ control

12 1 Manual changeover 0 or 2 0—Auto changeover

2—Fixed auto changeover

13 0 Adaptive Intelligent

Recovery™ control is activated (system

1 Conventional recovery

(system starts recovery at programmed time)

—

starts early so setpoint is reached by start of program period)

Degree temperature display

14 0 Temperature is

displayed in °F

1 Temperature is displayed

in °C Not used 15 — — — — — Clock format 16 0 12-hour clock format 1 24-hour clock format Not used 17 and 18 — — — — — Extended fan

operation in heating

Extended fan operation in cooling

19 0 No extended fan

operation after the call for heat ends

20 0 No extended fan

operation after the call for cool ends

1 Fan operation is extended

90 seconds after the call for

heat ends.

1 Fan operation is extended

90 seconds after the call for

cool ends. Not used 21 thru 23 — — — — — Outdoor

temperature display (models with OT terminals)

24 0 No outdoor

temperature is displayed

1 Outdoor temperature is

displayed. Needs a

C7089B1000 Outdoor Sensor

to operate. Not used 25 thru 29 — — — — — Deadband 30 3 Heating and cooling

setpoints can be set no closer than 3°F (1.5°C)

4 thru 10 Heating and cooling setpoints

can be set no closer than the

chosen value:

4—4°F (2°C) 5—5°F (2.5°C) 6—6°F (3°C) 7—7°F (3.5°C) 8—8°F (4°C) 9—9°F (4.5°C) 10—10°F (5°C)

The cycle rate for the last stage of heat is adjustable with 6 cph being the factory setting.

(continued)

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T8624D CHRONOTHERM® IV DELUXE PROGRAMMABLE THERMOSTAT

Table 6. Thermostat Installer Setup Options (continued).

Select

Installer Setup

Number (Press

Time ▲ key to

change)

Factory-Setting

(Press ▲ or ▼ key to change)

Display Description Display Description

Other Choices

Actual

Setting

Not used 31 and 32 — — — — — Minimum off time

for the compressor

33 5 5 minute minimum off

time for the compressor

0 thru 4 Minimum number of minutes

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

Temperature range stops in heating

34 90 Highest setpoint

heating can be set to

40 to 89 Temperature range (1°F

increments) heating setpoint can be set to

Temperature range stops in cooling

35 45 Lowest setpoint

cooling can be set to

46 to 99 Temperature range (1°F

increments) cooling setpoint

can be set to Not used 36 — — — — — Temperature

display adjustment

37 0 No difference in

displayed temperature and actual room temperature

-3 thru 3

1—Display adjusts to 1°F

higher than actual room temperature

2—Display adjusts to 2°F

higher than actual room temperature

3—Display adjusts to 3°F

higher than actual room temperature

-1—Display adjusts to 1°F lower than actual room temperature

-2—Display adjusts to 2°F lower than actual room temperature

-3—Display adjusts to 3°F lower than actual room temperature

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 with these 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 power up or after an extended power

Set Current

Day/Time

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

Time Set Program

Set Current

Run

Day/Time

Program

Hold Temp

Leave

Wake

Return Sleep

Heat/Cool

Day

Daylight

Time

System Fan

Settings

Copy

Set Day/Time

Mon

M10312

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T8624D CHRONOTHERM® IV DELUXE PROGRAMMABLE THERMOSTAT

2. Press Day until the current day is displayed.

NOTE: Sun=Sunday, Mon=Monday, Tue=Tuesday,

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

Set Day/Time

Day

Time Set Program

Set Current

Run

Day/Time

Program

Hold Temp

Leave

Wake

Return Sleep

Heat/Cool

Day

Daylight

Time

System Fan

Settings

Copy

Tue

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

displayed.

NOTE: Tapping the Set Current Day/Time will change

the time in one hour increments.

Time

Time Set Program

Set Current

Run

Day/Time

Program

Hold Temp

Leave

Wake

Return Sleep

Heat/Cool

Day

Daylight

Time

System Fan

Settings

Copy

Set Day/Time

Tue

NOTE: If the current time is Daylight Savings Time,

press Daylight Time until DST is displayed.

Set Day/Time

DST

Daylight

Time

Time Set Program

Set Current

Run

Day/Time

Program

Hold Temp

Leave

Wake

Return Sleep

Heat/Cool

Day

Daylight

Time

System Fan

Settings

Copy

Tue

4. Press Run Program.

DST

Run

Program

Time Set Program

Set Current

Run

Day/Time

Program

Hold Temp

Leave

Wake

Return Sleep

Heat/Cool

Day

Daylight

Time

System Fan

Settings

Copy

Tue

Wake

System Fan

Heat

M10313

M10314

M10315

Room

Auto

M10316

Set Program

Hold for

Em Ht

Start Time

Aux Ht

Mon

TueWedThuFriSatSun

LeaveReturnSleep

Wake

Set Day/Time

System Fan

Off Auto

Heat

Cool

Temporary Setting Enrg

Heat

Recovery

DST

Wait

Cool

Auto

Room

%Humid

Outdoor

Repl Batt

Fig. 10. Display of all the segments of the LCD.

TEST NUMBER

M10257A

Fig. 11. Display of test number.

Table 7. Tests Available in Installer System Test.

Test

Number System Test Description

10-19 Heating equipment can be turned on and off 30-39 Cooling equipment can be turned on and off 40-49 Fan equipment can be turned on and off

60 0 to

Keyboard keys test

60 19

70-79 Thermostat information including date code and

software versions are displayed

Refer to Table 8 for the directions and results of the specific tests.

Sav

Auto

M10345

INSTALLER SYSTEM TEST

Use the Installer System Test to check the thermostat operation. Refer to Table 7 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 are displayed for three seconds before 10 appears. See Fig. 10 and 11.

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

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

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T8624D CHRONOTHERM® IV DELUXE PROGRAMMABLE THERMOSTAT

Table 8. Installer System Test Options.

Key to

Press

Test

Number Description

Heating Equipment System Test

Time ▲ 10 Enter heating equipment system test.

▲ 11 Stage-one heat comes on. The system fan is also energized. ▲ 12 Stage-two heat comes on. Stage-one heat and system fan remain on. ▼ 11 Stage-two heat turns off. ▼ 10 Stage-one heat and system fan turn off.

Cooling Equipment System Test

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

▲ 31 Stage-one cool and system fan come on. ▲ 32 Stage-two cool comes on. Stage-one cool and system fan remain on. ▼ 31 Stage-two cool turns off. ▼ 30 Stage-one cool and system fan turn off.

Fan Equipment SystemTest

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

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

Key Operation System Test

Time ▲ 60 2 Change from fan to key operation system test.

NOTE: Press any key and the displayed numbers will

change. Press Time ▼▼ to go to the previous test and Time ▲▲ to go to the next test. The Run Program key will not exit from this test. To exit, go to a different test and press Run Program.

Thermostat Information

1. Press the Time ▲ ▲ key to access the thermostat

information.

M4934

2. Press the increase ▲ 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).

M10351

3. Press the increase ▲ key again to display the software

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

M4932A

4. Press the increase ▲ key again to display the software

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

M10229

5. Press the increase ▲ key again to display the

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

M4933A

6. Press the Run Program key to exit the system test.

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

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T8624D CHRONOTHERM® IV DELUXE PROGRAMMABLE THERMOSTAT

▲▲

PROGRAMMING

The keyboard is located behind the thermostat cover with three frequently used keys by the display. The thermostat display shows day, time, program period, temperature, system and fan operation selection.

The thermostat can be set for four times and up to eight temperatures for each day of the week (28 independent time and 56 temperature settings). The

Table 9. Default Time, Setpoints and Fan Settings.

Period Start Time Heat Setpoint Cool Setpoint Fan Setting Monday

Wake [6:00 AM] [70°F (21°C)] [78°F (25.5°C)] [Auto] Leave [8:00 AM] [62°F (16.5°C)] [85°F (29.5°C)] [Auto] Return [6:00 PM] [70°F (21°C)] [78°F (25.5°C)] [Auto] Sleep [10:00 PM] [62°F (16.5°C)] [82°F (28°C)] [Auto]

Tuesday

Wednesday

Thursday

Friday

Saturday

Sunday

Before starting the programming procedure, use Table 9 to organize the program schedule. The factory preprogrammed time, temperature and fan settings are shown in brackets. If a 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.

and ▼▼ keys provide quick temporary temperature changes to increase comfort. The Hold Temp key provides energy efficient operation for extended periods of time.

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T8624D CHRONOTHERM® IV DELUXE PROGRAMMABLE THERMOSTAT

Setting the Current Day and Time

IMPORTANT

Always press the keys with your fingertip or similar blunt tool. Sharp instruments like pens and pencil points can damage the keyboard.

1. Press Set Current Day/Time.

NOTE: On initial power up or after an extended power

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

Set Day/Time

Set Current

Day/Time

Run

Program

Hold Temp

Leave

Wake

Return Sleep

Day/Time

Heat/Cool

Day

Settings

Daylight

Copy

Time

System Fan

Mon

Time Set Program

Set Current

2. Press Day until the current day is displayed.

NOTE: Sun=Sunday, Mon=Monday, Tue=Tuesday,

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

Day

Run

Program

Hold Temp

Leave

Wake

Day/Time

Day

Daylight

Time

Return Sleep

Heat/Cool

System Fan

Settings

Copy

Tue

Time Set Program

Set Current

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

is displayed.

Set Day/Time

M10312

M10313

Programming the First Day

Start by programming the Wake time and temperature (and fan operation on select models) for any one day:

1. Press Wake.

Set Program

Start Time

Wake

Time Set Program

Set Current

Run

Program

Hold Temp

Leave

Wake

Day/Time

Day

Daylight

Time

Return Sleep

Heat/Cool

System Fan

Settings

Copy

Tue

Wake

System Fan

Heat

2. Press Day until the desired day is displayed.

Set Program

Start Time

Day

Time Set Program

Set Current

Run

Program

Hold Temp

Leave

Wake

Return Sleep

Day/Time

Heat/Cool

Day

Settings

Daylight

Copy

Time

System Fan

Mon Wake

System Fan

Heat

3. Press Time ▲ ▲ or Time ▼ ▼ until the desired Wake time

is displayed.

NOTE: The program times are in fifteen minute

intervals. (Example: 8:00, 8:15, 8:30).

Time

Time Set Program

Set Current

Run

Program

Hold Temp

Leave

Wake

Day/Time

Heat/Cool

Day

Settings

Daylight

Copy

Time

Return Sleep

System Fan

Set Program

Start Time

Mon Wake

System Fan

Heat

Setting

Heat

Auto

M10317

Setting

Heat

Auto

M10318

Setting

Heat

Auto

M10319

NOTE: Tapping the Set Current Day/Time will change

the time in one hour increments.

Time

Time Set Program

Set Current

Run

Program

Hold Temp

Leave

Wake

Day/Time

Day

Daylight

Time

Return Sleep

Heat/Cool

System Fan

Settings

Copy

Set Day/Time

Tue

NOTE: If the current time is Daylight Savings Time,

press Daylight Time until DST is displayed.

Set Day/Time

DST

M10315

Daylight

Time

Time Set Program

Set Current

Run

Day/Time

Program

Hold Temp

Leave

Wake

Return Sleep

Heat/Cool

Day

Daylight

Time

System Fan

Settings

Copy

Tue

4. Press Run Program.

DST

Run

Program

Time Set Program

Set Current

Run

Program

Hold Temp

Leave

Wake

Day/Time

Day

Daylight

Time

Return Sleep

Heat/Cool

System Fan

Settings

Copy

Tue

Wake

System Fan

Heat

M10314

Room

Auto

M10316

4. Press increase ▲ or decrease ▼ key until the desired

Wake temperature is displayed.

NOTE: The setpoint temperature range is 40 to 90°F

(7 to 31°C) for heating and 45 to 99°F (9 to 37°C) for cooling.

Set Program

Start Time

Time Set Program

Set Current

Run

Program

Hold Temp

Leave

Wake

Return Sleep

Day/Time

Heat/Cool

Day

Settings

Daylight

Copy

Time

System Fan

Mon Wake

System Fan

Heat

Setting

Heat

Auto

M10320

NOTE: Press Fan to modify fan operation. Auto

means the fan will run only when the heating or cooling equipment is operating. On means the fan will run continuously for the entire period.

68-0166—1

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T8624D CHRONOTHERM® IV DELUXE PROGRAMMABLE THERMOSTAT

5. Press Heat/Cool Settings to switch to other system

temperature setpoint.

NOTE: The program times are the same for both

heating and cooling.

Setting

Cool

Heat/Cool

Settings

Set Program

Start Time

Time Set Program

Set Current

Run

Day/Time

Program

Hold Temp

Leave

Wake

Return Sleep

Mon

System Fan

Wake

System Fan

Heat

Heat/Cool

Day

Settings

Daylight

Copy

Time

6. Press increase ▲ or decrease ▼ key until the other

desired temperature setpoint is displayed.

Set Program

Start Time

Time Set Program

Set Current

Run

Program

Hold Temp

Leave

Wake

Return Sleep

Day/Time

Heat/Cool

Day

Settings

Daylight

Copy

Time

System Fan

Mon Wake

System Fan

Heat

Setting

Cool

M10322

7. Press Leave, Return or Sleep and repeat steps 3, 4, 5 and 6 for programming the rest of the day. The first day is now programmed.

IMPORTANT

Repeat steps

through 7 for each day of the week that has a different program than the first day. Refer to Copying a Day section to copy any program day to another.

Auto

M10321

Auto

3. Press Copy.

Copy

Time Set Program

Set Current

Run

Program

Hold Temp

Leave

Wake

Return Sleep

Day/Time

Heat/Cool

Day

Settings

Daylight

Copy

Time

System Fan

Mon

4. Press Day until the day to be copied to is displayed.

Day

Run

Program

Hold Temp

Leave

Wake

Return Sleep

Mon

Day/Time

Heat/Cool

Day

Daylight

Time

System Fan

Settings

Copy

Wed

Time Set Program

Set Current

5. Press Copy.

NOTE: donE will be displayed for two seconds

and then the normal program display will be shown.

Copy

Time Set Program

Set Current

Run

Program

Hold Temp

Leave

Wake

Day/Time

Day

Daylight

Time

Return Sleep

Heat/Cool

System Fan

Settings

Copy

6. Repeat steps 2 through 5 for all the days desired.

7. Press Run Program.

Clearing Program Period

M10326

M10327

M10328

8. Press Run Program when all days are programmed.

Run

Program

Time Set Program

Set Current

Run

Program

Hold Temp

Leave

Wake

Day/Time

Day

Daylight

Time

Return Sleep

Heat/Cool

System Fan

Settings

Copy

Tue

Wake

System Fan

Heat

Room

DST

Auto

M10323

Copying a Day

NOTE: The thermostat must be in the program mode to use

the copy feature. Go to step 2 if the thermostat is already in the program mode.

1. Press Wake.

Set Program

Start Time

Wake

Time Set Program

Set Current

Run

Program

Hold Temp

Leave

Wake

Day/Time

Day

Daylight

Time

Return Sleep

Heat/Cool

System Fan

Settings

Copy

Tue

Wake

System Fan

Heat

2. Press Day to select the day to be copied if different

from the day displayed.

Set Program

Start Time

Day

Time Set Program

Set Current

Run

Day/Time

Program

Hold Temp

Leave

Wake

Return Sleep

Mon

System Fan

Wake

System Fan

Heat

Heat/Cool

Day

Settings

Daylight

Copy

Time

Setting

Heat

Auto

M10324

Setting

Heat

Auto

M10325

NOTE: The thermostat must be in the program mode to use

the clear feature. Go to step 2 if the thermostat is already in the program mode.

1. Press Wake, Leave, Return or Sleep.

Setting

Heat

Auto

M10329

Leave

Set Program

Start Time

Time Set Program

Set Current

Run

Program

Hold Temp

Leave

Wake

Return Sleep

Day/Time

Heat/Cool

Day

Settings

Daylight

Copy

Time

System Fan

Mon

Leave

System Fan

Heat

2. Press Day until the desired day is displayed.

Setting

Heat

Auto

M10330

Day

Set Program

Start Time

Time Set Program

Set Current

Run

Day/Time

Program

Hold Temp

Leave

Wake

Return Sleep

Heat/Cool

Day

Daylight

Time

System Fan

Settings

Copy

Leave

System Fan

Heat

Sat

3. Press Leave, Return or Sleep until the start time and

temperature setting are cleared (approximately 3 seconds).

NOTE: Wake cannot be cleared.

Setting

Heat

M10331

Leave

Set Program

Start Time

Time Set Program

Set Current

Run

Day/Time

Program

Hold Temp

Day

Leave

Wake

Return Sleep

Heat/Cool

System Fan

Settings

Daylight

Copy

Time

Leave

Sat

68-0166—1

Page 15

T8624D CHRONOTHERM® IV DELUXE PROGRAMMABLE THERMOSTAT

4. Repeat steps 2 and 3 for all the periods to be cleared.

5. Press Run Program.

Setting Temporary Temperatures

Changing Temperature Setting Until the Next Program Period

Press increase ▲ or decrease ▼ key until the desired temperature setpoint is displayed.

NOTE: If ▼ or ▲ appear under the temperature display, it

means that both the heating and cooling setpoints are being adjusted. Tapping the key will change both the heat and cool setpoints by one degree. Press i after the desired setpoint is reached to check the setpoints.

Temporary Setting

Time Set Program

Set Current

Run

Day/Time

Program

Hold Temp

NOTE: The temporary temperature setting is displayed for

approximately 3 seconds. The setting is canceled when the next period starts or when Run Program is pressed.

Leave

Wake

Return Sleep

System Fan

Wake

Heat/Cool

Day

Settings

Daylight

Copy

Time

Heat

M10332

NOTE: The display changes from the setpoint to the

room temperature after approximately 3 seconds.

5. Press Run Program to cancel the Hold and to return to

the program.

Changing Temperature Setting Until a Designated Day and Period

1. Press Hold Temp twice.

Setting

Heat

M10337

Setting

Heat

M10338

Hold Temp

Time Set Program

Set Current

Run

Program

Hold Temp

Leave

Wake

Day/Time

Heat/Cool

Day

Settings

Daylight

Copy

Time

Return Sleep

System Fan

Hold for

Wake

2. Press Time ▲ ▲ or Time ▼ ▼ until the desired number of

days is displayed (1 to 256 days). (Example: 18 = Hold will override the daily programs for 18 days)

Time

Return Sleep

System Fan

Hold for

Wake

Time Set Program

Set Current

Run

Day/Time

Program

Hold Temp

Leave

Wake

Heat/Cool

Day

Settings

Daylight

Copy

Time

Changing Temperature Setting Indefinitely

1. Press Hold Temp.

Setting

Time Set Program

Set Current

Run

Hold Temp

Program

Hold Temp

2. Press increase ▲ or decrease ▼ key to change the

setting, if desired.

Set Current

Run

Program

Hold Temp

3. Press Heat/Cool Settings to change between heat and

cool settings.

Run

Program

Hold Temp

4. Press increase ▲ or decrease ▼ key to adjust

temperature settings.

Day/Time

Day

Daylight

Time

Day/Time

Day

Daylight

Time

Set Current

Day/Time

Day

Daylight

Time

Leave

Wake

Heat/Cool Settings

Copy

Time Set Program

Leave

Wake

Heat/Cool Settings

Copy

Time Set Program

Leave

Wake

Heat/Cool

Settings

Copy

Return Sleep

System Fan

Return Sleep

System Fan

Return Sleep

System Fan

Heat

M10333

Setting

Heat

M10334

Setting

Cool

M10336

3. Press Wake, Leave, Return or Sleep to select the

period the program will start. (Example: Return = thermostat will stop the Hold at the Return period start time)

Setting

Heat

M10339

Return

System Fan

Hold for

Sleep

Return

Time Set Program

Set Current

Run

Program

Hold Temp

Leave

Wake

Day/Time

Heat/Cool

Day

Settings

Daylight

Copy

Time

4. Press increase ▲ or decrease ▼ key to adjust the

temperature setting, if desired. (Example: Heat 54° = heating equipment will operate when the room temperature is below 54°F)

Setting

Heat

M10340

Return Sleep

System Fan

Hold for

Return

Time Set Program

Set Current

Run

Program

Hold Temp

Leave

Wake

Day/Time

Heat/Cool

Day

Settings

Daylight

Copy

Time

NOTE: When the System is set for Auto, both heat and cool

settings are needed. If the System is set for Heat, only the Heat setpoint is needed or if Cool is selected, only the Cool setpoint is needed.

5. Press Heat/Cool Settings to change between heat and

cool settings.

Setting

Time Set Program

Set Current

Run

Program

Hold Temp

Leave

Wake

Day/Time

Day

Daylight

Time

Return Sleep

Heat/Cool

System Fan

Settings

Copy

Cool

M10336

68-0166—1

Page 16

T8624D CHRONOTHERM® IV DELUXE PROGRAMMABLE THERMOSTAT

6. Press increase ▲ or decrease ▼ key to adjust the

temperature setting, if desired. (Example: Cool 84° = cooling equipment will operate when the room temperature is above 84°F)

NOTE: In this example, the thermostat uses the Hold

setting for eighteen days and returns to the daily programs at the Return period start time. The temperature settings are heating 54°F and cooling 84°F. Only the heating temperature is used because the System is set for Heat. The thermostat will use both the heating and cooling temperature settings when the System is set to Auto.

IMPORTANT

If the Hold needs to be canceled before the designated time, press Run Program to return to the program.

Setting Temporary Fan Operation

Press Fan until the desired fan operation is selected. This fan setting will be in effect until the next regularly scheduled period starts.

Using Daylight Savings Time Feature

This feature allows you to change in and out of Daylight Savings Time with a key press. When Daylight Time is pressed in the fall, the time will go back one hour. In the spring, the time will go ahead one hour and the display will show DST. See Setting the Current Day and Time section for initial setting instructions.

NOTE: Pressing Daylight Time more than once within a five

minute period will scroll you through various time options (example: one hour earlier or later with or without DST). Pressing Daylight Time six times in a five minute period will return you to your original settings.

OPERATION

P+I Control

The thermostat microprocessor based control requires that the user understands temperature control and thermostat performance. A conventional electromechanical or electronic thermostat does not control temperature precisely at setpoint. Typically, there is an offset (droop) in the control point as the system load changes. This is a phenomenon that most people in the industry know and accept. Many factors contribute to offset including switch differential, thermal lag, overshoot, cycle rates and system load.

The thermostat microprocessor simultaneously gathers, compares and computes data. Using this data, it controls a wide variety of functions. The special proprietary algorithm (program) in the thermostat eliminates the factors causing offset. This makes temperature control more accurate than the conventional electromechanical or electronic thermostats. The temperature control algorithm is called proportional plus integral (P+I) control.

The thermostat sensor, located on the thermostat or remote, senses the current space temperature. The proportional error is calculated by comparing the sensed temperature to the programmed setpoint. The deviation from the setpoint is the proportional error.

The thermostat also determines integral error, which is a deviation based on the length of error time. The sum of the two errors is the (P+I) error. The cycle rate used to reach and maintain the setpoint temperature is computed using the P+I. The addition of the integral error is what differentiates the thermostat from many other electronic and electromechanical thermostats. See Fig. 12.

THERMOSTAT COOL SETPOINT

PROPORTIONAL COOL CONTROL POINT

P+I CONTROL POINT

Daylight

Time

Time Set Program

Set Current

Run

Program

Hold Temp

Leave

Wake

Day/Time

Day

Daylight

Time

Return Sleep

Heat/Cool

System Fan

Settings

Copy

Tue

Wake

System Fan

Heat

Room

Auto

M10341

Displaying the Outdoor Temperature

If your thermostat is equipped with an outdoor sensor, you can check the temperature at the sensor by pressing i once.

Time Set Program

Set Current

68-0166—1

Run

Program

Hold Temp

Leave

Wake

Day/Time

Day

Daylight

Time

Return Sleep

Heat/Cool

System Fan

Settings

Copy

Outdoor

M10342

P+I CONTROL POINT

TEMPERATURE

100 50 0 50 100

PROPORTIONAL HEAT CONTROL POINT

THERMOSTAT HEAT SETPOINT

HEATING

PERCENT LOAD

COOLING

M4414

Fig. 12. Proportional temperature control

versus P+I temperature control.

Page 17

T8624D CHRONOTHERM® IV DELUXE PROGRAMMABLE THERMOSTAT

70°F

60°F

SLEEP

HEATING MODE

WAKE

SETPOINT TEMPERATURE

ACTUAL TEMPERATURE

M6185A

Operation Sequence

The thermostat energizes specific terminals depending what the Fan and System are set to. The LCD will display the time, room temperature, system and fan selection. Symbols will be displayed when the heating, cooling or fan is energized. See Ta ble 10 for specific information.

NOTE: Not all the thermostat models have all the terminals

Auto Off None None None On Off None G

Auto Cool None O None

Auto Cool or

Auto Heat None B None

Auto Heat or

Auto Auto None

listed in the Energize column.

Table 10. Multistage System Sequence of Operation.

Selection

Fan System Call Energize Display

Auto

Stage 1 Cooling

Stage 2 Cooling

Stage 1 heating

Stage 2 heating

O, G and Y1

O, G, Y1 and Y2

B, G

and W1

B , G

, W1

and W2

O or B

and

None

G is energized and fan symbol is displayed on duel fuel models when set for electric heat.

Based on last piece of equipment called (cooling = O or heating = B) and Installer Setup selection.

Table 11. Default Time, Setpoint and Fan Settings.

Heat

Period Time

Setpoint

Wake 6:00 AM 70°F (21°C) 78°F

Cool

Setpoint

Fan

Setting

Auto

(25.5°C)

Leave 8:00 AM 62°F

(16.5°C)

Return 6:00 PM 70°F (21°C) 78°F

85°F

(29.5°C)

Auto

(25.5°C)

Sleep 10:00 PM 62°F

(16.5°C)

82°F

(28°C)

Auto

Adaptive Intelligent Recovery® Feature

Adaptive Intelligent Recovery® control assures that the comfort setting is achieved at the programmed time regardless of weather conditions. Conventional recovery, however, starts recovery at the beginning of the programmed time period and used the equipment to achieve the comfort settings as soon as possible.

Adaptive Intelligent Recovery® control calculates the recovery ramp based on the number of degrees away from the desired setpoint, previous equipment performance, and weather history to initiate recovery at the optimal time to achieve the comfort setting at the desired time.

Once the recovery ramp is intersected, the setpoint changes from the setback setpoint to the comfort setpoint. This change

snaps on

until the setpoint is reached. If the setpoint is reached too early or too late, the ramp is adjusted for the next days’ recovery. See Fig. 13.

both stages of the equipment and runs both stages

Equipment Protection

As part of the operational sequence, the thermostat microprocessor also incorporates minimum off time for all heating and cooling stages. Using the minimum off time assures that rapid cycling of equipment does not occur, which extends equipment life. Minimum off times are set in the Installer Setup.

Thermostat Operation

Startup

When power to the thermostat is turned on, a startup and initialization program begins. The startup occurs only on initial powerup. After total loss of power for an extended period, the current time and day may need to be set, but the user program is held. See Table 11 for the default values.

NOTE: Immediately following initialization, the user can

enter new setpoints to be used in place of the default values.

Fig. 13. Gradual temperature change in recovery.

68-0166—1

Page 18

T8624D CHRONOTHERM® IV DELUXE PROGRAMMABLE THERMOSTAT

TROUBLESHOOTING GUIDE

Refer to Table 12 for troubleshooting information.

Table 12. Troubleshooting Information.

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 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.

Heating will not come on.

Thermostat is not being powered. • Check for 24 Vac between R and C 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.

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.

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

Heating or cooling equipment is not operating.

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

Thermostat minimum off time is activated.

System selection is not set to Heat.

Heating setpoint is below room temperature.

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 40 to 90°F (7 to 31°C)

• Cooling limits are 48 to 99°F (9 to 37°C) .

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

Add resistor in parallel with load or install interface relay.

Verify operation of heating or cooling equipment in system test.

— 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)

68-0166—1

Page 19

T8624D CHRONOTHERM® IV DELUXE PROGRAMMABLE THERMOSTAT

Table 12. Troubleshooting Information (continued).

Symptom Possible Cause Action

Cooling will not come on.

Outdoor temperature not displayed

Outdoor temperature display is incorrect

Available on select models.

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

— 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.

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

Outdoor sensor is connected

incorrectly.

Wrong sensor. Replace sensor with C7089B1000 sensor.

• 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.

have OT terminals and a C7089B1000 installed.

Refer to C7089B1000 installation instructions and check wiring between the thermostat and sensor.

CROSS REFERENCE

Refer to Table 13 for thermostat cross referencing information.

Table 13. Thermostat Cross Reference Information.

Model Number Description

T8624C Two-stage heat and two-stage cool conventional thermostat; powered direct from 24 Vac

transformer; manual changeover; system switch—HEAT-OFF-COOL-AUTO; fan switch—ON-AUTO; O and B terminals

T8624C1008 Trane; Premier White color; part no.

TAYSTAT302A.

T8624D Two-stage heat and two-stage cool conventional thermostat; powered direct from 24 Vac

transformer; automatic changeover; system switch—HEAT-OFF-COOL-AUTO; fan switch—ON-AUTO; O and B terminals

T8624D1006 TRADELINE thermostat; Honeywell logo. T8624D2004 Configure changeover to auto in

T8624D1014 Carrier Weathermaker. T8624D2004 Configure changeover to auto in

T8624D1022 Carrier Zone Perfect. T8624D2004 Configure changeover to auto in

T8624D1030 TRADELINE thermostat; Honeywell logo;

Premier White color.

T8624D1055 York logo. T8624D2004 Configure changeover to auto in

T8624D1063 Trane; Premier White color. T8624D2004 Wiring differences (old=new): B=C;

TRADELINE

Replacement Remarks

T8624D2004 Wiring differences (old=new): B=C;

jumper R to Rc; taupe color.

Installer Setup 12.

T8624D2004 Configure changeover to auto in

Installer Setup 12; taupe color.

Installer Setup 12.

jumper R to Rc; taupe color.

68-0166—1

Page 20

T8624D CHRONOTHERM® IV DELUXE PROGRAMMABLE THERMOSTAT

WIRING DIAGRAM (FIG. 14)

THERMOSTAT

Y1 G C

OT OTB

RW1

HEAT DAMPER

HEAT RELAY 2

HEAT RELAY 1

OUTDOOR SENSOR

L1 (HOT)

HEATING TRANSFORMER

M11309

FAN RELAY

COMPRESSOR CONTACTOR 1

L1 (HOT)

COOLING TRANSFORMER

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

JUMPER RC TERMINAL TO R TERMINAL WHEN INSTALLED ON A ONE TRANSFORMER SYSTEM.

CAN BE USED FOR CHANGEOVER VALVE ON HEAT

PUMP SYSTEMS.

COMPRESSOR CONTACTOR 2

COOL DAMPER

Fig. 14. Typical hookup of T8624D in multistage system.

Home and Building Control

Honeywell Inc. Honeywell Plaza P.O. Box 524 Minneapolis MN 55408-0524

Honeywell Latin American Region

480 Sawgrass Corporate Parkway Suite 200 Sunrise FL 33325

68-0166—1 J.H. Rev. 10-97

68-0166—1

Home and Building Control

Honeywell Limited-Honeywell Limitée 155 Gordon Baker Road North York, Ontario M2H 3N7

Honeywell Europe S.A.

3 Avenue du Bourget 1140 Brussels Belgium

Printed in U.S.A. on recycled paper containing at least 10% post-consumer paper fibers.

Honeywell Asia Pacific Inc.

Room 3213-3225 Sun Hung Kai Centre No. 30 Harbour Road Wanchai Hong Kong

Helping You Control Your World

www.honeywell.com/yourhome

Honeywell T8624D User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual