HONEYWELL T8602D Programmable Thermostats
APPLICATION
The T8602 Chronotherm® IV Programmable Thermostat provides electronic control of 24 Vac single-stage heating and cooling systems or 750 mV heating and 750 mV cooling. Refer to Table 1 for a general description of the thermostat. All T8602 Thermostats are powered by batteries.
Table 1. Description of T8602 Thermostats.
|
T8602 |
System |
Changeover |
System Selection | Fan Selection |
Comments |
| D | Heat-Cool | Manual or Automatic Selectable | Heat-Off-Cool or Heat-Off-Cool-Auto | On-Auto | System and fan selections are done by keyboard. |
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 control.
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
INSTALLATION
When Installing this Product…
- Read these instructions carefully. Failure to follow the instructions can damage the product or cause a hazardous condition.
- Check the ratings given in the instructions and on the product to make sure the product is suitable for your application.
- Installer must be a trained, experienced service technician.
- 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.
- Position and level the wallplate (for appearance only). The thermostat will function properly even when not level.
- Use a pencil to mark the mounting holes. See Fig. 2.
- Remove the wallplate from the wall and drill two 4.76 mm (3/16 in.) holes in the wall (if drywall) as marked. For firmer material such as plaster, drill two 5.56 mm (7/32 in.) holes. Gently tap anchors (provided) into the drilled holes until flush with the wall.
- Position the wallplate over the holes, pulling wires through the wiring opening.
- Loosely insert the mounting screws into the holes.
- Tighten mounting screws.
WIRING
All wiring must comply with local electrical codes and ordinances. Refer to Fig. 3 through 6 for typical hookups. A letter code is located near each terminal for identification.
CAUTION Electrical Hazard.
Can cause electrical shock or equipment damage.
Disconnect power before wiring.
- Loosen the terminal screws on the wallplate and connect the system wires. See Fig. 7.
IMPORTANT Use 18 gauge, color-coded thermostat cable for proper wiring. - Securely tighten each terminal screw.
- Push excess wire back into the hole.
- Plug the hole with nonflammable insulation to pre-vent drafts from affecting the thermostat.
Mounting Thermostat
- Engage tabs at the top of the thermostat and wall-plate. See Fig. 7.
- 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.
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.
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. 10. 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.
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 2 for the default program settings. 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 Owner’s Guide, form 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°C | 25°C | Auto |
| Leave | 8:45 AM | 4.5°C | 37°C | Auto |
| Return | 5:00 PM | 20°C | 25°C | Auto |
| Sleep | 10:00 PM | 4.5°C | 37°C | Auto |
INSTALLER SETUP
NOTE: For most applications, the thermostat factory settings do not require changing. Review the factory settings in Table 2 and, if no changes are necessary, go to Installer Self-Test 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 is 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. 11 and 12. - To advance to the next Installer Setup, press the Time ∆ key.
- To change a setting, use the increase or decreasekey.
- To scroll the Installer Setup numbers backward, press the Time ∇ key.
- To exit the Installer Setup, press Run Program.
CAUTION Electric Heat Configuration Hazard.
Can cause equipment damage.
Configure electric heat system to 1 in Installer Setup number 2 to prevent system running without fan.
IMPORTANT Only configured 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 com-plete, review the settings to confirm that they match the system.
Table 3. Thermostat Installer Setup Options.
|
Select |
Installer Setup Number (Press Time D key to change) |
Factory Setting |
Other Choices
(Press .A or T key to change) |
Actual Setting |
||
| Display | Description | Display | Description | |||
| Not Used. | 1 | — | — | — | — | — |
| Fan operation. | 2
(Number 2 must be set to 1 to extend fan operation.) |
0 | Conventional applications where equipment controls fan operation in heat mode. | 1 | Heat pump or electric heat applications where thermostat controls fan operation in heat mode. | |
| Not Used. | 3 | — | — | — | — | — |
| Heating cycle rate. | 4 | 6 | 6—6 cph used for conventional heat. | 1, 3, or
9 |
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. |
|
| Not Used. | 5 thru 11 | — | — | — | — | — |
| System setting adjustment | 12 | 1 | Manual changeover | 0 or 2 | 0—Auto changeover 2—Auto only | |
| Adaptive Intelligent Recovery™ control. | 13 | 1 | Conventional recovery (system starts recovery at programmed time). | Adaptive Intelligent Recovery™ control is activated (system starts early so setpoint is reached by start of program period). | — | |
| Not Used. | 14 thru 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. | 1 | Outdoor temperature is displayed. Needs a C7089B1000 Outdoor Temperature Sensor to operate. | |
| Not Used. | 25 thru 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 | 32.0 | Highest setting for heating setpoint. | 4.5 to 31.5 | Temperature range (0.5°C increments) of heating setpoint settings. | |
| Temperature range stops in cooling. | 35 | 7.0 | Lowest setting for cooling setpoint. | 7.5 to 37.0 | Temperature range (0.5°C increments) of cooling setpoint settings. | |
| Not Used. | 36 | — | — | — | — | — |
|
Select |
Installer Setup Number (Press Time D key to change) |
Factory Setting |
Other Choices
(Press .A or T key to change) |
Actual Setting |
||
| Display | Description | Display | Description | |||
| Temperature display adjustment. | 37 | 0 | No difference in displayed temperature and actual room temperature. | 1.5 thru
-1.5 |
.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 – .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. |
|
| Furnace Air Filter Timer. | 43 | 0 | Off | 1, 2, 3,
4 |
1 – 10 days
2 – 30 days 3 – 60 days 4 – 120 days (Time counted when heat, cool or fan is running.) |
|
| Humidifier Pad Monitor. | 44 | 0 | Off | 1, 2, 3 | 1 – 90 days
2 – 180 days 3 – 365 days (Time counted by calendar days in heat mode.) |
|
| Ultraviolet (UV) Air
Treatment System Lamp Monitor. |
45 | 0 | Off | 1 | 1 – 365 days (Times counted by
calendar days in any mode.) |
|
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
- 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.
- Press Day until the current day is displayed.
NOTE:- Sun=Sunday, Mon=Monday,
- Tue=Tuesday, Wed=Wednesday,
- Thu=Thursday, Fri=Friday, Sat=Saturday.
- Press Time ∆ or Time ∇ until the current time is displayed.
NOTE: Tapping the Set Current Day/Time changes the time in one hour increments.
NOTE: If the current time is Daylight Savings Time, press Daylight Time until DST is displayed.
- Press Run Program.
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.
CAUTION Equipment Damage Hazard.
Minimum compressor off-time is bypassed during Installer System Test.
Avoid cycling compressor quickly.
To start the system test:
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. 13 and 14.
Table 4. 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
60 19 |
Keyboard keys test. |
| 70-79 | Thermostat information, including date code and software versions, is displayed. |
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.
| Keys 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 ∆ | 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 does not exit this test. Press Time ∆ or Time ∇ and then the Run Program key to exit.
THERMOSTAT INFORMATION
- Press the Time ∆ key to access the thermostat information.
- 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).
- Press the increase key again to display the software identification code.
(Example: 02 = software ID code 2).
- Press the increase key again to display the software revision number.
(Example: 001 = Revision number 1).
- Press the increasekey again to display the EEPROM identification code.
(Example: 314 = EEPROM ID 314).
- Press the Run Program key to exit the system test. The system test times out after four minutes without any key presses.
CHECKOUT
Outdoor Temperature Sensor
(Select Models)
Allow the outdoor temperature sensor to absorb the outdoor air for a minimum of five minutes before taking a reading.
TROUBLESHOOTING GUIDE
Table 6. Troubleshooting Guide.
| Symptom | Possible Cause | Action |
| Display will not come on. | Thermostat is not being powered. | • Check if batteries are present and installed correctly.
— If batteries are present and installed correctly, replace thermostat. |
| Temperature display is incorrect. | Room temperature display has been reconfigured. | Enter Installer Setup number 37 and reconfigure the display. |
| Thermostat is configured for °F or °C display. | Enter Installer Setup number 14 and reconfigure the display. | |
| Bad thermostat location. | Relocate the thermostat. | |
| Temperature settings will not change. (Example: Cannot set the heating higher or the cooling lower.) | The upper or lower temperature limits were reached. | Check the temperature setpoint:
• Heating limits are 4.5 to 32°C • Cooling limits are 7 to 37°C |
| The setpoint temperature range stops were configured. | Check Installer Setup numbers 34 and 35 and reconfigure the setpoint stops. | |
| Heating will not come on. | No power to the thermostat. | • Check for 24 Vac between R and W terminals (check for 750 mV on PowerPile® Systems).
— 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. | Wait up to five minutes for the system to respond. | |
| System selection is not set to Heat. | Set system selection to Heat. | |
| Heating setpoint is below room temperature. | Check heating setpoint. Set heating setpoint to desired temperature. | |
| Cooling will not come on. | 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. | • Wait up to five minutes for the system to respond.
• Enter Installer Setup number 33. Reconfigure minimum off time (if required). |
|
| System selection is not set to Cool. | Set system selection to Cool. | |
| Cool setpoint is above room temperature. | Check cooling setpoint. Set cooling setpoint to desired temperature. | |
| Heating or cooling come on momentarily and shut off. | Heat or cool circuit is opening up or becoming high impedance. | Add resistor in parallel with load or install interface relay. |
| Symptom | Possible Cause | Action |
| System on indicator (flame=heat, snowflake=cool) is displayed, but no warm or cool air is coming from the registers. | Fan operation set for 0 (con- ventional heat) when it should be set for 1 (electric heat). | Enter Installer Setup number 2 and reconfigure the fan operation. |
| Conventional heating equipment turns on the fan when the furnace has warmed up to a setpoint. | Wait a minute after seeing the on indicator and then check the registers. | |
| Heating or cooling equipment is not operating. | Verify operation of heating or cooling equipment in self-test. | |
| Outdoor tempera-
ture not displayeda |
Option not activated. | Enter Installer Setup number 24 and set to 1. Thermostat must have OT terminals and a C7089B1000 Sensor installed. |
| Outdoor temperature display is incorrecta | Outdoor sensor is connected incorrectly. | Refer to C7089B1000 Installation Instructions and check wiring between the thermostat and sensor. |
| Wrong sensor. | Replace sensor with C7089B1000 Sensor. |
Automation and Control Solutions
Honeywell International Inc. 1985 Douglas Drive North Golden Valley, MN 55422
Honeywell Limited-Honeywell Limitée 35 Dynamic Drive
Scarborough, Ontario
M1V 4Z9
Printed in U.S.A. on recycled paper containing at least 10% post-consumer paper fibers.
www.honeywell.com/yourhome
Reference
Download manual:
HONEYWELL T8602D Programmable Thermostats Installational Instruction
HONEYWELL T8602D Programmable Thermostats Installational Instruction
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