HONEYWELL T8700B Electronic Round Programmable Thermostat PRODUCT DATA

HONEYWELL T8700B Electronic Round Programmable Thermostat 

APPLICATION

The T8700 Electronic Round™ Programmable Thermostats provide single-stage, programmable temperature control for 24V heating and/or cooling systems. See Table 1 for model descriptions.
Table 1. T8700 Thermostat Description.

Model	System Selection	Fan Selection	Wiring Terminals Used
T8700B1007	HEAT-OFF	NONE	R,W
T8700B1015	HEAT-OFF	ON-AUTO	R,G,W
T8700C1005	HEAT-OFF- COOL	ON-AUTO	R,G,W,Y

FEATURES

• Attractive neutral styling complements any decor.
• Easy to use means fewer homeowner questions and increased homeowner satisfaction.
• Large easy-to-read display.
• Keys are located near the display for easy access.
• Fan and System switches are located on the top of the wallplate to eliminate accidental setting changes.
• Quick and easy installation.
• Two-period programming for added energy savings.
• The manual changeover from heat to cool eliminates unexpected system operation (T8700C).
• °F or °C temperature display for added model flexibility.
• selectable heating cycle rate (1, 3, 6 or 9 cph) allows a variety of applications and reduced inventory.
• Cooling (T8700C) cycle rate fixed at 3 cph (the standard setting for compressors) allows a speedy installation.
• Programming is permanently held in memory (no batteries needed) and retained during power outages for increased installer and homeowner convenience.
• Compatible with most equipment and application needs including gas, oil and electric forced air; condensing gas furnaces; hydronic heat; and gravity and radiant heat systems.
• Powerstealing eliminates the need to run additional wires.

SPECIFICATIONS

IMPORTANT
The specifications given in this publication do not include normal manufacturing tolerances; therefore, an individual unit might not exactly match the listed specifications. Also, this product is tested and calibrated under closely controlled conditions and some minor differences in performance can be expected if those conditions are changed. T8700 TRADELINE® models include a thermostat, wallplate, decorator cover plate and owner’s guide. The package also includes a resistor for use with Taco zone valves. See Fig. 11.

• Power: T8700: 24 Vac nominal, 18 to 30 Vac, 60 Hz.
• Electrical Ratings:
  • Heating: .02 to 1.2A run; 3.5A inrush.
  • Cooling: .02 to 1.2A run; 6.0A inrush.
  • Fan: .02 to 0.5A run; 2.5A inrush.
• Current Draw:
  T8700 Power Stealing Thermostat requires only 2.5 mA current draw when the thermostat calls for heat or cool and is compatible with most 24V systems. It can be used in most non-millivolt applications. See Power Stealing in the Operation section.
• Temperature Adjustment:
  • Setpoint temperature is adjusted by using the or keys.
  • One press changes the setpoint one degree; pressing and
  • holding changes the setpoint several degrees.
• Temperature Setting Range: 40°F (4°C) to 99°F (37°C).
• Operational Ambient Temperature Range: 30°F (4°C) to 110°F (43°C).
• Shipping Temperature Range: -20°F (29°C) to 120°F (49°C).
• Operating Relative Humidity: 5% to 90% RH, noncondensing.

ORDERING INFORMATION

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

1. Order number.
2. Accessory, if desired.

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 Logistics Honeywell Inc., 1985 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. Cycle Rates (at 50 Percent Load): Heating: Selectable at 1, 3, 6 or 9 cph. See Table 2 for heating cycle rates and corresponding system equipment. Cooling (T8700C): Fixed at 3 mph.
   Table 2. Heating Cycle Rates.

System	Cycles per Hour (cph)
Steam, Gravity	1
Hydronic Heat, Condensing Gas Furnaces	3
Gas or Oil Forced Air	6
Electric Furnace	9

Finish:
T8700: Premier White® color.
Dimensions:
See Fig. 1.

INSTALLATION

When Installing this Product…

1. Read these instructions carefully. Failure to follow them could damage the product or cause a hazardous condition.
2. Check the ratings given 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 installation is complete, check out product operation as provided in these instructions.
   CAUTION
   Damage To Heating/Cooling System Possible. Be careful when handling wires during installation. Disconnect power at furnace or at main breaker/fuse box before starting installation.

RECYCLING NOTICE
If this control is replacing a control that contains mercury in a sealed tube, do not place your old control in the trash. Contact your local waste management authority for instructions regarding recycling and the proper disposal of an old control containing mercury in a sealed tube.
Fig. 2. Typical thermostat location.

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 the sun or appliances.
• Concealed pipes and chimneys.
• Unheated (uncooled) areas such as an outside wall behind the thermostat.

Mounting Decorator Cover Plate and Wallplate to Wall
IMPORTANT
Position and level the wallplate for appearance only. The thermostat functions properly even when not level.
Mount decorator cover plate (if desired), wallplate, T8700 and the screws as follows; see Fig. 3:

1. Place the decorator cover plate and the wallplate on the desired wall location.
2. Pull the thermostat wire through the entrance hole onthe decorator cover plate, then through the wallplate entrance hole.
3. Plug the wiring hole behind the thermostat to prevent drafts from affecting the thermostat.
4. Select the two mounting holes that best fit the application.
5. Fasten the decorator cover plate and the wallplate to the wall using the provided anchors (if necessary) and screws.

Wiring

CAUTION
Damage To Heating/Cooling System Possible. Be careful when handling wires during installation.
Disconnect power at furnace or at main breaker/fuse box.
IMPORTANT
Use an 18-gauge maximum wire for wiring the T8700 Thermostat. All wiring must comply with local electrical codes and ordinances. A letter is located near each terminal for identification.
NOTE: To ensure proper mounting of thermostat, restrict all wiring to the left side of the terminals. See Fig. 4.

The shape of the terminals permits insertion of straight or wraparound wiring connections; either method is acceptable. See Fig. 5.

The T8700 Thermostat steals power through the heating and/or cooling system controls and is adaptable to most, 24 Vac systems. Refer to Fig. 6 through 11 for typical wiring hookups.

Adjust Fan Operation Switch
The thermostat fan operation switch, labeled Fuel switch, is set at the factory in the F position. See Fig. 12. This is the correct setting for most systems. If this system is an electric heat system, set the switch to the E position. The E setting allows the fan to turn on immediately with the heating or cooling equipment in a system where the G terminal is connected.

Mounting Thermostat to Wallplate

1. Align and attach bottom center notch on the thermostat with bottom center tab on wallplate.
2. Next align tabs and connector at top of thermostat to the pins on the wallplate. Press firmly to attach.
   NOTE: To remove the thermostat from the wallplate, grasp the thermostat on both sides and pull the thermostat straight out.

SETTINGS AND ADJUSTMENTS

Setting Fan and System Switches
Fan and system settings are controlled manually using the switches located at the top of the thermostat wall plate. See Fig. 14 for switch locations.

Fan Switch
The Fan switch settings for the T8700B1015 with Fan and T8700C are:

• ON: The fan runs continuously. Use to improve air circulation.
• AUTO: Normal setting for most homes. In cooling, the fan starts and stops with the cooling equipment. In heating, the heating system directly controls the fan equipment. The fan may start a few minutes after the heating equipment turns on (for most systems). When the thermostat Fuel switch is set to the E position for electric heat, the fan starts and stops with heating equipment. Slide the Fan switch on the thermostat to the desired fan setting.

System Switch
The T8700B System switch controls the thermostat as follows:

• HEAT: The thermostat controls the heating system.
• OFF: The heating is off.

The T8700C System switch controls the thermostat as follows:

• COOL: The thermostat controls the cooling system.
• OFF: Both heating and cooling are off.
• HEAT: The thermostat controls the heating system.
  Slide the System switch on the thermostat to the desired system setting.

SETTING THE CLOCK

1. To set the current time:
   • Press the key once. You will see a flashing clock.
   • Use the keys to set the current time.
   • press the key until End is displayed.

PROGRAMMING

The thermostat is preprogrammed for your convenience with the following time and temperature settings, see Table 3.
Table 3. Preprogrammed Time/Temperature Settings.

Period	Start Time	Heating Setpoint	Cooling Setpointa
WAKE	6:00 AM	70°F (21°C)	78°F (25.5°C)
SLEEP	10:00 PM	62°F (16.5°C)	82°F (28°C)

a T8700C only.
WAKE is the time period when you want the house at a comfortable temperature during the day.
SLEEP is the time period you can set for an energy-saving the temperature while you sleep.
NOTE: The heating and cooling program times are the same. Changing your cooling WAKE time also changes your heating WAKE time.
The following is a heating program example. The System switch is in the HEAT position. To change to the cooling program (T8700C), move the System switch to the COOL position and enter the cooling temperature settings.
IMPORTANT
When programming the T8700B, first move the System switch to the heat position.
To program your own Time and Temperature settings follow steps 1 through 6.

1. Set the current time.
   • Press the key once. You will see a flashing clock.
   • Use the keys to set the current time. The clock is now set.
     Preprogrammed Time and Temperature settings.
     After the clock is set, you can use the preprogrammed Time and Temperature settings, (see table 3) press the key until the End is displayed. The preprogrammed Temperature settings can now be used.
2. Set your WAKE time.
   • Press the key once. You will see a flashing WAKE time.
   • Use the keys to set your desired WAKE time. The WAKE time is now set.
3. Set your WAKE temperature.
   • Press the key once. You will see a flashing WAKE temperature.
   • Use the keys to set your desired WAKE temperature. The WAKE temperature is now set.
4. Set your SLEEP time
   • Press the key once. You will see a flashing SLEEP time.
   • Use the keys to set your desired SLEEP time. The SLEEP time is now set.
5. Set your SLEEP temperature.
   • Press the key once. You will see a flashing SLEEP temperature.
   • Use thekeys to set your desired SLEEP temperature. The SLEEP temperature is now set.
6. Run program.
   Press the key once. You have completed your program changes. End is displayed for five seconds indicating the end of programming. The thermostat then displays the current time and room temperature.
   NOTE: To exit the programming mode at any time, press the key until End is displayed.

Operating the Thermostat

To Display Temperature Setting.
Press once to display present temperature setting. After approximately five seconds, the thermostat displays current time and room temperature.
To Make a Temporary Temperature Change.

• Press until desired temperature is displayed.
• TEMPORARY is displayed. The TEMPORARY change is in effect until the next program period.

NOTE: To cancel your TEMPORARY change, press until End is displayed.
To Use Hold Function.
To hold the thermostat at one temperature indefinitely, program both WAKE and SLEEP to the same temperature.
Installer Setup
The following instructions provide the information necessary to change the heating cycle rate, select either Fahrenheit (F °) or Celsius (C °) and 12- or 24-hour clock format.
NOTE: To exit at any time, press until End is displayed.

1. Enter Installer Setup.
   • Use keys to set the temperature setpoint to 52°F (11°C).
   • After the thermostat reverts back to displaying room temperature (approximately five seconds), simultaneously press keys and hold for three seconds. Release the keys after the display changes.
   • Press within five seconds.
2. Select Cycles Per Hour. The display changes to show the current cycle rate setting.
   Use select 1, 3, 6, or 9 cups. Refer to Table 4.
   Table 4. Heating Cycle Options

   System	Program Setting (cph)
   Steam, Gravity	1
   Hydronic Heat, Condensing Gas Furnaces	3
   Gas or Oil Forced Air	6
   Electric Heat	9

3. Select Fahrenheit – Celsius Temperature.
   • Press to display the current °F or °C setting.
   •  Use to choose between °C and °F.
4. Clock Format.
   • Press to display the current 12- or 24-hour clock setting.
   • Usechoose either a 12- or 24-hour clock format.

Press once to exit Installer Setup. Upon exiting, the temperature setting will be at 52°F (or 11°C). Press six times to return the thermostat to the normal operating mode with End appearing on the display.

Zero Droop Performance
The T8700 Thermostat can control temperature closer to setpoint than electromechanical thermostats. This is because proportional plus integral control (P + I) maintains a constant indoor temperature independent of the outdoor temperature. This feature allows the T8700 Thermostat to provide tight temperature control with virtually no noticeable swings in temperature, a condition referred to as droop. This zero droop performance provides improved comfort and occupants do not need to continually adjust thermostat settings to be comfortable, even during extreme weather.
Power Stealing
The T8700 Thermostat steals power through the heating and/or cooling system controls; therefore, it can be used in applications where it is not possible to run additional wires. See Fig. 15. The T8700 Thermostat requires only 2.5 mA of load current when the heating and/or cooling is on. When the heating and/or cooling is off, the thermostat operates at 0.1 mA. This low current draw allows the T8700C to be used with most 24V heating and/or cooling systems.
The T8700 Thermostat operates only when mounted on the wallplate with 24V applied. Batteries are not required for operation. Temperature setpoints, programming and configuration settings are retained permanently in memory.
Sequence of Operations
The Heat and Cool outputs are transistor-controlled. A loss of ac power or a change in the System switch setting can turn off outputs. Table 5 shows the Fan and System sequence of operations.
Fan Control
The FAN switch settings for the T8700B1015 with Fan and T8700C are ON and AUTO.

• ON: The fan runs continuously.
• AUTO: In cooling, the fan starts and stops with the cooling equipment. In heating, the fan starts a few minutes after the heating equipment turns on. With the Fuel switch in the E position for electric heat, the fan starts and stops with the heating equipment.

Heat Mode
With the T8700 system switch in the HEAT position, the thermostat controls the heating system. On a call for heat, the W terminal is energized and a flame icon shows on the digital display.
If the Fuel switch is in the E position, both the W and G terminals are energized on a call for heat.
Cool Mode
With the T8700C System switch in the Cool position, the thermostat controls the cooling system. On a call for cool, the G and Y terminals are energized and a snowflake icon shows on the digital display. A flashing snowflake indicates that the minimum-off timer is in effect.
Minimum Off-Timer T8700C
A minimum off-timer for the T8700C assures that the cooling compressor does not come on again for at least five minutes after it turns off. The minimum-off timer is triggered when the compressor turns off or when the System switch is changed. If the compressor turns off when the setpoint is changed, the minimum-off timer is triggered. Power interruption and power restoration also trigger the minimum off-timer.

Table 5. The sequence of Operations.

Fan Switch Settings	System Switch Settings	Call for Action	Energize Terminals	Display Icons
AUTO	OFF	None	None	None
ON	Any	Any	G	None
AUTO	COOLb	Coolingb	G, Y
AUTO	HEAT	Heating	W,Ga

• when the fuel switch is in the E position. (T8700B with Fan and T8700C).
  
• T8700C only.

CHECKOUT

Heating (T8700B, C)

1. Slide the System switch to HEAT and the Fan switch to AUTO. (For the T8700B1007 Heat Only model, a Fan switch is not an option).
   
2. Press and hold the key to raise the temperature setting several degrees above the room temperature the heating equipment should start. In conventional systems, the system turns on the fan through limit control. When using the thermostat with the fuel switch set to the E position for electric heat, the fan starts immediately.
   
3. Press the key to lower the temperature setting below the room temperature. The heating equipment should stop. Cooling (T8700C)
   

CAUTION
Equipment Damage Possible.
Operating at too low of an outdoor temperature can cause compressor damage. Do not attempt to operate cooling when the outdoor temperature is below 50°F (10°C). Refer to manufacturer recommendations.

IMPORTANT
A minimum off-timer for the T8700C assures that the cooling compressor does not come on again for at least five minutes after it turns off. The minimum-off timer is triggered when the compressor turns off or when the System switch is changed. If the compressor turns off when the setpoint is changed, the minimum off timer is triggered. Power interruption and power restoration also trigger the minimum off-timer.

1. Slide the System switch to COOL and the Fan switch to AUTO.
   
2. To start the cooling equipment, press the key to lower the temperature setting several degrees below room temperature. The fan starts and stops with the cooling equipment.
   
3. Press the key to raise the temperature setting above the room temperature. The cooling system should shut down.
   

Fan (T8700B1015 with Fan, T8700C)

1. Slide the System switch to OFF and the Fan switch to ON. The Fan should run continuously.
   
2. Slide the Fan switch to AUTO. In heating, the fan is controlled directly by the heating equipment and starts a few minutes after the heating equipment turns on (for most systems). When using the thermostat with the Fuel switch set to the E position for electric heat, the fan starts and stops with the heating equipment. In cooling, the fan starts and stops with the cooling equipment. Make certain all equipment responds properly to the thermostat.

TROUBLESHOOTING

Symptom	Possible Cause	Corrective Action
Heating/cooling equipment does not operate.	No ac power.	Check power to heating/cooling equipment: —     On/Off switch. —     Fuse or circuit breaker. —     Loose 24V connection: at thermostat; at furnace/air conditioner. —     Incorrect wiring: check appropriate wiring diagram.
	Thermostat inoperative.	See the Checkout section.
	Incorrect wiring.	Check wiring.
	Heating/cooling equipment is inoperative.	Consult equipment manufacturer instructions.
	The system switched on the thermostat in wrong position.	Reset the System switch.
Flashing        Snowflake	Minimum-off timer in thermostat operating for cooling.	Wait five minutes or follow steps in Checkout section.
Partial display.	Still in installer setup mode.	See Installer Setup section for instructions on how to exit.
	Damaged thermostat.	Replace thermostat.
Displaying only time and not temperature.	Power to the thermostat is currently interrupted.	Check the power to the thermostat.
Blank display.	No power to the thermostat.	Check the power to the thermostat.
	The thermostat is mounted incorrectly on the wallplate.	See installation instructions for correct mounting.
The temperature display is incorrect.	The thermostat is configured incorrectly for °F or °C.	Reconfigure display. See Installer Set-up for instructions to change display.
Cannot change the temperature setting.	Upper or lower temperature setpoints were reached.	Check temperature setpoints; temperature setting range is 40°F (4°C) to 99°F (37°C).
Time loss.	Power to the thermostat was interrupted for longer than 20 minutes.	Reset clock. See Setting The Clock

Home and Building Control
Honeywell Inc. Honeywell Plaza P.O. Box 524 Minneapolis MN 55408-0524
Home and Building Control
Honeywell Limited-Honeywell Limitée 155 Gordon Baker Road North York, Ontario M2H 3N7
Honeywell Asia Pacific Inc.
Room 3213-3225 Sun Hung Kai Centre No. 30 Harbour Road Wanchai Hong Kong
Honeywell Latin American Region
480 Sawgrass Corporate Parkway Suite 200 Sunrise FL 33325
Honeywell Europe S.A. 3 Avenue du Bourget 1140 Brussels  Belgium

www.honeywell.com/yourhome

Reference:

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HONEYWELL T8700B Electronic Round Programmable Thermostat PRODUCT DATA

HONEYWELL T8700B Electronic Round Programmable Thermostat PRODUCT DATA