Honeywell T8602A Programmable Thermostats
APPLICATION
These thermostats provide energy saving control for 24 Vac conventional heating/cooling system or 750 mV heating and 24 Vac cooling as indicated in Table 1. Power is supplied for the device by three AA alkaline batteries (included). This allows the thermostat to be compatible with all control applications. Cycle rates are adjustable for heating. The TS8602 current rating in heating is 0.1A at 750 mV. The current rating on all other models is 1.6A maximum, up to 30 Vac. Adaptive Intelligent Recovery™/Conventional Recovery selection screw is included on the back of the thermostat. Fan operation switch is included on the back of some T8602C models to select either independent or direct thermostat control of the fan in heating. 12/24 hour clock conversion and °C/°F conversion are available on some models only.
INSTALLATION
- Read these instructions carefully. Failure to follow them could damage the product or cause a hazardous condition.
- Check the ratings given on the product to make sure the product is suitable for your application.
- Installer must be a trained, experienced service technician.
- After installation is complete, check out product operation as provided in these instructions.
- Allow thermostat to warm to room temperature before operating
Thermostat Models.
Thermostat |
Stages | Switching |
Application |
||
Heat | Cool | System | Fan | ||
T8602A | 1 | — | — | — | Gas, oil or electric with independently controlled fan. |
T8602B | 1 | — | — | ON-AUTO | |
T8602B | 1 | — | HEAT-OFF | — | |
T8602C | 1 | 1 | HEAT-OFF-COOL | ON-AUTO | |
T8602D | 1 | 1 | HEAT-OFF-COOL-AUTO | ON-AUTO | |
T8602C | 1 | 1 | HEAT-OFF-COOL | ON-AUTO | Fan operation in heating selectable for thermostat or independent control; with O and B terminals for changeover control. |
TS8602A | 1 | — | — | — | Millivolt heating system. |
TS8602Ca | 1 | 1 | HEAT-OFF-COOL | ON-AUTO | Millivolt heating and 24 Vac cooling system. |
Location
- Install thermostat and wallplate about 5 ft (1.5m) above the floor in an area with good air circulation at room temperature.
- Do not install the thermostat where it can be affected by:
- drafts or dead spots behind doors, in corners, or under cabinets.
- hot or cold air from ducts.
- radiant heat from sun or appliances.
- concealed pipes and chimneys.
- unheated (uncooled) areas such as an outside wall, behind the thermostat.
If Replacing An Existing Thermostat
Turn off power to the thermostat at the furnace or boiler. A two-transformer system can require turning off two switches or disconnects. Remove any existing wallplate or subbase from the wall. Write down the letter or number on each wiring terminal, as the wire is removed, to avoid miswiring later.
If New Installation
Run cable to the hole in the selected wall location, and pull about 3 in. (76 mm) of wire through the opening. Colorcoded, 18 gauge thermostat cable with at least one conductor for each wiring terminal is recommended. Push excess wire back into the hole, and plug the hole with nonhardening caulk, putty or insulation to prevent drafts from affecting the thermostat operation.
Mounting Wallplate
Remove thermostat from wallplate. The wallplate does not require leveling for operation, but for appearance only.
The wallplate mounts directly onto the wall with the screws included. Using the wallplate as a template, with a pencil, mark two (of three) mounting screw positions on the wallplate that fit the application. Use a 3/16 in. bit to drill holes for the anchors. Gently tap anchors into the holes until flush with the wall surface. Thread wires through the center opening of the wallplate. Mount the wallplate using the two screws provided. Gently tighten the screws, level the top surface of the wallplate, and then securely tighten the screws
Wiring
All wiring must comply with local electrical codes and ordinances. Disconnect power before wiring to prevent electrical shock or equipment damage. The shape of the terminal barrier permits insertion of straight or conventional wraparound wiring connections. Either method is acceptable. Refer to Fig. 4 through 15 for typical wallplate and thermostat hookups.
Removing thermostat from wallplate.
Keep wiring restricted to the ribbed area surrounding terminals.
TS8602 in typical millivoltage heating circuit.
TS8602C in typical millivoltage heating and 24 Vac cooling circuit
T8602A,B heating-only circuit in a continuous pilot gas system.
T8602A,B heating-only circuit in an oil system.
T8602A,B heating-only circuit in an electric baseboard or ceiling cable system
T8602A,B heating-only circuit in a Honeywell Intermittent Pilot Gas Burner Ignition System
T8602A,B circuit for controlling incompatible or three-wire zone valves or dampers. Heating or cooling equipment is operated by an end switch on the zone valve or motor, or by a thermostat in a master zone
T8602A,B circuit for controlling Honeywell or compatible two-wire zone valves or dampers. Heating or cooling equipment is operated by an end switch on the zone valve or motor, or by a thermostat in a master zone.
T8602C,D heating/cooling circuit in a two-transformer (one for heating, one for cooling) system with gas heat and electric cooling RC and R terminals
T8602C,D heating/cooling circuit in a single transformer system with gas heat/electric cooling and electric furnace/electric cool. Controls fan in cooling only (typical multi-speed fan application)
T8602C,D heating/cooling circuit in an oil heating and electric cooling system. Heating transformer is in oil primary.
T8602C heating/cooling circuit in a two transformer system (gas heating and electric cooling). Includes O and B terminals for changeover control. See Table 2 to set fan operation switch.
Cycle rate adjustment
SETTING AND ADJUSTMENTS Adjusting Cycle Rate
The room air temperature will vary slightly from the comfort temperature setting with the cycling of the furnace or air conditioner. The equipment cycles off and on as the room temperature approaches the setpoint. The cycle rate of this thermostat is set for heating at six cycles per hour and for cooling at three cycles per hour as shipped from the factory. The cooling cycle rate cannot be adjusted. On all models, except the TS8602, the heating cycle rate can be adjusted by turning one or both cycle rate adjustment screws located on the back of the thermostat. See Fig. 16. The screws should only be backed out about one-half to one turn, or be turned in until tight.
Adaptive Intelligent Recovery™/ Conventional Recovery
The thermostat is factory-set for Adaptive Intelligent Recovery™, but may be converted to conventional recovery using screw 3A on the back of the thermostat as in-dicated With Adaptive Intelligent Recovery™, the room will reach the comfort temperature at the exact time programmed into the thermostat. The control temperature will increase gradually, and turn the equipment on and off several times to reach the comfort temperature slowly and on time. There will be no wasted of energy associated with rapid temperature changes and temperature overshoot. With conventional recovery, the start time should be programmed to be earlier than the desired comfort time. It may require some trial and error to arrive at the best starting time.
Setting Time/Temperature (Some Models) The display readout may be converted between a 12 and 24 hour clock or °C and °F using screws 2A and 2B as indicated
Setting Fan Operation Some T8602C models include a fan operation switch on the back of the thermostat on the lower left corner to determine correct setting of fan operation switch
Installing Batteries
Power is supplied for the thermostat by three AA alkaline batteries. Batteries are included with thermostat. Install batteries in back of thermostat as shown in Fig. 17. The display will flash 1:00 PM and room temperature. When the batteries are going dead, the display will flash REPL BAT. If device has system switch, set to OFF. Remove the thermostat from the wall and install three new AA alkaline batteries. We recommend Energizer® batteries. Change batteries within approximately 30 seconds from the time the batteries are removed to prevent program loss and the necessity to reprogram.
Mounting The Thermostat
Hang the thermostat on the tabs at the top of the base. See Fig. 18A. Swing down and press on the lower edge until the thermostat snaps into place. Open the cover, and tighten the captive mounting screws.
Setting Day and Time
Set the present day and time. When the thermostat is first turned on, the display will read 1:00 PM and the room temperature. It will go off for only a few seconds, then begin to flash on and off.
Press
Press TIME to set the current time.
Press
Press to set the current day. Each press of the DAY key advances the display one day.
If the display will not come on:
- Check the mounting of thermostat to wallplate. If loose or misaligned, remove thermostat and reinstall on the wallplate, making sure it is firmly attached.
- Check to see that all the batteries are good and installed correctly
CHECKOUT
Heating
Move the system switch to HEAT and the fan switch to AUTO. Press the WARMER key until the setting is about 10°F (6°C) above room temperature. The heating should start and the fan should run (may be a short delay on forced air systems). Press COOLER key until the setting is about 10°F (6°C) below room temperature. The heating equipment should shut off.
Cooling
Move the system switch to COOL and the fan switch to AUTO. Press the COOLER key until the setting is about 10°F (6°C) below room temperature. The cooling equipment and fan should start. Press the WARMER key until the setting is about 10°F (6°C) above room temperature. The cooling equipment and fan should stop
Fan
Move the system switch to OFF, and the fan switch to ON. The fan should run continuously. When the fan switch is in the AUTO position, the fan cycles with the heating or cooling system.
Installer Self-Test (Optional)
- Perform the following test as a check of all thermostat functions. If the thermostat does not respond as indicated, replace the thermostat.
- Press AHEAD and BACK keys at the same time.
- While holding down the keys, all segments of the display should be on.
- Set system switch to OFF, where applicable. Press AHEAD and BACK and PRESENT SETTING keys at the same time to enter self-test.
- Press each key as listed below, and look for responses listed as key is held down and released.
End Self-Test
For electric heat fan operation, the fan will operate with the heating system when the fan switch is in AUTO. A HEAT displayed when system switch is in HEAT, COOL when in COOL, HEAT and COOL when in AUTO, neither when in OFF. Also, a four-digit code is displayed, with each digit explained as follows.
Honeywell
- Home and Building Control
- Honeywell Inc.
- 1985 Douglas Drive North
- Golden Valley, MN 55422
- Home and Building Control
- Honeywell Limited-Honeywell Limitée
- 740 Ellesmere Road
- Scarborough, Ontario
- M1P 2V9
Reference
Download Manual:
Honeywell T8602A Programmable Thermostats Installation Instructions
Honeywell T8602A Programmable Thermostats Installation Instructions
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