Honeywell Trol-A-Temp T8090T User manual

69-0432-1
ZoneThermostat
Heating/CoolingThermostat and
Subbase orWallplate
ModelT8090T
OWNER’SMANUAL

269-0432—1
Welcome to the world of energy savings with your new Honeywell Trol-A-Temp Zone®
Thermostat.
Your new thermostat will automatically control the temperature in your home to provide a high
level of comfort plus energy savings when programmed according to the instructions in this
manual.
With zone control, you heat or cool each zone or living area only when needed. The indepen-
dent control of each zone provides additional energy savings.
Recycling Notice
This control contains mercury in a sealed tube. Do not place control in the trash at the end of
its useful life.
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 the control, or of an old control containing mercury in a sealed tube.
If you have questions, call Honeywell Inc. at 1-800-468-1502.
M3375

369-0432—1
Table of Contents PAGE
Features of Your Thermostat ............................................................................................................ 4
Setting the Temperature ................................................................................................................... 7
Inserting Clock Batteries ................................................................................................................... 8
Setting the Clock ............................................................................................................................... 9
Programming................................................................................................................................... 11
Troubleshooting .............................................................................................................................. 15
Servicing the Thermostat ................................................................................................................ 21
Heat Anticipator Setting .............................................................................................................. 21
Thermometer Adjustment............................................................................................................ 22

469-0432—1
Features ofYour
Thermostat 1FLIP-UP COVER. Lift it up to set clock for
energy savings and normal temperature
periods.
2THERMOSTAT COVER.
3THERMOMETER. Provides accurate room
temperature reading.
4CLOCK. This clock provides a 24-hour
slotted dial to hold the programming pins.
5CLOCK HANDS. Turn minute hand clock-
wise to match the correct AM or PM
time to the time indicator.
6TIME INDICATOR. Arrow head indicates
time for 24-hour dial.
7PROGRAM INDEX WHEEL. Controls high
and low temperature at specific time of
day as set by program pins.
8TEMPERATURE SETTING LEVERS. Left
(blue mark) controls the low temperature;
right (red mark) controls the high tempera-
ture.
2
1
3
M8693

569-0432—1
9PROGRAM PINS. Must be inserted into
24-hour clock dial slots to control program
index wheel.
10 PIN SLOTS. Located on 24-hour dial at
10-minute intervals for program pin
insertion.
11 MANUAL PROGRAM ADVANCE BUTTON.
Allows change from comfort to energy
savings setting and vice versa without
changing the program.
12 HEAT ANTICIPATOR SCALEPLATE.
Calibrated to match the heating system
current draw in amperes.
13 ANTICIPATOR SETTING LEVER. Must be
set at 0.1A for proper system operation.
14 MERCURY BULB AND BIMETAL
ELEMENT(2). Provide automatic tempera-
ture control by switching the heating or
cooling system on and off.
58
97611 12 13
10 14
M8691
4

669-0432—1
15 WALLPLATE
Provides mounting base and wiring con-
nections for control of zones other than
zone 1 in heating or heating-cooling
systems.
16 SUBBASE
Provides mounting base, wiring connec-
tions and manual switching for control of
zone 1 in heating or heating-cooling
systems.
M2421
15
M8690
W
Y
R
G
16

769-0432—1
Setting The Temperature
For Heating:
■Set the left lever (blue mark) to the energy
savings temperature you want when you are
sleeping or the associated zone is unoccu-
pied.
■Set the right lever (red mark) to the temp-
erature you want for normal comfort
periods.
NOTE: You may override the time program by
setting both the red and blue levers to the
same temperature setpoint.
For Cooling:
■Set the left lever (blue mark) to the tempera-
ture you want for normal comfort periods.
■Set the right lever (red mark) to the energy
savings temperature you want when you are
sleeping or the associated zone is unoccu-
pied.
Fig. 1—Setting high and low
temperature setting levers.
8
9
10
12
11
1
2
3
4
5
6
7
8
9
10
12
11
1
2
3
4
5
6
7
50 60 70 80
12
6
3
9
50 60 70 80
by Honeywell
HIGH
TEMPERATURE
SETTING
LEVER
(RED MARK)
LOW TEMPERATURE
SETTING LEVER
(BLUE MARK)
M641A

869-0432—1
Inserting Clock
Batteries
Power is supplied to the clock by two AAA
alkaline batteries (included). Install batteries in
thermostat as shown in Fig. 2. Once a year or
when batteries are dead, replace with two new
AAA alkaline batteries. We recommend
Energizer®batteries.
BATTERY LOCATION FOR
(2) AAA BATTERIES;
INSTALL WITH POSITIVE
ENDS UP
M7188
Fig. 2—Inserting clock batteries.

969-0432—1
Setting the Clock
Lift thermostat flip-up cover and you’ll find
the 24-hour program dial, slotted in 10-minute
increments. Adjust the clock to the current time
by moving the minute hand carefully in a clock-
wise direction. DO NOT reverse the
minute hand.
When time is correctly set, the time indicator
arrow (see Fig. 3) will point to the correct time
and corresponding daytime (light) or nighttime
(dark) band of the program dial.
EXAMPLE: For 11 PM, the time indicator arrow
will point directly to the darkband. For 11 AM,
the arrow will point to them light band on the
dial.
TIME
INDICATOR
ARROW
MINUTE
HAND
M8561
Fig. 3—Setting the clock.

10 69-0432—1
Daylight Savings Time
When Daylight Savings Time starts, move the minute hand carefully in a clockwise
direction one hour. When Daylight Savings Time ends, move the minute hand carefully in a
clockwise direction 23 hours. Do NOT reverse the minute hand, or damage to the
timer mechanism may occur.

11 69-0432—1
Programming
You can program your thermostat to
automatically lower and raise the temperature
one or more times every 24 hours.
Before setting your program
■To insert a pin, push it straight into the
selected notch on the program dial until it is
completely seated.
■Lift thermostat flip-up cover and you’ll find
the 24-hour program dial. The slots on the
program dial (Fig. 4) are for the program
pins, which can be inserted at 10-minute
intervals.
■Three red and three blue program pins are
included with your thermostat. The red pins
start the high-temperature period; the blue
pins start the low-temperature period. A
heating program is preprogrammed. A red Fig. 4—Program components.
24-HOUR PROGRAM DIAL
(GRAY AREA FOR
NIGHT SETTINGS
FLIP-UP
COVER
PROGRAM
PINS
THERMOSTAT
COVER
PROGRAM PIN SLOT
PROGRAM INDEX WHEEL
PROGRAM PIN
STORAGE
TIME INDICATOR
ARROW
MANUAL PROGRAM
ADVANCE BUTTON M8692

12 69-0432—1
pin is inserted at 6:00 AM for high temperature (comfort period); a blue pin is inserted at 10:00
PM for low temperature (energy saving period). Two additional sets of pins are located in the
program pin storage area. You can set up to six temperature changes with the pins supplied.
We recomment at least five hours for each energy saving period.
■To change the pins add a new energy saving period.
■To remove a pin, press against the program dial and pull the pin straight out. DO NOT attempt
to change a pin if it is engaged with the program index wheel.
■On heating/cooling systems, be sure to reset the pins when the seasons change. You will also
probably want to change the lever positions.

13 69-0432—1
Setting the Heating Program
■Decide when you want the temperature to reach the comfort level. Find the notch on the dial
that is one-half hour before this time and insert a
red pin. The half-hour head start gives the
furnace time to heat the house before you wake up or arrive home.
■Decide when you want the energy
saving period to start and insert a
blue pin at the notch that corre-
sponds to this time. After the blue
pin engages, the furnace will be off
until room temperature drops to the
energy saving setpoint.
■You can set both a day and a night
program. See Fig. 5 for program
examples.
WINTER SUMMER
TEMPERATURE PROGRAM
PIN IN
CONTROL
NIGHT
ENERGY
SAVING
PERIOD
DAY
ENERGY
SAVING
PERIOD
BEGINS
10:00 PM
ENDS
6:00 AM
BEGINS
7:30 AM
ENDS
4:00 PM
TEMPERATURE PROGRAM
PIN IN
CONTROL
°C
27
24
27
24
RED
BLUE
RED
BLUE
°F
58
68
58
68
°C
14
20
14
20
°F
80
75
80
75
BLUE
RED
BLUE
RED
M626A
Fig. 5—Programming examples.

14 69-0432—1
Setting the Cooling Program
■Decide when you want the temperature to reach the comfort level. Find the notch on the dial
that is one-half hour before this time and insert a
blue pin. The half-hour head start gives the
air conditioner time to cool the house before you wake up or arrive home.
■Decide when you want the energy saving period to start and insert a
red pin at the notch that
corresponds to this time. After the red pin engages, the air conditioner will be off until the room
temperature rises to the energy saving setpoint.
Start or End Programs With Manual Program Advance Button
IMPORTANT
To prevent damage to the program advance mechanism, DO NOT use the program
advance button within a 30-minute period before or after a program change.
The manual program advance button enables immediate, one-time-only program changes to
accommodate temporary schedule changes.
Press the button to immediately begin an energy saving period or return to the normal setting.
After pressing the button, check the program indicator to assure the system is in the desired
mode. If the program indicator shows blue, the lower temperature is in effect; if the program
indicator shows red, the higher temperature is in effect. Using the manual advance button will not
affect the stored program.

15 69-0432—1
Troubleshooting
Your Honeywell Trol-A-Temp®Thermostat requires little or no attention. Most problems can be
traced to the following.
(continued)
PROBLEM CHECK ACTION
No heat. —system switch. May be in OFF or
COOL position. 1Move system switch to HEAT position.
—fuse or circuit breaker. If blown or tripped, replace fuse or
reset breaker.
—furnace power switch. May be Off. Move switch to ON.
—heating equipment for proper
operation. See manufacturer’s instructions.
—thermostat connections. Turn Off power. Check for correct
terminal hookups. Repair any frayed
or broken wires. Firmly tighten all
terminal screws.
—airflow at register. Zone damper
may be closed. If damper is closed, contact a qualified service technician for
assistance.

16 69-0432—1
Troubleshooting (continued)
(continued)
PROBLEM CHECK ACTION
No heat. —other. Contact a qualified service technicial
for assistance.
Energy saving
temperature program
12 hours off.
—program dial for proper day or
night phase. Turn clock ahead 12 hours. Move minute hand clockwise only.
Rooms do not warm
up at programmed
time.
—timer program for heating system.
May need more time to warm up
rooms.
Move red pin one-half hour earlier on
the program dial.
Temperature change
occurs at the wrong
time.
—program pins for correct time
locations. Relocate pins to desired settings.
Room temperatures
are not correct. —positions of thermostat setpoint levers. Reset to desired temperatures.
—position of subbase system
switch. 1Move to desired operating position.
—air flow at register. Damper may be operating improperly.
Contact a qualified service technician
for assistance.

17 69-0432—1
Troubleshooting (continued)
(continued)
PROBLEM CHECK ACTION
Room temperatures
are not correct. —thermostat circuits. HEATING—Make sure zone 1 sy- stem switch is set at HEAT and fan
switch is set at AUTO. Move temp-
erature setting levers on the appro-
priate zone thermostat 5° F [3° C]
above room temperature. Heating
should start; damper should be open.
COOLING—Make sure zone 1
system switch is set at COOL and fan
switch is set at AUTO. Move temp-
erature setting levers on the
appropriate zone thermostat 5° F
[3° C] below room temperature.
Cooling should start; damper should
open. IF SYSTEMS DO NOT
OPERATE, CONTACT A QUALIFIED
SERVICE TECHNICIAN.

18 69-0432—1
Troubleshooting (continued)
(continued)
PROBLEM CHECK ACTION
No cooling. 2—system switch. May be in OFF or
HEAT position. 1Move switch to COOL position.
—fuse or circuit breaker. If fuse is blown or breaker tripped,
replace or reset.
—condenser switch position.
Located outdoors and may be
turned Off.
Move to ON position.
—cooling equipment for proper
operation. See manufacturer instructions.
—thermostat connections. Turn Off power. Check for correct
terminal hookups. Repair any frayed
or broken wires. Firmly tighten all
terminal screws.
—airflow at register. Zone damper
may be closed. If damper is closed, contact a qualified service technician for
assistance.
—other. Contact a qualified service technician
for assistance.

19 69-0432—1
Troubleshooting (continued)
1 Applicable on zone 1 thermostat only.
2Not applicable on heating-only system.
If this Troubleshooting section has not solved the problem, call a qualified Trol-A-Temp®
customer service at or service technician, 1-800-828-8367 for additional assistance.
PROBLEM CHECK ACTION
Clock does not run. —voltage across the C and R
terminals. Remove thermostat from the wall- plate or subbase, and measure the
voltage. Refer to page 20 for cause
and action.
Thermostat setting
and thermometer
reading disagree.
—level position of thermostat. Reinstall thermostat wallplate or
subbase. Use a spirit level.
—area around thermostat for drafts
or radiant heat. Thermostat should be about 5 ft [1.5m] above floor on an inside wall.
Contact qualified service technician
for change of location.
—calibration of thermometer. See instructions on page 22.

20 69-0432—1
Voltage at Clock Terminals
AC VOLTAGE AT
C-R TERMINALS POSSIBLE CAUSE CHECK ACTION
0 Vac 1. System power is Off. 1. Restore power.
2. Short in clock power supply wiring. 2. Replace wiring.
3. Limit switch contacts stuck open. 3. Free or replace limit switch.
4. Transformer supplying power is
burned out. 4. Replace transformer.
Up to 15 Vac. 1. System transformer used to power
the clock is inadequate. 1. Use additional (separate) transformer.
2. Additional (separate) transformer
used to power the clock has
inadequate voltage.
2. Install transformer with proper
secondary voltage.
15 to 30 Vac. 1. Spring fingers on thermostat are
not making proper contact with the
subbase terminals.
1. Rebend spring fingers to a 45
degree angle to assure proper
contact.
2. Clock has failed. 2. Replace the thermostat.