Honeywell T8024D Thermostat User Manual

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T8000C, T8001C,T8024D  
Programmable Thermostats  
PRODUCT DATA  
FEATURES  
Attractive styling complements any decor to the  
homeowner s delight.  
Preprogrammed for your convenience.  
Program up to four time periods and temperature  
setpoints to complement your lifestyle.  
Programs are permanently held in non-volatile memory  
in the event of a power failure.  
Indefinite setpoint temperature hold for added comfort  
and energy savings.  
Ease-of-use means fewer homeowner questions and  
increased homeowner satisfaction.  
Large temperature display for quick easy readability.  
Conveniently sized thermostat (5-1/2 x 3-1/2) with  
optional decorator cover plates (7-3/8 x 5-3/4) make it  
easy to install in a variety of locations.  
Keys are located by the display for easy access.  
FAN and SYSTEM switches are located on the lower  
edge to eliminate accidental setting changes.  
Easy installation, setup and self-test saves time and  
increases installer productivity.  
Manual changeover from heat to cool eliminates  
unexpected system operation.  
APPLICATION  
The T8000C, T8001C and T8024D Programmable  
Thermostats provide programmable temperature control for  
°F or °C temperature display for added model flexibility.  
Selectable heating cycle rate (1, 3, 4, 5, 6, 9 or 12 cph) for  
a variety of applications which reduces the amount of  
inventory.  
Cooling cycle rate is fixed (3 cph), the standard setting  
for compressors, for speedy installation.  
Setpoints are permanently held in non-volatile memory  
(no batteries required) and retained during power  
outages for increased installer and homeowner  
convenience.  
Power stealing and hardwired models available for  
virtually all equipment and application needs including;  
gas, oil and electric forced air, condensing gas furnaces,  
forced air zoning systems, single stage heat pumps,  
hydronic heat, gravity and radiant floor heat systems.  
2
4 Vac heating-cooling systems with manual changeover  
from heat to cool. The T8000C and T001C provide single-  
stage heating and cooling control and the T8024D provides  
two-stage heating and two-stage cooling contorl. Heating  
cycle rates are selectable at 1, 3, 4, 5, 6, 9, or 12 cph.  
Cooling cycle rates are fixed at 3 cph. Temperature indication  
can be set for °F or °C.  
The T8000C is powered through the heating/cooling system  
controls. The T8001C and T8024D are powered directly  
through the system transformer.  
Contents  
Application ..........................................................................  
1
1
2
2
3
6
8
9
Features ..............................................................................  
Specifications ......................................................................  
Ordering Information ...........................................................  
Installation ...........................................................................  
Installer Setup .....................................................................  
Operation ............................................................................  
Checkout .............................................................................  
Troubleshooting .................................................................. 12  
®
U.S. Registered Trademark  
Copyright © 2001 Honeywell  
• All Rights Reserved  
68-0195-2  
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T8000C, T8001C AND T8024D PROGRAMMABLE THERMOSTATS  
Cycle Rates (at 50% Load):  
SPECIFICATIONS  
Heating: Selectable at 1, 3, 6, 9 or 12 cph. See Heating  
Cycle Rates, Table 1, for cycle rate options and  
corresponding system equipment.  
IMPORTANT  
The specifications given in this publication do not  
Cooling: Fixed at 3 cph.  
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.  
Finish:  
T8000C and T8024D TRADELINE¤ MODELS: are  
available in Premier White¤ and Taupe finish.  
T8001C MODELS: are available in Premier White¤ color.  
Accessory:  
The TRADELINE¤ models include a thermostat, wallplate  
and owner s guide. A 7 3/8 in. x 5 3/4 in. (188 mm x 146 mm)  
decorator cover plate (for covering wall marks) is available  
separately. Order Honeywell part no. 209649A (taupe) or part  
no. 209649B (white).  
Decorator cover plates; for covering wall marks are available  
separately. Order Honeywell part no. 209649A for Taupe, or  
part no. 209649B for White. 7-3/8 in. (188 mm) x 5-3/4 in.  
(
146 mm).  
Dimensions: See Fig. 1.  
Power: 24 Vac nominal, 18 to 30 Vac, 50 or 60 Hz.  
WALLPLATE  
4-3/8 (111)  
Electrical Ratings:  
T8000C:  
3-5/16 (84)  
Heating: .02-1.2A run; 3.5A inrush.  
Cooling: .02-1.2A run; 6.0A inrush.  
T8001C and T8024D:  
Heating: .02 to 1.5A run; 3.5A inrush.  
Cooling: .02 to 1.5A run; 7.5A inrush.  
T8000C, T8001C and T8024D:  
Fan: .02 to 0.5A run; 2.5A inrush.  
2
(70)  
-3/8  
Current Draw:  
T8000C Power Stealing Thermostat requires only 2.5 mA  
current draw when the thermostat calls for heat and is  
compatible with most 24V microprocessor systems. For  
further detail, see Power Stealing in the OPERATION section.  
THERMOSTAT  
AND WALLPLATE  
THERMOSTAT  
5-1/2 (140)  
1-3/16  
(55)  
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.  
Hold  
Select  
PM  
TUE  
3-1/2  
Temperature Setting Range: 30 to 99°F (4 to 37°C).  
Ambient Temperature Range: 30 to 110°F (4 to 43°C).  
Shipping Temperature Range: -20 to 120°F (-29 to 49°C).  
(89)  
FAN  
Auto On  
SYSTEM  
Cool Off Heat  
M14675  
Operating Relative Humidity: 5% to 90% RH, non-  
condensing.  
Fig. 1. T8000/T8001 Thermostat dimensions in in. (mm).  
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
2
.
.
Your local Home and Building Control Sales Office (check white pages of your phone directory).  
Home and Building Control Customer Relations  
Honeywell, 1885 Douglas Drive North, MN10-1461  
Golden Valley, Minnesota 55422-4386 1-800-468-1502  
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.  
68-0195–2  
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T8000C, T8001C AND T8024D PROGRAMMABLE THERMOSTATS  
INSTALLATION  
MERCURY NOTICE  
If this control is replacing a control that contains  
mercury in a sealed tube, do not place your old  
When Installing this Product…  
control in the trash. Dispose of it properly.  
1
. Read these instructions carefully. Failure to follow them  
could damage the product or cause a hazardous  
condition.  
Contact your local waste management authority for  
instructions regarding recycling and the proper  
disposal of a control. If you have questions, call the  
Honeywell Customer Response Center at 1-800-468-  
2
. Check the ratings given in the instructions and on the  
product to make sure the product is suitable for your  
application.  
1502.  
3
4
. Installer must be a trained, experienced service  
technician.  
. After installation is complete, check out product  
operation as provided in these instructions.  
Location  
Install the thermostat about 5 ft (1.5m$I 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:  
CAUTION  
Damage to Heating/Cooling System Possible.  
Be careful when handling wires during installation.  
Disconnect power at furnace or main breaker/fuse box.  
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.  
YES  
NO  
NO  
5
FEET  
[
1.5 METERS]  
NO  
M11338  
Fig. 2. Typical location of thermostat.  
Mounting Wallplate to Wall  
1. Place the wallplate at the desired location on the wall.  
2
3
4
. Pull the thermostat wire through the wallplate entrance  
hole.  
IMPORTANT  
. Fasten the wallplate to the wall using the anchors and  
screws provided.  
Level only for appearance. The thermostat functions  
normally even when not level.  
. After wiring the wallplate, plug the hole with non-  
flammable insulation to prevent drafts from affecting the  
thermostat; see Wiring section.  
Mount wallplate and the T8000C/T8001C with the screws  
provided (see Fig. 3) as follows:  
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T8000C, T8001C AND T8024D PROGRAMMABLE THERMOSTATS  
Refer to Fig. 6 through 10 for typical wiring hookups.  
WALL  
WALL  
ANCHORS (2)  
TERMINAL FOR STRAIGHT  
FOR WRAPAROUND  
STRIP 7/16 IN. (11 MM)  
SCREW  
INSERTION STRIP  
/16 IN. (8 MM)  
5
G
C
W2  
Y2  
R
MOUNTING  
SCREWS (2)  
WALLPLATE  
M12202  
W1  
Y
Fig. 3. Mounting wallplate to wall.  
B
O
Wiring  
IMPORTANT  
M20212  
Use an 18-gauge maximum wire for wiring the  
thermostats.  
Fig. 4. Wiring connections.  
KEEP WIRING IN  
SHADED AREA  
All wiring must comply with local electrical codes and  
ordinances. Disconnect the power supply to prevent electrical  
shock or equipment damage.  
G
The shape of the terminals permits insertion of straight or  
wraparound wiring connections; either method is acceptable.  
A letter code is located near each terminal for identification.  
See Fig. 4.  
C
R
NOTE: To ensure proper mounting of thermostat, restrict all  
wiring to the shaded area in the center of the  
terminals. See Fig. 5.  
W2  
The T8000C Thermostats are powered through the heating/  
cooling system controls and are adaptable to most 18 to 30  
Vac heating-cooling systems.  
W1  
Y
B
The T8001C and T8024D Thermostats are powered directly  
from the system transformer. The T8001C Thermostats are  
adaptable to most 18 to 30 Vac single-stage heating/cooling  
systems and the T8024D is adaptable to multistage systems.  
All T8001C and T8024D thermostats require a common wire  
connected to the system transformer to operate properly.  
O
WIRING ENTRANCE  
HOLE  
MOUNTING  
MOUNTING  
SCREW HOLE  
SCREW HOLE  
Fig. 8. T8000C wiring diagram in heat-cool  
system with two transformers.  
M18503  
Fig. 5. Restrict wiring to shaded area.  
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T8000C, T8001C AND T8024D PROGRAMMABLE THERMOSTATS  
T8000C THERMOSTAT  
G
T8000C THERMOSTAT  
G
Rc  
Rc  
3
R
1
R
W
W
B
Y
B
O
Y
2
O
ZONE 1  
HEAT  
RELAY  
O1  
COOL  
T8  
DAMPER  
2
G1  
1
T7  
FAN  
RELAY  
COMPRESSOR  
CONTACTOR  
HEAT  
L1  
HOT)  
DAMPER  
B1  
E1  
(
T6  
T5  
T4  
L2  
TRANSFORMER  
CHANGEOVER  
CONTROL  
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD  
PROTECTION AS REQUIRED.  
1
JUMPER R TO RC.  
M12563  
2
CAN BE USED FOR CHANGEOVER VALVE ON SINGLE-STAGE HEAT  
PUMP SYSTEMS.  
Fig. 8. T8000C heat-cool wiring diagram on a  
zone 1 MABS II Mastertrol control panel.  
3
JUMPER R TO Rc.  
M12561  
Fig. 6. T8000C heat-cool wiring diagram in single  
transformer system with gas heat/electric cooling.  
T8001 THERMOSTAT  
G
C
G
Rc  
R
R
W
2
4
2
B
Y
W
Y
O
B
2
O
HEAT  
RELAY  
COOL  
DAMPER  
2
1
FAN  
RELAY  
COMPRESSOR  
CONTACTOR  
HEAT  
DAMPER  
L1  
(HOT)  
3
3
FAN  
RELAY  
L2  
COOL  
DAMPER  
HEAT  
DAMPER  
TRANSFORMER  
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD  
PROTECTION AS REQUIRED.  
COMPRESSOR  
CONTACTOR  
HEAT  
RELAY  
1
1
L1  
2
CAN BE USED FOR CHANGEOVER VALVE ON SINGLE-STAGE HEAT  
L1  
HOT)  
(
HOT)  
PUMP SYSTEMS.  
(
M12566  
L2  
L2  
Fig. 9. T8001C heat-cool wiring diagram in single  
transformer system with gas heat/electric cooling.  
COOLING  
TRANSFORMER  
HEATING  
TRANSFORMER  
T8001 THERMOSTAT  
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD  
PROTECTION AS REQUIRED.  
G
C
2
3
REMOVE RC TO R JUMPER WHEN INSTALLED ON A TWO TRANSFORMER  
SYSTEM.  
R
CAN BE USED FOR CHANGEOVER VALVE ON SINGLE-STAGE HEAT  
PUMP SYSTEMS.  
W
B
Y
4
POWER TO R TERMINAL IS REQUIRED WHEN THE SYSTEM SWITCH IS IN  
THE OFF POSITION.  
O
M12562  
ZONE 1  
O1  
G1  
B1  
Fig. 7. T8000C wiring diagram in heat/cool  
system with two transformers.  
T8  
T7  
T6  
E1  
T5  
CHANGEOVER  
CONTROL  
T4  
M1  
M12567  
Fig. 10. T8001C heat-cool wiring diagram on a  
zone 1 MABS II Mastertrol control panel.  
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T8000C, T8001C AND T8024D PROGRAMMABLE THERMOSTATS  
DASHED LINES INDICATE TABS  
ON BACK OF THERMOSTAT  
T8024 THERMOSTAT  
G
C
W2  
R
Y2  
W1  
B
Y
Hold  
O
STAGE-  
Select  
TWO  
COOL-  
ING  
STAGE-  
ONE  
HEAT  
RELAY  
COOL  
DAMPER  
STAGE-  
TWO  
FAN  
Auto On  
1
HEAT  
RELAY  
FAN  
RELAY  
STAGE ONE  
COOLING  
HEAT  
DAMPER  
L1  
HOT)  
(
Cool Off Heat  
SYSTEM  
L2  
TRANSFORMER  
A
ENGAGE TABS AT TOP OF THERMOSTAT  
WITH SLOTS ON WALLPLATE.  
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD  
PROTECTION AS REQUIRED.  
M20214  
Fig. 11. T8024D multistage heat/cool wiring diagram.  
Setting Fan Operation (Fuel) Switch  
The fan operation (fuel) switch is preset at the factory in the F  
position. See Fig. 11. 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.  
PM  
Hold  
TUE  
Select  
FAN  
Au  
to  
O
n
SYSTEM  
Cool Off Heat  
E
F
FAN OPERATION (FUEL) SWITCH  
M12580  
B
PRESS LOWER EDGE OF  
CASE TO LATCH.  
M14674  
Fig. 12. Fan operation (fuel) switch.  
Fig. 13. Mounting thermostat to wallplate.  
Mounting Thermostat to Wallplate  
1
. Slide SYSTEM switch to the Off position.  
. Engage the tabs at the top of the thermostat and  
wallplate.  
1
. Enter Installer Setup.  
2
a. Use  or  keys to set  
the temper-ature  
SET  
3
. Swing down the thermostat and press the lower edge of  
setpoint to 52 °F (11°C).  
HT.  
the thermostat onto the wallplate to latch. See Fig. 12.  
M12582A  
b. Press the  and  keys  
simultaneously for more  
than two seconds to  
enter installer setup.  
When released a  
INSTALLER SETUP  
Setting °F/°C Indication and Heat Cycle Rate  
The following instructions provide the information necessary  
to change the heating cycle rate to match the heating  
equipment and to choose either Fahrenheit (°F) or Celsius  
software revision code  
is displayed.  
M12583A  
(
°C) display.  
c. Press the  key.  
Factory config-uration  
NOTE: All four steps must be completed to save changes to  
(
FC) is displayed (A  
the °F/°C indication and the heat cycle rate.  
typical example is  
shown, but information  
displayed varies by  
M12584A  
model. This information is for factory use only).  
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T8000C, T8001C AND T8024D PROGRAMMABLE THERMOSTATS  
4
. Setting 2nd Stage Heat Cycle Rate (see Table 1) for the  
Optional System Checkout  
cycle rate options and  
When in steps 1c and 1d only, pressing the  key can be  
used to turn heat or cool outputs on and off. Change the  
SYSTEM switch setting to test heat or cool outputs. No  
action takes place If the system switch is in the Off  
position.  
equipment).  
a. Press the  key to  
display the current  
heat cycle rate setting  
of 1, 3, 6, 9, or 12 cph.  
M12588A  
Examples: System setting at HEAT: If heat is on, pressing  
the key turns it off; if heat is off, pressing  
the key turns it on.  
NOTE: If the desired cycle rate is displayed, press the ▼  
key to exit the installer setup.  
b. To change the second  
cycle rate, press the  
System setting at COOL: If cool is on,  
pressing the key turns it off; if cool is off,  
pressing the key turns it on. The five minute  
minimum off time is bypassed.  
key until your  
choice of 1, 3, 4, 5, 6,  
, or 12 is displayed.  
9
M12589A  
NOTE: For T8024D, a second press turns  
on the 2nd stage.  
c. Press the  key to  
display cooling  
algorithm configu-  
ration default.  
CAUTION  
M14691  
Allow compressor to remain off for 5 minutes before  
restarting. Refer to manufacturer recommendations.  
d. Press the  key again to change algorithm to C1  
or C3.  
C1 = Standard algorithm.  
C3 = Agressive algorithm (can cause  
overshooting).  
NOTE: In Installer Setup only, each press of the ▼  
key momentarily displays 1. Each press of the  
key momentarily displays 2. When the keys  
are released, these one-digit codes are no  
longer displayed.  
e. Press the  key again.  
Current configuration  
(
CC) is displayed. A  
2
. Setting °C or °F.  
a. Press the  key again to  
display the current  
setting.  
typical example is  
shown, but CC varies  
by model. (This  
information is for factory use only.)  
M14692  
M12587A  
5
. Exit Installer Setup.  
a. Press the ▼  
key to save  
all changes  
and return to  
normal  
b. Press the  key to  
change the °C or °F  
indication.  
PM  
M12586A  
operation.  
3
. Setting number of heat/cool  
M12590A  
stages (T8024 only).  
a. Press  to display  
Table 1. Heating Cycle Rates  
System  
number of cooling stages.  
Cycles  
Per Hour  
M20215  
M20216  
M20217  
M20218  
b. Press  to change  
Steam, Gravity  
1
3
number of cooling stages.  
a
Hydronic Heat, Condensing Gas Furnaces  
Gas or Oil Forced Air  
Electric Heat  
6
9
c. Press  to display  
b
Special Applications  
12  
number of heat stages.  
a
b
High efficiency furnace (90+).  
Refer to the equipment manufacturer s Instructions.  
d. Press  to change  
number of heat stages.  
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T8000C, T8001C AND T8024D PROGRAMMABLE THERMOSTATS  
OPERATION  
Setting the Current Time and Day  
1
. To Set Current Time.  
a. Press Select twice.  
b. Press  or  to set  
current time. While setting  
the current time, the word  
SET is displayed.  
SET  
Setting FAN and SYSTEM Switches  
PM  
Fan and system settings are controlled manually by using the  
switches located at the bottom of the thermostat case. See  
Fig. 14.  
M12591A  
2
. To Set Day of Week.  
a. Press Select again.  
b. Press  or  to set  
current day.  
M12593A  
NOTE: To use the preprogrammed time and temperature  
(see Table 2), press Hold to exit Programming.  
Hold  
SLEEP  
Select  
Table 2. Preprogrammed Time and Temperature Settings.  
Period  
Time  
Heat Setpoint  
Cool  
Setpoint  
Wake  
Leave  
Return  
Sleep  
6:00 AM  
8:00 AM  
6:00 PM  
10:00PM  
70°F (21°C)  
62°F (17°C)  
70°F (21°C)  
62°F (17°C)  
78°F (26°C)  
85°F (29°C)  
78°F (26°C)  
82°F (28°C)  
FA  
Au  
N
to On  
SYSTEM  
Cool Off Heat  
M12547  
Setting the Weekday Program  
Slide the SYSTEM switch to the position, heating or cooling,  
you want to program. The flame (heating) or the snowflake  
Fig. 14. Digital Display and System Switches.  
(
cooling) will appear in the lower right corner of the display.  
FAN Switch  
Fan switch settings are:  
3
. WAKE  
On: The fan runs continuously. Use for improved air  
circulation and air quality.  
Auto: Normal setting for most homes. In cooling, the fan  
starts and stops with the cooling equipment. In heating,  
the fan is controlled directly by the heating equipment  
and may start a few minutes after the heating  
a. Press Select.  
Press or to set  
WAKE time.  
M12624A  
b. Press Select.  
equipment turns on (most systems). When the fan  
operation (fuel) switch is in the E position, the fan starts  
and stops with the heating equipment.  
Press or to set  
WAKE temperature.  
Slide the FAN switch in the lower left corner of the thermostat  
to select the desired fan setting.  
M12625B  
4
. LEAVE  
a. Press Select.  
SYSTEM Switch  
Press or to set  
LEAVE time.  
System switch settings control thermostat operation as follows:  
Cool: The thermostat controls the cooling system.  
Off: Both heating and cooling are off.  
M12626A  
Heat: The thermostat controls the heating system.  
b. Press Select.  
Press or to set  
Slide the SYSTEM switch in the lower right corner of the  
thermostat to select the desired system setting.  
LEAVE temperature.  
5
. RETURN  
PROGRAMMING  
a. Press Select.  
M12627A  
Press or to set  
RETURN time.  
The thermostat is flexible and can be programmed for  
different schedules for weekdays and weekends.  
Four time periods are available during weekdays and  
weekends W AKE, LEAVE, RETURN, and SLEEP.  
M12628A  
b. Press Select.  
Press or to set  
RETURN  
temperature.  
IMPORTANT  
Always press the keys with your fingertip or similar  
blunt tool. Sharp instruments like pens and pencil  
points can damage the keyboard.  
M12629A  
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T8000C, T8001C AND T8024D PROGRAMMABLE THERMOSTATS  
6
. SLEEP  
11. End Programming.  
Press Select. End is  
a. Press Select.  
Press or to set  
SLEEP time.  
displayed. Programming is  
complete. The thermostat  
will revert to displaying the  
M12630A  
M12511A  
current day, time and  
b. Press Select.  
temperature in five seconds.  
Press or to set  
SLEEP temperature.  
NOTE: To reset the thermostat to the preprogrammed time  
and temperature settings (see Table 1):  
1
.
Press and hold the Hold and Select keys  
simultaneously. The display will begin counting  
down from 36 to zero.  
M12631B  
2
3
.
.
The thermostat display will go blank, then will  
display the current time and temperature.  
Release keys, the program has reverted to the  
preprogrammed settings.  
Setting the Weekend Program  
7
8
9
. WAKE  
a. Press Select.  
Press or to set  
WAKE time.  
Setting Temperature Hold  
Slide the SYSTEM switch to the heat or cool position.  
M12632A  
b. Press Select.  
Temporary Temperature Hold  
1. Press  or  key to set a  
temporary temperature  
Press or to set  
WAKE temperature.  
TEMPORARY  
PM  
setting.  
M12633B  
WED  
M12640A  
. LEAVE  
a. Press Select.  
NOTE: The temporary temperature setting is displayed  
for approximately 3 seconds. The setting  
remains in effect until the next program period.  
To cancel, press Hold twice.  
Press or to set  
LEAVE time.  
M12634A  
b. Press Select.  
Indefinite Temperature Hold  
Press or to set  
LEAVE temperature.  
The Hold key allows you to indefinitely hold a temperature.  
When Hold is active, the letters Hld are displayed continuously.  
Hold can be canceled by pressing the Hold key again.  
M12635A  
M12636A  
M12637A  
1
. Press Hold  
. RETRUN  
a. Press Select.  
2
. Press  or  key to set  
indefinite temperature  
setting.  
Press or to set  
RETRUN time.  
M12641A  
b. Press Select.  
NOTE: Indefinite hold remains in effect until the Hold  
key is pressed to cancel it.  
Press or to set  
RETRUN  
temperature.  
CHECKOUT  
1
0. SLEEP  
a. Press Select.  
Heating  
Press or to set  
SLEEP time.  
1
. Slide the SYSTEM switch to Heat and the FAN switch  
to Auto.  
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 the use of  
a time delay relay or through a limit control. When the  
fan operation (fuel) switch is in the E position, the fan  
starts immediately.  
M12638A  
b. Press Select.  
Press or to set  
SLEEP temperature.  
M12639B  
3
. Press the  key to lower the temperature setting below  
the room temperature. Heating equipment should stop.  
68-0195–2  
9
href="
T8000C, T8001C AND T8024D PROGRAMMABLE THERMOSTATS  
thermostat, the fan starts and stops with the heating  
equipment. In cooling, the fan starts and stops with the  
cooling equipment.  
Cooling  
CAUTION  
Make certain all equipment responds properly to the  
thermostat.  
Damage To Compressor Possible.  
Operating at too low of an outdoor temperature  
may cause compressor damage.  
Power Stealing  
Do not operate cooling if outdoor temperature is below  
50°F (10°C).  
Unlike hard wired thermostats which are powered directly  
from the system transformer, the T8000C Thermostat steals  
power through the heating and cooling system controls and  
can be used in applications where existing wiring does not  
permit using hard wired thermostats. See Fig. 15 and 16.  
Allow compressor to remain off for five minutes before  
restarting. Refer to manufacturer’s recommendations.  
1. Slide the SYSTEM switch to Cool and the FAN switch  
to Auto.  
Previous Honeywell power stealing thermostats required 80 mA  
of load current when the heating and cooling was on. The  
T8000C Thermostat requires only 2.5 mA of load current (1/32  
of previous models) when the heating or cooling is on. When  
the heating or cooling is off, the thermostat operates at 0.1 mA  
2
. Press the  key to lower the temperature setting  
several degrees below the room temperature; the  
cooling equipment should start. The fan starts and  
stops with the cooling equipment.  
3
. Press the  key to raise the temperature setting above  
(
1/100 of previous models). Other Honeywell power stealing  
the room temperature. Cooling system should shut down.  
thermostats are available, but they have different powering  
requirements than the T8000C. This low current draw makes  
the T8000C applicable to most 24V heating and cooling  
systems.  
NOTE: To prevent damage to the compressor the T8000C/  
T8001C have a built-in off-timer. See page 11.  
The thermostats only operate when mounted on the wallplate  
with 24V applied. Batteries are not required for operation  
because temperature setpoints and configuration settings are  
retained permanently in nonvolatile memory.  
Fan  
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 may  
start a few minutes after the heating equipment turns  
on (most systems). When using an electric heat  
The T8000C is packaged with a 7870 ohm resistor to insure  
compatibility with TACO zone valves. See Fig. 17.  
THERMOSTAT  
WALLPLATE  
SYSTEM COMPONENTS  
L1  
(HOT)  
POWER  
R
SUPPLY  
SYSTEM  
2
L2  
SWITCH  
1
LOGIC/  
W
CONTROL  
CIRCUIT  
HEAT  
HEAT RELAY  
B
OFF  
HEAT CHANGEOVER RELAY  
COOL CHANGEOVER RELAY  
COOL  
MOSFET  
STAGE 1  
HEAT OR  
COOL  
O
L1  
HOT)  
(
RC  
COMPRESSOR  
RELAY  
L2  
MOSFET  
HEAT 2  
1
Y
FAN  
SWITCH  
FAN RELAY  
FUEL  
SWITCH  
E
F
ON  
G
AUTO  
1
2
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.  
FACTORY INSTALLED JUMPER.  
M11730  
Fig. 15. T8000C power stealing internal schematic.  
68-0195–2  
10  
href="
T8000C, T8001C AND T8024D PROGRAMMABLE THERMOSTATS  
THERMOSTAT  
WALLPLATE  
SYSTEM COMPONENTS  
L1  
(
HOT)  
POWER  
SUPPLY  
R
SYSTEM  
SWITCH  
L2  
1
LOGIC/  
C
CONTROL  
CIRCUIT  
HEAT RELAY  
W
HEAT  
OFF  
HEAT CHANGEOVER  
RELAY  
COOL  
STAGE 1  
B
HEAT OR  
COOL  
COOL CHANGEOVER  
RELAY  
K1  
O
COMPRESSOR  
RELAY  
Y
FAN  
SWITCH  
FAN RELAY  
M11731  
ON  
AUTO  
E
F
G
FUEL  
SWITCH  
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.  
Fig. 16. T8001C hardwired internal schematic.  
THERMOSTAT  
Sequence of Operations  
The Fan, Heat and Cool outputs are relay or mosfet  
controlled. A loss of ac power or a change in the SYSTEM  
switch setting can cause the outputs to turn off. The truth  
table shows the sequence of operations for the FAN settings  
and SYSTEM modes. See Table 3, Sequence of Operations.  
R
W
TACO ZONE VALVE  
Minimum Off-Timer  
1
RESISTOR  
L1  
HOT)  
A minimum off-timer in the T8000C and T8001D assures that  
the 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 and when the SYSTEM switch  
position 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. The minimum off-timer operates in cooling on the  
1
2
3
(
L2  
T8000C and T8001C. A flashing snowflake  
minimum off-timing is in effect.  
indicates the  
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND  
OVERLOAD PROTECTION AS REQUIRED.  
M11677  
Fig. 17. Connect resistor to the TACO zone  
valve terminal numbers 1 and 2.  
Table 3. Sequence of Operations.  
FAN Switch Settings  
SYSTEM Switch Settings  
Call for Action  
None  
Energize Terminals  
Display Icons  
None  
Auto  
On  
Off  
Any  
Cool  
None  
G
Any  
None  
Auto  
Cooling  
G,Y  
a
Auto  
Heat  
Heating  
W,G  
a
When the Fuel switch is in the E position.  
68-0195–2  
1
1
href="
T8000C, T8001C AND T8024D PROGRAMMABLE THERMOSTATS  
TROUBLESHOOTING T8000/T8001  
SYMPTOM  
POSSIBLE CAUSE  
ACTION  
HEATING OR COOLING EQUIPMENT  
WON'T OPERATE.  
NO AC POWER TO THERMOSTAT.  
CHECK THAT C TERMINAL IS CONNECTED TO  
THE SYSTEM TRANSFORMER (T8001 ONLY).  
CHECK POWER TO HEATING AND COOLING EQUIPMENT  
ON/OFF SWITCH  
FUSE OR CIRCUIT BREAKER  
LOOSE 24V CONNECTION  
AT THERMOSTAT  
AT FURNACE/AIR CONDITIONER  
INCORRECT WIRING (SEE WIRING DIAGRAM)  
THERMOSTAT INOPERATIVE.  
CONDUCT SELF-TEST; SEE CHECKOUT SECTION.  
PRESENT SETTING TOO LOW/HIGH.  
ADJUST TEMPERATURE BY PRESSING  
RESET THERMOSTAT SYSTEM SWITCH.  
OR  
KEYS.  
SYSTEM SWITCH ON THERMOSTAT  
IN WRONG POSITION.  
MINIMUM/OFF-TIMES IN THERMOSTAT  
IN OPERATION ON COOLING.  
WAIT FIVE MINUTES OR FOLLOW STEPS IN  
CHECKOUT SECTION.  
INCORRECT WIRING.  
CHECK WIRING DIAGRAM.  
HEATING OR COOLING EQUIPMENT  
INOPERATIVE.  
CONSULT EQUIPMENT MANUFACTURER INSTRUCTIONS.  
IS FLASHING AND COOLING WILL  
NOT OPERATE  
MINIMUM/OFF-TIMES IN THERMOSTAT  
IN OPERATION ON COOLING.  
WAIT FIVE MINUTES OR FOLLOW STEPS IN  
CHECKOUT SECTION.  
PARTIAL DISPLAY  
STILL IN INSTALLER SETUP MODE.  
INOPERATIVE THERMOSTAT.  
NO POWER TO THERMOSTAT.  
SEE THE INSTALLER SETUP SECTION FOR INSTRUCTIONS.  
REPLACE THERMOSTAT.  
NO DISPLAY  
CHECK THAT C TERMINAL IS CONNECTED TO  
THE SYSTEM TRANSFORMER (T8001 ONLY).  
CHECK POWER TO HEATING AND COOLING EQUIPMENT  
ON/OFF SWITCH  
FUSE OR CIRCUIT BREAKER  
LOOSE 24V CONNECTION  
AT THERMOSTAT  
AT FURNACE/AIR CONDITIONER  
INCORRECT WIRING (SEE WIRING DIAGRAM)  
THERMOSTAT MOUNTED  
INCORRECTLY ON WALLPLATE.  
SEE INSTALLATION INSTRUCTIONS FOR  
CORRECT MOUNTING.  
TEMPERATURE DISPLAY IS  
INCORRECT.  
THERMOSTAT IS CONFIGURED FOR  
°F OR °C DISPLAY.  
RECONFIGURE THE DISPLAY. SEE INSTALLER SETUP  
SECTION.  
TEMPERATURE SETTINGS WILL NOT  
CHANGE. (EX: CANNOT SET THE  
HEATING HIGHER OR THE  
COOLING LOWER).  
THE UPPER OR LOWER  
TEMPERATURE LIMITS WERE  
REACHED.  
CHECK THE TEMPERATURE SETPOINTS; TEMPERATURE  
SETTING RANGE IS 40°F (4°C) TO 99°F (37°C).  
FAN DOES NOT OPERATE PROPERLY  
IN HEAT OR COOL MODES.  
INCORRECT WIRING.  
CHECK WIRING DIAGRAM.  
HEATING OR COOLING EQUIPMENT  
INOPERATIVE.  
CONSULT EQUIPMENT MANUFACTURER INSTRUCTIONS.  
M11733  
Home and Building Control  
Honeywell  
Home and Building Control  
Honeywell Limited-Honeywell Limitée  
35 Dynamic Drive  
1
985 Douglas Drive North  
Golden Valley, MN 55422  
Scarborough, Ontario  
M1V 4Z9  
Printed in U.S.A. on recycled  
paper containing at least 10%  
6 8-01952 G.H. Rev. 10-01  
post-  
consumer paper fibers.  
www.honeywell.com/yourhome  

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