Honeywell Tradeline T8024D User manual

® U.S. Registered Trademark
Copyright © 2000 Honeywell • • All Rights Reserved
INSTALLATION INSTRUCTIONS
69- 1387- 1
T8024D Programmable
Multistage Thermostat
The T8024 Programmable Multistage Thermostat
provides electronic control of single-zone, multistage
heating and cooling systems. First stage and second
stage cooling cycle rates are fixed at 3 cph. Heating
cycle rate is selectable. Temperature indication can be
set for °F or °C.
The T8024 Thermostat is powered from the system
transformer. Batteries are not required because setpoints
are held permanently by non-volatile memory.
T8024 includes a thermostat, wallplate (for wiring and
mounting thermostat) and owner’s guide.
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.
Contact your local waste management authority
for instructions regarding recycling and the
proper disposal of an old control containing
mercury in a sealed tube.
If you have questions, call Honeywell Inc. at
1-800-468-1502.
INSTALLATION
When Installing this Product…
1. Read these instructions carefully. Failure to follow
them could damage the product or cause a hazard-
ous 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
Electrical Shock or Equipment Damage
Hazard.
Can shock individuals or short equipment
circuitry.
Disconnect power supply before installation.
Location
Install the thermostat about 5 ft (1.5m) 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 the sun or appliances.
— concealed pipes and chimneys.
— unheated (uncooled) areas such as an outside wall
behind the thermostat.
This thermostat is a precision instrument and was
carefully adjusted at the factory. Handle it carefully.
Mounting Wallplate to Wall
IMPORTANT
Level only for appearance. The thermostat func-
tions normally even when not level.
Mount wallplate, T8024 and the screws provided (see
Fig. 2) as follows:
1. Place the wallplate at the desired location on the
wall.
2. Pull the thermostat wire through the entrance hole
on the decorator cover plate, then through the wall-
plate entrance hole.
3. Select the two mounting holes that best fit the
application.
4. Fasten the wallplate to the wall using the anchors
and screws provided.
5. After wiring the wallplate, plug the hole to prevent
drafts from affecting the thermostat; see Wiring
section.

T8024D PROGRAMMABLE MULTISTAGE THERMOSTAT
69-1387-1 2
Fig. 1. Typical location of thermostat.
Fig. 2. Mounting wallplate to wall.
Wiring
IMPORTANT
Use an 18-gauge maximum wire for wiring the
T8024 Thermostat.
All wiring must comply with local electrical codes and
ordinances. Disconnect the power supply to prevent
electrical shock or equipment damage.
NOTE: To ensure proper mounting of thermostat,
restrict all wiring to the shaded area. See Fig. 3.
The shape of the terminals permits insertion of straight or
wraparound wiring connections; either method is
acceptable. See Fig. 4.
The T8024 Thermostat is powered through the system
transformer and is adaptable to most 24 Vac multistage
heating-cooling systems. Refer to Fig. 5 for typical wiring
hookups.
Fig. 3. Restrict wiring to shaded area.
5 FEET
[1.5 METERS]
YES
NO
NO
NO
M11338
M12202A
WALL WALL
ANCHORS (2)
WALLPLATE
WHEN USING WALL ANCHORS, DRILL 3/16 INCH
HOLES FOR DRYWALL, 7/32 INCH HOLES FOR
PLASTER OR WOOD.
MOUNTING
SCREWS (2)
1
1
KEEP WIRING IN
SHADED AREA
MOUNTING
SCREW HOLE
MOUNTING
SCREW HOLE
WIRING ENTRANCE
HOLE
M20211
G
C
R
Y
W1 Y2
W2
B
O

T8024D PROGRAMMABLE MULTISTAGE THERMOSTAT
3 69-1387-1
Fig. 4. Wiring connections.
Fig. 5. Typical hookup of T8024 in two-stage heat and
two-stage cool system with manual changeover.
Mounting Thermostat to Wallplate
1. Engage the tabs at the top of the thermostat and
wallplate.
2. Swing down the thermostat and press the lower
edge of the thermostat onto the wallplate to latch.
See Fig. 6.
OPERATION
Setting FAN and SYSTEM Switches
Fan and system settings are controlled manually by
using the switches located at the bottom of the
thermostat case. See Fig. 7.
Fig. 6. Mounting thermostat wallplate.
FAN Switch
Fan switch settings are:
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 equipment turns on (on most systems).
When using an electric heat thermostat, the fan
starts and stops with the heating equipment.
Slide the FAN switch in the bottom left corner of the
thermostat to select the desired fan setting.
SYSTEM Switch
System switch settings control thermostat operation as
follows:
Cool: The thermostat controls the cooling system.
Off: Both heating and cooling are off.
Heat: The thermostat controls the heating system.
TERMINAL
SCREW
M20212
G
R
C
Y
W1 B
O
FOR STRAIGHT
INSERTION STRIP
5/16 IN. (8 MM)
FOR WRAPAROUND
STRIP 7/16 IN. (11 MM)
Y2
W2
L1
(HOT)
L2
M20214
FAN
RELAY
STAGE-
ONE
HEAT
RELAY
STAGE ONE
COOLING
TRANSFORMER
HEAT
DAMPER
COOL
DAMPER
1POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD
PROTECTION AS REQUIRED.
1
Y
G
C
W1
R
B
O
Y2
T8024 THERMOSTAT
W2
STAGE-
TWO
COOL-
ING
STAGE-
TWO
HEAT
RELAY
M14674
DASHED LINES INDICATE TABS
ON BACK OF THERMOSTAT
ENGAGE TABS AT TOP OF THERMOSTAT
WITH SLOTS ON WALLPLATE.
PRESS LOWER EDGE OF
CASE TO LATCH.
A
B
SYSTEM
Cool Off Heat
Auto On
FAN
Hold
Select
SYSTEM
Cool Off Heat
Auto On
FAN
Hold
Select
TUE
PM

T8024D PROGRAMMABLE MULTISTAGE THERMOSTAT
69-1387-1 4
Slide the SYSTEM switch in the bottom right corner of
the thermostat to select the desired system setting.
Fig. 7. Digital display and system
switches (FAN and SYSTEM).
INSTALLER SETUP
Setting °F/°C Indication and Heat
Cycle Rate
The following instructions provide information to change
the heating cycle rate to match the heating equipment
and to choose either Fahrenheit (°F) or Celsius (°C).
NOTE: All four steps must be completed to save
changes to °F/°C indication and heat cycle rate.
1. Enter Installer Setup.
a. Use ▲or ▼key to set the temperature setpoint
to 52°F (11°C)
.
b. Press the ▲and ▼keys simultaneously for
more than two seconds to enter installer setup.
c. When released, a software revision code is dis-
played.
d. Press the ▲key. Factory configuration (FC) is
displayed A typical example is shown, but infor-
mation displayed varies by model. This infor-
mation is for factory use only.
OPTIONAL SYSTEM CHECKOUT
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.
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.
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.
CAUTION
Equipment Damage Hazard.
Can short equipment.
Allow compressor to remain off for 5 minutes
before restarting. Refer to manufacturer
recommendations.
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.
2. Setting °C or °F.
a. Press the ▲key again to display the current
setting.
b. Press the ▼ key to change the °C or °F
indication.
3. Setting Number of Cool/Heat Stages (T8024 only).
a. Press ▲to display number of cooling stages.
SYSTEM
Cool Off Heat
Auto On
FAN
T8024
M18504
Hold
Select
TUE
PM
M12582A
SET
HT.
M12583A
SET
HT.
M12584A
M12587A
M12586A
M20216

T8024D PROGRAMMABLE MULTISTAGE THERMOSTAT
5 69-1387-1
b. Press ▼to change number of cooling stages.
c. Press ▲to display number of heat stages.
d. Press ▼ to change number of heat stages.
4. Setting Heat Cycle Rate (see Table 1) for the cycle
rate options and equipment).
a. Press the ▲key to display the current heat
cycle rate setting of 1, 3, 4, 5, 6, 9, or 12 cph.
NOTE: If thermostat is set up to operate two stages of
heat, both stages operate at the selected cycle
rate.
b. If the desired cycle rate is displayed, press the
▲key to exit the Installer Setup.
c. To change the heat cycle rate, press the ▼ key
until your choice of 1, 3, 4, 5, 6, 9, or 12 is
displayed.
d. Press the ▲key to display algorithm configura-
tion default.
e. Press the ▲key again to change algorithm to
C1 or C3.
C1 = Standard algorithm.
C3 = Aggressive algorithm (can cause over-
shooting).
f. Press the ▲ key again. Current configuration
(CC) is displayed. A typical example is shown,
but CC varies by model. (This information is for
factory use only.)
5. Exit Installer Setup.
a. Press the ▲ key to save all changes and return
to normal operation.
Table 1. Heating Cycle Rates for Stage-Two Heating.
aHigh efficiency furnace.
bRefer to equipment manufacturer’s instructions.
PROGRAMMING
The thermostat is flexible and can be programmed for
different schedules for weekdays and weekends.
Four time periods are available during weekdays and
weekends —WAKE, LEAVE, RETURN, and SLEEP.
IMPORTANT
Always press the keys with your fingertip or sim-
ilar blunt tool. Sharp instruments like pens and
pencil points can damage the keyboard.
Setting the Current Time and Day
1. To set current time.
a. Press Select twice.
b. Press ▲or ▼to set current time.
NOTE: While setting the current time, the word SET is
displayed.
2. To set day of week.
a. Press Select again.
b. Press ▲or ▼to set current day.
To use the preprogrammed time and temperature (see
Table 2), press Hold to exit the programming mode. For
instructions on programming the thermostat, refer to the
Owner’s Guide.
M20215
M20217
M20218
M12589A
M12588A
M14691
M14692
System Cycles Per Hour
Steam, gravity 1
Hydronic heat, condensing gas
furnacea
3
Special applicationsb4,5
Gas or oil forced air (default) 6
Electric heat 9
Special applicationsb4, 5, 12
M12590A
PM
M12591A
SET
PM
M18534
SET

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Table 2. Preprogrammed Time and
Temperature Settings.
CHECKOUT
Heating
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 tempera-
ture. After approximately ten seconds, 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
using an electric heat thermostat, the fan starts
immediately.
3. Press the ▼key to lower the temperature setting
below the room temperature. Heating equipment
should stop.
Cooling
CAUTION
Low Temperature Hazard.
Operating at too low of an outdoor
temperature may cause compressor damage.
Do not operate cooling if outdoor temperature is
below 50°F (10°C). Refer to manufacturer’s
recommendations.
• Allow compressor to remain off for five minutes
before restarting.
1. Slide the SYSTEM switch to Cool and the FAN
switch to Auto.
2. Press the ▼ key to lower the temperature setting
several degrees below the room temperature. After
approximately five minutes, the cooling equipment
should start. The fan starts and stops with the cool-
ing equipment.
3. Press the ▲key to raise the temperature setting
above the room temperature. Cooling system
should shut down.
NOTE: To bypass the 5 minute delay, see the Optional
System Checkout section.
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 equip-
ment turns on (on most systems). When using an
electric heat thermostat, 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.
Period Time Heat Setpoint Cool Setpoint
WAKE 6:00 AM 70°F (21°C) 78°F (26°C)
LEAVE 8:00 AM 62°F (17°C) 85°F (29°C)
RETURN 6:00 PM 70°F (21°C) 78°F (26°C)
SLEEP 10:00 PM 62°F (17°C) 85°F (29°C)