Honeywell CT2095 User manual

Place Bar Code Here
69- 1385
OWNER’S GUIDE
Honeywell/20
Programmable Thermostat
Weekday/Weekend (5-day/2-day)
Programmable Heat and/or Cool
Low Voltage (20 to 30 Vac)
Thermostat and Mounting Plate
Model CT2095

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Welcome to the world of comfort and energy
savings with your new Honeywell
Programmable Thermostat.
Your new thermostat will automatically control
the temperature in your home, keeping you
comfortable while saving energy when
programmed according to the instructions in
this manual.
Direct any questions concerning the application
of this thermostat to Honeywell Consumer
Services at 1-800-468-1502, Monday-Friday,
7:00 a.m.-5:30 p.m., Central time.
MERCURY NOTICE
If this thermostat is replacing a thermo-
stat that contains mercury in a sealed
tube, do not place your old thermostat in
the trash. Dispose of properly.
Contact your local waste management
authority for instructions regarding recy-
cling and the proper disposal of your old
thermostat. If you have questions, call
Honeywell Customer Response Center
at 1-800-
468-1502.
Typical location of
a mercury switch
in a thermostat.
M3701
MERCURY
SWITCH

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Contents
Step 1. Prepare for Installation ..................................................................................................... 4
Step 2. Remove Old Thermostat ..................................................................................................6
Step 3. Install Batteries ................................................................................................................ 8
Step 4. Program Thermostat ........................................................................................................ 11
Step 5. Adjust Fan Operation Switch, As Required ...................................................................... 19
Step 6. Adjust System On-Time, °F/°C, As Required ................................................................... 19
Step 7. Mount Thermostat Mounting Plate ................................................................................... 21
Step 8. Wire Thermostat Terminals ..............................................................................................23
Step 9. Mount Thermostat ............................................................................................................ 27
Step 10. Check Thermostat Operation After Programming and Installing ................................... 28
Step 11. Set Fan and System Switches ....................................................................................... 30
Troubleshooting Guide ................................................................................................................. 31
Limited One-Year Warranty .......................................................................................................... 35

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Step 1. Prepare for Installation
❑Check Table 1 to make sure this thermostat is compatible with your system. If not, return it to the
retailer. For more information, call Honeywell Consumer Services, 1-800-468-1502, Monday -
Friday, 7 am to 5:30 pm, Central time.
Not compatible with any 120/240 volt circuit.
aCompatible with Honeywell 2-wire zone valves. Isolating relay required for 3-wire thermostats for zone valves.
Not compatible with 2-wire White-Rodgers no. 1361 valves.
bCompatible with hot water baseboard systems. Does not work efficiently on steam or gravity systems.
Table 1. Compatibility Information.
System Type Compatible with CT2095
Gas—Standing Pilot Yes
Gas—Electronic Ignition Yes
Gas-Fired Boilers Yesa,b
Gas—Millivolt No
Oil-Fired Boilers Yesa,b
Oil-Fired Furnace Yes
Electric Furnace Yes
Electric Air Conditioning Yes
Baseboard Electric (120/240 Line Volt) No
Heat Pumps/Multistage Equipment No

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❑Acquire tools and items as needed (see illustration). Also purchase two AA alkaline batteries; we
recommend Energizer® batteries.
M13544
CROSS-RECESSED
SCREWDRIVER
HAND OR
POWER DRILL
WITH 3/16 INCH
DRILL BIT, IF NEEDED
TO DRILL HOLES
IN WALL
WIRE CUTTER/STRIPPER OR SHARP
KNIFE, IF NEEDED TO STRIP WIRES
LEVEL, IF NEEDED TO LEVEL
THERMOSTAT FOR APPEARANCE

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Step 2. Remove Old Thermostat
❑Test to be sure your heating and cooling
systems are working properly. If either does
not work, contact your local heating/air
conditioning dealer. To avoid compressor
damage, do not operate the cooling system
when outdoor temperature is below 50°F
(10°C).
❑Turn off power to the system at the furnace,
or at the fuse/circuit breaker panel.
❑Carefully unpack your new thermostat and
mounting plate, saving package of screws,
instructions and receipt.
❑Remove cover from old thermostat. If it does
not snap off when pulled firmly from the
bottom, check for a screw used to lock on
the cover.
❑Loosen screws holding thermostat to
subbase, wallplate or wall, and lift away.
❑Disconnect wires from old thermostat or
subbase. As you disconnect each wire,
attach one of the enclosed labels to each old
terminal designation. If there are only two
wires, they do not need labeling. If there is
an extra wire that is not connected to your
old thermostat, you also do not connect it to
your new thermostat. Keep the wires from
falling back into the wall by wrapping them
around a pencil as shown.
WIRES THROUGH
WALL OPENING
M5136

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Replacing a Clock Thermostat that has
C or C1 Clock Terminals?
If you are replacing a Honeywell Chronotherm®
Thermostat, you may find one or two wires that
go to the C or C1 clock terminals on the
Chronotherm®Thermostat wiring wallplate. Do
not allow them to touch, or you can damage
your transformer. Disconnect the wires and
wrap them separately, using electrical tape. Do
not wrap them together. Place the wires where
they do not interfere with the operation of the
new thermostat. Recordthe colors andterminal
designation labels of the remaining wires.
Six or more wires?
If there are six or more wires (excluding clock
wires attached to terminals), you probably have
a variation of a heat pump or multistage
system. This thermostat is not compatible with
those systems so return the product to the
retailer. If you want information about the
programmable thermostats that work with your
system, call Honeywell Consumer Services at
1-800-468-1502.
Three thermostat wires?
If you have three wires for heating only and can
operate the fan using the fan On switch, this
thermostat works with your system. However,
some hot water (zoned) heating systems have
three thermostat wires. The thermostat does
not work without installing an isolating relay on
these systems. For details, call Honeywell
Consumer Services at 1-800-468-1502.

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Step 3. Install Batteries
IMPORTANT
Batteries must be installed for the pro-
gramming and operation of the ther-
mostat and heating/cooling system.
❑Purchase two AA alkaline batteries; non-
alkaline batteries do not last as long, and
can leak, causing damage to the thermostat
or the wall surface. We recommend
Energizer®batteries.
❑Open the top cover of thermostat to access
control panel and battery compartment.
❑Make sure the thermostat is set to the Off
position.
❑Use a coin to remove the battery cover.
M12492
REMOVING
BATTERY
DOOR
BATTERY
DOOR COVER

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❑Install the fresh batteries as shown, making
sure positive and negative terminals are
oriented correctly.
❑Replace the battery cover.
As the batteries run low, a bAt Lo indicator
flashes for one to two months before the
batteries run out completely. Replace the
batteries as soon as possible after the indicator
starts flashing. If you do not replace the
batteries sometime during the flashing bAt Lo,
the indicator eventually stops flashing. bAt Lo
then stays on without flashing, indicating the
thermostat and heating/cooling system have
stopped working and the batteries are almost
completely dead.
After the batteries are completely dead, the
bAtLo indication disappears, leaving a
completely blank display.
INSTALL TWO AA ALKALINE
BATTERIES AS SHOWN
M1713

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Press down on the left ends of batteries to
remove them. If you insert the new batteries
within 20 to 30 seconds of removing the old
ones, you do not need to reprogram the
thermostat. However, if the display is blank, the
batteries are dead or incorrectly installed and
you must reprogram. See Step 4.
IMPORTANT
Although the thermostat has a low bat-
tery indicator, replace the batteries
once a year to prevent the thermostat
and heating/cooling system from shut-
ting down due to lack of battery power.
As a precaution, when leaving home
for longer than a month, change bat-
teries before you leave to prevent the
system from shutting down due to lack
of battery power.

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Step 4. Program Thermostat
After the batteries are installed, the thermostat
can be easily programmed in your hand before
it is installed on the wall.
If you prefer to program the thermostat after it is
installed on the wall, go to Step 7 and return
later to this programming section.
The Personal Programming Chart, Tables 2 and
3, may be helpful for planning your program
schedule of time and temperature settings for
various times of the day.
Four time periods are available during
weekdays —WAKE, LEAVE, RETURN, and
SLEEP; view these periods individually on the
display as you press the Weekday key.
•WAKE is the time period youwant the house
at a comfortable temperature when you get
up and while you get ready for work or
school. (This is a higher temperature during
heating season and a lower temperature dur-
ing cooling season.)
•LEAVE is the time period you can set for an
energy-saving temperature while you are
away at work or school. (This is a lower tem-
perature during heating season and a higher
temperature during cooling season.)
•RETURN is the time period you want the
houseat a comfortable temperature for activ-
ities before bedtime. (This is a higher tem-
perature during heating season and a lower
temperature during cooling season.)
•SLEEP is the time period you can set for an
energy-saving temperature while you are
sleeping. (This is a lower temperature during
the heating season and a higher tem-
perature during the cooling season.)

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Set one schedule for weekdays and another for
weekends because your requirements are
usually different for each. Also, during week-
ends, only the WAKE and SLEEP time periods
are available.
Fill in the times and temperatures you desire for
weekdays and weekends. If you decide not to
program the thermostat, it automatically con-
trols heating at 68°F (20°C), and cooling at 78°F
(26°C), 24 hours a day. Also, you donot need to
enter a time and temperature program for all
periods if your schedule does not require it. For
example, a house that is occupied during week-
days would require programs only for WAKE
and SLEEP.
If no program is entered for the weekends, the
thermostat operates on the weekday SLEEP
program all weekend.
Before programming, remove the clear plastic
overlay covering the display.
When pressing the keys, use the ball of your
finger or asoft pencil eraser. Using sharp finger-
nails or pencil points can damage the keypad.
If you make an error at any time during program-
ming, just press the Run Program key, and
continue again at the previous step in your
sequence.

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aThe temperatures cannot be set any higher than 88°F (31°C) or any lower than 45°F (7°C).
bIf you decide not to enter weekend programs, the thermostat operates on the weekday SLEEP pro-
gram all weekend.
Table 2. Personal Programming Chart for Heating.
Days of Week Heating Program Start Time Heating Temperaturea
Weekdays
WAKE
LEAVE
RETURN
SLEEP
Weekendsb
WAKE
SLEEP

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.
aThe temperatures cannot be set any higher than 88°F (31°C) or any lower than 45°F (7°C).
bIf you decide not to enter weekend programs, the thermostat operates on the weekday SLEEP pro-
gram all weekend.
Table 3. Personal Programming Chart for Cooling.
Days of Week Cooling Program Start Time Cooling Temperaturea
Weekdays
WAKE
LEAVE
RETURN
SLEEP
Weekendsb
WAKE
SLEEP

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NOTE: Batteries are required for operation and programming. When inserting batteries, set the
System switch to Off. Remove the battery door (on the thermostat left side) using a coin at
the bottom. Follow instructions in Step 3. Also see the label inside the battery cover for
abbreviated programming procedures for your thermostat.
Set Current Time/Day
To set time, press and release once, press until current shows. To set day, press and
release again, press until current day shows; then press .
Heating Program
With System switch at Heat, press and release once. WAKE, MON FRI (Monday-Friday), and
SET appear on display.
Use toprogramWAKEtimeand toprogramWAKEtemperatureforMONFRI(Monday-Friday).
Repeat sequence for LEAVE, RETURN, SLEEP.
Clock/Day
Time
Clock/Day Time Run Program
Weekday
Time TEMP

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Press untilSATSUN(Saturday-Sunday),WAKEandSETappearondisplay.Use toprogram
WAKE time and to program WAKE temperature for SAT SUN (Saturday-Sunday).
Repeat sequence for SLEEP. Press and release to start the program.
Cooling Program
With System switch at Cool, follow the same instructions as for the Heating Program.
After programming, adjust the Fan and System switches, as desired. Press and release to
start the program.
Weekend
Time
TEMP
Run Program
Run Program

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Operating Your Thermostat
System switch must be set to Heat or Cool to perform the following:
Temporarily Change Temperature for current period only — Press ; temporaryindicator shows
on display and cancels itself at the next scheduled change; to cancel sooner, press .
Hold a Temperature Indefinitely (such as when on vacation) —Press and ; HOLD
appears on display; to cancel, press .
Check Current Temperature Setting — Press .
Check Programs — Press , repeatedly to see each time and temperature; then press
.
TEMP
Run Program
Hold Temp TEMP
Run Program
Present Set
Weekday Weekend
Run Program

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Cancel Program — Press , until program to cancel shows; then press .
Check Usage — Press to see length of time heat or air conditioning has run today since
midnight; press again for yesterday’s usage, press again for cumulative; press to clear
cumulative reading, if desired; then press .
Permanently Change a Program — Repeat Heating Program or Cooling Program steps, as
applicable.
Return to Normal Program or Start Program —Press .
Weekday Weekend Clear
Usage
Clear
Run Program
Run Program

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Step 5. Adjust Fan Operation
Switch, As Required
❑The thermostat fan operation switch, labeled
FUELSWITCH(seeillustration)isfactory-set
intheF position.Thisisthecorrectsettingfor
most systems. If your system is an electric
heat system, set the switch to E to allow the
fan to turn on immediately with the heating in
a system when the G terminal is connected.
Step 6. Adjust System On-Time,
°F/°C, As Required
❑The thermostat on-time is factory-set for a
warmair, gas or oil heatingsystem. If youare
installing it on another type of system, adjust
the on-time accordingly by setting screws A
and B on the back of the thermostat. Use the
heating system table shown in theillustration
as a guide. The system on-time should be
optimized according to the type of system to
maximizecomfort.Settingthescrew“outone
turn”means turning the screw approximately
360°counterclockwise, or about one com-
plete turn.
RRc
W Y G
B D
A C
THERMOSTAT BACK
M8796A
DISPLAY °F
DISPLAY °CC–IN C–OUT
1 TURN
FOR HIGH EFFICIENCY FURNACE (90%+ AFUE)
ADJUST: SCREW A–OUT ONE TURN
SCREW B–IN
FUEL SWITCH – F POSITION
FE
FUEL SWITCH
WARM AIR
FURNACE
HOT WATER
BOILER
ELECTRIC
FURNACE
A–IN
A–OUT
1 TURN
A–IN
ADJUST SCREWS THROUGH HOLES
TO SELECT OPERATION DESIRED
B–IN
B–IN
B–OUT
1 TURN
FUEL SWITCH
POSITION
F
F
E
HEATING SYSTEM

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In the unlikely event that you want a longer
furnace on-time, readjust screws A and/or B as
follows:
First, turn both screws in completely, then
adjust for system type:
•Warm Air Furnace—Set at the Hot Water
setting (A—out one turn, B—leave in).
•Electric Furnace—Leave at the Warm Air
Furnace setting (A—leave in, B—leave in).
NOTE: This thermostat does not have a set-
ting for steam/gravity air; cycles would
not be long enough for accurate tem-
perature control.
IMPORTANT
When using a high efficiency furnace
such as a 90 percent or greater Aver-
age Fuel Utilization Efficiency (AFUE)
unit, adjust screw A out one turn and
leave screw B in.
❑Thethermostatisset toreadthetemperature
in degrees Fahrenheit. If readings are
desired in degrees Celsius, adjust screw C
out one turn.