Honeywell CT3500 User manual

OWNER’S GUIDE
® U.S. Registered Trademark
© 2004 Honeywell International Inc.
All Rights Reserved 69-1199—4
Honeywell CT3500/CT3595
PROGRAMMABLE THERMOSTAT
Weekday, Saturday and Sunday
Programmable Heat and/or Cool
Low Voltage (20 to 30 Vac) Thermostat and Wallplate
Model CT3500/CT3595
Para pedir estas instrucciones en español, llame al 1-800-468-1502.
Pour obtenir ce ode demploi en français, composer le 1-800-468-1502.
Table of Contents
Step 1. Prepare for Installation................................................................................................................................................ 5
Step 2. Remove Old Thermostat............................................................................................................................................. 6
Step 3. Mount Thermostat Wallplate....................................................................................................................................... 7
Step 4. Wire Wallplate Terminals ............................................................................................................................................ 8
Step 5. Install the Batteries ..................................................................................................................................................... 9
Step 6. Set Fan Operation Switch........................................................................................................................................... 10
Step 7. Mount the Thermostat ................................................................................................................................................ 11
Step 8. Customize Your Thermostat ....................................................................................................................................... 11
Step 9. Set the Clock .............................................................................................................................................................. 13
Step 10. Programming ............................................................................................................................................................ 14
Step 11. Operating Your Thermostat....................................................................................................................................... 17
Step 12. Set the Fan and System Switches............................................................................................................................ 18
If You Have a Problem ............................................................................................................................................................ 19
Smart Response™ Technology .............................................................................................................................................. 21
Wiring Diagrams ..................................................................................................................................................................... 22

69-1199—4 2
Total comfort temperature management with Smart Response™ Technology.
Congratulations! You made a smart choice by purchasing your new Honeywell thermostat the smart thermostat that;
•Keeps you comfortable by automatically calculating exactly when the furnace or air conditioning should go on to
have the house at the desired comfort temperature by the time you wake up or return home.
•Saves the maximum amount of energy and money by automatically remembering to adjust the temperature when
you leave home or go to sleep.
•Provides the ultimate in comfort and convenience. It comes preprogrammed. You can use the preprogrammed
schedule, or set your own.
This manual answers many of the questions that can arise as you become familiar and comfortable with your
Honeywell thermostat — the state of the art in home comfort controls.
Read these instructions carefully. Failure to follow these instructions can damage the product or cause a hazardous
condition.
MERCURY NOTICE
If this thermostat 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 this control, or of an old control containing mercury in a sealed
tube.
If you have questions, call Honeywell Customer Care at 1-800-468-1502.
M10614
MERCURY
SWITCH
TYPICAL LOCATION OF A MERCURY
SWITCH IN A THERMOSTAT

3 69-1199—4
Time Set Program
Run
Program
Hold Temp
Set Current
Day/Time
Day Heat/Cool
Settings System
Fan
Wake Leave Return Sleep
Heat Off Cool
On Auto
M18589
RAISES TEMPERATURE
SETTING
LOWERS TEMPERATURE
SETTING
DISPLAYS CURRENT
HEAT/COOL
TEMPERATURE SETTING
PROGRAM PERIODS
WAKE/LEAVE/RETURN/SLEEP:
ENTERS PROGRAMMING MODE
FAN SWITCH
SELECTS AUTO/ON
SYSTEM SWITCH
SELECTS HEAT/OFF/COOL
DIGITAL DISPLAY
SET CURRENT
DAY/TIME
SETS CURRENT
TIME AND DAY
RUN PROGRAM
RETURNS
THERMOSTAT
TO NORMAL
OPERATING MODE
HEAT/COOL SETTING
SWITCHES BETWEEN
HEAT SETPOINTS AND
COOL SETPOINTS
WHILE PROGRAMMING
TIME /TIME
SETS TIME FORWARD OR BACK
DAY
SETS DAY OF
THE WEEK
HOLD TEMP
SETS A HOLD
TEMPERATURE
A
ND ACTIVATES
VACATION HOLD
FEATURE.

69-1199—4 4
M18590
Aux Ht
System
O
f
f
A
u
to
WakeLeaveReturnSlee
p
Mon
Wait
In
Room
Humid
Outdoor
Filter
AM
Hold for
Repl Batt
Recovery
C
oo
l
TueWedThuFriSatSun
D
a
ys
Set Program Set Day/Time
Temporary Setting
Em Heat
Em Ht
DISPLAYS EITHER CURRENT
TIME OF DAY OR PROGRAM TIMES
SHOWS THERMOSTAT IS IN
THE SET DAY/TIME MODE
SHOWS TEMPERATURE SETTING
CHANGED FOR THIS PROGRAM PERIOD
SHOWS THE TEMPERATURE
DISPLAYED IS THE CURRENT
SET TEMPERATURE
SHOWS THE TEMPERATURE
DISPLAYED IS THE CURRENT
ROOM TEMPERATURE
SHOWS THE BATTERIES ARE
LOW AND MUST BE
REPLACED
DISPLAYS EITHER ROOM
OR SET TEMPERATURES
INFORMATION AND WAITING TO CALL FOR HEAT OR COOL
SHOWS SMART RESPONSE IS
CHANGING THE TEMPERATURE
TO MEET THE CURRENT PROGRAMS
SHOWS THAT THERMOSTAT IS
SHOWS CURRENT
SYSTEM SWITCH POSITION
HEAT/OFF/COOL
SHOWS CURRENT
PROGRAM PERIOD
OR PERIOD BEING
PROGRAMMED
SHOWS CURRENT
DAY OR DAYS BEING
PROGRAMMED
SHOWS VACATION
HOLD DURATION
SHOWS WHEN
THERMOSTAT IS IN THE
PROGRAMMING MODE
SHOWS SMART RESPONSE IS OFF
CONVENTIONAL RECOVERY IS ON

5 69-1199—4
STEP 1. PREPARE FOR INSTALLATION
qCheck Table 1, the compatibility chart, to make sure the thermostat is compatible with your system. If your system
is not compatible, call Honeywell Customer Care, toll-free, 1-800-468-1502.
Table 1. Compatibility Chart.
aCompatible with 2-wire Honeywell and Taco zone valves. Not compatible with 3-wire zone valves or 2-wire White
Rodgers no. 1361 zone valves.
bMillivolt system must be heating only.
cNot compatible with any 120/240 volt system.
Package Contents
• Thermostat • Wallplate • Screws and anchors
• Wiring labels • Owners manual
Tools Required
• Screwdriver
• Drill
System Type Compatibility with CT3500/CT3595
Gas — Standing Pilot Yes
Gas — Electronic Ignition Yes
Gas-fired Boilers Yesa
Gas — 750 Millivolt Heat OnlybYes
Oil-Fired Boilers Yesa
Oil-Fired Furnace Yes
Electric Furnace Yes
Electric Air Conditioning Yes
Baseboard Electric (120/240 line volt)cNo
Single Stage Heat Pump Yes
Multistage Heat Pumps/Multistage Equipment No

69-1199—4 6
STEP 2. REMOVE OLD THERMOSTAT
qTest your heating and cooling systems to make sure they work properly. If either system 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).
qTurn off power to the system at the furnace or the fuse/circuit breaker panel.
qCarefully unpack your new thermostat and wallplate. Save package of screws, instructions, and receipt.
qRemove the cover from the old thermostat. If the cover does not snap off when pulled firmly from the bottom, check
for a screw or screws used to lock on the cover.
qLoosen the screw or screws holding the thermostat to the wallplate and lift the thermostat away.
qDisconnect the wires from the old thermostat. As you disconnect each wire, attach the enclosed labels with the old
terminal designation. If there are only two wires, they do not need to be labeled. Wrap the wires around a pencil as
shown to keep them from falling back into the wall.
Special Installations
Read this section if you are replacing:
• Clock thermostat with separate wires for the clock.
• Thermostat with six or more wires connected to it.
• Thermostat in a heating only system with three wires.
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 going to the C or C1 clock terminals on the Chronotherm wiring wallplate. Do not allow them to touch, or you can
damage the transformer. Disconnect the wires and wrap them separately using electrical tape. Do not wrap them
together. Place the wires where they will not interfere with the operation of the new thermostat. Record the colors and
terminal designation labels of the remaining wires.
Replacing a Thermostat that has Six or More Wires
If there are six or more wires (excluding clock wires attached to terminals), you probably have a variation of a
multistage heat pump or other multistage system. This thermostat is not compatible with multistage systems, so return
the product to the place of purchase. For information about which programmable thermostats will work with your
system, call Honeywell Customer Care at 1-800-468-1502.
WIRES THROUGH
WALL OPENING
M5136

7 69-1199—4
Replacing a Thermostat that has Three Wires
If you have three wires for a heating only system and can operate the fan using the fan ON switch this thermostat
works with your system. However, some hot water (zoned) heating systems also have three wires. Your thermostat will
work only if you install an isolating relay on these systems. For details, call your local heating and/or cooling contractor.
STEP 3. MOUNT THERMOSTAT WALLPLATE
qSeparate the wallplate from the thermostat by placing your thumb or fingers between
the bottom of the wallplate and the thermostat, and pulling the wallplate up and away
from the thermostat. See illustration at right.
qPosition the wallplate on the wall. Level the wallplate for appearance if desired. Use a
pencil to mark the two mounting holes that best fit the application.
qRemove the wallplate from the wall. Drill two 3/16 in. holes in wall
(if drywall) as shown. For materials such as plaster or wood, drill
7/32 in. holes where marked. Gently, tap the (provided) anchors
into the drilled holes until they are flush with the wall.
qReposition the wallplate over the holes. Pull the wires through the
wiring opening. Loosely insert mounting screws into each of the
holes.
qLevel the wallplate if desired. Thermostat functions properly when
not level.
qTighten mounting screws.
M16427
WIRES
THROUGH WALL
WALL
MOUNTING
HOLES
M15044
MOUNTING
SCREWS
WALL
ANCHORS (2)

69-1199—4 8
STEP 4. WIRE WALLPLATE TERMINALS
IMPORTANT
All wiring must comply with local codes and ordinances. If unsure about household wiring procedures, call
your local heating/air-conditioning contractor.
Refer to the labels you placed on the wires when you removed the
old thermostat (see illustration).
qMatch the letter of your old thermostat wire with the
corresponding terminal letter on your new thermostat. Refer to
Table 2.
qRemove the factory-installed jumper connecting terminals R and
RC if wires are connected to both of those terminals.
qFor wiring diagrams, if needed, see pages 22-23.
qLoosen the terminal screws. Slip each wire beneath its matching
terminal. Wraparound and straight connections are both
acceptable, (see illustration). Tighten the terminals.
qPlug the hole in the wall with insulation to help prevent drafts
from adversely affecting thermostat operation. M16425
R
W
Y
G
M4826
FOR WRAPAROUND
INSERTION STRIP
7/16 IN. (11 MM).
FOR STRAIGHT INSERTION
STRIP 5/16 IN. (8 MM).

9 69-1199—4
Table 2. Terminal Designations on Old and New Thermostats.
aIf both RH and R terminals are present on existing thermostat, remove jumper and connect Rh to R and R to Rc.
bDo not connect both O and B when wiring to a single stage heat pump. Connect O to O. Tape off B.
cTape off end of the wire with electrical tape and push the taped wire back into the wiring hole in the wall.
STEP 5. INSTALL THE BATTERIES
IMPORTANT
Three fresh AA alkaline batteries must be installed for pro-
gramming and operation of the thermostat and the heat-
ing/cooling system.
qInstall the batteries in the wallplate so the positive terminals all
point up (see illustration).
Terminal on Old Thermostat Connect To Description
R, RHa, 4, V RPower
Rc, RaRc Power for cooling
W, W1, H W Heat
Y, Y 1, M Y Cooling
G, F G F an
O O Changeover in cool. (Single stage heat pump only).
BbBbChangeover in heat. (Single stage heat pump only).
Cc, Xc, BbDo not connect. Transformer common
W2, H2Do not continue installation.
Call 1-800-468-1502.
Second stage heat.
Y2Second stage cool.
M10622
INSTALL 3 AA ALKALINE BATTERIES
AS SHOWN, POSITIVE (+) TERMINALS
TOWARD TOP.
W A LLPL A TE
B
RRCOWYG

69-1199—4 10
qIf the thermostat is already mounted on the wall, remove the
thermostat by placing your thumb between the thermostat and
wallplate and pulling the thermostat up and away as shown.
When the batteries are running low, a REPL BAT message flashes
for one to two months before the batteries run out completely.
Replace the batteries as soon as possible once the message
flashes.
IMPORTANT
Although the thermostat has a low battery indicator,
replace the batteries once per year to prevent leakage
and to prevent the thermostat and heating/cooling sys-
tem from shutting down due to lack of battery power in
the thermostat.
If you insert new batteries within 20 to 30 seconds of removing the
old batteries, the system retains the current time and day. If the
display is blank, the batteries are dead or installed incorrectly. You must reset the time and day. Refer to Set the Clock
for instructions.
As a precaution when leaving home for longer than a month, change batteries before leaving to prevent
the system from shutting down due to lack of power. Always use fresh alkaline batteries. Nonalkaline
batteries do not last as long. They also can leak, causing damage to the thermostat and the wall
surface.
STEP 6. SET FAN OPERATION SWITCH
The thermostat fan operation switch, labeled FUEL SWITCH is factory set
in the F position. This is the correct setting for most systems. If your
system is an electric heat system, set the switch to E. The E setting allows
the fan to turn on immediately with the heating or cooling in a system
where the G terminal is connected.
M16424
80
90
70
60
90
80
70
60
M12676
FUEL SWITCH

11 69-1199—4
STEP 7. MOUNT THE THERMOSTAT
STEP 8. CUSTOMIZE YOUR THERMOSTAT
Your Honeywell thermostat comes preset to the most commonly used settings. The settings are:
— Gas or oil forced air furnace.
— Smart Response technology on.
— Temperature °F.
— 12-hour clock format.
You can change any or all of these settings.
IMPORTANT
Always press the keys with your fingertip or a similar blunt tool. Sharp instruments like pens and pencil
points can damage the keyboard.
qPress and hold down , , and , simultaneously until the screen shows.
You now can change any of these settings.
M12703A
B . PRESS LOWER
EDGE OF CASE
TO LATCH.
A . ENGAGE TABS AT TOP
OF THERMOSTAT
AND WALLPLATE.
M13330
FEATURE
NUMBER
OPTION

69-1199—4 12
System Type (Feature Number 4)
System type options are:
— 1 = Gravity or steam system.
— 3 = Hot water, high efficiency furnace (90% or better), or single stage heat pump.
— 6 = Gas or oil forced air furnace (preset).
— 9 = Electric furnace.
To change your system type:
qPress until display shows your furnace or boiler type.
qPress Time to move to next feature or to return to main display.
Smart Response™ Technology (Feature Number 13)
Smart Response technology options are:
— 0 = Smart Response technology on (preset).
— 1 = Smart Response technology off.
To turn Smart Response technology on or off:
qPress once.
qPress Time to move to next feature or to return to main display.
NOTE: See Smart Response technology (page 21) for information about this feature.
Temperature Format (Feature Number 14)
Temperature format options are:
— 0 = °F (preset).
—1=°C.
To change temperature format:
qPress once.
qPress Time to move to next feature or to return to main display.
Run
Program
M13343
Run
Program
M13344
Run
Program

13 69-1199—4
Time Format (Feature Number 16)
Time format options are:
— 0 = 12-hour clock (preset).
— 1 = 24-hour clock.
To change time format:
qPress once.
qPress to return to main display.
Factory Set Function (Feature Number 37)
Do not change this setting.
STEP 9. SET THE CLOCK
Set Current Day and Time
NOTE: On initial power-up, the screen flashes 1:00 pm until you press a key.
qPress .
qPress until screen shows current day.
qPress time or until screen shows current time. (Tapping the will advance the time in one hour
increments).
qPress .
M13345
Run
Program
M13346
Set Curent
Day/Time
Day
Set Curent
Day/Time
Run
Program

69-1199—4 14
STEP 10. PROGRAMMING
The keyboard is located behind the thermostat cover. The three most frequently used keys are near the display.
Pressing displays the current temperature settings. Pressing the and keys change the temperature. The
thermostat displays day, time, program period, temperature and system settings.
There is an individual key for each of the four program periods:
—The program period when you want 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 the heating season and a lower
temperature during the cooling season).
—The program period you can set for an energy-saving temperature while you are away at work or school.
(This is a lower temperature during the heating season and a higher temperature during the cooling
season).
—The program period when you want the house at a comfortable temperature for activities before bedtime.
(This is a higher temperature during the heating season and a lower temperature during the cooling
season).
—The program 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 temperature during the cooling season).
Table 3 can be helpful when planning your schedule for time and temperature settings. The thermostat
preprogrammed settings are shown in parentheses ( ).
Wake
Leave
Return
Sleep

15 69-1199—4
Table 3. Personal Programming Table.
aYour heating setpoints cannot be higher than 90°F (32°C) or lower than 40°F (4.5°C).
bYour cooling setpoints cannot be higher than 99°F (35°C) or lower than 45°F (7°C).
Program Weekdays
Start by programming the wake time and temperature for weekdays.
qPress and release .
qPress until (Mon-Fri) displays.
qPress Time or key until the desired time shows in the display.
NOTE: Program times are in 15 minute intervals. For example, 8:00, 8:15, 8:30.
qPress or key until the desired wake temperature displays.
Period Default Setting Weekday (Mon-Fri) Saturday (Sat) Sunday (Sun)
Wake Time (6:00AM)
Heata(70°F/21°C)
Coolb(78°F/25.5°C)
Leave Time (8:00AM)
Heata(62°F/16.5°C)
Coolb(85°F/29.5°C)
Return Time (6:00PM)
Heata(70°F/21°C)
Coolb(78°F/25.5°C)
Sleep Time (10:00PM)
Heata(62°F/16.5°C)
Coolb(82°F/28°C)
Wake
Day

69-1199—4 16
The setpoint temperature range is 40°F to 90°F (5°C to 2°C) for heating and 45°F to 99°F (7°C to 37°C) for cooling.
qPress to switch between heating and cooling setpoints.
NOTE: Program times are the same for heating and cooling.
qPress or until the display shows the desired temperature setpoint.
qPress , or and repeat these steps for each time period. Your weekday is now programmed.
Program Saturday and Sunday
Repeat each step in Program Weekdays for Saturday and Sunday.
qPress when the entire week is programmed.
Clear a Program Period
NOTE: Wake cannot be cleared.
qPress , , or for the program period you want to clear.
qPress until the desired day displays (Mon-Fri Sat; Sun).
qPress and hold the , , or for approximately 3 seconds until the time and temperature clear.
qRepeat the above steps for each period to be cleared.
qPress .
Heat/Cool
Settings
Leave
Return
Sleep
Run
Program
Leave
Return
Sleep
Day
Leave
Return
Sleep
Run
Program

17 69-1199—4
STEP 11. OPERATING YOUR THERMOSTAT
Change Temperature Setting Until the Next Program Period (Temporary Change)
qPress or until the screen shows the desired temperature setting.
NOTE: The temporary temperature setting is displayed for about 3 seconds and then the room temperature is
displayed. Temporary appears in the display. The setting cancels when the next program period starts or
when you press .
Change Temperature Setting Indefinitely (Hold)
qMove the System switch to the desired position (Heat or Cool).
qPress then or to change your setting if desired. (The display changes from showing the setpoint
temperature to room temperature after approximately three seconds).
qTo cancel “Hold” press .
Change the Temperature Setting Until a Designated Day and Period (Vacation Hold)
qPress twice.
qPress or until the display shows the desired temperature setpoint.
qPress Time until the desired number of days that you will be away (1 through 255) is displayed.
qPress , , or to select the program period when you want the program to restart.
NOTE: If the Vacation Hold needs to be cancelled before the designated time, press to return to the
program.
Run
Program
Hold Temp
Run
Program
Hold Temp
Wake Leave
Return
Sleep
Run
Program

69-1199—4 18
STEP 12. SET THE FAN AND SYSTEM SWITCHES
First set the fan switch. Fan On: The fan runs continuously. Use for improved air
circulation or for more efficient central air cleaning. (In a
heat-only system, fan runs continuously only if fan relay is
connected to the G thermostat terminal).
Fan Auto: Normal setting for most homes. The equipment
controls the fan operation.
Then set the system
switch.
Heat: The thermostat controls your heating system.
Off: Both the heating and air conditioning systems are off.
Cool: The thermostat controls your air conditioning system.
On Auto
Fan
On Auto
Fan
Heat Off
System
Cool
Heat Off
System
Cool
Heat Off
System
Cool

19 69-1199—4
IF YOU HAVE A PROBLEM
Table 4. Solution Guide.
If... Then…
Display does not appear. •Make sure the batteries are fresh and installed correctly.
•Make sure the thermostat is mounted and latched on the wallplate.
Mount and latch the thermostat on the wallplate if it is not.
Temperature settings will not change
(example; cannot set the heating higher
or the cooling lower).
•Make sure the temperature setpoints are:
—40°F to 90°F (4.5°C to 32°C) for heating.
—45°F to 99°F (7°C to 35°C) for cooling.
Heating does not come on. •Make sure the heating setpoint is above the room temperature.
•Make sure the circuit breaker is not tripped, and reset it if necessary.
•Make sure the power switch at the equipment is in the On position, and
set it to On if it is in the Off position.
•Wait five minutes for the system to respond.
•Set the system switch to Heat.

69-1199—4 20
Toll-Free Customer Assistance
Please read and follow the provided instructions for this thermostat. For additional information, go to
www.honeywell.com/yourhome or call Honeywell Customer Care at 1-800-468-1502.
Before calling, please have the following information available:
• Thermostat model number. (Located on back of thermostat).
• Thermostat date code. (Located below model number).
• Type of heating/cooling system (for example, hot water, warm air, oil, or gas).
• Location and number of wires connected to the thermostat.
Cooling does not come on. •Make sure the cooling setpoint is below the room temperature.
•Make sure the circuit breaker is not tripped, and reset it if necessary.
•Make sure the system switch at the air conditioner is in the On position,
and set it to On if it is in the Off position.
•Wait five minutes for the system to respond.
•Set the system switch to Cool.
System on indicator ( = heat, =
cool) is lit, but no warm or cool air is
coming from the registers.
Wait five minutes after seeing the flame or snowflake and check the
registers again. If no there is no hot or cool air coming from the registers,
refer to Heating does not come on or Cooling does not come on. If all of this
has been checked, contact your local heating and cooling contractor.
Display flashes during programming. Temperature setting limit has been reached. The heating setting range is
40°F to 90°F (4.5°C to 32°C). The cooling setting range is 45°F to 99°F
(7°C to 35°C).
Temperature changes occur at the
wrong times.
•Check the program times for the period in question.
•Make sure the AM and PM settings are correct.
•Make sure the current time and day settings are correct.
•Reprogram any incorrect settings.
NOTE: If your thermostat is set for Smart Response™ technology, the
start times occur before your programmed comfort period.
Table 4. Solution Guide.
If... Then…