Honeywell T8665C Thermostat User Manual

Contents

Introduction ....................................................................................................................................

Using this Guide ............................................................................................................................

Thermostat Features .....................................................................................................................

Operating Your Thermostat ........................................................................................................... 11

Setting the Clock ........................................................................................................................... 12

Programming Your Thermostat ..................................................................................................... 25

Replacing the Batteries (T8665C Only) ......................................................................................... 38

Adaptive Intelligent Recovery™ Control ........................................................................................ 40

Troubleshooting (Table 3) .............................................................................................................. 43

Warranty ........................................................................................................................................ 50

Customer Assistance .................................................................................................................... 51

9-1538

Although the EnergyPro™ Thermostat can be

used standalone, it is intended to be part of a

communicating system provided by your

Energy Utility.

INTRODUCTION

Congratulations on purchasing your new

EnergyPro™ Thermostat. This exciting new

product is designed to add a new level of

service, energy savings and convenience to

your home comfort system. As part of a larger

system of products and services from your

Energy Utility, your new thermostat allows you

to take advantage of special programs offered

through your Energy Utility. These programs

allow you to further increase your energy

savings beyond the efficiency of a traditional

programmable thermostat.

Read this document thoroughly to take

advantage of the convenience and energy

saving benefits of using this product.

69-1538

USING THIS GUIDE

Keyboard and Display Description

The T8665C,D,E Communicating Thermostat

uses two-way radio frequency (RF) to send and

receive information. This information can be

used to make changes to your thermostat

settings, or settings from your Energy Utility.

Keyboard

The keyboard is located behind the thermostat

cover. Three frequently used keys: increase ꢀ,

decrease ꢁ, and i key are located next to the

display. See Fig. 1.

The following symbols will help you identify the

features that apply to your system:

Display

The thermostat displays important information

such as day, time, schedule period,

temperature, filter information, system and fan

operation. See Fig. 2.

—

– Tip symbol. Look for helpful

tips throughout this guide

when you see this symbol.

WARNING: This product operates under

provisions of Part 15 of the FCC Rules.

Modifications to this product not specifically

authorized by Honeywell may void the user’s

authority to operate this device.

—

– Compressor with the word,

Heat Pump, below.These

features are availble when

used with a heat pump.

HEAT PUMP

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TIME

/ TIME

WAKE

SET WAKE TIMES AND

TEMPERATURES

LEAVE

SET LEAVE TIMES AND

TEMPERATURES

DIGITAL

DISPLAY

INCREASE

SETS TIME

RAISES TEMPERATURE SETTING

FORWARD OR BACK

DECREASE

LOWERS TEMPERATURE SETTING

SET CURRENT DAY/TIME

SETS CURRENT

DAY AND TIME

INFORMATION

DISPLAYS CURRENT HEAT/COOL

TEMPERATURE SETTING, FILYER

STATUS, AND OUTDOOR

RUN PROGRAM

RETURNS THERMOSTAT TO

NORMAL OPERATING MODE.

TEMPERATURE (WHEN INSTALLED).

PRESS AND HOLD TO CANCEL

ENERGY SAVINGS AND

PRE-HEAT/PRE-COOL MODES

RETURN

SET RETURN TIMES AND

TEMPERATURES

(MY CHOICE).

Run

Set Current

Leave

Set Program

Filter

SLEEP

SET SLEEP TIMES AND

TEMPERATURES

DAY

Program

Day/Time

Wake

Return

Sleep

Fan

SETS DAY OF THE WEEK

Time

Copy

Heat/Cool

Settings

HOLD TEMP

Hold Temp

Day

System

PROGRAM SCHEDULING

WAKE LEAVE RETURN SLEEP

ENTERS PROGRAMMING MODE

SETS A HOLD TEMPERATURE

SETTING AND ACTIVATES

VACATION HOLD FEATURE

Daylight

Time

FAN

DAYLIGHT TIME

SELECTS AUTO/ON

SELECTS STANDARD TIME

OR DAYLIGHT SAVING TIME

SYSTEM

SELECTS HEAT/OFF/COOL (AUTO)

COPY

COPIES SETTINGS FROM ONE DAY TO

HEAT/COOL SETTINGS

SWITCHES BETWEEN HEAT SETPOINTS AND

COOL SETPOINTS WHILE PROGRAMMING

FILTER

ANOTHER DAY FOR QUICKPROGRAMMING

SELECTS FILTER TIMER REMINDER

PERIOD (0, 15, 30, 60, 90, 120 DAYS)

M20893A

Fig. 1. Thermostat keyboard description.

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SHOWS WHEN

THERMOSTAT

IS IN THE

PROGRAMMING

MODE

SHOWS

THERMOSTAT

IS IN THE

SET CURRENT

DAY/TIME MODE

SHOWS

SHOWS TEMPERATURE

DISPLAYED IS THE CURRENT

SET TEMPERATURE

TEMPERATURE

SETTING CHANGED

FOR THIS

PROGRAM

PERIOD

SHOWS ACTIVE

PRICE TIER

SHOWS THAT THERMOSTAT

IS CALLING FOR

(HIGH, MEDIUM OR LOW)

System

SHOWS CRITICAL

PRICE TIER IS ACTIVE

HiMedLo Set Program Set Day/Time Temporary Setting

Critical

Hold for

SHOWS VACATION

HOLD DURATION

SHOWS CURRENT

SYSTEM KEY POSITION

HEAT/OFF/COOL

Em Heat

Off Wait

SHOWS FILTER TIMER

EXPIRED (TIME TO

REPLACE FILTER)

Filter Em Ht Aux Ht Days

Fan

SHOWS CURRENT FAN

KEY POSITION ON/AUTO

MonTueWedThuFriSat Sun Repl Batt Room

Wake Leave Return Sleep Recovery DST

Auto

SHOWS CURRENT

DAY OR DAYS BEING

PROGRAMMED

SHOWS BATTERIES

NEED REPLACING

SHOWS SMART

RESPONSE IS OFF

AND CONVENTIONAL

RECOVERY IS ON

SHOWS ADAPTIVE

INTELLIGENT RECOVERY

IS IN EFFECT

SHOWS CURRENT

PROGRAM PERIOD

OR PERIOD BEING

PROGRAMMED

SHOWS THERMOSTAT IS

CALLING FOR THE FAN

SHOWS SYSTEM ON

DAYLIGHT SAVING TIME

SHOWS THERMOSTAT

IS COMMUNICATING

SUCCESSFULLY

DISPLAYS EITHER ROOM

OR SET TEMPERATURE

DISPLAYS

EITHER CURRENT

TIME OF DAY OR

PROGRAM TIMES

SHOWS TEMPERATURE

DISPLAYED IS THE CURRENT

ROOM TEMPERATURE

M20894

Fig. 2. Example of thermostat display.

9-1538

•

Set the filter indicator (0, 15, 30, 60, 90, or

120 days) to remind you to change the

THERMOSTAT FEATURES

filter.

•

Adaptive Intelligent Recovery™ Control

Information at the press of a button—use

the i (information) key to see the outdoor

temperature (C7089B Outdoor Temper-

ature Sensor optional accessory), the

current setpoints, or the filter status.

for comfort and energy savings.

•

Customize the program schedule—

program your own schedule to fit your

needs.

•

Temporary schedule override—set the

thermostat higher or lower for the current

program schedule.

•

Daylight Time key for quick time changes

between Daylight and Standard time.

Backlit display for improved readability

•

Permanent schedule override—set the

(press any key to activate).

thermostat higher or lower indefinitely.

Optional outdoor temperature display—

ask your installer to install an outdoor

temperature sensor to activate this

feature.

Vacation mode (1 to 255 days) for added

comfort and energy savings. Set the

temperature higher or lower for energy

savings while on vacation. At the same

time, set the comfort level you want when

you return.

•

For additional features, see the System

User’s Guide provided by your Energy

Utility or systems provider.

69-1538

of this thermostat or these special programs

and features, please contact your local Energy

Utility.

Special Energy Saving Features

The EnergyPro™ Thermostat supports

Demand Response and Price Response

Programs from your Energy Utility. If you have

any questions concerning the application of this

thermostat or these special programs and

features, please contact your local Energy

Utility.

System

Set Program Set Day/Time

Cool

Em Ht Aux Ht

Fan

Sat

Room

Demand Response

If your utility offers a Demand Response

Wake

DST

Auto

M20901

Program, this thermostat can be managed by

your utility to reduce your energy consumption

during times of peak demand. When your

thermostat is helping your Energy Utility to

manage energy in your community, the word,

SAVE, is displayed on the thermostat as shown.

If you have any questions about the application

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Pre-Cool and Pre-Heat

Price Response

Your Energy Utility may decide to use the

Pre-cool /Pre-heat feature to slightly raise or

lower your home temperature setting

If your utility offers a Price Response Program,

this thermostat works with your Energy Utility to

inform you of the rate in effect at any given time

and automatically adjust your energy use for

each rate. The rate in effect is indicated on the

thermostat display as shown (Critical, Hi, Med,

and Lo). This typically involves controlling your

home at a higher temperature during cooling

season and a lower temperature during heating

season to reduce energy consumption.

immediately prior to a Demand Response

event to minimize the effect on your comfort.

When the Pre-heat or Pre-cool option is in

effect, the thermostat displays PrE.

System

Set Program Set Day/Time

Cool

Em Ht Aux Ht

Tue

Wake

Fan

Room

DST

Auto

M20902

69-1538

System

Set Program Set Day/Time

Med

Set Program Set Day/Time

Cool

Critical

Em Ht Aux Ht

Fan

Tue

Wake

Room

Fan

Tue

Room

Wake

DST

Auto

DST

Auto

M20904

M20906

Display shows Critical rate in effect.

Display shows Medium rate in effect.

System

Set Program Set Day/Time

Lo Set Program Set Day/Time

Cool

Em Ht Aux Ht

Fan

Tue

Room

Tue

Wake

Room

DST

Wake

DST

Auto

M20905

M20903

Display shows High rate in effect.

Display shows Low rate in effect.

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If the utility does not offer the My Choice

feature, pressing and holding the Run Program

key will not cancel the energy-saving event.

My Choice

There may be times when you need to cancel

an energy-saving event such as Demand

Response, Pre-heat or Pre-cool. Your Energy

Utility may offer a program that incorporates the

My Choice feature. To use My Choice and

cancel an energy-saving event, press and hold

Run Program key for three seconds until the

thermostat displays Done.

Call your Energy Utility provider for

further information.

Run

Program

OPERATING YOUR

THERMOSTAT

Your new thermostat saves energy and keeps

you comfortable at the same time. You may be

wondering how to program your thermostat and

how to use some more time and energy-saving

features. First, let’s look at features you’ll be

using often, like setting the System and Fan

keys, how to override the current programming

mode or to hold the thermostat at a specific

temperature while you go on vacation. You can

M14596

69-1538

even program the thermostat to return to your

regular programming schedule on your last day

of vacation so you are comfortable when you

return and yet save energy while you are away.

1. Press Set Current Day/Time key.

Mon

SETTING THE CLOCK

M14580

Press Set Current Day/Time key to show information

displayed.

Setting Current Day and Time

Setting the clock can be controlled as part of

the system using two-way

RF communication; then

the time is automatically

updated.

IMPORTANT

Always press keys with your fingertip

or similar blunt tool. Sharp instruments

like pens and pencil points can

damage keyboard.

Press Day key until current

day displays.

On initial powerup or after an extended power

loss, “1:00 PM” flashes on display until a key is

pressed.

Day

9-1538

Mon = Monday, Tue = Tuesday,

Tap Set Current Day/Time key to

advance time in

one-hour

Wed = Wednesday,

Thu = Thursday,

Fri = Friday, Sat = Saturday,

Sun = Sunday.

increments.

Press Run Program key to

return to normal operation.

Run

Program

M14581

Press Day key to set current day. Example display

shows Tuesday.

Press Time ∆ or

Time ∇key until

M14582

Press Time ∆ or Time ∇ key to set current time.

Example display shows 8:15 AM.

current time displays.

69-1538

Pressing Daylight Tiime key more than once in

a five-minute period scrolls

you through various time

Daylight Saving Time

NOTE: If current time is Daylight Saving Time,

press Daylight Time key to display

options (example: one-hour

earlier or later with or

“DST.”

Daylight

Time

without DST). Pressing

Daylight Time six times in a

five-minute period returns

you to your original setting.

Setting System and Fan Keys

Use the System and Fan keys to change the

system and fan settings. The fan settings can

be set for each schedule period individually.

System selection is for all schedule periods.

M14583

Press Daylight Time key to set Daylight Saving Time.

9-1538

Heat: The thermostat controls the heating.

Off: Both the heating and cooling are off.

Cool: The thermostat controls the cooling.

CAUTION

Equipment Damage Hazard.

Can cause permanent damage to the

compressor or other equipment.

To avoid possible compressor damage,

allow compressor to remain off for five

minutes before restarting.

Auto: The thermostat automatically changes

between heating and cooling operation,

depending on the indoor temperature.

To avoid possible equipment damage,

do not operate cooling when outside

temperature is below 50°F (10°C). See

equipment manufacturer instructions.

Em.Ht: Emergency heat is controlled as stage 1

heat. The Cooling system is

off. The compressor is de-

energized.

HEAT PUMP

Setting System Key

Press the System key until the

desired system (Heat, Off, Cool,

or Auto) displays.

System

69-1538

Setting Fan Key

Changing Temperature to Temporary

Setting Until Next Schedule Period

Press Fan key until desired mode

Fan

(

On or Auto) displays:

Press increase ꢀ or decrease ꢁ key until the

On: Fan operates continuously.

Auto: Fan operates only when heating

or cooling.

desired temperature setpoint displays.

Temporary Setting

Setting Temporary Temperatures

You can override the current schedule period to

temporarily change the temperature setting

until the next schedule period, or you can

change and hold the temperature setting

indefinitely. You can also change the

M14563

While selecting a temporary setting, only the setpoint

displays.

temperature setting until a designated day and

period (for example, while you are on vacation).

The temporary temperature setting you select

displays for approximately three seconds. The

display reads “Temporary” until the next period

begins or when you cancel the temporary

temperature setting.

9-1538

Press the Run Program key to

cancel the temporary temperature

setting before the designated time.

If ꢀ or ꢁ appears under temperature display,

both heating and cooling

Run

Program

setpoints are being

adjusted. Tapping ꢀ or ꢁ

key changes both heat and

cool setpoints one degree.

System

Heat

Temporary

(

Press i key after setpoint is

reached to verify setpoints.)

Fan

Mon

Heat

Auto

Changing and Holding Temperature

M14564

Setting Indefinitely

After selecting a temporary setting, the display reads

Temporary” until cancelled. Example display shows

temporary heat setting of 70° at 6:00 AM.

Hold Temp

“

1. Press Hold Temp key once.

2. Press ꢀ increase or decrease ꢁ key to

change temperature setpoint, if desired.

69-1538

NOTE: The Display changes from setpoint to

room temperature after approximately

three seconds.

Changing Temperature Setting Until a

Designated Day and Period (Vacation

Hold)

Press Run Program key to

cancel hold.

Hold Temp

Press Hold Temp key twice.

System

Heat

Setting

System

Heat

Setting

Hold for

Fan

Days

Fan

Heat

Auto

M14565

Wake

Heat

Auto

Press Hold Temp key once to display the thermostat

in Hold mode. Example display shows temporary

heat setting of 60°.

M14833

Press Hold Temp key twice to display thermostat in

Vacation mode. Example display shows temporary

heat setting of 60°.

9-1538

IMPORTANT

3. Press Wake, Leave, Return or Sleep key

To cancel Vacation Hold before desig-

to select the period the Hold ends.

nated time, press Run Program key.

Wake

Leave

Return

Sleep

Press Time ∆ or Time ∇

until desired number of

days (1 to 255 days)

displays.

System

Heat

System

Heat

Setting

Fan

Hold for

Auto

Days

Fan

M14571

In this example, the Hold ends after the 18 day at the

beginning of the Return period.

Wake

Heat

Auto

M14834

Press Time ∆ or Time ∇ key to select number of

vacation days. Example display shows 18 vacation

days.

Press ꢀ increase or decrease ꢁ to

adjust temperature setting, if desired.

69-1538

NOTE: Only the heating temperature is used

when System is set to Heat. Similarly,

only the cooling temperature is used

when System is set to Cool. The

thermostat uses both heating and

cooling temperatures when System is

set to Auto.

5. Press Heat/Cool Settings key

to change between heat and

cool settings.

Heat/Cool

Settings

6. Press ꢀ increase or decrease ꢁ to

adjust temperature setting, if desired (for

example, if cool is set to 84°, cooling

equipment operates when room

temperature is above 84°F).

Press Run Program to start

over or return display to

normal.

Run

Program

System

Heat

Fan

Auto

M14572

Press ꢀ increase or decrease ꢁ key to select a new

Hold temperature. Example display shows temporary

heat setting of 55°.

9-1538

If filter status is expired, refer to Filter Indicator

Using the i (Information) Key

section. Sequence of i key presses is:

•

Filter status.

Outdoor temperature (if equipped).

Current setpoint of mode in use (Heat or

Cool).

System

Em Heat

Fan

Tue

Wake

Room

•

Setpoint of mode not currently in use.

DST

Auto

INFORMATION KEY

M20896

Displaying Outdoor Temperature

The i (information) key provides information at

your fingertips in this sequence of key presses:

•

Outdoor temperature (if equipped).

Current setpoint of mode in use (Heat or

Cool).

Outdoor

INFORMATION KEY

M20897

•

Setpoint of mode not currently in use.

Filter status.

Press i key once to display outdoor temperature.

Example display shows outdoor temperature at 50°.

Press i key once to display outdoor temperature

(if equipped).

69-1538

If filter status is expired, press i key twice to

display outdoor temper-

ature. See Filter Indicator

section for instructions on

resetting filter indicator.

Cool

Displaying Current Settings

M2089

Press i key twice to check current temperature

setpoint. Press i key three times to check

temperature setpoint of mode not currently in

use.

Press i key twice to display current setpoint. Example

display shows cooling setpoint of 75°.

Without outdoor temperature sensor, press

i key once to display current setpoint;

press i key twice for opposite setpoint.

If filter status is expired, press i key three times

80 90

to check current temper-

ature setpoint, if equipped

with outdoor sensor.

80 90

9-1538

Filter Indicator

Setting or Resetting Filter Indicator

Your thermostat comes preset to a 30-day

setting. To change this setting or reset after

filter expiration:

System

Em Heat

1. Press Filter key to enter Filter

Filter

Tue

Wake

Fan

Filter

Room

mode.

DST

Auto

FILTER EXPIRATION INDICATOR

M20899

Your thermostat monitors the amount of time

the fan is running and lets you know when to

replace the filter, based on the number of fan

run-time days you select. On expiration,

thermostat displays “Filter.”

M14577

Press Filter key to display filter information. Example

display shows current fan run time set to 30 days with

filter set to expire in five days.

One fan run-time day equals 24 fan run-time

hours. (If fan is on only one-

third of the time each day, it

takes three days to deduct

Press and hold Filter key for

at least three seconds to

reset fan run time.

Filter

one fan run-time day.)

69-1538

LED Indicators (T8665D Only)

Setting

HEAT PUMP FAULT

MONITOR LED

EQUIPMENT

MONITOR LED

Filter

Days

M17762A

Hold down Filter key to reset counter.

Press Time ∆ or Time ∇ until desired

number of days display (0, 15, 30, 60, 90,

or 120).

M19467

Press Run Program key to

Run

Two LED indicators located on upper right of the

thermostat indicate when a Heat Pump Fault Monitor

or Equipment Monitor signal is sent to the thermostat

from the system. When Heat Pump Fault Monitor

LED indicator lights (red), see Troubleshooting

section.

Program

return to normal operation.

IMPORTANT

To track time fan is running, you must

select a setting other than 0 (0 means

off). If setting is 0 days, display always

shows “0 Days; 0 Setting” when Filter

key is pressed.

9-1538

Heat Pump Fault Monitor LED lights red when

heat pump failure is

System

Heat

Temporary

detected. Switch thermostat

to Em. Ht. and contact you

heat pump service com-

Fan

Mon

HEAT PUMP

Heat

Auto

pany. Heating with Em. Ht.

M17763

is expensive, so act quickly.

Successful Communication Indicator

PROGRAMMING YOUR

THERMOSTAT

The thermostat periodically sends and receives

messages. The small triangle right of the

temperature display indicates the thermostat

successfully communicated with the system

controller installed by your Energy Utility.

7-Day Program and Operation

Your thermostat is 7-day programmable, which

means you can set your thermostat for four

periods (Wake, Leave, Return and Sleep) and

up to eight temperatures (four Heat and four

Cool) for each day of the week. Each day can

be the same or different.

69-1538

Program Periods:

and a cooler temperature during cooling

season and it follows the energy-saving

LEAVE period.

WAKE—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 heating season and a cooler temper-

ature during cooling season.)

SLEEP—The program period you set for an

energy-saving temperature while you are

sleeping. This is a lower temperature during

heating season and a higher temperature

during cooling season and it follows the

RETURN period.

LEAVE—The program 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 higher

temperature during cooling season and it

follows the WAKE period.

-Day Preprogrammed Schedule

Your thermostat is preprogrammed with the

schedule shown in Table 1 (same schedule for

all days of the week). You may keep this

schedule or develop your own. Before starting

the programming procedure, use Table 2 to

plan your schedule.

RETURN—The program period when you

want the house at a comfortable tempera-

ture for activities before bedtime. This is a

higher temperature during heating season

9-1538

Instructions:

3. Draw a circle around the fan operation

Write the time you want for each program

period.

you desire for each period.

Write the heating and cooling tempera-

tures you want for each period.

Table 1. 7-Day Preprogrammed Schedule.

LEAVE RETURN

Day

WAKE

SLEEP

All Days

TIME

FAN

6:00 AM

TIME

FAN

8:00AM

TIME

FAN

H 70

(21)

6:00 PM

TIME

FAN

10:00 PM

AUTO

C 78

(2.5)

AUTO

C 85

AUTO

C 78

AUTO

C 82

(28)

H 70

H 62

(16.5)

H 62

(16.5)

(

21)

(29.5)

(25.5)

69-1538

Customizing Your Own 7-Day Schedule

Table 2. Your 7-Day Schedule.

LEAVE RETURN

Day

WAKE

SLEEP

SUN

TIME

FAN

TIME

FAN

TIME

FAN

TIME

FAN

AUTO

MON

TUES

WED

TIME

FAN

TIME

FAN

TIME

FAN

TIME

FAN

AUTO

TIME

FAN

TIME

FAN

TIME

FAN

TIME

FAN

AUTO

TIME

FAN

TIME

FAN

TIME

FAN

TIME

FAN

AUTO

9-1538

Table 2. Your 7-Day Schedule. (Continued)

Day

WAKE

LEAVE

RETURN

SLEEP

THURS

TIME

FAN

TIME

FAN

TIME

FAN

TIME

FAN

AUTO

FRI

TIME

FAN

TIME

FAN

TIME

FAN

TIME

FAN

AUTO

SAT

TIME

FAN

TIME

FAN

TIME

FAN

TIME

FAN

AUTO

69-1538

Programming the First Day

To modify the preprogrammed schedule, start

by programming the Wake time and temper-

ature and fan operation for any one day.

System

Heat

Set Program

Setting

Fan

Wake

Mon

Wake

Press the Wake key.

Heat

Auto

M14588

System

Heat

Press Day key to select day to program. Example

display shows Monday is selected and ready to

program.

Fan

Auto

Press Time ∆ or Time ∇ key until desired

M14586

Wake time displays.

Press Wake key to enter program mode. Example

display shows 6:00 AM Tuesday with Heat set to

70°F.

Press Day key until desired

day displays.

Day

9-1538

System

Heat

System

Heat

Set Program

Setting

Set Program

Setting

Fan

Mon

Wake

Mon

Wake

Auto

Heat

Auto

Heat

M14590

M14589

Press ꢀ increase or decrease ꢁkey to select

Press the Time ∆ or Time ∇ key to select time Wake

period will begin. Example display shows Wake

period will begin at 6:30 AM.

temperature for Wake period. Example display

hows heating Wake period set for 68°.

Setpoint temperature range is 40° to 90°F

The program times are in fifteen-minute

intervals; for example, 8:00,

(

4° to 32°C) for heating;

80 90

55° to 99°F (13° to 37°C)

for cooling.

8:15, 8:30.

80 90

Press ꢀ increase or decrease ꢁ until

desired Wake temperature displays.

69-1538

Press Fan key to modify fan

operation. Selecting Auto

means fan runs only when

Fan

System

Heat

Set Program

Setting

Cool

heating or cooling equipment is operat-

ing. Selecting On means fan runs contin-

uously for entire schedule period.

Fan

Mon

Wake

Auto

M14591

Press Heat/Cool Settings key to select cooling

system (if you previously set heating temperature).

Current setting displays. Example display shows

cooling system previously set for 78°.

Press Heat/Cool Settings

Heat/Cool

Settings

key to make selections for

opposite system setting

(either Heat or Cool).

9-1538

Press ꢀ increase or decrease ꢁ key until

IMPORTANT

Repeat steps 1 through 7 for each day

desired temperature setpoint displays.

of the week that has a different

System

Heat

schedule from the first day. Or refer to

Copying a Day section to copy any

programmed day to another day.

Set Program

Setting

Fan

Mon

Wake

Cool

Auto

9. Press Run Program key to return to

M14592

normal operation.

Run

Press ꢀ increase or decrease ꢁto select cooling

Wake temperature. Example display shows cooling

Wake period set for 76°.

Program

Copying a Day

Press Leave, Return or Sleep and repeat

steps 3 through 6 to program entire day.

The day (first day of a 7-day schedule) is

now programmed.

The thermostat must be in program mode to

use the copy feature. Go to

step 2 if the thermostat is

already in program mode

(set program displays in

upper left corner).

Leave

Return

Sleep

69-1538

Press Wake, Leave, Return or Sleep key

to enter program mode.

3. Press Copy key.

Copy

Wake

Leave

Return

Sleep

Press Day key to select the

day to copy from.

Day

Mon

System

Set Program

Setting

Heat

M14594

Press Copy key to copy a day schedule into memory.

Example display shows Monday schedule was coped

into memory.

Fan

Mon

Wake

Heat

Auto

M14590

4. Press Day key until day to be

Day

copied to is displayed.

Press Day key to select the day schedule to copy.

Example display shows thermostat in program

mode with Monday ready to be copied.

9-1538

Mon

Wed

M14596

Press Copy key again to complete copy command.

Example display shows “donE”. Monday schedule

was successfully copied to Wednesday (Monday and

Wednesday now have the same schedule).

M14595

Press Day key again to select the day to copy to.

Example display shows Monday and Wednesday.

Because Monday was already selected, Monday

schedule will be copied to Wednesday.

NOTE: “donE” displays for two seconds

before the normal display returns.

Press Copy key.

Copy

Repeat steps, as necessary, for all peri-

ods and days desired.

Press Run Program key to

return to normal operation.

Run

Program

69-1538

Clearing a Program Period

System

Heat

Set Program

Setting

Thermostat must be in program mode to use

clear feature. Go to step 2 if

thermostat is already in

program mode (Set

Fan

Mon

Leave

Heat

Program displays in upper

left corner.

M14597

Press Leave, Return, or Sleep to enter the

program mode. Example display shows 8:00 AM on

Monday in Leave period with Heat set for 62°.

Press Leave, Return or Sleep key to

enter program mode.

2. Press Day key until desired

Day

day displays.

Leave

Return

Sleep

System

Heat

Set Program

Setting

Fan

Sat

Leave

Heat

M14598

Press Day key to select the day to begin clearing the

periods. Example display shows Saturday is selected.

9-1538

Press and hold Leave, Return or Sleep

key until start time and temperature set-

ting clear (approximately three seconds).

You do not have to program a replacement time

for the remaining periods;

for example, Wake and

Sleep. If you clear only

Leave

Return

Sleep

Leave and Return periods

for Saturday (or any day),

thermostat remains in Wake

period for all of Saturday

until Sleep period.

Set Program

Setting

Repeat steps, as necessary, for all

periods to be cleared.

Sat

5. Press Run Program key to

Run

Leave

Heat

Program

M14599

return to normal operation.

Press and hold Leave, Return or Sleep key to clear

the period for that day. Example display shows

Saturday Leave period cleared.

NOTE: Wake cannot be cleared.

69-1538

REPLACING THE BATTERIES

T8665C ONLY)

WALLPLATE

(

IMPORTANT

Three AA alkaline batteries are

included with the thermostat. Batteries

must be installed for programming and

operation of the thermostat and the

heating/cooling system.

Day

Install batteries in wallplate so positive

terminals all point up (as shown).

If 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 on the

next page.

INSTALL 3 AA ALKALINE BATTERIES

AS SHOWN, POSITIVE (+) TERMINALS

TOWARD TOP.

M10622

9-1538

MPORTANT

Although thermostat has a low battery

indicator, replace batteries yearly to

prevent leakage and thermostat and

heating/cooling system from shutting

down due to lack of thermostat battery

power.

If you insert new batteries within 20 to 30

seconds of removing old batteries, the

system retains current time and day. If the

display is blank, batteries are dead or

installed incorrectly. You must reset time

and day. See Setting the Clock section.

M16424

When batteries are running low, a REPL

BAT message flashes for one to two

months before batteries run out com-

pletely. Replace batteries as soon as pos-

sible after message flashes.

As a precaution, when leaving home for longer

than a month, change

70 80 90

batteries before leaving to

prevent system shutting

down due to lack of power.

80 90

69-1538

Always use fresh alkaline batteries. Non-

alkaline batteries do not last as long and can

leak, causing damage to the thermostat and

wall surface.

reads both the temperature of the wall and in

the air, and responds to temperature changes

as little as one degree Fahrenheit, so room

temperature is more likely to feel right to you

and your family.

The thermostat acts like a computer. When

calculating the time to turn on your heating or

cooling system, it considers air temperature,

wall temperature, and the time you want to

reach the comfort temperature. After

ADAPTIVE INTELLIGENT

RECOVERY™ CONTROL

Your new thermostat is so smart, it’s almost

human. You perceive temperature from a

variety of sources, not only from the air in the

room, but also from your surrounding walls,

windows and furnishings. Humans feel

considering these three things, Adaptive

Intelligent Recovery™ control gradually

changes the temperature from the energy

savings setting to the comfort setting (for

example, from a heating temperature of 62° at

night to 70° in the morning).

differences in temperature as slight as two

degrees Fahrenheit. Common household

thermometers and standard thermostats sense

only air temperature, which may not reflect how

hot or cold the room actually new thermostat

The system runs continuously until the comfort

temperature you choose is reached without

overshooting the setting. This saves energy.

9-1538

How do you know when the system is in

recovery? The thermostat displays “Recovery”

whenever the thermostat activates Adaptive

Intelligent Recovery™ control. (See display.)

adjusts the next day’s recovery start time

accordingly. After four to eight days, the

thermostat has adjusted to local weather, your

lifestyle, the construction of your home, and

your heating and cooling system.

“

Recovery” displays during recovery time from

Sleep to Wake and from Leave to Return.

Optimum Comfort and Energy

Savings

System

Set Program Set Day/Time

In Fig. 3, Adaptive Intelligent Recovery™

control starts to recover at 5:00 AM and

reaches the comfort temperature of 68° at

6:30 AM. Recovery time varies with the starting

temperature and the comfort temperature you

choose.

Heat

Em Ht Aux Ht

Fan

Mon

Wake

Room

Recovery

Auto

M20895

After installation or new schedule programming,

your thermostat learns from experience. Each

day it checks how closely it hit the recovery

target (for example, 70° at 6:00 AM) and

69-1538

At 7:00 AM System

Operating in Comfort Mode

System

Heat

At 6:00 AM

Recovery

Continues

Fan

Wake

Room

Auto

System

Heat

Fan

At 5:00 AM

Recovery

Continues

Mon

Room

Auto

Sleep Recovery

System

Heat

Fan

Mon

Room

At 4:00 AM

Recovery Begins

Sleep Recovery

Auto

System

Heat

Fan

Mon

Room

Sleep Recovery

Auto

ENERGY

SAVINGS

PERIOD

COMFORT

PERIOD

RECOVERY FROM ENERGY SAVINGS

TIME

THE THERMOSTAT USES THE SAME SCHEME TO RETURN GRADUALLY TO LOWER COMFORT TEMPERATURE DURING THE COOLING SEASON.

M19473

IF In Recovery IS DISPLAYED, PRESS

TO SEE THE COMFORT SETPOINT.

Fig. 3. Explanation of Adaptive Intelligent Recovery™ control.

9-1538

TROUBLESHOOTING (TABLE 3)

Table 3. Troubleshooting.

Possible Cause

Symptom

Action

Display does not

come on.

Thermostat is not being

powered.

Check if the thermostat is mounted and

latched on the wallplate—mount and latch

the thermostat on the wallplate.

Check if the circuit breaker is tripped—

reset the circuit breaker.

Check if the fuse at the fuse box is

blown—replace the fuse.

Check if System switch at equipment is in

the Off position—set to On position.

Check if batteries are correctly installed—

be sure they are fresh and installed

correctly. Replace them, if necessary.

69-1538

Table 3. Troubleshooting. (Continued)

Possible Cause

Symptom

Action

Temperature

The upper or lower

temperature limits were

reached.

Check that the temperature setpoints are

Heating: 40 to 90° (4.5 to 32 °C).

Cooling: 45 to 99° (7 to 37 °C).

setting does not

change (Example:

cannot set the

heating higher or

the cooling lower).

9-1538

Table 3. Troubleshooting. (Continued)

Possible Cause

Symptom

Action

Heating does not

come on.

The thermostat is part of a

Demand Response event.

If thermostat indicates SAVE, wait until

energy saving event is complete. To

cancel energy saving event, if available,

press and hold Run Program.

Check that setpoint is above room

temperature.

No power to thermostat.

System selection is not set

to Heat.

Check if circuit breaker is tripped—reset

circuit breaker.

Heating setpoint is below

room temperature.

Check if fuse at fuse box is blown—

replace fuse.

Check if System switch at equipment is in

Off position—set to On position.

Wait five minutes for System to respond

(

thermostat displays “Wait”).

Set System selection to Heat.

69-1538

Table 3. Troubleshooting. (Continued)

Possible Cause

Symptom

Action

Cooling does not

come on

The thermostat is part of a

Demand Response event.

If thermostat indicates SAVE, wait until

energy saving event is complete. To

cancel energy saving event, if available,

press and hold Run Program.

Check that setpoint is below room

temperature.

No power to thermostat.

System selection is not set

to Cool.

Check if circuit breaker is tripped—reset

circuit breaker.

Cooling setpoint is above

room temperature.

Check if fuse at fuse box is blown—

replace fuse.

Check if System switch at equipment is in

Off position—set to On position.

Wait five minutes for System to respond—

(

thermostat displays “Wait”).

Set System selection to Cool.

9-1538

Table 3. Troubleshooting. (Continued)

Possible Cause

Symptom

System on

Action

Heating/cooling equipment

turns on the fan when the

equipment has reached the

preset time or temperature.

Wait a minute after seeing the

indicator—

and then check the registers.

for heat;

for cool—

is lit, but no warm

or cool air is

coming from the

registers.

Heat Pump Fault

Monitor LED is

lighted.

The heat pump signaled the

thermostat to indicate a

problem.

Move the System switch to Em. Ht setting

(heat pump only). See Heat pump

Operating Instructions or call your local

heat pump dealer or Energy Utility for

assistance.

69-1538

Table 3. Troubleshooting. (Continued)

Possible Cause

Symptom

Action

Room temperature

is cooler than

Thermostat is operating in

Pre-cool mode. If the

thermostat displays PrE,

wait until the Pre-cool event

is complete.

If PrE does not display, contact your local

heating contractor or Energy Utility.

current setting and

air conditioner is

still running.

To cancel, press and hold

Run Program for three

seconds until DONE is

displayed.

Outdoor

Installer did not activate this

option.

Contact installer or service technician.

temperature is not

displayed or is

incorrect.

Outdoor sensor is connected

incorrectly.

Press i key twice for outdoor temperature

when filter expiration shows on display.

Refer to the Filter Indicator section.

Filter expired.

9-1538

Table 3. Troubleshooting. (Continued)

Possible Cause

Symptom

Action

COM is displayed. The thermostat is unable to

communicate with Energy

Utility management system

controller.

Contact your energy utility for assistance.

Heat or cool turns

on before

Adaptive Intelligent

Adaptive Intelligent Recovery™ control

brings the heat or cool on early to meet the

temperature set for the programmed

period. See Adaptive Intelligent

Recovery™ control is on.

programmed time.

Recovery™ control section. To disable

Adaptive Intelligent Recovery™ control,

contact you local Heating and Air

Conditioning contractor.

69-1538

Honeywell Return Goods

Dock 4 MN10-3860

WARRANTY

885 Douglas Drive North

Honeywell warrants this product, excluding battery, to be free

from defects in the workmanship or materials, under normal

use and service, for a period of one (1) year from the date of

purchase by the consumer. If, at any time during the warranty

period, the product is defective or malfunctions, Honeywell

shall repair or replace it (at Honeywell’s option) within a

reasonable period of time.

Golden Valley, MN 55422

This warranty does not cover removal or reinstallation

costs. This warranty shall not apply if it is shown by

Honeywell that the defect or malfunction was caused

by damage which occurred while the product was in

the possession of a consumer.

Honeywell’s sole responsibility shall be to repair or replace

the product within the terms stated above. HONEYWELL

SHALL NOT BE LIABLE FOR ANY LOSS OR DAMAGE OF

ANY KIND, INCLUDING ANY INCIDENTAL OR

CONSEQUENTIAL DAMAGES RESULTING, DIRECTLY OR

INDIRECTLY, FROM ANY BREACH OF ANY WARRANTY,

EXPRESS OR IMPLIED, OR ANY OTHER FAILURE OF

THIS PRODUCT. Some states do not allow the exclusion or

limitation of incidental or consequential damages, so this

limitation may not apply to you.

If the product is defective:

(

i) return it, with a bill of sale or other dated proof of

purchase, to the retailer where you purchased it, or

(

ii) package it carefully, along with proof of purchase

including date of purchase) and a short description of

(

the malfunction, and mail it, postage prepaid, to the

following address:

9-1538

THIS WARRANTY IS THE ONLY EXPRESS WARRANTY

HONEYWELL MAKES ON THIS PRODUCT. THE

CUSTOMER ASSISTANCE

DURATION OF ANY IMPLIED WARRANTIES, INCLUDING

THE WARRANTIES OF MERCHANTABILITY AND FITNESS

FOR A PARTICULAR PURPOSE, IS HEREBY LIMITED TO

THE ONE YEAR DURATION OF THIS WARRANTY. Some

states do not allow limitations on how long an implied

warranty lasts, so the above limitation may not apply to you.

After reading this guide, if you have any

questions about the operation of your

thermostat, please visit the Honeywell website

at www.honeywell.com/yourhome. For service,

contact your Installer or Energy Utility company

or service provider.

This warranty gives you specific legal rights, and you may

have other rights which vary from state to state.

If you have any questions concerning this warranty, please

write our Honeywell Customer Relations, 1985 Douglas Drive

North, Golden Valley, MN 55422. In Canada, write Retail

Products ON15-02H, Honeywell Limited/Honeywell Limitée,

5 Dynamic Drive, Scarborough, Ontario M1V 4Z9.

69-1538

Automation and Control Solutions

Honeywell International Inc.

985 Douglas Drive North

Golden Valley, MN 55422

Honeywell Limited-Honeywell Limitée

35 Dynamic Drive

Scarborough, Ontario

M1V 4Z9

Printed in U.S.A. on recycled

paper containing at least 10%

post-consumer paper fibers.

9-1538 G.H. 04-03