honeywell chronoterhm iii

Chronotherm IIIfor Comfort and Convenience

OWNER'S GUIDE

Residential andResidential andHelping You Control Your World

Building Controls DivisionBuilding Controls Division

Honeywell Inc.Honeywell LimitedHoneywell Limite

1985 Douglas Drive North740 Ellesmere Road

Golden Valley, Minnesota 55422Scarborough, Ontario

M1P 2V9

Congratulations! You made a smart choice when you purchased your new Honeywell CommunicatingChronotherm III Thermostat. Its the smart thermostat that:

n Keeps you comfortable by automatically calculating exactly when the furnace or air conditioningshould go on to have the house at the desired comfort temperature by the time you wake up.n Saves the maximum amount of energy and money by remembering to automatically set back the heator air conditioning when you leave home.n Provides the ultimate in comfort and convenience by coming to you already programmed. But its yourchoiceuse the preprogrammed schedule or set your own.n Can be connected to a Honeywell's TotalHome system for external access and control. TotalHomesystem devices communicate using HBus, a Honeywell communications protocol.

Features

3 Set the cooling temperatures. Seepage 7.

4 Set the system and fan switches. Seepage 12.

1 Set the current time and day. See page 1.

2 Set the program schedule and heatingtemperatures. See page 2.

Simple Four-Step ProgrammingOf course, you can use the schedule preprogrammed into your new thermostat. SeeGlossary, page 40-42). But its an easy matter to program the thermostat to fit your lifestyle.

Choosemanual orprogrammedthermostatoperation.

Program upto fourdifferent timeperiods ineachschedule.

Set differentschedules forweekdays,Saturday, andSunday.

Choosesystem andfan operationwith thethermostatswitches (onsubbase).

AUX. HT. and EM. HT. on T8631R.See Glossary, page 40.

Bypass thestoredprogram fora singleperiod.

Set thetemperaturewarmer orcooler with thetouch of a key.

Monitor thermostat operation; readcurrent time and room temperature ata glance.

Check status light to see if the thermostatis on, even in the dark.

TABLE OF CONTENTSProgramming Your Thermostat ........................... 1-13

Setting the current day and time ............................. 1Setting the program schedule and heating tempera-

tures.................................................................... 2Setting the cooling temperatures ............................ 7Setting the system and fan switches on the

subbase ............................................................ 12

Operating Your Thermostat ............................... 14-20Temporarily changing the program ....................... 14Permanently changing the program ...................... 15Operating the thermostat manually ....................... 16Canceling program settings................................... 17Checking the program times and temperatures .... 18Checking the current temperature setting ............. 19External access and control of thermostat ............ 20

Maintaining Your Thermostat ............................ 21-24Removing the thermostat ...................................... 21Replacing the thermostat ...................................... 22Replacing the batteries.......................................... 23Power outages ...................................................... 24

Adaptive Intelligent Recovery ........................ 25-28Selecting Recovery Setting ................................ 29-30Heat Pumps with Supplemental Heat ................ 31-32Answering Common Questions About the Chrono-therm III Thermostat ............................................ 33-36Saving Energy Across the U.S. .......................... 37-39Glossary ............................................................... 40-42Your Personal Program ...................................... 43-44Troubleshooting Guide....................................... 45-46Quick Reference to the Keys ............................. 47-48Index ..................................................................... 49-50Warranty.................................................................... 51

i

STEP 1SETTING THE CURRENTDAY AND TIME

You can program this thermostatonly on the wall with 24 Vac appliedto R and C terminals.

Always press the keys with yourfingertip or similar blunt tool. Sharpinstruments like a pen or pencilpoint can damage the keyboard.

NOTE: Check the glossary, page40, for definitions of unfamiliarwords.

1

2

SETPRESENTDAY/TIME

MONPM

Press and release. The displayshows 1:00 PM Mon.

Press and hold until the current dayappears in the display.

Press and hold until the current timeappears in the display. Be sure AMor PM appears as desired.

You have programmed the currentday and time. Go on to Step 2.

DAY

AHEAD

BACK

TUEPM

TUEPM

STEP 2SETTING THE PROGRAMSCHEDULE AND HEATINGTEMPERATURES

Before You BeginThe schedule form on page 43provides an opportunity to plan yourschedule.

NowStart by programming the WAKEtime and temperature for weekdays.

The thermostat requires a programfor WAKE. You can programLEAVE, RETURN and SLEEP ornot, as you please.

SETHEAT/COOL

Press and release. Note that thedisplay shows WAKE, thepreprogrammed time and tempera-ture.

If the display reads COOL, press andrelease to switch to HEAT.

If display reads SAT or SUN, pressand hold until MON TUE WED THUFRI appears.

Press and hold until the displayshows the desired starting time. Ifusing T8631A in ConventionalRecovery ( n n visible in display). SeeGlossary section. With ConventialRecovery the time should be set 30or more minutes ahead of desiredcomfort time to get the housecomfortable.

WAKE

DAY

AHEAD

BACK

MON TUE WED THU FRI ON HEATWAKE

AM SETPT


AM SETPT


AM SETPT


AM SETPT

PROGRAMMING YOUR THERMOSTAT

43

Program the LEAVE time andtemperature, if desired.

NOTE: You can cancel the LEAVE,RETURN or SLEEP program byholding down the key until thetime and temperature disappearfrom the display.


AHEAD

BACK

WARMER

COOLER

WARMER

COOLER

MON TUE WED THU FRI ON HEATLEAVE

SETPTLEAVE


AM SETPT


AM SETPT

Press and release. The displayshows LEAVE, but no time ortemperature.Press and hold until the displayshows the desired starting time.

Press and hold until the displayshows the desired temperature.

Program the RETURN time andtemperature, if desired.

Press and release. The displayshows RETURN, but no time ortemperature.

Press and hold until the displayshows the desired starting time.T8631A using Conventional Recov-ery ( n n visible in display) should beset 30 or more minutes ahead ofdesired comfort time.


AHEAD

BACK

RETURNMON TUE WED THU FRI ON HEAT

RETURN

SETPT

MON TUE WED THU FRI ON HEATRETURN

PM SETPT


If the display starts to blink whileyou are holding down TEMPERA-TURE WARMER or COOLER, youhave reached the setting limit.


AM SETPT

WARMER

COOLER

MON TUE WED THU FRI ON HEATRETURN

PM SETPT

Press and release. The displayshows SLEEP, the preprogrammedtime and temperature.

Press and hold until the displayshows the desired starting time.

SLEEPProgram the SLEEP time andtemperature, if desired. MON TUE WED THU FRI ON HEAT

SLEEP

PM SETPT

AHEAD

BACK

MON TUE WED THU FRI ON HEATSLEEP

PM SETPT


PM SETPT


5

WARMER

COOLER

DAY

LEAVE

RETURN

AHEAD

BACK

WARMER

COOLER

SUN ON HEATSLEEP

PM SETPTDAY

SLEEP

WAKE LEAVE

RETURN

AHEAD

BACK

WARMER

COOLER

RUNPROGRAM

6


Press and release until SAT appearson the display.

Press WAKE, LEAVE, RETURN orSLEEP to select the time period.

Press the AHEAD/BACK keys to setthe time and the WARMER/COOLERkeys to set the temperature.

SAT ON HEATSLEEP

PM SETPTSet the SATURDAY schedule. Usethe same procedure as for week-days.

SLEEP

WAKE

Set the SUNDAY schedule. Usethe same procedure as for week-days.

Press and hold until SUN appears onthe display.


Press the AHEAD/BACK keys to setthe time and the WARMER/COOLERkeys to set the temperature.

You have completed setting theprogram schedule and heatingtemperatures. To set air conditioning,go to Step 3,

If you do not want to program cooltemperature, skip Step 3 and pressRUN PROGRAM key.

78

PROGRAMMING YOUR THERMOSTATSTEP 3SETTING THE COOLINGTEMPERATURES

The program times are the samefor both heating and cooling. Onlythe cooling temperatures need tobe programmed if you have alreadyprogrammed for heating. If youchange program times for cooling,you are also changing them forheating! To set times as youprogram the cooling temperatures,use the TIME AHEAD and BACKkeys as described in Step 2.

First program the WAKE tempera-ture for weekdays.

WAKEPress and release. The displayshows WAKE, the time and tempera-ture you programmed for heating.

Press and release so COOL showson the display, along with theprogrammed cooling temperature.

If display reads SAT or SUN, pressand hold until MON TUE WED THUFRI appears.

SETHEAT/COOL

DAY

SUN ON HEATWAKE

AM SETPT

MON TUE WED THU FRI COOLWAKE

AM SETPT

SUN COOLWAKE

AM SETPT


If the display blinks while you holddown TEMPERATURE WARMER orCOOLER, you have reached thesetting limit.

WARMER

COOLER

MON TUE WED THU FRI COOLWAKE

AM SETPT

Press and release. The displayshows LEAVE, the time programmedfor heating and 78 F.


Program the LEAVE temperature, ifdesired. LEAVE MON TUE WED THU FRI COOL

LEAVE

AM SETPT

MON TUE WED THU FRI COOLLEAVE

AM SETPTWARMER

COOLER

Program the RETURN tempera-ture, if desired. RETURN

Press and release. The displayshows RETURN, the time pro-grammed for heating and 78 F. MON TUE WED THU FRI COOLRETURN

PM SETPT


9

10

WARMER

COOLER

MON TUE WED THU FRI COOLRETURN

PM SETPTPress and hold until the displayshows the desired temperature.

Program the SLEEP temperature ifdesired.

Press and release. The displayshows SLEEP, the time programmedfor heating and 78 F.


SLEEPMON TUE WED THU FRI COOL

SLEEP

PM SETPT

WARMER

COOLER

MON TUE WED THU FRI COOLSLEEP

PM SETPT

Set the cooling temperatures forthe SATURDAY schedule. Use thesame procedure as for weekdays.

Press and hold until SAT appears onthe display.DAY SAT COOL

SLEEP

PM SETPT


Press the WARMER/COOLER keysto set the temperature.

SLEEP

WAKE LEAVE

RETURN

WARMER

COOLER

Set the cooling temperatures forthe SUNDAY schedule. Use thesame procedure as for weekdays.

DAYPress and hold until SUN appears onthe display.


SUN COOLSLEEP

PM SETPT

SLEEP

WAKE LEAVE

RETURN


11

12

Press the WARMER/COOLER keysto set the temperature.

You have completed programmingthe cooling temperatures.

Press and release to start theprogram.

Go to Step 4.

WARMER

COOLER

RUNPROGRAM

TUELEAVE

PM SETPT

STEP 4SETTING THE SYSTEM AND FANSWITCHES ON THE SUBBASE

The T8631A does not have the EM.HT. switch position. Note thepositions provided on your sub-base, then set the switch(s) asdesired.

First set the fan switch.

Then set the system switch.

FAN ON: Use for improved aircirculation during special occasionsor for more efficient electronic aircleaning. The fan runs continuously.

FAN AUTO: Normal setting for mosthomes and businesses. T8631A: thefan starts and stops with the airconditioner and with the heatingequipment when the fan switch (4A)is set for electric heat. When 4A isset for conventional heat, the fan iscontrolled by the heating equipment.T8631R: the fan starts and stops withthe compressor in heat pumpsystems when the system switch isset to HEAT or COOL. When systemswitch is set to EM. HT., the fanoperates with the auxiliary heat (onsome models).EM. HT. (T8631R only): The thermo-stat controls only the backup heat.The heat pump is off.

FAN

AUTOON

FAN

AUTOON

EM. HT. HEAT OFF COOL

13

14





Now, while you enjoy precisiontemperature control, read on tolearn about the operating flexibilitythat makes this thermostat THESMART CHOICE.

OPERATING YOUR THERMOSTAT

TEMPORARILY CHANGINGTHE PROGRAM

These features let you tailor theprogram for those times whensomeone comes home early, oryoure staying up late, or you planto be out for the evening.

SKIPNEXT

PERIOD TUELEAVE RETURN

PM

TUEWAKE TEMPORARY

PM

Press and release. The name of theperiod to be skipped will flash in thedisplay until the next regularlyscheduled period starts.

Press and release. The display willshow the name of the previousperiod and flash TEMPORARY untilthe next regularly scheduled periodsstarts.

HEAT: The thermostat controls yourheating system.

OFF: Both your heating and coolingsystems are off.

COOL: The thermostat controls yourcooling system.

You have finished programming yourthermostat.

CHANGETO LASTPERIOD

15

To temporarily raise or lower thetemperature for the current periodonly.

If you change your mind.

WARMER

COOLER

TUELEAVE

PM SETPTRUN

PROGRAM

AHEAD

BACK

RUNPROGRAM

WARMER

COOLER

SLEEP

WAKE LEAVE

RETURN

DAY

Press and hold until the desiredtemperature is reached. The displaywill flash TEMPORARY until the nextprogrammed time period starts.

Press and release to cancel any ofthe temporary settings.

Press and release the desired periodkey.

Press and hold until the desired dayschedule shows on the display.

PERMANENTLY CHANGING THEPROGRAM

If your schedule changes or youwant a different temperature, youcan update any setting withoutaffecting the rest of the program.

Press and hold the Time or Tem-perature keys until the display showsthe desired new program.

Press and release to return tonormal operation.

OPERATING THE THERMOSTATMANUALLY

This feature lets you set onetemperature that the thermostat willhold continuously. Your presetschedule will resume when youpush the RUN PROGRAM key.

Press and release.

Press and hold to change thetemperature setting. After a fewseconds, the display will show thecurrent temperature.

Press and release to check thetemperature setting.

Press and release to cancel hold.

ON HEAT

SETPT

ON HEAT

SETPT

PRESENTSETTING

RUNPROGRAM

HOLDTEMP

WARMER

COOLER

ON HEAT

SETPT


TUELEAVE

PM

16

17

18

OPERATING YOUR THERMOSTATCANCELING PROGRAMSETTINGS

The thermostat requires time andtemperature settings in the WAKEperiod, but any of the other periodscan be canceled. Weekday,Saturday and Sunday settings arecanceled separately.

Press and hold the desired periodkey until the time and temperatureclear from the display (about 3seconds).


SLEEP

LEAVE

RETURN

RUNPROGRAM


MONRETURN

PM

CHECKING THE PROGRAMTIMES AND TEMPERATURES

You can check all the storedsettings without affecting thepermanent program.

SLEEP

WAKEPress and release the desiredperiod key. The start time andtemperature setting will appear onthe display.

Press and release to display thenext daily time and temperature forthat period.


LEAVE

RETURN


PM SETPT

SAT ON HEATSLEEP

PM SETPT

RUNPROGRAM

MONRETURN

PM

DAY

19

20

CHECKING THE CURRENTTEMPERATURE SETTING

Press a single key to comparecurrent room temperature to thesetting at any time.

PRESENTSETTING

Press and release. The display willshow the current temperature settingfor several seconds, then revert tothe room temperature.

ON HEAT

SETPT

ACCSING EXTERNAL SYSTE


EXTERNAL ACCESS ANDCONTROL OF THERMOSTAT

The T8631 CommunicatingChronotherm III Thermostat canbe connected to a HoneywellTotalHome system for externalaccess and control.

A TotalHome system allows youto change thermostat settingsfrom the system's user interfacepanels. depending on the systemchosen, you can also use atouchtone phone to adjust yoursetting. Whenever the thermostatis controlling to TotalHOmesystem setting, a ss appearsunder the room temperaturedisplay.

You can easily make temporarytemperature setting changes bypushing the WARMER orCOOLER key on the T8631. Thetemporary override setting lasts

until the next period starts. Topermanently change the tempera-ture set point, push the desiredperiod key, then the WARMER orCOOLER key. Use the RUNPROGRAM key to change fromexternal system control to thermo-stat control of program times andtemperatures until a new commandis received from the TotalHomesystem.

The T8631 Thermostat cancommunicate on an HBus networkover four-wire conductor cables.This cable connects to the H1, H2,H3 and H4 terminals on thethermostat.

HBus is a Honeywell proprietarycommunications protocol.

For assistance, call ConsumerServices, 1-800-468-1502, Monday-Friday, 7:30 a.m. to 5:00 p.m.,Central time.

MONWAKE

AM SETPT

22

REMOVING THE THERMOSTAT

1 Loosen the two captive screws atthe bottom corners of the case.

2 Pull out the thermostat from thebottom.

3 Lift the thermostat up and off thebase.

AUX. HEAT

HEAT AUTO COOL OFF

ON AUTO

FAN

M5066

SYSTEM

EM. HT. HEAT OFF

ON AUTO

FAN

M5013

COOL

EM. HT. AUX. HEAT

SYSTEMPM

RETURNMON HEAT ON

SYSTEM

M5062

RUNPROGRAM

TIME

TEMPERATURE

PRESENTSETTING

SKIPNEXT

PERIOD

CHANGETO LASTPERIOD

SETPRESENTDAY/TIME

HOLDTEMP

DAY

SETHEAT/COOL SLEEP

LEAVE AHEAD WARMER

RETURN BACK COOLER

WAKE

PERIOD

3 Tighten the captive screws.

M5014HEAT AUTO

COOL OFFON AUTO

FAN

EM. HT.AUX. HEA

T

PMRETURN

MONHEAT ON

SYSTEM

AUTO

M5063

REPLACING THE THERMOSTAT

1 Hang the thermostat on the tabsat the top of the subbase.

2 Swing down and press bottomedge until thermostat snaps inplace.

21

MAINTAINING YOUR THERMOSTAT

PMRETURN

MON HEAT ON

SYSTEM

M5075

RUNPROGRAM

TIME

TEMPERATURE

PRESENTSETTING

SKIPNEXT

PERIOD

CHANGETO LASTPERIOD

SETPRESENTDAY/TIME

HOLDTEMP

DAY

SETHEAT/COOL SLEEP

LEAVE AHEAD WARMER

RETURN BACK COOLER

WAKE

PERIOD

23

24

MAINTAINING YOUR THERMOSTATREPLACING THE BATTERIES

Your thermostat uses three AAA alkaline batteries. Thedisplay will flash REPL BAT when the batteries get low.You wont have to reprogram the thermostat if youinsert the new batteries within 20-30 seconds of takingout the old ones.

To replace:n Set the system switch to OFF.n Remove the thermostat from the wall. See page 21.n Lift the batteries out of the holder.n Insert the new batteries, making sure the positive (+)

terminals all face toward the right.n Replace the thermostat on the wall. See page 22.n Reprogram, if necessary.

M5065

POWER OUTAGES

Backup batteries will hold the programming and keepon the display during most power outages. Once thepower is restored, the system will resume normaloperation.

If the display goes off when power is lost, either thebackup batteries need to be replaced or were notinstalled. When power is restored, the display will flash1:00 PM to remind you to reprogram. If the colon is notflashing, there is no AC power or the thermostat is notproperly connected to the subbase.

25

26

ADAPTIVE INTELLIGENT RECOVERY

M 168

ADAPTIVE INTELLIGENTRECOVERYBREAK-THROUGH TECHNOLOGYSENSES TEMPERATURE MORELIKE YOU DO

Your new thermostat is so smart,its almost human.

n Your body perceives temperature from a variety of sources, not only fromthe air in the room, but also from your surroundingswalls, windows andfurnishings.

n Human beings feel differences in temperature as slight as two degreesFahrenheit.

n Common household thermometers and standard thermostats sense onlyair temperature, which may or may not reflect how hot or cold the roomactually feels to a human being.

n Your new thermostat reads both the temperature of the wall and the airand responds to temperature changes as little as one degree Fahren-heitso room temperature is more likely to feel right to you and yourfamily.

27

28

AMPM

SUN MON TUE WED THU FRI SAT COOL ON HEAT ONWAKE LEAVE RETURN SLEEP TEMPORARY UNOCCUIPIED

REPLBAT

SETPT

AMPM


REPLBAT

SETPT

AMPM


REPLBAT

SETPT

AMPM


REPLBAT

SETPT

System Operatingin Energy Savings Mode

Recovery Begins Recovery Continues

System Operatingin Comfort Mode

ENERGYSAVINGSPERIOD

RECOVERY FROM ENERGY SAVINGS COMFORTPERIODTIME

TEM

PER

ATU

RE

THE THERMOSTAT USES THE SAME SCHEME TO RETURN GRADUALLYTO LOWER COMFORT TEMPERATURE DURING THE COOLING SEASON. M 171

THE OPTIMUM COMFORT ANDENERGY SAVINGS SOLUTION

n This thermostat is actually a small but powerful computer. When calculat-ing the exact time to turn on your furnace or air conditioner, it considers(1) air temperature, (2) temperature of the wall and (3) when you wantthe comfort temperature established.

n During the Adaptive Intelligent Recovery setting, the thermostat in-creases the control temperature gradually and turns the equipment onand off several times to save energy by avoiding overshooting thecomfort temperature. You can see the current control temperatureanytime during recovery by pressing the PRESENT SETTING key.

n This smart control learns from experience. Each day it checks howclosely it hit the target and adjusts the recovery start time accordingly.

n It typically takes four to eight days after installation for this thermostat toadjust to the weather, your life style, home construction and heating/cooling system. The thermostat calculates the LEAVE/RETURN recoveryseparately from the SLEEP/WAKE recovery.

n With the T8631A, you can choose whether you want to use AdaptiveIntelligent Recovery or conventional recovery. Use the AdaptiveIntelligent Recovery setting if you want to choose the exact time that theroom reaches your comfort temperature. Use conventional recovery ifyou prefer to choose the exact time your furnace or air conditioner comeson to start recovery.

ADAPTIVE INTELLIGENT RECOVERY

SELECTING RECOVERY SETTING

29

30

Your T8631A Thermostat includes a screw on the backmarked 2A, allowing for the Adaptive Intelligent Recov-ery/Conventional Recovery choice.Your thermostat was shipped from the factory with thescrew positioned for Adaptive Intelligent Recoverysetting. Your installer may have left the screw in thisposition, or may have changed it to ConventionalRecovery. Before programming, you must know whichrecovery method your thermostat has been set for. With the Adaptive Intelligent Recovery setting, the

dwelling will reach the comfort temperature at theexact time you have programmed into the thermo-stat.

With Conventional Recovery, the programmed timewill be the time your furnace comes on to startrecovery; therefore, you should program the starttime to be earlier than the desired comfort time. Itmay require some trial and error for you to arrive atthe best starting time, and the best starting time willvary as the seasons change.

SYSTEM

GRAVITYAIR/WATER

HOTWATERGAS/OIL

WARM AIRELECTRICWARM AIR

1A

OUT1 TURN

OUT 1 TURN

OUT 1 TURN

OUT 1 TURN

1B

IN

IN

(FACTORY SETTING)IN IN

M3064

1A 1B

2A 2B

DISPLAY TEMPERATURE2BoC

Fo OUTIN

2B

2A

OUTIN

2A

RECOVERY OPTIONADAPTIVECONVENTIONAL

HEAT CYCLE RATE

To determine which type of recovery isset into your T8631A Thermostat,make sure your thermostat is mountedand powered on the wall.

Press key. Check thermostat display.

If the nn shows in the lower right-hand corner (see illustration), thethermostat is set for ConventionalRecovery. If you would rather havethe Adaptive Intelligent Recoverysetting, remove thermostat fromwall, turn screw 2A (on back ofthermostat) clockwise until itbottoms. DO NOT OVERTIGHTEN.

If the nn does not show, thethermostat is set for AdaptiveIntelligent Recovery. If you wouldrather have Conventional Recov-ery, remove thermostat from wall,turn screw 2A (on back of thermo-stat) out 1/2 to 1 turn.

MONWAKE

AM

M5058

INDICATES THERMOSTAT IS SET FOR CONVENTIONAL RECOVERY

RUNPROGRAM

HEAT PUMP WITH SUPPLEMENTAL HEATHEAT PUMPS ARE DIFFERENT (T8631R)n Heat pump systems usually have a supplemental,

second stage heating system that operates onlywhen necessary. The Honeywell Chronotherm IIIThermostat for heat pumps is designed to minimizethe more expensive second-stage operation,indicated by the green AUX light on the switchingsubbase.

n With your Chronotherm III Thermostat, you willnotice that your compressor operates continuouslyduring the recovery period. This may appear towaste energy, but it is actually more efficient.Multiple ON-OFF cycles are neither necessary toachieve comfort, nor as efficient for heat pumpsystems. By reducing the number of cycles, youreduce the strain on your system and extendequipment life.

AUXILIARYHEATINGELEMENTOFFOUTDOOR

AIR

INDOORAIR

HEATTRANSFER

INDOORSOUTDOORS

AUXILIARYHEATINGELEMENTONOUTDOOR

AIR

INDOORAIR

HEATTRANSFER

INDOORSOUTDOORS

MILD WEATHER SEVERE WEATHER

n In mild weather, almost all of the demand for heat inbuildings can be met by the heat pump compressor.This first stage process of moving heat indoors isvery economical. As the air becomes colder outside,the first stage may be unable to deliver enough heatto maintain the desired comfort level in the building.

n During high heat demand, the thermostat will call foradditional second stage power from the auxiliaryheat system. This auxiliary heat is commonlyelectric resistance heat and is two to three timesmore expensive to operate than the compressor.

31

32

HEAT PUMPS ARE TWO SYSTEMS IN ONE

33

34

ANSWERING COMMON QUESTIONS ABOUT THE CHRONOTHERM III THERMOSTAT

3. Why does the T8631 follow a schedule notprogrammed into the thermostat?When the s s is displayed, the thermostat is control-ling to the setting in your TotalHome system.

4. How many hours in advance of my WAKE timeshould the furnace come on?The time will vary, up to 24 minutes per degreeFahrenheit difference between the energy savingand comfort temperatures, depending on outsidetemperature and performance during the past 24hours. A microchip computer with Adaptive IntelligentRecovery allows the thermostat to think for itselfand adjust the furnace or air conditioning recoverytime to reach your desired comfort temperature atthe programmed time. Whenever the temperature ismore than one degree hotter or colder than thecomfort temperature at the programmed time, thesystem turns on earlier the next day. This approachensures the temperature wont over- or under-shootthe set point and allows the proper amount of timefor recovery.

5. What does the HOLD key do?It bypasses all program settings and holds thetemperature at the present setting. To increase ordecrease the temperature while on HOLD, use theWARMER-COOLER keys. Pressing the thermostatsRUN PROGRAM key or entering a change at theexternal system will return the device to programmedoperations.

6. How long does the HOLD key hold?Forever! The HOLD key will hold the temperatureindefinitely. The only way to release it is to press theRUN PROGRAM key or enter a change at theTotalHome system.

7. How can the T8631A Thermostat save energywhen it comes on and off so many times early inthe morning hours?Two ways. First, it saves energy (and money) bysetting back the temperature for blocks of timeduring the day or night. Second, it conserves energyby recovering gradually to the desired temperature.

1. The temperature displayed on the Chronotherm IIIThermostat doesnt always match the roomtemperature on another thermometer locatedright next to it. Why?The Chronotherm III Thermostat is a very accurateinstrument designed to sense both air temperatureand wall temperature, like your body does. It gives anaverage reading over a period of time. Because itadjusts itself, it will take a few days after installationto adjust to your home.

2. A ss triangle symbol is on the display sometimes.What does it mean?The T8631 Communicating Chronotherm III Thermo-stat can be connected to a Honeywell TotalHomesystem for external access and control. Wheneverthe thermostat is controlling to TotalHome systemsettings, a ss appears under the room temperaturedisplay.

This prevents overshooting your comfort set point(and wasting energy) or under-shooting the comfortset point (and forcing you to change the thermostatsetting, also wasting energy).Honeywell experts have invested years of engineer-ing and in-home testing to assure that this is themost effective way to set back and save energywhile optimizing your comfort.

8. Sometimes my Chronotherm III Thermostatdoesnt allow the house temperature to drop tomy SLEEP setting before it starts bringing thefurnace on. Why?Many factors affect your comfort and energysavings. If those factors, such as weather, humidity,etc. were always consistent, an unchanging programwould work just fine. But factors change. The wholepoint of Adaptive Intelligent Recovery is to saveenergy without sacrificing comfort. If necessary, theAdaptive Intelligent Recovery will override yourtemperature settings to assure accurate temperaturerecovery with optimum comfort and energy savingsfor the current conditions.

35

36

ANSWERING COMMON QUESTIONS ABOUT THE CHRONOTHERM III THERMOSTAT

Heres how to override Adaptive Intelligent Recoverysetting:n Set the desired WAKE program temperature.n Set the WAKE program time 30 to 60 minutes before

the time you normally get up. (You can adjust thistime. If the house reaches the comfort temperaturetoo early, set the time later; if it reaches the comforttemperature too late, set the time earlier, but dont gobeyond 90 minutes.)

n Set the desired SLEEP program time and tempera-ture. The SLEEP temperature must not be more than10 degrees below the comfort setting.

n Set the RETURN program time to 10 minutes beforeyour programmed WAKE time.

n Set the RETURN program temperature the same asthe SLEEP temperature.

n The LEAVE program remains blank unless you wanta day energy saving period. See page 3.

n The thermostat will think that it doesnt need to startrecovery until 10 minutes before your WAKE time. Itwill run the furnace constantly until the comforttemperature is reached.

9. Can I stop the thermostat from bringing the heaton so early in the morning? How?T8631A has screws on the back of the thermostatthat will allow you to turn off Adaptive IntelligentRecovery.On the T8631R without the screw to overrideAdaptive Intelligent Recovery, you will only be ableto set one completely automatic energy savingsperiod; the second period must be ended manually.Also, since recovery starts at the time you pro-grammed, the comfort temperature may not bereached by the desired time.

EXAMPLE:TEMPERATURE

PERIOD TIME SETTING SETTINGWAKE 5:30 AM 70 FLEAVE SLEEP 10:00 PM 60 F

RETURN 5:20 AM 60 F

If you want a day program:n Set the desired LEAVE time and temperature. The

thermostat will automatically initiate an energysavings period.

n The first person home must push the CHANGETO LAST PERIOD key to start warming thehouse. The furnace will run constantly until thecomfort temperature is reached.

Do you have a heat pump with auxiliary heat?If so, we dont recommend overriding Adaptive Intelli-gent Recovery because the amount of expensiveauxiliary heat needed for recovery can cost more thanthe energy saved by lowering the temperature.

10. I have a high efficiency furnace and my heat isshort cycling. What can I do?Some high efficiency furnaces need the cycle rate setat the Hot Water setting instead of the factory settingof gas/oil warm air. Turn out the 1A screw with screw1B left turned in.

Additional Questions? Call Honeywell ConsumerServices: 1-800-468-1502 Monday-Friday, 7:30 a.m. to5:00 p.m., Central time.

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SAVING ENERGY ACROSS THE U.S.

9% TO 11%

12% TO 13%

14% TO 15%16% TO 18%

ONE 10 F ENERGY SAVINGS PERIOD*70 TO 60 F; 8 HRS/DAY

18% TO 24%

23% TO 25%

25% TO 29%UP TO 30%

TWO 10 F ENERGY SAVINGS PERIODS*70 TO 60 F; 8 HRS/DAY, 8 HRS/NIGHT

M 167B

o

o o

o

o

o

o

o

PERCENTAGE OF HEATING ENERGY YOU CAN SAVE

* Savings for a 5 F heating setback are at least1/2 of savings for a 10 F setback.Actual savings depend on your home, geographic location,number of energy saving periods and energy savings temperature.

SEATTLE, WA12% - 24%

BILLINGS, MT10% - 20% MPLS., MN

9% - 18%

CHICAGO, IL11% - 21%

CINCINNATI, OH12% - 24%

NEW YORK, NY12% - 23%

SAN FRANCISCO, CA14% - 26%

LOS ANGELES, CA15% - 30%

DODGE CITY, KS12% - 23%

If you have a heat pump, your heating savings may be greater than those shown.

DC

PHOENIX, AZ16% - 30%

DALLAS, TX15% - 28%

ATLANTA, GA15% - 27%

ALBUQUERQUE, NM12% - 24%

NEW ORLEANS, LA16% - 30%

MIAMI, FL18% - 30%

GREENSBORO, NC14% - 25%

n Save up to 30% in energy costs. Chronotherm IIIThermostats offer you complete comfort and a low-cost easy way to save on your energy bills.

n The energy-saving percentages listed on the mapson pages 38 and 39 are based on setting thethermostat down in winter or up in summer for eighthours.

n If the time period you choose for setback is longer,you may see even greater energy savings. Theenergy saving period must be at least two hours longto save any energy.

Find the city closest to your home. The energy savinglisted will be similar to the saving you can expect.

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7% TO 9%

10% TO 11%

12% TO 14%15% TO 18%

ONE 5 F ENERGY SAVINGS PERIOD*75 TO 80 F; 8 HRS/DAY

11% TO 15%

16% TO 18%

19% TO 22%23% TO 33%

TWO 5 F ENERGY SAVINGS PERIODS*75 TO 80 F; 9 HRS/DAY, 7 HRS/NIGHT

M 211B

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o o

o

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PERCENTAGE OF COOLING ENERGY YOU CAN SAVE

* Actual savings depend on your home, geographic location,number of energy saving periods and energy savings temperature.

SEATTLE, WA16% - 23%

BILLINGS, MT9% - 16% MPLS., MN

12% - 20%

CHICAGO, IL13% - 20%

CINCINNATI, OH12% - 19%

NEW YORK, NY13% - 20%

SAN FRANCISCO, CA14% - 19%

LOS ANGELES, CA20% - 27%

DODGE CITY, KS9% - 15%

DC

PHOENIX, AZ16% - 30%

DALLAS, TX15% - 28%

ATLANTA, GA15% - 27%

ALBUQUERQUE, NM12% - 24%

NEW ORLEANS, LA16% - 30%

MIAMI, FL18% - 30%

GREENSBORO, NC14% - 25%

SAVING ENERGY ACROSS THE U.S.

GLOSSARYAdaptive Intelligent RecoveryThe time when the thermostat operates the heating orcooling equipment to return the house from the energysavings to the comfort temperature. The thermostatstarts the recovery period early so the house will be atthe comfort setting by the time youve chosen.

Comfort temperatureThe temperature you want in the morning and eveningwhen youre home.

Conventional RecoveryThe time set for a program period when the heating orcooling equipment will first start getting the room to theset temperature.

Energy-saving temperatureThe lower (heating) or higher (cooling) temperature thatlets you save on heating and cooling costs when youreasleep or away. Also called the setback (heating) orsetup (cooling) temperature.

HBusA Honeywell proprietary communications protocol.

Period keyOne of the four keysWAKE, LEAVE, RETURN orSLEEPthat you press to check or program the starttime and temperature for a time period.

Preprogrammed scheduleThe schedule programmed into your thermostat at thefactory. It sets a night program that provides energysavings if you dont set your own program, or if yourpersonal program is lost for any reason. The program,which is the same for all days of the week, is:

Start TemperaturePeriod Time Heating CoolinGWAKE 6:00 AM 70 F 78 FLEAVE - - - - - No program - - - - - - - - - -RETURN - - - - - No program - - - - - - - - - -SLEEP 10:00 PM 60 F 78 F

GLOSSARY

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EM HT light [T8631R only] (red)this light glowswhenever the thermostat system switch is in the EMHT position (located on subbase). On some systemsit may also indicate the need to switch to EM. HEATbecause of a problem with the heat pump.

Sunday program scheduleThe schedule of WAKE, LEAVE, RETURN and SLEEPperiod start times and temperatures that you program torun on Sundays.

Time periodOne of four program periods: WAKE, LEAVE, RETURNand SLEEP available with the Chronotherm III Thermo-stat. One period begins when the previous period ends.

WAKEThe time period when you want the houseat a comfortable temperature while the family gets upand gets ready to leave for work and school. This isthe only period that must contain a time and tem-perature.LEAVEThe time period when you can set back(winter) or up (summer) the temperature for energysavings because the family is usually away fromhome.

RETURNThe time period when you want thehouse at a comfortable temperature for familyactivities in the evening before bedtime.SLEEPThe time period when you can set back(winter) or up (summer) the temperature for energysavings because the family is sleeping. Set it to startat your familys normal bedtime. Often the SLEEPprogram is set only for the heating season so familymembers can sleep cool in summer.

TotalHomeA Honeywell system that lets you control your homeenvironment from a user interface panel. Depending onthe system chosen, you can also use a touchtonephone to adjust your settings. TotalHome offersconvenience and flexible control of your security systemand home environment.

Weekday program scheduleThe schedule of WAKE, LEAVE, RETURN and SLEEPperiod start times and temperatures that you program torun Monday through Friday.

PROGRAMMING YOUR THERMO

ProgramThe times and temperatures you set to define thecomfort and energy savings periods for each schedule(weekdays, Saturday, Sunday).Saturday program scheduleThe schedule of WAKE, LEAVE, RETURN and SLEEPperiod start times and temperatures that you program torun on Saturdays.

SetbackReducing the temperature in the house for a set periodevery day in winter for energy savings. The lowertemperature is the energy savings temperature.

SetupRaising the temperature in the house for a set periodevery day in summer for energy savings. The highertemperature is the energy savings temperature.

Set pointThe temperature you set on the thermostat. Thethermostat turns the heating or cooling equipment onand off to maintain this temperature at the thermostatlocation until another temperature setting goes intoeffect.

STATUS LIGHTSLights that show system operationsettings.

SYSTEM light (yellow)This light glows wheneverthe thermostat is calling for heating or cooling(located on thermostat).AUX HT light [T8631R only] (green)This lightglows whenever the thermostat is calling for opera-tion of the backup heater. Backup (auxiliary) heat ismore expensive to operate than the heat pump andtypically is used only when the heat pump is unableto handle the load (located on subbase).

Weekday ProgramSTART HEATING COOLING

PERIOD TIME TEMPERATURE TEMPERATUREWAKELEAVERETURNSLEEP

Saturday ProgramSTART HEATING COOLING


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YOUR THERMOSTAT

YOUR PERSONAL PROGRAMYou can use the tables below to plan your schedulebefore you begin programming. If you choose not to

program a daytime energy savings period, leave theLEAVE and RETURN periods blank.

Sunday ProgramSTART HEATING COOLING


TROUBLESHOOTING GUIDEIF THENDisplay will not come on. n Check that heat or cool system power is on. You need 24V from R to C

terminals.n Make sure thermostat is correctly mounted on subbase.

Display flashes during programming. n You have reached the temperature setting limit. The setting range is45 F to 88 F.

Display flashes during operation. n Programming has been lost because of a power outage. You mustreprogram.

Program is lost due to power n Check that backup batteries are installed correctly. Replace if necessary.outage. Reprogram the thermostat.Colon in display does not flash. n Check for 24V from R to C terminals on the subbase.

n Make sure thermostat is mounted correctly on the subbase.Temperature change occurs n Check for s s on display screen. If ss is present, check your externalat the wrong times. system for the command that is bypassing the thermostat program.

n Check the program times for the period in question. Be sure that AM andPM indications are correct. Make sure the current day and time arecorrect. Reprogram if necessary.

n Remember that with Adaptive Intelligent Recovery the heating orcooling system comes on before the WAKE and RETURN start timesso the house will be at the desired temperature when the period starts.

n Check if T8631A is set for Conventional Recovery ( n n visible on display)or Adaptive Intelligent Recovery.

Heating will not come on. n Check the fuse or circuit breaker and replace or reset if necessary.n Check that switch on thermostat is set to HEAT.n T8631R has a built-in time delay which can add to time delays in the

heating equipment. Allow up to 10 minutes after changing the settingbefore the compressor starts.

n If temperature setting is higher than current temperature, and displaysays HEAT ON or SYSTEM light is on, contact your heating and airconditioning contractor.

Cooling will not come on. n Check the fuse or circuit breaker and replace or reset if necessary.n Check that switch on thermostat is set to COOL.n The thermostat has a built-in time delay, which can add to time delays in

the cooling equipment. Allow up to 10 minutes after changing the settingbefore the compressor starts.

n If temperature setting is lower than current temperature, and display saysCOOL ON or SYSTEM light is on, contact your heating and airconditioning contractor.

The building is too warm or too cool. n Press PRESENT SETTING to check the current temperature setting.n If desired, change the time or temperature setting. See page 21.n Check for ss on display screen. If ss is present, check your external

system for the command that is bypassing the thermostat program.Display says HEAT ON or system n Allow time for the heating equipment to heat up beforelight is on, but no heat is coming checking for heat at the register.from the registers.Display flashes REPL BAT or n Install fresh AAA alkaline batteries. See page 23.goes blank when power is turned off.

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QUICK REFERENCE TO THE KEYSPress these keys to: Begin the current day or time

programming.

Set the day of the week and selectthe program day during program-ming.

Select the time period to program orreview.

Switch between heat and coolsettings during programming orwhen reviewing the program.

Set the time ahead and back. Holdeither key down to change thesetting faster.

Set the temperature while program-ming and temporarily change thetemperature during operation. Holdeither key down to change thesetting faster.

Hold any temperature you desire foran extended period.

Change the temperature to the setpoint of the previous period.

Maintain the current temperaturethrough the next program period.

Start your programmed schedule;cancel temporary program changes.

See the current temperature setting.Setting may not match programmedsetting during recovery from energysavings.

SETPRESENTDAY/TIME

DAY

LEAVE

RETURNSLEEP

WAKE

SETHEAT/COOL

AHEAD

BACK

WARMER

COOLER

SKIPNEXT

PERIOD

RUNPROGRAM

PRESENTSETTING

HOLDTEMP

CHANGETO LASTPERIOD

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INDEXAccessing external system control .............................. 20Adaptive Intelligent Recovery .......................... 25-28,40Auxiliary heat light ....................................................... 41Batteries, replacement ................................................ 23Blinking display ........................................................ 3,10Canceling programs .................................................... 17Change temperature ................................................... 15Checking present setting............................................. 19Checking programs ..................................................... 18Clock display .............................................................. *,1Comfort temperature ................................................... 40Conventional recovery ................................................ 40Cooling temperatures .............................................. 7-11Day ................................................................................ 1Display ....................................................................... *,1Emergency heat light .................................................. 42Energy-saving temperature ......................................... 40

Fan switch ................................................................... 12Features ........................................................................ *Flashing display .......................................................... 45Glossary ................................................................ 40-42HBus ........................................................................... 40Heating temperatures................................................ 2-6Hold temperature ................................................... 16,48Keys ...................................................................... 47-48LEAVE.................................................................... 42,47Lights ..................................................................... 41-42Maintenance.......................................................... 21-24Manual operation ........................................................ 16Operation .............................................................. 14-20Period keys ............................................................ 40,42Personal program.................................................. 43-44Power outage .............................................................. 24Preprogrammed schedule ........................................... 40

Setting limits ............................................................... 3,8Setup ........................................................................... 41Skip ............................................................................. 48Sunday program.................................................. 6,10,42Switch, fan................................................................... 12Switch, system ...................................................... 12-13System light ................................................................. 41System switch ....................................................... 12-13Table of Contents ........................................................... iTemporary program changes ...................................... 14Time .............................................................................. 1Time period ................................................................. 42Troubleshooting .................................................... 45-46WAKE..................................................................... 42,47Warranty ...................................................................... 51Weekday program .......................................... 2-5,7-9,42

*See the product features inside the front cover.

Present setting ....................................................... 19,48Program schedule ......................................................... 2Programming overview ................................................. *Programming steps ................................................. 1-13Quick reference to the keys .................................. 47-48Recovery Setting ................................................... 29-30Removing thermostat .................................................. 21Replacing batteries ..................................................... 23RETURN ................................................................ 42,47SLEEP.................................................................... 42,47Saturday program ........................................... 5,9-10,41Set cooling temperatures ........................................ 7-11Set current day .............................................................. 1Set current time ............................................................. 1Set fan switch .............................................................. 12Set heating temperatures .............................................. 2Set program schedule ................................................... 2Set system switch ....................................................... 12Setback ....................................................................... 41

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LIMITED ONE-YEAR WARRANTYHoneywell warrants this thermostat, excluding battery, to be free from defects in the workmanship or materials, under normal use and service, for a periodof 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, Honeywellshall repair or replace it (at Honeywells option) within a reasonable period of time.If the thermostat is defective,

(i) return it, with a bill of sale or other dated proof of purchase, to the dealer or contractor from which 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:Honeywell Inc.Return Goods Department1050 Berkshire LanePlymouth, MN 55441-4437

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 causedby damage which occurred while the product was in the possession of a consumer.Honeywells sole responsibility shall be to repair or replace the product within the terms stated above. HONEYWELL SHALL NOT BE LIABLE FOR ANYLOSS OR DAMAGE OF ANY KIND, INCLUDING ANY INCIDENTAL OR CONSEQUENTIAL DAMAGES RESULTING, DIRECTLY OR INDIRECTLY FROMANY BREACH OF ANY WARRANTY, EXPRESSED OR IMPLIED, OR ANY OTHER FAILURE OF THIS PRODUCT. Some states do not allow the exclusionor limitation of incidental or consequential damages, so this limitation may not apply to you.THIS WARRANTY IS THE ONLY EXPRESS WARRANTY HONEYWELL MAKES ON THIS PRODUCT. THE DURATION OF ANY IMPLIED WARRANTIES,INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, IS HEREBY LIMITED TO THE ONE YEARDURATION OF THIS WARRANTY. Some states do not allow limitations on how long an implied warranty lasts, so the above limitation may not apply toyou.

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 Consumer Services Department, Honeywell Inc. 1885 Douglas Dr. N., Golden Valley,MN 55422-3992, or call 1-800-468-1502, Monday-Friday, 7:30 a.m. to 5:00 p.m., Central time.

Chronotherm IIIfor Comfort and Convenience

OWNER'S GUIDE

R e s i d e n t i a l a n d R e s i d e n t i a l a n d H e l p i n g Y o u C o n t r o l Y o u r W o r l d

B u i l d i n g C o n t r o l s D i v i s i o n B u i l d i n g C o n t r o l s D i v i s i o n

H o n e y w e l l I n c . H o n e y w e l l L i m i t e d H o n e y w e l l L i m i t e

1 9 8 5 D o u g l a s D r i v e N o r t h 7 4 0 E l l e s m e r e R o a d

G o l d e n V a l l e y , M i n n e s o t a 5 5 4 2 2 S c a r b o r o u g h , O n t a r i o

M 1 P 2 V 9

Congratulations! You made a smart choice when you purchased your new Honeywell CommunicatingChronotherm III Thermostat. Its the smart thermostat that:

nKeeps you comfortable by automatically calculating exactly when the furnace or air conditioningshould go on to have the house at the desired comfort temperature by the time you wake up.nSaves the maximum amount of energy and money by remembering to automatically set back the heator air conditioning when you leave home.nProvides the ultimate in comfort and convenience by coming to you already programmed. But its yourchoiceuse the preprogrammed schedule or set your own.nCan be connected to a Honeywell's TotalHome system for external access and control. TotalHomesystem devices communicate using HBus, a Honeywell communications protocol.

honeywell chronoterhm iii

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