Your new Honeywell Chronotherm IIIFuel Saver Thermostat is a precisioninstrument that’s quality-built to giveyou many years of satisfactoryservice. Each day of the week can beprogrammed independently so that,regardless of your schedule, you’llsave fuel while automaticallymaintaining the standard of comfortyou require.This User’s Guide will show you howto get the most benefit from your newthermostat.

Programming Your Thermostat ............... l-1 8

Enter the day and time ......................... 1

Set the program times andtemperatures for one day ................... 2

Copy the program to the desired days ....... 11Set the program times and temperatures

for the remaining days ..................... 14

Set the system and fan switcheson the subbase ............................. 17

Operating Your Thermostat ................. 19-26

Temporarily changing the program ......... .19

Permanently changing the program ......... .21

Operating the thermostat manually .......... .23

Canceling program settings ................. .24

Checking the program times andtemperatures .............................. ,215

Checking the current temperature setting ... .26Maintaining Your Thermostat ............... 27-30

Removing the thermostat .................... .27Replacing the thermostat .................... .28

Replacing the batteries . . . . . . . . . . . . . . . . . . . . . . .29

Power outages .............................. .30

Glossary ..................................... 31-32

Your Daily Program ......................... 33-34

Model Identification Guide .................. 35-36

Troubleshooting Guide ...................... 37-38

Quick Reference to the Keys ... . . . . . . . . . . . . . 39-40

Index ......................................... 41-42

Warranty ........................................ .43

I

I

STEP 1ENTER THE DAY AND TIME

You can program this thermostaieither on the wall or in yourhand. SEE PAGE 27 TO FINDOUT HOW TO REMOVE THETHERMOSTAT FROM THEWALL

Always press the keys with yourfingertip or similar blunt tool.Sharp instruments like a pen orpencil point can damage thekeyboard.

NOTE: Check the glossary, page31, for definitions of unfamiliarwords.

STEP 2SET THE PROGRAM TIMESAND TEMPERATURES FORONE DAY

Before You Begin. . .The schedule form on page 33provides an opportunity to planyour daily program.

Now. . .Choose a day to program first.We’ll use Monday in the exam-ples, but you can start with anyday. Start by programming theMORNING time and tempera-tures. The thermostat requires aMORNING program every day.You can set additional programsas desired.

SET0 Press and release. The displayPRESENTDAY/TIME shows 1:00 PM Mon.

Press and hold until the currentday appears in the display.

TIME

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Press and hold until the currentA, time appears in the display. Be

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sure AM or PM appears as:’ desired.

You have set the current day andtime. Go on to Step 2.

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1

m¶ Press and release. Note that the- ‘.. display shows MORNING and

the preprogrammed time andtemperature.

If the display reads COOL, pressand release to switch to HEAT.

Press and hold until MONDAY(or the desired day) appears inthe display.

Press and hold until the displayshows the time you want thetemperature at the comfort

I setting.

00 -mlPress and hold until the displayshows the desired heatingtemperature.

If the display flashes while youare holding down TEMPERA-TURE WARMER or COOLER,you have reached the settinglimit. If your thermostat canswitch automatically betweenheating and cooling, the heatingtemperature must be at least 3degrees below the air condition-ing temperature. For example, ifthe cooling setting is 75’ F, themaximum heating setting is 72”F. To set a higher heatingtemperature, you must first raisethe cooling setting.

Program the MIDDAY time andheating temperature if desired.

NOTE: You can cancel anyperiod showing on the displayexcept MORNING by pushingthe the CANCEL PERiOD key.To move to the next periodwhile programming, simply ml’ ”press the PERIOD key again.

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

Press and hold until the displayshows the time you want roomtemperature to start driftingtoward the energy saving setting.

Press and hold until the displayshows the desired temperature.

4

Program the EVENING time andtemperature, if desired.

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

Press and hold until the displayshows the time you want thetemperature to be at the comfortsetting.

Press and hold until the displayshows the desired heatingtemperature.

Program the NIGHT time andtemperature, if desired.

Press and release. The displayshows NIGHT and the prepro-grammed time and temperature.

Press and hold until the displayshows the time you want thetemperature to start driftingtoward the energy saving setting.

Press and hold until the displayshows the desired heatingtemperature.

5

6

Set the cooling temperatures forall the periods you’veprogrammed.

Press and release. The displayshows COOL, the prepro-grammed cooling temperatureand the programmed start timefor NIGHT.

7

Press and hold until the displayshows the desired coolingtemperature for NIGHT.

If the display blinks while you areholding down TEMPERATUREWARMER or COOLER, you havereached the setting limit. If yourthermostat can switch automatic-ally between heating and cooling,the heating temperature must beat least 3 degrees below the airconditioning temperature. Forexample, if the heating setting is72’ F, the minimum cooling set-ting is 75’ F. To set the coolingtemperature lower, you must firstlower the heating setting.

8

Press and release. The displayshows the preprogrammed cool-ing temperature and the pro-grammed start time forMORNING.

Press and hold until the displayshows the desired coolingtemperature for MORNING.

Press and release. The displayshows the preprogrammed cool-ing temperature and the pro-grammed start time for MIDDAY.

Press and hold until the displayshows the desired coolingtemperature for MIDDAY.

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m¶ Press and release. The display= -.. shows the preprogrammed cool-

ing temperature and the pro-grammed start time for EVENING.

Press and hold until the displayshows the desired coolingtemperature for EVENING.

You have completed setting theprogram schedule for one day.Go to Step 3 to copy this pro-gram to additional days.

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STEP 3COPY THE PROGRAM TO THEDESIRED DAYS

You can copy one day’s programto any other day or combinationof days. The new program willreplace any program already setin the day selected.

If necessary, press and releaseto enter the programming mode.

Press and hold until the daycontaining the program to becopied shows in the display.

Press and release. The day to becopied will show, and the nextday will flash, in the display.

Press and release if you wish tocopy the program into the daythat’s flashing in the display. Notethat the next day now starts toflash.

Press and release if you don’twish to copy into the day that’sflashing. Note that the next daynow starts to flash.

Press and release the COPY TOkey again to select the day that’sflashing, or the DAY key to by-pass it.

Continue until all desired daysare showing in the display andare not flashing.

Press and release to copy theprogram into all the days youhave selected.

NOTE: The display will show32” F instead of the currenttemperature until the thermo-stat is mounted on the sub-base and the system ispowered.

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STEP 4SET THE SCHEDULES ANDTEMPERATURES FOR THEREMAINING DAYS

Use the procedures described inSteps 2 and 3 and summarizedin this step to program theremaining days.

Press and release to enter theprogramming mode.

Press and hold until the day youwish to program shows on thedisplay.

If COOL shows on the display,press and release to switch toHEAT.

Use the AHEAD/BACK keys toset the time and theWARMER/COOLER keys to setthe heating temperature.

13

Press and release the PERIODkey to step through the remain-ing time periods. Use theAHEAD/BACK keys to set the _.time and the WARMER/COOLERkeys to set the heating tempera-ture for each time period.

Press and release so COOLshows on the display.

Press and release the PERIODkey to step through the timeperiods, and use the WARMER/COOLER keys to set the coolingtemperature for each period.

14

You have completed the time l ’and temperature program for I!H-aanother day. Now you can copyit into additional days if you wish.

l -H0

H,’

NOTE: The display will show32” F until the thermostat ismounted on the subbase andthe system is powered.

Press and release to enter thecopy mode. The next day flasheson the display.

Press and release the Copy Tokey to select the day that’sflashing, or the Day key tobypass it.

Continue, using the Copy To keyto bring up the next day, followedby Copy To to select, or Day tobypass the day, until all desireddays are selected.

Press and release to completethe copy.

Repeat Step 4 as needed until alldays are programmed.

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16

TEMPORARILY CHANGINGTHE PROGRAM

These features let you custom-tailor the program for those timeswhen someone comes homeearly, or you or a colleague isworking late, or you plan to beout for the evening.Changes made with these keysare active for one programperiod and then are cancelled.

To keep the current temperaturethrough the next program period:

Press and release. The name ofthe period to be skipped willflash in the display until the starttime of the skipped period.During the skipped period thedisplay will flash “temporary” toshow that the programmedtemperature for this period is notbeing used.

19

To go back to the temperatureof the previous program period:

To temporarily raise or lower thetemperature for the currentperiod only:

If you change your mind:

CHANGE0TO LASTPERIOD

Press and release. The displaywill show the name of the pre-vious period and flash “tempor-ary” until the next regularlyscheduled period starts.

Press and hold until the desiredtemperature is reached. The dis-play will flash “temporary” untilthe next programmed time periodstarts.

Press and release to cancel anyof the temporary settings. [,,..I

PERMANENTLY CHANGINGTHE PROGRAM

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

Press and hold until the desiredtime period shows on thedisplay.

Press and hold until the desiredschedule day shows on thedisplay.

- S

You can copy the new programinto other days if you wish. Whenyou copy a program, all the timesand temperatures for that day arecopied.

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Press and hold the Time orTemperature keys until thedisplay shows the desired newprogram.

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Press and release. The next day .will flash on the display. PressCopy To to copy into, or Day to.

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bypass, the day. Continue untilthe program has been copiedinto all desired days.

Press and release to return tonormal operation.

22

OPERATING THETHERMOSTAT MANUALLY

Press and release.

This feature is particularly usefulwhen you go on vacation orother extended absence. It doesnot cancel your program.

CANCELING PROGRAMSETTINGS

The thermostat requires time andtemperature settings in theMORNING time period for eachday, but any of the others can becanceled. Each time period foreach day must be canceledseparately.

You can use the copy function tocancel the program from otherdays, but remember: all theprograms will be copied, not justthe cancellation.

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Press and hold to change thetemperature setting. After a fewseconds the display will showthe current temperature.

Press and release to check thetemperature setting.

Press and release to cancelmanual control.

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Press and hold until the desiredtime period shows on thedisplay.

Press and hold until the desiredday shows on the display.

Press and release to cancel thetime and temperature settings forthat time period. Both the heatingand cooling temperatures will becanceled.

Press and release to return tonormal operation.

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24

CHECKING THE PROGRAMTIMES AND TEMPERATURES

You can check all the storedsettings without affecting thepermanent program.

IPREAI

CHECKING THE CURRENTTEMPERATURE SETTING

PRESENT0SETTING

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

Press and hold until the desiredperiod shows on the display. Thestart time and temperature set-ting will appear on the display.

Press and release to display thenext day’s time and temperaturefor that period.

Press and release to return tonormal operation. [“:]

Press and release. The displaywill show the current tempera-ture setting for several seconds,then revert to the roomtemperature.

I”““1

During recovery from energysavings, the setting displayed willnot match the programmed set-ting. This is because the ther-mostat gradually changes thetemperature setting during rec-overy to provide maximum com-fort combined with most efficientuse of the heating or coolingequipment

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26

REMOVING THE THERMOSTAT

1 Loosen the two captive screws at 2 Pull the thermostat outthe bottom cornerg of the case. from the bottom.

3 Lift the thermostat up and off thebase.

REPLACING THE THERMOSTAT2 Swing down and press

1 Hang the thermostat on the tabs on lower edge until ther-at the top of the base. mostat snaps in place.

27

3 Tighten the captive screws.

28

REPLACING THE BATTERIES

Your thermostat uses three AAAalkaline batteries. The display willflash “REPL BAT” when the bat-teries get low. Unless the displayis blank (indicating the batteriesare dead) when you start, youwon’t have to reprogram thethermostat if you can insert thenew batteries within 20-30seconds of taking out the oldones.

POWER OUTAGES

Reasonably fresh backup batter-ies will hold the programmingand keep the display on duringmost power outages. Once thepower is restored, the system willresume normal operation.

To replace: n Insert the new batteries, mak-n Set the system switch to OFF. ing sure the positive (+) termi-n Remove the thermostat from nals all face toward the right.

the wall. See page 27. n Replace the thermostat on then Lift the batteries out of the wall. See page 28.

holder. n Reprogram, if necessary.

If the display goes off whenpower is lost, either the backupbatteries need to be replaced orare not installed. When power isrestored, the display will flash1:00 PM to remind you toreprogram.

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30

AUX HT light (heat pump modelsonly) -This light glows whenever thethermostat is callina for ooera-tion of the backup fieater.’Backup (auxiliary) heat is moreexpensive to operate than theheat pump and typically is usedonly when the heat pump isunable to handle the load.

C$Klight (heat pump models

Consult your heat pump equip-ment literature to determinewhether this light is used and itsmeaning.

Comfort temperatureThe temperature you want whenyou’re active and occupying thebuilding.

EM HT light (beat pump modelsonly)This light glows whenever thethermostat system switch is inthe EM HT~ position.

Energy-saving temperatureThe lower (heating) or higher(cooling) temperature that letsyou save on heating and coolingcosts when you’re asleep oraway. Also called the setback(heating) or setup (cooling)temperature.

Preprogrammed scheduleThis is the schedule pro-grammed into your thermostat atthe factory. It sets a night pro-gram that provides energy sav-ings if you don’t set your ownprogram, or if your personal pro-

temperature. The thermostatstarts the recovery period earlyso the house will be at the com-foh;o;;ng by the time you’ve

SetbackReducing the temperature in thehouse for a set period every dayin winter for energy savings. Thelower temperature is the energysavings temperature.

S e t u pRaising the temperature in thehouse for a set period every dayin summer for energy savings.The higher temperature is theenergy savings temperature.

Set pointThe thermostat temperature set-ting you select. The thermostatturns the heating or coolingequipment on and off to maintainthis temperature at the thermo-

day.MIDDAY-The time periodwhen you can set back (win-

stat location until anothertemperature setting (set point)goes into effect.

SYSTEM lightThis light glows whenever thethermostat is calling for heatingor air conditioning.

Time periodOne of four program periods:MORNING, MIDDAY, EVENING,and NIGHT; available with theChronotherm Ill thermostat. Oneperiod begins when the previousprogram period ends.

MORNING-The time periodwhen’you bring the building toa comfortable temperature tobegin the day. This is the onlyperiod that must contain atime and temperature for every

gram is lost for any reason. Theprogram, which is the same forall days of the week, is:

slan TemperabJrePeriod Time &¶Ii”g CoDringMORNING co0 AM 70’F 78OFM,DW,, NO p,,Jgmm _____........svss,no . . . . . . NO programN I G H T 10.00PM 60OF 78-F

ProgramThe times and temperatures youset to define the comfort andenergy savings periods for eachday’s schedule.

RecoveryThe time when the thermostatoperates the heating or air condi-tioning equipment to return thehouse from the energy savingstemperature to the comfort

31

ter) or up (summer) thetemperature for daytimeenergy savings if.the buildingis unoccupied.

EVENING-The time periodwhen you want the building ata comfortable temperature forevening activities after daytimeenergy savings.NIGHT-The time periodwhen you can set back (win-ter) or up (summer) thetemperature for energy sav-ings because family membersare asleep or the building isunoccupied. Often a NIGHTenergy savings temperature isset only for the heating sea-son so family members cansleep cool in summer.

You can use the table below to plan your schedule before you begin programming. If you choose not toprogram a daytime energy savings program, leave the MIDDAY and EVENING periods blank.After you have written in your schedule, mark the days that have identical programs.

34

THERMOSTATS FOR GAS, OIL,OR ELECTRIC HEAT SYSTEMSThese thermostats vary in theswitching configurations theyprovide.

HEAT-OFF-COOL HEAT-AUTO-COOL-OFF

35

THERMOSTAT FOR HEATPUMP SYSTEMS

EM HT-HT-OFF-AUTO-COOL

Program is lost dueto power outage.Temperature change occursat the wrong times.

Heating will not come on.

IF. . .Display will not come on.

THEN. . .a Check that heat or cool system power is on. If you use batteries,

replace with fresh ones.n Make sure thermostat is correctly mounted on base.

Display flashes during programming. a YOU have reached the temperature setting limit The setting range is45°F to 88°F. In models with automatic heat-cool changeover, theCOOL temperature setting must be at least 3°F above the HEATtemperature setting.

. Programming has been lost because of a power outage. You mustreprogram.

. Check that backup batteries are installed correctly. Replace ifnecessary. Reprogram the thermostat

. Check the program times for the period in question. Be sure thatAM and PM indications are correct Make sure the current day andtime are correct Reprogram if necessary.

. Rememberthatthe heating equipmentorairconditionercomesonbefore the MORNINGS and EVENING start times so the house willbe at the desired temperature when the period starts.

n Checkthefuseorcircuitbreakerand replaceorresetif necessary.n Check that switch on thermostat is set to HEAT or AUTO. s,

Cooling will not come on.

The building is toowarm or too cool.

Display says HEAT ON or systemlight is on, but no heat is comingfrom the registers.Display flashes REPL BAT or goesblank when power is turned off.

n Heatpumpthermostatshaveabuilt-in timedelay which may add totime delays in the heating equipment. Allow up to 10 minutes afterchanging the setting before the compressor starts.

. If temperature setting is higher than current temperature, anddisplaysaysHEATONorSYSTEM light ison, contactyourheatingand air conditioning contractor.

. Check thefuseor circuit breaker and replaceor reset if necessary.

. Check that switch on thermostat is set to COOL or AUTO.

. The thermostat has a built-in time delay, which may add to timedelays in the cooling equipment Allow up to 10 minutes afterchanging the setting before the air conditioner starts.

n If temperature setting is lower than current temperature, anddisplaysaysCOOLONorSYSTEM light ison, contactyourheatingand air conditioning contractor.

w Press PRESENT SETrING to check the current temperaturesetting.

. If desired, change the time or temperature setting. See page 21.

. Allowtimefortheheating equipmenttoheatupand thefan to comeon before checking for heat at the register.

. Install fresh alkaline batteries.

Press these keys to: Begin the current day or time programming

Set the day of the week, select the program day duringprogramming, and bypass a day while copying.

Select the time period to program, review or cancel

Cancel the day and time period shown on the display,(ex,cept MORNING) as well,as both the heating andcooling temperatures.

Switch between heat and cool modes duringprogramming or when reviewing the program.

Set the time ahead and back. Hold either key down tochange the setting faster.

Set the temperature while programming and temporarilychange the temperature during operation. Hold eitherkey down to change the setting faster. 39

Select one day’s program to copy to another day

Select a day to copy a program to

Hold any temperature you desire for an extendedperiod.

Chrmi,e the temperature to the set point of the previous

Maintain the current temperature through the nextprogram period.

Start your programmed schedule, cancel temporaryprogram changes, and cancel Hold Temp.

See the current temperature setting. Setting may notmatch programmed setting during recovery fromenergy savings.

Batteries. replacement ... . . . . . .29Slinking display ............ .30,37

Canceling programs .......... .24Change temperature .... .20,21,23Checking present

setting ...................... .26Checking programs .......... .25Clock display ................. *,lCooling temperatures .......... 7

Daily Program ................ .33Day ............................. 1Display., ...................... *,l

Energy-savingtemperature ................ (31

Evening ....................... .32

Fan switch ..................... 17Features *........................Flashing display ... . . . . . . . . .30,37

Setting limits .................. 3,6Setup ......................... .32Skip. ........................... 19Switch, fan ..................... 17Switch, system,, ............... 17

Glossary . . . . . . . . . . . . . . . . . . . . . . .31

Heating temperatures .......... 2Hold temperature ............. .23

Identification. model .......... .35

Keys . . . . . . . . . . . . . . . . . . . . . . . . . . .39

Light *............................

Maintenance. . . . . . . . . . . . . . . . . . .29Manual operation ............. .23Midday,, ...................... .32Model descriptions ........... .35Morning . . . . . . . . . . . . . . . . . . . . . . . .32

Night .......................... .32

Operation .................. 19-24

Period, Time .................. (32Power outage. ................ .30Preprogrammed

schedule.. . . . . . . . . . . . . . . . . ..3 1

System light . . . . . . . . . . . . . . . . . . . .32System switch ................ (17

Table of Contents ................ iTemporary program

changes ................. 19-24

*See the product features inside the front cover.

Present setting.. .26Program schedule. . . 2.33Programming

overvtew. *Programming steps 1

Quick reference tothe keys .39

Remov ing thermos ta t 27Replacing batteries .29

Setback.. _. _. 31Set cooling

temperatures 7Set current day _. 1Set current time.. 1Setfan switch ,............__._ 17Set heating

temperatures 2Set program schedule. . 2Set system switch 17

Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Time period ................... .32Troubleshooting .............. .37

Warranty ...................... .42

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Together.we can find the answers.

Honeywell