OPERATION GUIDE 1F90W-51 · the program period is displayed ( MOR , DAY , EVE, or NHT). Alternately displays room temperature (F denotes degrees Fahrenheit and C denotes degrees Celsius)

OPERATION GUIDE

5 Day/2 Day ElectronicDigital Thermostat

1F90W-51

Operator: Save this booklet for future use!

WHITE-RODGERS

WHITE-RODGERS

2

About Your New Thermostat . . .

Your new White-Rodgers Digital Thermostat uses the technology of a solid-state microcomputerto provide precise time/temperature control. This thermostat offers you the flexibility to designheating and cooling programs that fit your needs.

Please read this manual thoroughly before operating or programming your thermostat. If you havequestions, write to us at the address shown on the back cover of this manual.

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PROGRAMMING YOURTHERMOSTAT .................................... 16PLANNING FOR YOUR NEEDSENTERING YOUR PROGRAM

Set Current Time and DayEnter Heating ProgramEnter Cooling Program

CHECK YOUR PROGRAMMINGQUESTIONS AND ANSWERS ................. 26

YOUR NEW THERMOSTAT'SFEATURES ............................................ 4

OPERATING YOUR THERMOSTAT ......... 5PARTS OF THE THERMOSTAT

The Back Of the Thermostat BodyThe DisplayThe Thermostat Buttons

OPERATING FEATURES

In This Guide . . .

Operator: Save thisbooklet for future use!

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• Separate 5-day (weekday) and 2-day (week-end) setback programming

• Simultaneous heat and cool program stor-age

• Four separate time/temperature settings per24-hour period

• Computed Energy Management Recovery(EMR)

• Armchair programming capability• Backlit LCD displays continuous set point,

time, and room temperature• 1.5 volt "AA" Energizer® alkaline battery

backup

YOUR NEW THERMOSTAT’S FEATURES

• Preprogrammed temperature control• Adjustable cycle times• Compressor short cycle protection• Programmable blower control• Blower delay in the cooling cycle• Audio and visual prompting during opera-

tion• Two hour temperature override• Manual program override (HOLD tempera-

ture)• "Advance Program" key• °F/°C convertibility• Temperature range 40° to 99°F

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OPERATING YOUR THERMOSTAT

SUBBASE

THERMOSTATBODY

Before you begin programming your thermo-stat, you should be familiar with its features andwith the display and the location and operationof the thermostat buttons. The information inthis section will help you become familiar withyour new thermostat so that you can easilyprogram it.

Your thermostat consists of two parts: thethermostat body and the subbase .

Remove power from the system at thecircuit breaker/fuse box before removingor attaching the thermostat body. Equip-ment damage and/or personal injury couldoccur.

The subbase is attached to the wall, but you canremove the thermostat body for easy program-ming. To remove the thermostat body from thesubbase, grasp the thermostat body and gentlypull it straight out from the subbase. To attachthe thermostat body, line up the six terminal pinson the upper section of the thermostat back withthe matching connector on the subbase. Insert

CAUTION!

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for approximately a year. If power loss is longenough for the program to be lost, the thermo-stat will automatically return to the factory pro-grammed temperatures (64°F heating and 82°Fcooling) when power is restored. You mustreprogram the thermostat if this happens.If the word BATTERY is flashing in the displaywindow, the batteries are low and should bereplaced with fresh "AA" Energizer® alkalinebatteries.

Before removing thermostat from thewall to replace the batteries, remove24vAC power from the thermostat at thebreaker/fuse box.

these, then gently pivot the thermostat bodydown to connect the three pin connectors on thelower portion of the thermostat back. Gentlypush until the snap connectors engage. DONOT FORCE OR PRY THE THERMOSTAT, asthis may damage the unit.

PARTS OF THE THERMOSTAT

The Back of The Thermostat Body

Turn the thermostat body over. On the back arethe 3 "AA" Energizer® alkaline batteries.

The "AA" Energizer® alkaline batteries providepower to the thermostat when the 24vAC poweris interrupted (for example, when you removethe thermostat from the wall for programming).Fresh batteries will maintain the stored program

CAUTION!

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Other than and , the buttons arelocated behind the thermostat door. To open thedoor, pull the door out from the top, then swingit down on its hinges.

On the following pages there are brief descrip-tions of the display and the thermostat buttons.

BACK OF THERMOSTAT BODY

3-pin Connector

6-pin Connector Batteries

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S3

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The word BATTERY flashes on the displaywhen the "AA" alkaline batteries are weakand should be replaced. The word BAT-TERY is displayed continuously (non-flash-ing) when thermostat is running on batterypower only.

FAN ON is displayed when the blower isoperating continuously. FAN AUTO is dis-played during automatic fan operation (whenthe blower cycles with the heating or coolingsystem).

The Display

Continuously displays system mode (HEAT,OFF, COOL, HOLD). During programming,the program period is displayed (MOR, DAY,EVE, or NHT).

Alternately displays room temperature (Fdenotes degrees Fahrenheit and C denotesdegrees Celsius) and time of day (A de-notes AM time and P denotes PM time).

Displays the setpoint temperature.

5 DAY indicates that the displayed programis the weekday program. 2 DAY indicatesthat the displayed program is the weekendprogram.

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1

2

4

5

6

9

1 2 3

4 6 6

2 DAY 5 DAY

2

3

4

FAN AUTO FAN ON

5 DAY FAN AUTO

5

BATTERY

TIMEFWD

SYSTEMHEAT-OFF-COOL

SETCLOCK

VIEWPRGM

HOLDTEMP

TIMEBACK

FANON - AUTO

SETDAY

RUNPRGM

ADVPRGM

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Used to initiate or review thermostat pro-gramming.

Used to start program operation after pro-gramming. Also used to return thermostatto program operation after being in HOLDmode.

Used to manually override programming tohold at a selected temperature (when HOLDis displayed).

Used to advance thermostat program to thenext program period (for example, from theMOR program to the DAY program).

(Red arrow) Raises temperature setting(99°F or 37°C maximum).

(Blue arrow) Lowers temperature setting(40°F or 4°C minimum).

The red indicator light glows whenever heat-ing, cooling, or fan are in operation.

The Thermostat Buttons

Sets the system mode (HEATing, OFF, orCOOLing).

Selects fan operation (see #6, above). Thisbutton is also used to program the fan to runcontinuously during a program period.

Runs display forward or backward throughtime, day, or anticipation settings duringprogramming.

Used with TIMEFWD and TIME

BACK to set current

time.

Used with TIMEFWD and TIME

BACK to set the current

day of the week. Also used in conjunction

with SETCLOCK to enter anticipation setting mode.

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8

9

10

11

12

13

14

15

16

17

18

11

10 11 12 13 14 15

1617 18

9

7

8

5 DAY FAN AUTO

TIMEFWD

SYSTEMHEAT-OFF-COOL

SETCLOCK

VIEWPRGM

HOLDTEMP

TIMEBACK

FANON - AUTO

SETDAY

RUNPRGM

ADVPRGM

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OPERATING FEATURES

Now that you are familiar with the thermostatdisplay and buttons, read the following informa-tion to learn about the many features of thethermostat.

• COMPUTED ENERGY MANAGEMENTRECOVERY (EMR) — At installation, thethermostat can be set to automatically cal-culate the time it will take to change thetemperature to the next program setting.Then the thermostat will activate the heat-ing or cooling system to change the tem-perature so that the desired temperature isreached at the beginning of the next pro-gram period. As an example of this feature,assume that you have programmed yourthermostat to provide an overnight heating

temperature of 62°F, and that during thenext program period, beginning at 6:00 AM,you have programmed a temperature of70°F. The thermostat will automaticallyactivate the heating system at about 5:00AM, so that the programmed 70°F tempera-ture is reached by about 6:00 AM.The thermostat is configured at the factoryso that this feature is disabled. If you wishto have this feature, refer to the installationinstructions for this thermostat, or contactyour local heating/cooling contractor.

• TWO HOUR TEMPERATURE OVER-RIDE — Press or until thedisplay shows the temperature youwant. The thermostat will override cur-rent programming and keep the roomtemperature at the selected tempera-ture for two hours. After two hours, the

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thermostat will automatically revert tothe program.

• HOLD TEMPERATURE — The thermostatcan hold any temperature within its rangefor an indefinite period, without reverting to

the program. Press HOLDTEMP . HOLD will be

displayed. Then choose the desired holdtemperature by pressing or .The thermostat will hold the room tempera-ture at the selected setting until you press

RUNPRGM to start program operation again.

This feature is ideal for energy conservationwhen the building is unoccupied for an ex-tended period of time.

• "ADVANCE PROGRAM" BUTTON —

Press ADVPRGM to change the thermostat to the

next program period. This will temporarily

override the program, until the next programperiod begins (for example, pressing thiskey while in the DAY program will advancethe thermostat to the EVE program, whichwill remain in effect until the NHT programbegins).

• °F/°C CONVERTIBILITY — Press TIMEFWD

and TIMEBACK at the same time until the tem-

perature display is in °C (Celsius). Todisplay °F, repeat the process.

• ADJUSTABLE HEATING AND COOLINGCYCLE TIMES (ANTICIPATION) — If theheating/cooling system is turning on and offtoo often (short cycles) or not often enough(long cycles), you may want to adjust theanticipation setting.

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A cooling anticipation setting of lessthan 10 may cause decreased compres-sor life.

To adjust heat anticipation, press SETCLOCK

and SETDAY at the same time. The display will

show HEAT 5 (this is the factory prepro-grammed heating anticipation setting). Youmay select any anticipation setting from 2 to40 (note that for hydronic systems, aminimum anticipation setting of 15 isrecommended ). Whenever adjusting an-ticipation, increase or decrease the dis-played number by only one or two digits,then let the system run for a while to see ifthe adjustment is sufficient. If the heat

cycles are too short, press TIMEFWD to increase

the cycle time. If the heat cycles are too long,

press TIMEBACK to decrease the cycle time. To

set cooling anticipation, press SETCLOCK and

SETDAY at the same time again. The display will

show COOL 14 (factory preprogrammed cool-

ing anticipation). Use the TIMEFWD and TIME

BACK

buttons to adjust anticipation. Press RUNPRGM to

return to your program.• LOW BATTERY INDICATOR — The word

BATTERY will flash on the display if the"AA" alkaline batteries are low and shouldbe replaced. The word BATTERY will bedisplayed continuously (non-flashing) when24v AC power is not being supplied to the

CAUTION!

15

thermostat and the thermostat is operatingon battery power only.

• AUDIO PROMPTING — Each time youpress a button, the thermostat will beep.

• BACKLIT DISPLAY — When you pressany button on the thermostat, the display islit for approximately eight seconds.

• SYSTEM INDICATOR LIGHT — The redlight on the upper right part of the thermostatindicates system operation (see PARTS OFTHE THERMOSTAT).

• COMPRESSOR SHORT CYCLE PROTEC-TION — To protect your compressor frompotential damage due to rapid cycling, thisthermostat has a built-in delay of 5 minutesbetween cooling cycles. The following maycause a time delay in COOL:

a) Return of power after a power outage.

b) Pressing SYSTEMHEAT-OFF-COOL to change operating

modes.c) Pressing , creating a call for COOL

too soon after a previous call.

PR

OG

RA

MM

ING

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Now you are ready to program your thermostat.This section will help you plan your thermostat'sprogram to meet your needs.

For maximum comfort and efficiency, keep thefollowing guidelines in mind when planning yourprogram.

• When heating (cooling) your building, pro-gram the temperatures to be cooler (warmer)when the building is vacant or during peri-ods of low activity.

• During early morning hours, the need forcooling is usually minimal.

PLANNING FOR YOUR NEEDS

First, answer the following questions to help youdecide what your needs are. If you are using thethermostat for a commercial application (a store,office building, etc.), answer questions 1 through4. If you are using the thermostat in your home,answer questions 5 through 8.

FOR COMMERCIAL APPLICATIONS:1a. What time does the first person arrive at the

building in the morning?b. What temperature should the building be at

this time? (heating? cooling?) These will beyour MOR (morning) temperature settings.

PROGRAMMING YOUR THERMOSTAT

PR

OG

RA

MM

ING

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2a. What time do the building occupants reacha maximum activity level (using lights, equip-ment, meeting rooms, etc.)?

b. What temperature should the building be atthis time? These will be your DAY tempera-ture settings.

3a. What time do the building occupants reacha minimum activity level (limited personnelin building)?

b. What temperature should the building be atthis time? These will be your EVE (evening)temperature settings.

4a. What time does the building become vacant?b. What temperature should the building be at

this time? These will be your NHT (night)temperature settings.

IN YOUR HOME:5a. What time does the first person get up in the

morning?b. What temperature should the house be at

this time? These will be your MOR (morn-ing) temperature settings.

6a. What time does the last person leave thehouse in the morning?

b. What temperature should the house be atthis time? These will be your DAY tempera-ture settings.

7a. What time does the first person arrive homein the evening?

b. What temperature should the house be atthis time? These will be your EVE (evening)temperature settings.

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8a. What time does the last person go to bed atnight?

b. What temperature should the house be atthis time? These will be your NHT (night)temperature settings.

Now look at the factory preprogrammed timesand temperatures shown below. If this program

will suit your needs, simply press RUNPRGM to begin

running the factory preset program.

If you want to change the preprogrammed timesand temperatures, do the following.

Determine the time periods and heating andcooling temperatures for your weekday pro-gram. You must program 4 periods for each day(MOR, DAY, EVE, and NHT). However, youmay use the same heating and cooling tempera-tures for consecutive time periods. You canchoose start times, heating temperatures, andcooling temperatures independently for both

Heating Program for ALL days of the Week: Cooling Program for ALL Days of the Week:

PERIOD TIME TEMP PERIOD TIME TEMPMORDAYEVENHT

5:00 AM9:00 AM4:00 PM10:00 PM

70707064

MORDAYEVENHT

5:00 AM9:00 AM4:00 PM10:00 PM

78827878

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weekday and weekend programs (for example,you may select 5:00 AM and 70° as the weekdayMOR heating start time and temperature, andchoose 7:00 AM and 76° as the weekday MORcooling start time and temperature). Use thefollowing table to plan your program time peri-ods, and the temperatures you want during eachperiod. You may also want to look at the sampleprogram table to get an idea of how the thermo-stat can be programmed.

ENTERING YOUR PROGRAM

Follow these steps to enter the heating andcooling programs you have selected.

We recommend that you remove the thermostatfrom the wall for programming (especially forentering cooling programming). Fresh "AA"Energizer® alkaline batteries must be installedto perform off-wall programming. BE SURESYSTEM SWITCH IS SET TO OFF POSITIONBEFORE REATTACHING THERMOSTAT TOSUBBASE!

Set Current Time and Day

1. Press SETCLOCK once. The display will show

minutes only.

EXAMPLE:

NOTE

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WEEKDAY (5 DAY) WEEKEND (2 DAY)

StartTime Temperature


MOR HEAT

DAY HEAT

EVE HEAT

NHT HEAT

MOR COOL

DAY COOL

EVE COOL

NHT COOL

Heating/Cooling Schedule Plan

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WEEKDAY (5 DAY) WEEKEND (2 DAY)



MOR HEAT

DAY HEAT

EVE HEAT

NHT HEAT

MOR COOL

DAY COOL

EVE COOL

NHT COOL

SAMPLEHeating/Cooling Schedule Plan

5:30 AM

8:00 AM

5:00 PM

10:30 PM

6:30 AM

2:00 PM

5:00 PM

10:30 PM

7:00 AM

11:00 AM

6:00 PM

11:30 PM

7:00 AM

12:30 PM

6:00 PM

11:30 PM

68°F

70°F

70°F

65°F

76°F

74°F

72°F

78°F

68°F

65°F

70°F

65°F

76°F

78°F

72°F

78°F

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2. Press and hold either TIMEFWD or TIME

BACK until

you reach the correct minutes.

3. Press SETCLOCK once. The display window will

show the hour only.

EXAMPLE:


BACK until

you reach the correct hour and AM/PMdesignation (AM begins at midnight; PMbegins at noon).

5. Press SETDAY once. The display will show the

day of the week as an abbreviation (MO forMonday, TU for Tuesday, etc.).


BACK until

you reach the current day of the week.

7. Press RUNPRGM once. The display will show the

correct time and room temperature alter-nately.

Enter Heating Program

During programming, if you don’t press anybuttons for 5 minutes, the thermostat will enterthe HOLD mode and will maintain a constanttemperature. The display will revert to thealternating time/temperature display. To re-sume programming after this happens, press

VIEWPRGM until you are at the point where you stopped

programming. Then you may continue to enteryour programs normally. If you want to stop

programming at any time, simply press RUNPRGM to

resume program operation.

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1. Press SYSTEMHEAT-OFF-COOL until HEAT is displayed.

2. Press VIEWPRGM once. 5 DAY (indicating week-

day program), and MOR, representing themorning heating period, will appear in thedisplay. Also displayed are the currentlyprogrammed start time for the MOR periodand the currently programmed tempera-ture.

EXAMPLE: 5 DAY

This display window shows that for theweekday MOR period, the start time is 5:00AM, and 70° is the programmed tempera-ture (this example reflects factory prepro-gramming).

3. To change the displayed start time to yourselected start time for weekday MOR heat

program, press TIMEFWD or TIME

BACK until your

selected time appears. The time will changein 15 minute increments.

4. Press or until you reach yourselected weekday MOR heating tempera-ture.

5. If you want the fan to run continuously

during this period, press FANON – AUTO until PRG

FAN is displayed.

6. Press VIEWPRGM . The currently programmed

start time and heating temperature for week-day DAY will be displayed.

7. Repeat steps 3 through 5 to select the starttime and heating temperature for the week-day DAY program.

8. Repeat steps 3 through 7 for the weekdayEVE and NHT heating programs.

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9. After entering your weekday heating pro-gram, repeat steps 1 through 8 for yourweekend programming (keep in mind thatfor weekend programming, the displayshould be changed from 5 DAY to 2 DAY).

10. When you have completed entering your

heating program, press RUNPRGM .

Enter Cooling Program

If outside temperature is below 50 °F, werecommend that you remove the ther-mostat from the wall before proceedingwith the following steps to program cool-ing temperatures. Personal injury orproperty damage may occur due to airconditioner compressor slugging. Fresh"AA" Energizer ® alkaline batteries must

CAUTION!

be installed to perform off-wall program-ming. Programming away from the wallshould prevent accidental compressoroperation. BE SURE SYSTEM SWITCHIS SET TO OFF POSITION BEFORE RE-ATTACHING THE THERMOSTAT TO THESUBBASE!

1. Press SYSTEMHEAT-OFF-COOL until COOL appears.

2. Follow the procedure for entering your heat-ing program, using your selected coolingtimes and temperatures.

CHECK YOUR PROGRAMMING

Follow these steps to check your thermostatprogramming one final time before beginningthermostat operation.

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1. Press SYSTEMHEAT-OFF-COOL until HEAT is displayed.

2. Press and hold VIEWPRGM to view the heating

period times and temperatures in sequencefor weekday, then weekend MOR, DAY,EVE, and NHT program periods.

3. Press RUNPRGM .

4. Press SYSTEMHEAT-OFF-COOL until COOL is displayed.

5. Repeat step 2 to check cooling tempera-tures.

6. Press RUNPRGM to begin program operation.

YOUR THERMOSTAT IS NOW COMPLETELYPROGRAMMED AND READY TO AUTOMATI-CALLY PROVIDE MAXIMUM COMFORT ANDEFFICIENCY!

Press SYSTEMHEAT-OFF-COOL until OFF is displayed. Reattach

thermostat to subbase. Turn on power to the

system. Then press SYSTEMHEAT-OFF-COOL to select the opera-

tion mode you want (HEAT or COOL). PressFAN

ON – AUTO until FAN AUTO is displayed (auto-

matic cycling).

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1. How can I permanently change a part ofmy program?

Press VIEWPRGM until you reach the time/tem-

perature schedule you want. Then pressTIMEFWD or TIME

BACK and and to

change the program. See PROGRAM-MING YOUR THERMOSTAT.

2. How can I have no change in tempera-ture from one time period to another?Simply select the same temperature foreach consecutive time period. For example,you may select the same weekday EVEcooling temperature as you did for weekdayDAY, which means the temperature will not

change when the EVE period begins. SeePROGRAMMING YOUR THERMOSTAT .

3. How can I finish my programming if thedisplay has already changed to time/temperature?During programming, if no buttons arepressed for five minutes, the thermostat willenter the HOLD mode and maintain a con-stant temperature. The display will changeto the time/temperature mode. To resume

programming, press VIEWPRGM until you return

to the point where you stopped program-ming. Then you may continue to programthe thermostat normally. If you want to stop

programming at this point, press RUNPRGM to

QUESTIONS AND ANSWERS

27

start the normal program function. SeePROGRAMMING YOUR THERMOSTAT .

4. What happens if the electricity goes offor is manually shut off?If you have not installed 3 "AA" alkalinebatteries, the display will go blank and theprogram will be lost in approximately oneminute. When electricity is restored, theclock will reset itself to 12:00 PM (noon) andthe thermostat will maintain a heating tem-perature of 64°F and a cooling temperatureof 82°F until you reenter your program.Setpoint temperature will not be displayed.

If fresh "AA" Energizer® alkaline batteriesare installed, the program will be main-tained for about one year with no 24vACpower present to the thermostat. See OP-ERATING YOUR THERMOSTAT .

5. What can cause the thermostat displayto freeze or go blank?A completely blank display may indicatethat power has been lost to the thermostatand the backup battery is also dead. How-ever, if there is power to the thermostat andthe display is blank or frozen, static dis-charge is probably the cause.

During periods of low humidity (especiallyduring cold weather), you may feel or see aspark discharge when you touch the ther-mostat. This may cause the program to belost or the thermostat to display incorrectly.To correct this, remove the thermostat fromthe wall and disconnect the battery. Waitabout one minute, then reconnect the bat-tery. The thermostat will revert to the factorypreset program until you reprogram thethermostat. If you don’t want to reprogram

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the thermostat immediately, press SYSTEMHEAT-OFF-COOL

until OFF is displayed and replace the ther-

mostat on the wall. Then press RUNPRGM to

begin the factory preset program. Or youmay reprogram the thermostat, then re-place it on the wall.

To prevent further static discharge prob-lems, touch another object to release staticbuild-up before touching the thermostat.See OPERATING YOUR THERMOSTAT .

6. The display is flashing BATTERY. Whatdoes this mean?The "AA" batteries installed in the thermo-stat are low and should be replaced withfresh "AA" Energizer® alkaline batteries. SeeOPERATING YOUR THERMOSTAT .

7. The display shows a continuous (non-flashing) BATTERY. What does thismean?The thermostat is not being supplied with24vAC power. The thermostat is operatingon battery power alone. See OPERATINGYOUR THERMOSTAT.

8. Why won’t the compressor turn on, eventhough the thermostat display is func-tioning normally?Either the compressor lockout feature is inoperation or the thermostat is not currentlycalling for cool. Wait about 5 minutes for thecompressor lockout to expire. If the systemis still not running, read the cautionary state-ment at right. Then, if conditions permit ,use the button to move the tempera-ture below the setpoint temperature. SeeOPERATING YOUR THERMOSTAT .

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See OPERATING YOUR THERMO-STAT.

• You have programmed the incorrect dayor time. Check your programming (besure that the times you programmed arecorrect AM or PM times). See PRO-GRAMMING YOUR THERMOSTAT .

• The thermostat is in the HOLD mode.

Press RUNPRGM to start program operation.

See OPERATING YOUR THERMO-STAT.

• The compressor lockout feature is oper-ating; wait about 5 minutes for system tobegin running. See OPERATING YOURTHERMOSTAT.

10. Why does the blower fan keep runningafter the system has turned off?• You have programmed the fan to run

If the outside temperature is below 50 °F,DO NOT use the button to move thetemperature below the setpoint tempera-ture. Property damage may result due tocompressor slugging.

9. Why doesn’t the temperature change atthe time I programmed?There may be a number of causes for thissituation. The following are primary rea-sons.

• The EMR function is operating. TheEMR function will automatically bring onthe system automatically to bring thetemperature to the selected level by thebeginning of the next program period.

CAUTION!

30

continuously during this period. SeePROGRAMMING YOUR THERMO-STAT.

• The blower delay feature is operating.This energy saving feature continues toblow conditioned air through the ductsafter the system has turned off, ratherthan letting the air dissipate.

11. Why is the system turning on and off sofrequently (seldom)?The anticipation setting is too low (high). Tochange anticipation settings, see OPER-ATING YOUR THERMOSTAT .

12. Between heating and cooling seasons, Iwant to turn my system off. Can I do thiswithout affecting my thermostat pro-gramming?Any time you wish to turn your system off,

simply press SYSTEMHEAT-OFF-COOL until the display shows

OFF. This will not affect your thermostat’sprogramming in any way. To turn the sys-

tem back on, press SYSTEMHEAT-OFF-COOL until HEAT,

COOL, etc. is displayed. The system willautomatically begin operating according tothe current thermostat program, unless thethermostat is in the HOLD mode. SeeOPERATING YOUR THERMOSTAT .

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13. I live in an area where daylight savingstime is observed. How do I change thethermostat clock twice a year withoutaffecting thermostat programming?To change your clock, follow the instruc-tions for setting current time and day. SeeENTERING YOUR PROGRAM. Thermo-stat programming is not affected when youchange the clock.

14. Do I have to reprogram my thermostatafter I change the batteries?When the thermostat is on the wall and thesystem has power, the thermostat is beingpowered by a 24v AC source. If power islost, or if the thermostat is removed from thewall, the program will be retained for ap-proximately one minute if there are nobatteries installed or if the installed batteriesare dead. If you are changing the batteries

after seeing a flashing BATTERY on thedisplay, the installed batteries may be dead.If you remove the old batteries and installfresh ones within one minute, you shouldnot lose your thermostat programming. Af-ter installing new batteries, follow the proce-dures in CHECK YOUR PROGRAMMINGto determine whether your programmingwas maintained. If the thermostat main-

tains programming, press SYSTEMHEAT-OFF-COOL until OFF

is displayed, put the thermostat back on the

wall, press SYSTEMHEAT-OFF-COOL to select the operating

mode you want, then press RUNPRGM to start

program operation. If the program is lost,reprogram the thermostat. See PROGRAM-MING YOUR THERMOSTAT.

Part No. 37-5090A

9139

If you need further information on programming or operation, write to us at:

White-Rodgers Division, Emerson Electric Co.9797 Reavis RoadSt. Louis, MO 63123Attn: Technical Service Department

R

OPERATION GUIDE 1F90W-51 · the program period is displayed ( MOR , DAY , EVE, or NHT). Alternately displays room temperature (F denotes degrees Fahrenheit and C denotes degrees Celsius)

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