White Rodgers 1F90-51 User manual

OPERATION GUIDE
5 Day/2 Day Electronic
Digital Thermostat
1F90-51
WHITE-RODGERS
Operator: Save this booklet for future use!

2
About Your New Thermostat . . .
Your new White-Rodgers Digital Thermostat uses the technology of a solid-state microcomputer
to provide precise time/temperature control. This thermostat offers you the flexibility to design
heating and cooling programs that fit your needs.
Pleasereadthismanualthoroughlybeforeoperatingorprogrammingyourthermostat.Ifyouhave
questions, write to us at the address shown on the back cover of this manual.

3
Operator: Save this
booklet for future use!
PROGRAMMING YOUR
THERMOSTAT .................................... 19
PLANNING FOR YOUR NEEDS
ENTERING YOUR PROGRAM
Set Current Time and Day
Enter Heating Program
Enter Cooling Program
CHECK YOUR PROGRAMMING
QUESTIONS AND ANSWERS................. 29
YOUR NEW THERMOSTAT’S
FEATURES ............................................ 4
OPERATING YOUR THERMOSTAT ......... 5
PARTS OF THE THERMOSTAT
The Back Of the Thermostat Body
The Display
The Thermostat Buttons
OPERATING FEATURES
In This Guide . . .

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• Separate5-day(weekday)and2-day(week-
end) setback programming
• Simultaneousheatandcoolprogramstorage
• Fourseparatetime/temperaturesettingsper
24-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
• Preprogrammed temperature control
YOUR NEW THERMOSTAT’S FEATURES
• Adjustable cycle times
• Compressor short cycle protection
• Programmable blower control
• Blower delay in the cooling cycle
• Audio and visual prompting during operation
• Two hour temperature override
• Manual program override (HOLD tempera-
ture)
• “Advance Program” key
•°F/°C convertibility
• Temperature range 40°to 99°F

5
OPERATING YOUR THERMOSTAT
Before you begin programming your thermo-
stat,youshouldbefamiliarwithitsfeaturesand
with the display and the location and operation
of the thermostat buttons. The information in
this section will help you become familiar with
your new thermostat so that you can easily
program it.
Your thermostat consists of two parts: the ther-
mostat body and the subbase.
Remove power from the system at the
circuit breaker/fuse box before remov-
ing or attaching the thermostat body.
Equipment damage and/or personal in-
jury could occur.
Thesubbaseisattachedtothewall,butyoucan
remove the thermostat body for easy program-
ming. To remove the thermostat body from the
subbase, grasp the thermostat body and gently
pull it straight out from the subbase. To attach
the thermostat body, line up the two terminal
pinsonthelowersectionofthethermostat back
with the matching connector on the subbase.
Insert these, then gently pivot the thermostat
bodyuptoconnectthesixpinconnectorsonthe
upper portion of the thermostat back. Gently
push until the snap connectors engage. DO
NOTFORCEORPRYTHETHERMOSTAT,as
this may damage the unit.
CAUTION
!

6
PARTS OF THE THERMOSTAT
The Back of The Thermostat Body
Turnthe thermostat body over.On the back are
the 3 “AA” Energizer®alkaline batteries.
The “AA” Energizer®alkaline batteries provide
powertothethermostatwhenthe24 VACpower
is interrupted (for example, when you remove
the thermostat from the wall for programming).
Freshbatterieswillmaintainthestoredprogram
for approximately a year. If power loss is long
enough for the program to be lost, the thermo-
stat will automatically return to the factory pro-
grammedtemperatures(64°Fheatingand82°F
cooling) when power is restored. You must
reprogram the thermostat if this happens.
If the word BATTERY is flashing in the display
window, the batteries are low and should be
replaced with fresh “AA” Energizer®alkaline
batteries.
Use
SYSTEM
SWITCH
to turn the thermostat OFF
beforeremovingthethermostatfromthe
wall to replace batteries.
CAUTION
!

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Other than and , the buttons are
locatedbehindthethermostatdoor.Toopenthe
door,putyourfingernailintheindentationatthe
topofthedoor,thenpullthedooroutfromthetop
and swing it down on its hinges.
On the following pages there are brief descrip-
tions of the display and the thermostat buttons.
BACK OF THERMOSTAT BODY
2-pin connector
6-pin connector Batteries
W14 S3

8
5
The word BATTERY flashes on the display
when the “AA” alkaline batteries are weak
and should be replaced. The word BAT-
TERYisdisplayedcontinuously(non-flash-
ing) when thermostat is running on battery
power only.
6
FAN ON is displayed when the blower is
operating continuously. FAN AUTO is dis-
playedduringautomaticfanoperation(when
theblowercycleswiththeheatingorcooling
system).
The Display
1
Continuouslydisplayssystemmode(HEAT,
OFF,COOL, HOLD).Duringprogramming,
theprogramperiodisdisplayed(MOR,DAY,
EVE, or NHT).
2
Alternately displays room temperature (F
denotesdegreesFahrenheitandCdenotes
degrees Celsius) and time of day (Ade-
notes AM time and Pdenotes PM time).
3
Displays the setpoint temperature.
4
5DAY indicatesthatthedisplayedprogram
is the weekday program. 2 DAY indicates
that the displayed program is the weekend
program.

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1 32
4
SYSTEM
SWITCH
FAN
SWITCH
HEAT-OFF-COOL-AUTO
TIME
FWD
TIME
BACK
SET
CLOCK
SET
DAY
VIEW
PRGM
RUN
PRGM
HOLD
TEMP
ADV
PRGM
2 DAY 5 DAYFAN AUTO FAN ON
ON-AUTO
5 DAY FAN AUTO
BATTERY
WHITE-RODGERS DIGITAL COMFORT SET II
4
3
6 6 2 5

10
12
Used to initiate or review thermostat pro-
gramming.
13
Used to start program operation after pro-
gramming.Alsousedtoreturnthermostatto
program operation after being in HOLD
mode.
14
Used to manually override programming to
holdataselectedtemperature(whenHOLD
is displayed).
15
Usedtoadvancethermostatprogramtothe
next program period (for example, from the
MOR program to the DAY program).
16
(Red arrow) Raises temperature set-
ting (99°F or 37°C maximum).
The Thermostat Buttons
7
Sets the system mode (HEATing, OFF, or
COOLing).
8
Selects fan operation (see #6, above). This
buttonisalsousedtoprogramthefantorun
continuously during a program period.
9
Runs display forward or backward through
time, day, or anticipation settings during
programming.
10
Used with
TIME
FWD
and
TIME
BACK
to set current time.
11
Used with
TIME
FWD
and
TIME
BACK
to set the day of the
week. Also used in conjunction with
SET
CLOCK
to
enter anticipation setting mode.

11
17
(Blue arrow) Lowers temperature set-
ting (40°F or 4°C minimum).
18
Theredindicatorlightglowswheneverheat-
ing, cooling, or fan are in operation.
17
910 11 12 13 14 15
8
7
SYSTEM
SWITCH
FAN
SWITCH
TIME
FWD
TIME
BACK
SET
CLOCK
SET
DAY
VIEW
PRGM
RUN
PRGM
HOLD
TEMP
ADV
PRGM
16 18
HEAT-OFF-COOL-AUTO
ON-AUTO
5 DAY FAN AUTO
WHITE-RODGERS DIGITAL COMFORT SET II

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OPERATING FEATURES
Now that you are familiar with the thermostat
displayandbuttons,readthefollowinginforma-
tion to learn about the many features of the
thermostat.
•COMPUTED ENERGY MANAGEMENT
RECOVERY (EMR) — The thermostat’s
microcomputer can be set to automatically
calculate the time it will take to change the
temperature 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 is
reached at the beginning of the next pro-
gram period. As an example of this feature,
assume that you have programmed your
thermostat to provide an overnight heating
temperature of 62°F, and that during the
nextprogramperiod,beginningat6:00AM,
you have programmed a temperature of
70°F. The thermostat will automatically ac-
tivatetheheatingsystematabout5:00AM,
so that the programmed 70°F temperature
is reached by about 6:00 AM.
The thermostat is configured at the factory
sothatthisfeatureisdisabled.Ifyouwishto
have this feature, refer to the installation
instructions for this thermostat, or contact
your local heating/cooling contractor.
•TWO HOUR TEMPERATURE OVER-
RIDE — Press or until the dis-
play shows the temperature you want. The
thermostat will override current program-
mingandkeeptheroomtemperatureatthe
selected temperature for two hours. After
twohours, the thermostat will automatically
revert to the program.

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•HOLD TEMPERATURE — The thermostat
can hold any temperature within its range
for an indefinite period, without reverting to
the program. Press
HOLD
TEMP
. HOLD will be dis-
played. Then choose the desired hold tem-
perature by pressing or . The
thermostat will hold the room temperature
attheselectedsettinguntilyoupress
RUN
PRGM
to
start program operation again. This feature
is ideal for energy conservation when the
building is unoccupied for an extended pe-
riod of time.
•“ADVANCE PROGRAM” KEY — Press
ADV
PRGM
to change the thermostat to the next
program period. This will temporarily over-
ride the program, until the next program
period begins (for example, pressing this
key while in the DAY program will advance
the thermostat to the EVE program, which
will remain in effect until the NHT program
begins).
•°F/°C CONVERTIBILITY — Press
TIME
FWD
and
TIME
BACK
at the same time until the temperature
display is in °C(Celsius). To display °F,
repeat the process.
•ADJUSTABLE HEATING AND COOLING
CYCLE TIMES (ANTICIPATION) — If the
heating/coolingsystemisturningonandoff
too often (short cycles) or not often enough
(long cycles), you may want to adjust the
anticipation setting.

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Acoolinganticipationsettingoflessthan
10maycausedecreasedcompressorlife.
To adjust heat anticipation, press
SET
CLOCK
and
SET
DAY
at the same time. The displaywillshow
HEAT 5 (this is the factory preprogrammed
heating anticipation setting). You may se-
lect any anticipation setting from 2 to 40
(note that for hydronic systems, a mini-
mum anticipation setting of 15 is recom-
mended).Wheneveradjustinganticipation,
increaseordecreasethedisplayednumber
byonlyoneortwodigits,thenletthesystem
run for a while to see if the adjustment is
sufficient. If the heat cycles are too short,
press
TIME
FWD
to increase the cycle time. If the
CAUTION
!
heat cycles are too long, press
TIME
BACK
to de-
creasethecycletime.Tosetcoolingantici-
pation,press
SET
CLOCK
and
SET
DAY
atthesametime
again.ThedisplaywillshowCOOL 14 (fac-
tory preprogrammed cooling anticipation).
Youmayselectanyanticipationsettingfrom
4to40.Use
TIME
FWD
and
TIME
BACK
toadjustanticipa-
tion. Press
RUN
PRGM
to return to your program.
•LOW BATTERY INDICATOR — The word
BATTERY will flash on the display if the
“AA” alkaline batteries are low and should
be replaced. The word BATTERY will be
displayedcontinuously(non-flashing)when
24 VAC power is not being supplied to the
thermostat and the thermostat is operating
on battery power only.

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•AUDIO PROMPTING — Each time you
press a button, the thermostat will beep.
•BACKLIT DISPLAY — When you press
any button on the thermostat, the display is
lit for approximately eight seconds.
•SYSTEM INDICATOR LIGHT — The red
lightontheupperrightpartofthethermostat
indicatessystemoperation(seePARTSOF
THE THERMOSTAT).
•COMPRESSORSHORTCYCLEPROTEC-
TION — To protect your compressor from
potential damage due to rapid cycling, this
thermostat has a built-in delay of 5 minutes
between cooling cycles. The following may
cause a time delay in COOL:
a) Return of power after a power outage.
b) Pressing
SYSTEM
SWITCH
to change operating
modes.
c) Pressing , creating a call for COOL
too soon after a previous call.
PROGRAMMING

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Nowyouare ready to program your thermostat.
Thissectionwillhelpyouplanyourthermostat’s
program to meet your needs.
For maximum comfort and efficiency, keep the
followingguidelinesinmindwhenplanningyour
program.
• When heating (cooling) your building, pro-
gramthetemperaturestobecooler(warmer)
when the building is vacant or during peri-
ods of low activity.
• During early morning hours, the need for
cooling is usually minimal.
PLANNING FOR YOUR NEEDS
First,answerthefollowingquestionstohelpyou
decidewhatyourneedsare.Ifyouareusingthe
thermostatforacommercialapplication(astore,
officebuilding,etc.),answerquestions1through
4. If you are using the thermostat in your home,
answer questions 5 through 8.
FOR COMMERCIAL APPLICATIONS:
1a. Whattimedoesthefirstpersonarriveatthe
building in the morning?
b. Whattemperature should the building be at
thistime?(heating?cooling?) Thesewillbe
your MOR (morning) temperature settings.
2a. What time do the building occupants reach
amaximumactivitylevel(usinglights,equip-
ment, meeting rooms, etc.)?
PROGRAMMINGYOURTHERMOSTAT
PROGRAMMING

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b. Whattemperature should the building be at
thistime? ThesewillbeyourDAYtempera-
ture settings.
3a. What time do the building occupants reach
a minimum activity level (limited personnel
in building)?
b. Whattemperature should the building be at
thistime? ThesewillbeyourEVE(evening)
temperature settings.
4a. What time does the building become va-
cant?
b. Whattemperature should the building be at
this time? These will be your NHT (night)
temperature settings.
IN YOUR HOME:
5a. Whattimedoesthefirstpersongetupinthe
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 the
house in the morning?
b. What temperature should the house be at
thistime? ThesewillbeyourDAYtempera-
ture settings.
7a. Whattimedoesthefirstpersonarrivehome
in the evening?
b. What temperature should the house be at
thistime? ThesewillbeyourEVE(evening)
temperature settings.
8a. Whattime does the last persongo to bed at
night?
b. What temperature should the house be at
this time? These will be your NHT (night)
temperature settings.

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choose start times, heating temperatures, and
cooling temperatures independently for both
weekday and weekend programs (for example,
youmayselect5:00AMand70°astheweekday
MOR heating start time and temperature, and
choose 7:00 AM and 76°as the weekday MOR
cooling start time and temperature).
Use the following table to plan your program
time periods, and the temperatures you want
duringeachperiod.Youmayalsowanttolookat
the sample program table to get an idea of how
the thermostat can be programmed.
Now look at the factory preprogrammed times
and temperatures shown below. If this program
will suit your needs, simply press
RUN
PRGM
to begin
running the factory preset program.
Ifyouwanttochangethepreprogrammedtimes
and temperatures, do the following.
Determine the time periods and heating and
cooling temperatures for your weekday pro-
gram.Youmustprogram4periodsforeachday
(MOR, DAY, EVE, and NHT). However, you
mayusethesameheatingandcoolingtempera-
tures for consecutive time periods. You can
Heating Program for ALL days of the Week:
FACTORY PREPROGRAMMING
Cooling Program for ALL Days of the Week:
PERIOD TIME TEMP PERIOD TIME TEMP
MOR
DAY
EVE
NHT
5:00 AM
9:00 AM
4:00 PM
10:00 PM
70
70
70
64
MOR
DAY
EVE
NHT
5:00 AM
9:00 AM
4:00 PM
10:00 PM
78
82
78
78

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WEEKDAY (5 DAY) WEEKEND (2 DAY)
Start
Time Temperature Start Time 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)
Start
Time Temperature Start Time Temperature
MOR HEAT
DAY HEAT
EVE HEAT
NHT HEAT
MOR COOL
DAY COOL
EVE COOL
NHT COOL
SAMPLE
Heating/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