1F90-71
5-Day/2-Day Electronic Digital Thermostat
WHITE-RODGERS
INSTALLATION INSTRUCTIONS
Operator: Save these insructions for future use!
FAILURE TO READ AND FOLLOW ALL INSTRUCTIONS CAREFULLY
BEFORE INSTALLING OR OPERATING THIS CONTROL COULD CAUSE
PERSONAL INJURY AND/OR PROPERTY DAMAGE.
DESCRIPTION
This wall-mounted, low voltage thermostat maintains
room temperature by controlling the operation of heating
and cooling systems. The user may program up to four
time/temperature settings per 24 hour period. The ther-
mostat stores independent heating and cooling programs
for 5-day (weekday) and 2-day (weekend) periods. The
thermostat will store both heating and cooling programs
simultaneously.Three“AA”Energizer® batterieswillmain-
tain the stored program for approximately one year, if
incoming power should fail. If power failure is extensive
and the program is lost, after power restoration, the
thermostat will automatically maintain a factory
preprogrammed heating temperature of 64°F or a cooling
temperature of 82°F.
PRECAUTIONS
Ifindoubtaboutwhetheryourwiringismillivolt,line,orlow Do not exceed the specification ratings.
voltage, have it inspected by a qualified heating and air
All wiring must conform to local and national electrical
codes and ordinances.
conditioning contractor, electrician, or someone familiar
with basic electricity and wiring.
This control is a precision instrument, and should be
handled carefully. Rough handling or distorting compo-
nents could cause the control to malfunction.
CONTENTS
CAUTION
!
Description ......................................................... 1
Precautions ........................................................ 1
Specifications..................................................... 2
Installation.......................................................... 2
New Installation
To prevent electrical shock and/or equipment
damage, disconnect electric power to system, at
main fuse or circuit breaker box, until installation
is complete.
Select Thermostat Location
Route Wires to Location
Replacement Installation
WARNING
!
Remove Old Thermostat
Attach Subbase to Wall
Attach Thermostat to Subbase
Operation ........................................................... 6
System Configuration
Do not use on circuits exceeding specified volt-
age. Higher voltage will damage the control and
could cause shock or fire hazard.
A. Set Group A Option Switches
B. Set Group B Option Switches
C. Electric Heat Systems
Donotshortoutterminalsongasvalveorprimary
control to test. Short or incorrect wiring will burn
out thermostat and could cause personal injury
and/or property damage.
Check Thermostat Operation
Fan Operation
Heating System
Cooling System
Troubleshooting
WHITE-RODGERS DIVISION
EMERSON ELECTRIC CO.
9797 REAVIS ROAD
PART NO. 37-5086B
Printed in U.S.A.
Replaces 37-5086A
9517
ST. LOUIS, MISSOURI 63123-5398
R
TABLE 1. OLD THERMOSTAT IDENTIFICATION
REPLACEMENT INSTALLATION
OLD
OLD THERMOSTAT
THERMOSTAT
REMOVE OLD THERMOSTAT
TERMINAL IDENTIFICATION
TYPE
1. Shut off electricity at the main fuse box until installa-
tion is complete. Verify power is off with a voltmeter.
Type
4
RH
M
W
W
H
RC
RC
V
Y
Y
G
G
F
1
Type
2
2. Remove the front cover of the old thermostat. With
wires still attached, remove wall plate from the wall.
Type
3
3. If the old thermostat has a wall mounting plate,
removethethermostatandthewallmountingplateas
an assembly.
C
Type
4
R5
R
4
Y6
Y
G
G
4. FOR HEATING ONLY SYSTEMS — Disconnect the
two wires from the old thermostat. Skip steps 5
through7belowandproceedtoATTACHSUBBASE
TO WALL.
Type
5
W
TABLE 2. WIRE IDENTIFICATION LABELS
5. FOR HEATING/COOLING SYSTEMS — Before re-
moving wires from old thermostat, identify the termi-
nals that have wires attached on the old thermostat.
ThenuseTable1toidentifythetypeofthermostatyou
are replacing. For example, if the old thermostat has
wires attached to terminals R, W, Y, and G, the old
thermostat is a type 5 (note that the old thermostat
may not have wires attached to all the terminals
identified in Table 1).
Type New Old New Old New Old New Old New Old
1
RH
4
W
W
RC RC
Y
Y
G
G
Type New Old New Old New Old New Old New Old
RH RH RC RC
2
W
W
Y
Y
G
G
Type New Old New Old New Old New Old New Old
RH RC
3
M
W
H
V
Y
C
G
F
6. Use the self-adhesive labels enclosed with your
new thermostat to identify the wires attached to
the old thermostat. The labels correspond to the
thermostattypenumberyouidentifiedinstep5above
(seeTable2). Forexample, ifyoudeterminedthatthe
old thermostat is a type 5, use the labels for the type
5 thermostat (you may not use all the labels for the
type number you’ve identified if the old thermostat did
not have wires attached to all the terminals).
Type New Old New Old
RH R5
New Old New Old
Y6
4
W
4
Y
G
G
Type New Old New Old
RH
New Old New Old
5
R
W
W
Y
Y
G
G
7. Label each wire as you disconnect it. The labels have
both the old terminal markings and the new terminal
identification. Discard any unused labels. PULL AT
LEAST SIX INCHES OF WIRE OUT OF THE WALL
WHEN YOU DISCONNECT IT - DO NOT ALLOW
THE WIRES TO FALL BACK INTO THE WALL.
PULL STRAIGHT OUT
ATTACH SUBBASE TO WALL
Figure 2. Removing thermostat from subbase
1. Remove the packing material from the thermostat.
Place the fingers of one hand on the center top and
bottom portion of the thermostat. Grasp the subbase
in the other hand on the top and bottom center, and
gentlypullstraightout(seefig. 2). Thethermostathas
pin and socket connectors. Forcing or prying on the
thermostat will cause damage to the unit.
Screw
anchors
Connect wires under
terminal screws
Activity
light
Mounting
hole
Mounting
hole
6
W
RC
G
6-pin connector
MV
2. Pull wires through opening in the center of the sub-
base. DO NOT LET WIRES FALL BACK INTO
WALL.
Y
RH
3-pin connector
3. Connect wires beneath terminal screws on sub-
base using appropriate wiring schematic (see figs.
3 through 11).
Pull wires through
this opening
(Installation instructions continue on page 5.)
Figure 3. Subbase
3
CAUTION
NOTE
!
All wiring diagrams are for typical systems only. Refer to
equipment manufacturers’ instructions for specific sys-
tem wiring information.
To prevent electrical shock and/or equipment
damage, disconnect electrical power at the main
fuse box or circuit breaker until installation is
complete.
From heating system
From 24 VAC transformer
THERMOSTAT
Y
6
MV
G
W
RC
RH
6
W
RC
G
SYSTEM
MV
Heating
System
Hot
Y
24 VAC
120 VAC
RH
Neutral
TRANSFORMER
Thermostat Terminal Connections
Figure 4. Typical wiring diagram for heat only, 2-wire, single transformer systems
From 24 VAC
transformer
From heating system
JUMPER
WIRE
THERMOSTAT
SYSTEM
6
W
RC
G
Y
6
MV
G
W
RC
RH
MV
NOTE
Fan
Heating
System
RED jumper wire (pro-
vided with thermostat)
must be connected be-
tween thermostat's RH
and RC terminals for pro-
per thermostat operation
with this system.
Relay
Hot
Y
24 VAC
120 VAC
RH
From fan relay
Neutral
CONNECT red jumper
wire (provided)
TRANSFORMER
Thermostat Terminal Connections
Figure 5. Typical wiring diagram for heat only, 3-wire, single transformer systems
From 24 VAC
transformer
THERMOSTAT
Y
6
MV
G
W
RC
RH
6
W
RC
G
SYSTEM
MV
Cooling
System
Fan
Relay
Hot
Y
24 VAC
120 VAC
From fan relay
From cooling system
RH
Neutral
TRANSFORMER
Thermostat Terminal Connections
Figure 6. Typical wiring diagram for cool only, 3-wire, single transformer systems
From heating system
CONNECT red jumper
wire (provided)
JUMPER
WIRE
THERMOSTAT
SYSTEM
Y
6
MV
G
W
RC
RH
6
W
RC
G
W
MV
RH
NOTE
Cooling
System
Fan
Heating
System
RED jumper wire (pro-
vided with thermostat)
must be connected be-
tween thermostat's RH
and RC terminals for pro-
per thermostat operation
with this system.
Relay
Hot
Y
24 VAC
120 VAC
From fan relay
Neutral
From cooling system
From 24 VAC
transformer
TRANSFORMER
Thermostat Terminal Connections
Figure 7. Typical wiring diagram for heat/cool, 4-wire, single transformer systems
4
From millivolt system
THERMOSTAT
SYSTEM
Y
6
MV
G
W
RC
RH
6
W
RC
G
MV
Millivolt
System
Y
RH
From millivolt system
Thermostat Terminal Connections
Figure 8. Typical wiring diagram for millivolt systems
From millivolt system
From 24 VAC
transformer
THERMOSTAT
Y
6
MV
G
W
RC
RH
6
W
SYSTEM
MV
RC
G
Millivolt
System
Cooling
System
Fan
Hot
Relay
24 VAC
120 VAC
Y
Neutral
RH
TRANSFORMER
From fan relay
From cooling system
Thermostat Terminal Connections
Figure 9. Typical wiring diagram for millivolt systems + cool only, 3-wire systems
From zone valve
THERMOSTAT
SYSTEM
6
W
RC
G
Y
6
MV
G
W
RC
RH
MV
6
1
4
2
5
Zone
Valve
Hot
Y
24 VAC
120 VAC
RH
From 24 VAC transformer
(through zone valve)
Neutral
TRANSFORMER
Thermostat Terminal Connections
Figure 10. Typical wiring diagram for heat only, 3-wire, zone valve systems
From heating
system
From 24 VAC
cooling transformer
THERMOSTAT
Y
6
MV
G
W
RC
RH
SYSTEM
Hot
6
W
MV
RC
G
24 VAC
Cooling
System
Fan
Heating
System
120 VAC
Relay
Neutral
HEATING TRANSFORMER
Hot
Y
From fan relay
RH
From cooling
system
24 VAC
120 VAC
From 24 VAC
heating transformer
Neutral
COOLING TRANSFORMER
Thermostat Terminal Connections
Figure 11. Typical wiring diagram for heat/cool, 5-wire, two-transformer system
4. Place subbase over hole in wall and mark mounting
hole locations on wall using subbase as a template.
mounting holes, or if holes drilled are too large and do
not allow you to tighten subbase snugly, use plastic
screw anchors to secure subbase.
5. Move subbase out of the way. Drill mounting holes.
7. Push excess wire into wall and plug hole with a fire-
resistant material (such as fiberglass insulation) to
prevent drafts from affecting thermostat operation.
6. Fasten subbase loosely to wall, as shown in fig. 3,
using two mounting screws. Place a level against
bottom of subbase, adjust until level, and then tighten
screws. (Leveling is for appearance only and will not
affect thermostat operation.) If you are using existing
5
from the front). Gently pivot the thermostat up until the six
pin connectors and the plastic snaps lock into place (see
fig. 12). Be gentle when attaching thermostat. If the
thermostat does not seem to be attaching to the subbase
easily, make sure that the connector pins and plastic
snaps are properly aligned, and that excess wire is
pushed into the wall. Damage to the thermostat may
occur if force is used.
ATTACH THERMOSTAT TO SUBBASE
IT IS RECOMMENDED THAT YOU SET OPTION
SWITCHESTODESIREDPOSITIONBEFOREATTACH-
ING ON SUBBASE (see OPERATION). IT IS ALSO
RECOMMENDED THAT YOU PROGRAM THE
THERMOSTAT WITH BATTERIES INSTALLED BE-
FORE ATTACHING ON SUBBASE (see OPERATION
GUIDE for programming instructions).
CAUTION
!
SYSTEM
SWITCH
USE
TO TURN THERMOSTAT OFF BE-
FORE ATTACHING THERMOSTAT TO WALL.
FAILURE TO TURN THERMOSTAT OFF BEFORE
ATTACHING TO WALL MAY CAUSE EQUIPMENT
DAMAGE DUE TO RAPID COMPRESSOR CY-
CLING.
To attach thermostat to subbase, line up the plastic snap
guides at the bottom of the thermostat and the three
connector pins on the thermostat with the connectors
near the bottom left section of the subbase (when viewed
ENGAGE TWO LOWER GUIDES;
PIVOT UP
Figure 12. Attaching thermostat to subbase
OPERATION
Batteries
6-pin connector
SYSTEM CONFIGURATION
A. SET GROUP A OPTION SWITCHES
NOTE
DO NOT REMOVE THE “AA” BATTERIES WHEN
CHANGING GROUP A OPTION SWITCHES. Any
time Group B option switches are changed, the bat-
teriesmustberemovedforaminimumoftwominutes.
(Group A)
(Group B)
1. Total Keypad Activity
Option switches
3-pin connector
ON
Figure 13. Back of thermostat
Switch #1 OFF
Switch #2 OFF
B. SET GROUP B OPTION SWITCHES
1
2
2. Total Keypad Lockout — All thermostat buttons are
NOTE
disabled.
ANY TIME GROUP B OPTION SWITCHES ARE
CHANGED,THE“AA”BATTERIESMUSTBEREMOVED
FOR A MINIMUM OF 2 MINUTES. DO NOT REMOVE
THE BATTERIES WHEN CHANGING GROUP A OP-
TION SWITCHES.
ON
Switch #1 ON
Switch #2 OFF
1
2
3. Limited Temperature Range — Temperature may
beraisedorloweredwithinprogrammedtemperature
limits (temperature adjustment cannot exceed the
lowest cooling or highest heating program tempera-
tures).
1. AutomaticChangeover(Heating/CoolingSystems
Only) — enables thermostat to automatically switch
between heating and cooling programs to maintain
desired room temperature.
ON
ON
Switch #1 ON
Switch #1 OFF
Switch #2 ON
Switch #2 OFF
Switch #3 (see step B5)
1
2
3
1
2
When thermostat is in Limited Temperature Range
only the following buttons are disabled:
ADV
HOLD
TEMP
SET
DAY
PRGM
6
2. Manual Changeover (Heating/Cooling Systems
FAN
SWITCH
2. Press
until FAN ON is displayed. The blower
Only)
should begin to operate (this will work only on sys-
tems with a G terminal).
ON
Switch #1 OFF
Switch #2 OFF
Switch #3 (see step B5)
1
2
3
Onthree-wireheatonlysystems,oronfour-wireheat/
cool systems, if the thermostat display is operating
3. Heat Only Systems
FAN
SWITCH
ON
properly, but the fan does not operate when
Switch #1 OFF
Switch #2 ON
ispressed,theredjumperwire(providedwiththermo-
stat) may not be properly installed between the RH
and RC terminals. Disconnect electrical power to
system and properly install the jumper wire per the
appropriate wiring diagram.
Switch #3 (see step B5)
1
2
3
4. Cool Only Systems
ON
Switch #1 ON
Switch #2 ON
Switch #3 (see step B5)
1
2
3
FAN
3. Press
until FAN AUTO is displayed. The
SWITCH
blower should stop operating within approximately
one minute.
5. Computed Energy Management Recovery
(EMR) — With EMR enabled, system will be ener-
gized before the next program period begins, to
achieve programmed temperature by the beginning
of the next program period (the thermostat’s micro-
computer calculates 15 minutes for every 2°F tem-
perature change). For example, assume that the
thermostat is programmed to provide an overnight
heating temperature of 62°F, and during the next
programperiod,programmedtobeginat6:00AM,the
programmed temperature is 70°F. With EMR acti-
vated, the thermostat will automatically activate the
heating system at 5:00 AM, so that the programmed
temperature of 70°F is reached by about 6:00 AM.
HEATING SYSTEM
SYSTEM
SWITCH
1. Press
untilHEATisdisplayed(itmayalready
be displayed).
2. Press
to adjust thermostat above room tem-
perature to call for heat. The heating system should
begin to operate.
(Instructions continue on next page.)
ON
Switch #1 (see steps B1–B4)
Switch #2 (see steps B1–B4)
Switch #3 OFF
1
2
3
C. ELECTRIC HEAT SYSTEMS
LOCKOUT BYPASS OPTION
For central electric heat systems where the blower is
energized by a separate circuit through the fan relay
(meaning that the fan turns on immediately on call for
heat), clipwireW14onthebackofthethermostat(seefig.
13). If the thermostat is energizing electric heat sequenc-
ers, DO NOT clip wire W14.
FOR QUALIFIED SERVICE TECHNICIANS’ USE
ONLY.OPERATORSSHOULDNOTUSETHISFEA-
TURE DUE TO POSSIBILITY OF EQUIPMENT OR
PROPERTY DAMAGE, OR PERSONAL INJURY.
COMPRESSOR SHORT TERM
CYCLE PROTECTION
CHECK THERMOSTAT OPERATION
This thermostat has a built-in short term (5-minute)
time delay. During this 5-minute period, the thermo-
stat will lock out the compressor to allow head pres-
sure to stabilize. If you want to override this feature
ADV
NOTE
When checking thermostat, Group B option switches #1
and #2 for automatic changeover must be in the OFF
position.Thiswillallowtemporarysettingofheatsetpoints
above cool setpoints. After system checkout, reset Group
Boptionswitch#1to ONpositionifautomaticchangeover
is desired (see SET GROUP B OPTION SWITCHES).
while testing thermostat operation, simply press
PRGM
HOLD
and
buttons at the same time at initial startup.
TEMP
FAN OPERATION
DO NOT USE THE LOCKOUT BYPASS OPTION
UNLESSTHECOMPRESSOROILHEATERSHAVE
BEEN OPERATIONAL FOR 6 HOURS AND THE
SYSTEM HAS NOT BEEN OPERATIONAL FOR AT
LEAST 5 MINUTES.
1. Turn on power to the system. If the heat source has
a standing pilot, be sure to light it.
7
After the system has been checked and is running prop-
erly, determine if automatic changeover is desired (see
SYSTEM CONFIGURATION).
COOLING SYSTEM
CAUTION
!
Refer to the OPERATION GUIDE if you need additional
To prevent compressor and/or property damage,
if power to the compressor has been off or inter-
rupted for more than 1 hour and the outdoor
temperature is below 50°F, DO NOT operate the
system for at least the amount of time the com-
pressor was off! This will allow the compressor
heaters to warm the compressor oils to avoid
damage due to slugging.
information on thermostat operation.
TROUBLESHOOTING
Refer to the Question & Answer section of the OPERA-
TION GUIDE for information on troubleshooting the ther-
mostat.
SYSTEM
SWITCH
1. Press
2. Press
until COOL is displayed.
to adjust thermostat below room tem-
perature to call for cool. The blower should come on
immediately, followed by cold air circulation. How-
ever, if the blower does not come on and the word
COOL is flashing, the compressor lockout feature is
operating (see Lockout Bypass Option to tempo-
rarily override the compressor lockout feature during
testing).
If the thermostat display is operating properly, but the
cooling system does not operate when the above
steps are performed, the red jumper wire (provided
with thermostat) may not be properly installed be-
tween the RH and RC terminals. Disconnect electri-
cal power to system and properly install the jumper
wire per the appropriate wiring diagram.
If you need further information about this product, please write to:
WHITE-RODGERS
Division of Emerson Electric Co.
9797 Reavis Road
St. Louis, MO 63123-5398
ATTN: Technical Service Department
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