1F56N-911
Low Voltage Heating/Cooling Thermostat
INSTALLATION INSTRUCTIONS
Operator: Save these instructions 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
M
SYSTE
OFF
FAN
TO
This low voltage thermostat is designed to provide conve-
nient control of the heating/cooling system. To provide
greater room comfort, the sensitive spiral bimetal is com-
bined with an adjustable heating anticipator and a fixed
cooling anticipator to provide maximum comfort.
H
EAT
ON
COOL
AU
°C
°C
32
90
32
90
80
70
60
80
70
60
21
10
21
10
50
50
PRECAUTIONS
Ifindoubtaboutwhetheryourwiringismillivolt,line,orlow This control is a precision instrument, and should be
voltage, have it inspected by a qualified heating and air handled carefully. Rough handling or distorting compo-
conditioning contractor, electrician, or someone familiar nents could cause the control to malfunction.
with basic electricity and wiring.
CAUTION
!
Do not exceed the specification ratings.
To prevent electrical shock and/or equipment
damage, disconnect electric power to system at
main fuse or circuit breaker box until installation
is complete.
All wiring must conform to local and national electrical
codes and ordinances.
CONTENTS
Do not short out terminals on gas valve or pri-
marycontroltotest. Shortorincorrectwiringwill
burn out heat anticipator and could cause per-
sonal injury and/or property damage.
Description ........................................................ 1
Precautions ....................................................... 1
Specifications .................................................... 2
Installation ......................................................... 2
Select Thermostat Location
WARNING
!
Route Wires to Location
Attach Subbase to Wall
Donotuseoncircuitsexceeding30volts. Higher
voltage will damage control and could cause
shock or fire hazard.
Special System Configurations
Electric Heat Furnaces (Single Trans-
former Systems Only)
Two-Transformer Systems
Heat Pump Applications
Special Application Terminals
Thermostat installation and all components of
the system shall conform to Class II circuits per
the NEC code.
Attach Thermostat to Subbase
Operation & Maintenance ................................. 5
Adjusting Heat Anticipator
Calibrating Thermostat
PART NO. 37-6923A
White-Rodgers is a division
of Emerson Electric Co.
0807
Heat Pump Applications
ATTACH SUBBASE TO WALL
This subbase WILL NOT provide multi-stage heating or
cooling operation. For single-stage heat pump applica-
tions, install a short jumper wire across terminals W and
Y. If the old thermostat has a terminal that is continuously
energized, disconnect the wire from the old thermostat's
terminal and connect it either to the: 1) B terminal, if the
reversing valve is energized on a call for heat; or to the 2)
O terminal, if the reversing valve is energized on a call for
cool. If the system heats on a call for cool, or vice versa,
this wire has been connected to the wrong terminal.
CAUTION
!
To prevent electrical shock and/or equipment
damage, disconnect electric power to system at
main fuse or circuit breaker box until installation
is complete.
1. Disconnect electrical power at main fuse or circuit
breaker.
2. Pull wires through opening near center of subbase
and connect wires beneath terminal screws (see figs.
2through6fortypicalwiringforeachapplication.Also
refertosubsectionsbelowforspecialsystemconfigu-
rations).
NOTE
RH and RC must be jumpered for single transformer heat
pump systems.
3. Push excess wiring into wall and plug hole with fire-
resistant material (such as fiberglass insulation) to
prevent drafts from affecting thermostat operation.
Special Application Terminals
The B and O terminals can provide switching for special
functions other than heat pump operation. When the
system switch is in the HEAT position, the B terminal is
energized. When the system switch is in the COOL
position, the O terminal is energized.
4. Positionsubbaseoverholeinwallandmarkmounting
hole locations on wall.
5. Drill mounting holes.
6. Fasten subbase loosely to wall, as shown, using two
mounting screws. Place a level against bottom of
subbase, adjust until level, and then tighten mounting
screws to secure subbase. If holes in wall are too
large and do not allow you to tighten subbase snugly,
use plastic expansion plugs to secure subbase.
ATTACH THERMOSTAT TO SUBBASE
1. Remove cover from thermostat base by gripping the
base in one hand. Use the other hand to pull gently at
the top or bottom of the cover.
SPECIAL SYSTEM CONFIGURATIONS
2. Carefully remove the shipping protective packing
from the switch.
Electric Heat Furnaces (Single Transformer Systems
Only)
3. Attachthermostatbasetosubbase,beingsurethatall
captivescrewsaretightenedsnugly, sincetheyserve
as electrical connections between thermostat and
subbase (see fig. 7).
The subbase as shipped may not operate the fan cor-
rectly. If both the heating and cooling system must oper-
ate the fan relay, remove the yellow factory-installed
jumper wire from the Y terminal and connect it to the A
terminal. The fan should now cycle when the thermostat
calls for either heat or cool.
4. Snap cover on thermostat and set switches and
temperature lever to desired set point (see OPERA-
TION section).
5. Turn on power to the system.
Two-Transformer Systems
FAN
SYSTEM
AUTO
ON
COOL OFF HEAT
CAUTION
!
If two transformers are used, they MUST be in
phase. Failure to do so may result in personal
injury and/or property damage.
G
RC
B
O
NOTE
Wire color DOES NOT indicate polarity. Polarity is ob-
W
tained from an oscilloscope or voltmeter.
RH
A
Y
Mounting screw
Mounting screw
KEEP THIS AREA
CLEAR OF WIRES
Hole
in wall
Figure 2. Thermostat subbase
3
CAUTION
NOTE
!
Take care when securing and routing wires so
they do not short to adjacent terminals or rear of
thermostat.Personalinjuryand/orpropertydam-
age may occur.
These typical wiring diagrams show only the terminal
identification and wiring hookup. Always refer to wiring
instructions, provided by equipment manufacturer, for
system hookup operation.
Fixed Cooling
Anticipator
Adjustable Heating
Anticipator
THERMOSTAT
Captive
Screws
Fan
Switch
System
Switch
COOL
HEAT
OFF
ON
AUTO
COOL
SUBBASE
H E A T
System
Switch
W
A*
B
RH
Y
G
RC
O
SYSTEM
Moveable
Yellow Jumper
*
Terminal "A" is not for field wiring. See
Factory-installed Jumper
SPECIAL SYSTEM CONFIGURATIONS
section for proper use of terminal "A".
Figure 3. Typical wiring diagram (see figs. 4, 5, and 6 for typical system/thermostat wiring)
KEEP THIS
AREA CLEAR
OF WIRES!
G
RC
B
Factory-installed
Red Jumper Wire
O
THERMOSTAT
WIRING
W
Factory-installed
Yellow Jumper Wire
RH
A
Y
Factory-Installed Jumper
RH
W
B
O
Y
G
RC
A
Heat
Relay
Compressor
Relay
Fan
Relay
Hot
* *
*
SYSTEM
24 VAC
120 VAC
Neutral
Terminal energized
in cooling
Terminal energized
* *
in heating
*
TRANSFORMER
Figure 4. Typical wiring for single transformer heating/cooling system
KEEP THIS
AREA CLEAR
OF WIRES!
G
RC
B
Factory-installed
Yellow Jumper Wire
O
THERMOSTAT
WIRING
W
NOTE: Remove factory-
installed jumper between
RC and RH terminals for
this application.
RH
A
Y
RH
W
B
A
O
Y
G
RC
TRANSFORMER
Hot
TRANSFORMER
Hot
Heat
Relay
Compressor
Relay
Fan
Relay
* *
*
24 VAC
24 VAC
120 VAC
Neutral
120 VAC
SYSTEM
Neutral
Terminal energized
in cooling
Terminal energized
* *
in heating
*
Figure 5. Typical wiring for two-transformer heating/cooling system
4
KEEP THIS
AREA CLEAR
OF WIRES!
G
RC
Factory-installed
Red Jumper Wire
B
O
THERMOSTAT
WIRING
W
Factory-installed
Yellow Jumper Wire
Field-installed
Jumper Wire
RH
A
Y
Factory-Installed Jumper
Field-Installed Jumper
RC
G
RH
O
W
Y
B
A
TRANSFORMER
Hot
Fan
Relay
Compressor
Relay
*
* *
24 VAC
120 VAC
Neutral
SYSTEM
Terminal energized
in cooling
Terminal energized
in heating
*
* *
Figure 6. Typical wiring for single transformer, single stage heat pump system
F
A
A
N
U
T
O
O
N
S
Y
C
S
O
T
O
E
L
M
O
F
F
H
E
A
T
90
80
70
60
50
90
80
70
Subbase
60
50
Thermostat
Cover
Figure 7. Attach thermostat to subbase
OPERATION &
MAINTENANCE
This thermostat is easy to operate. Fig. 8
shows how the heating/cooling system
and fan operate when the switches are in
various positions. Use the system switch
to select either heating or cooling, or to
turn the heating/cooling system off. Use
the fan switch to control fan operation.
When the fan switch is in the AUTO
position,thefanwillcyclewiththeheating
or cooling system (the fan will not run if
the system switch is in the OFF position
and the fan switch is in the AUTO posi-
tion). When the fan switch is in the ON
position, the fan will run continuously,
regardlessofsystemswitchposition(even
if the system switch is set to OFF, the fan
will run if the fan switch is in the ON
position).
Shows switch position
FAN
SYSTEM
OPERATION
AUTO ON
COOL OFF HEAT
No heating; no cooling; no fan
No heating; no cooling; fan runs continuously
Cooling system cycles from thermostat; fan runs
continuously
Cooling system and fan cycle from thermostat
Heating system cycles from thermostat; fan cycles
from fan control on furnace
Heating system cycles from thermostat; fan runs
continuously
Figure 8. Subbase switching and thermostat/system operation
5
1. The anticipator’s heat may adversely affect thermo-
stat recalibration. To prevent this, disconnect electri-
cal power to the thermostat at the furnace, main fuse,
or breaker box.
ADJUSTING HEAT ANTICIPATOR
CAUTION
!
The adjustable heat anticipator WILL BURN OUT
if 25 VAC is applied directly to the thermostat by
shorting out the primary control during testing.
This may cause personal injury and/or property
damage.
2. Movetemperatureadjustmentlevertoasettingabout
5° above room temperature.
3. Remove thermostat cover. Slip 7¦32” wrench onto hex
nut beneath bimetal (see fig. 10). While holding
temperature adjustment lever stationary, turn hex
nut clockwise until movable contact moves off of
magnet.
This thermostat is equipped with an adjustable heat
anticipator and was preset at the factory to provide
satisfactoryoperationoftheheatingsystemundernormal
conditions. If additional adjustments are necessary, they
may be made as follows (see fig. 9):
4. Move temperature adjustment lever to lowest setting.
5. Replace thermostat cover. Wait 10 minutes for bi-
metal temperature to stabilize. Do not stand near the
thermostat during this period, as your breath and
body heat will affect bimetal temperature.
1. Remove thermostat cover.
2. If heat cycle is too long, set heat anticipator to a
slightly lower dial setting (1¦2 division).
6. Move temperature adjustment lever to correspond to
actual room temperature. Then remove thermostat
cover.
3. If heat cycle is too short, set heat anticipator to a
slightly higher dial setting (1¦2 division).
7
7. Slip ¦32” wrench onto hex nut (see fig. 10). While
4. Replace thermostat cover.
holdingtemperatureadjustmentleverstationary, turn
hex nut counterclockwise until movable contact just
closes against magnet.
.25
.3
.4
8. Replace thermostat cover and set temperature ad-
justment lever to desired temperature. Turn on elec-
trical power to system.
.2
.5
.18
.6
.8
.15
1.
Move this lever to
adjust heat
Arrow points to the
matched current rating
of the primary control
anticipator
Figure 9. Anticipator adjustment
CALIBRATING THERMOSTAT
Temperature
adjustment
This thermostat has been carefully adjusted at the factory
and should not require recalibration.
lever
Bimetal
Duetoenvironmentalconditions,duringnormaloperation
there may be a few degrees of difference between the
indicator setting of the thermostat and actual room tem-
perature. If the disagreement is appreciable, however,
first make sure that the thermostat is properly located and
leveled. Then, if recalibration still seems necessary, pro-
ceed as follows:
7⁄32
”
Calibration
wrench
Figure 10. Calibrating thermostat
CAUTION
!
To prevent electrical shock and/or equipment
damage, disconnect electrical power to the sys-
tem until recalibration is complete.
6
7
HOMEOWNER HELP LINE: 1-800-284-2925
The Emerson logo is a
trademark and a service mark
of Emerson Electric Co.
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