CONTENTS
Installation Instructions for
Preparations.................................................. 1
Thermostat Details ........................................ 1
Removing Old Thermostat ............................ 1
Mounting and Wiring ..................................... 2
Check Thermostat Operation ........................ 3
Configuration Menu ....................................... 4
Specifications ................................................ 5
Troubleshooting ............................................ 5
Heating & Air Conditioning
1F78H
Non-Programmable Thermostat
YOUR THERMOSTAT REPLACES
PREPARATIONS
1
Typical System Compatibility Chart
1F78H
Assemble tools required as shown below.
Standard Heat Only Gas or Oil Fired Systems (24 volt)*
Electronic Ignition Heat Only Two Wire Systems (24 volt)*
Electronic Ignition Heat Only Gas or Oil Fired Systems (24 volt)*
Standard Heat/Cool Systems (24 volt)*
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Heat/Cool Systems Electric Heat (24 volt)*
Heat Only Electric Heat Systems (24 volt)*
Cool Only Systems (24 volt)*
FLAT BLADE SCREWDRIVER
WIRE CUTTER/STRIPPER
HAND OR POWER
DRILL WITH 3/16 INCH
DRILL BIT, IF NEEDED
Heat Pump Systems (No Aux or Emergency Heat)*
Hot Water Zone Heat Only Systems
SPIRIT LEVEL OR PLUMB BOB AND LINE OPTIONAL—
THERMOSTAT DOES NOT NEED TO BE LEVEL TO WORK PROPERLY
Hot Water Zone Heat Only (Three Wire) Systems
Line Voltage Heating or Baseboard 110/240 Volt Systems
Millivolt Systems Floor or Wall Furnaces
12 VDC Mobile Home Application
No
No
No
No
Failure to follow and read all instructions carefully
before installing or operating this control could cause
personal injury and/or property damage
Multistage Systems
No
Systems Exceeding 30VAC, 1.5 Amp
No
* Requires common wire for 24VAC at the thermostat
THERMOSTAT DETAILS
REMOVING OLD THERMOSTAT
2
3
Mounting
hole
CAUTION
!
To prevent electrical shock and/or equipment damage,
disconnect electrical power to the system at the main
fuse or circuit breaker until installation is complete.
Before removing wires from old thermostat’s switching subbase,
label each wire with the terminal designation it was removed from.
W
C
RH
B
RC
1. Remove Old Thermostat: A standard heat/cool thermostat
consists of three basic parts:
a. The cover, which may be either a snap-on or hinge type.
b. The base, which is removed by loosening all captive screws.
G
O
Y
Mounting
hole
W904
W905
W905
Clip for
Hydronic
System
c. The switching subbase, which is removed by unscrewing
themountingscrewsthatholditonthewalloradaptorplate.
ELEC GAS
2. Shut off electricity at the main fuse box until installation is
complete. Ensure that electrical power is disconnected.
3. Remove the front cover of the old thermostat. With wires still
attached, removewallplatefromthewall.Iftheoldthermostat
has a wall mounting plate, remove the thermostat and the wall
mounting plate as an assembly.
W904
Clip for
Celsius Display
Electric/Gas
Switch
Figure 1. Thermostat base
4. Identify each wire attached to the old thermostat.
5. Disconnect the wires from the old thermostat one at a time.
DO NOT LET WIRES FALL BACK INTO THE WALL.
6. Install new thermostat using the following procedures.
WHITE-RODGERS
EMERSON ELECTRIC CO.
9797 REAVIS ROAD
ST. LOUIS, MISSOURI 63123-5398
PART NO. 37-6450A
Printed in U.S.A.
0247
MOUNTING AND WIRING
CONTINUED FROM SECOND PAGE
4
JUMPER
THERMOSTAT
SYSTEM
Hot
WIRE
Y
C
B
O
G
W
RC
RH
THERMOSTAT
SYSTEM
Y
C
B
O
G
W
RC
RH
Cooling
System Relay System
Fan
Heating
24 VAC
120 VAC
Neutral
NOTE
For Heat only,
attach to RH and W
Fan
Relay
Heating
System
Hot
HEATING
TRANSFORMER
24 VAC
120 VAC
Neutral
Hot
TRANSFORMER
24 VAC
120 VAC
Neutral
Figure 2. Typical wiring diagram for
heat only, 4-wire, single transformer systems
COOLING TRANSFORMER
Figure 5. Typical wiring diagram for
heat/cool, 6-wire, two-transformer systems
JUMPER
WIRE
THERMOSTAT
Y
C
B
O
G
W
RC
RH
SYSTEM
JUMPER
WIRE
JUMPER
WIRE
THERMOSTAT
SYSTEM
Cooling
System Relay
Fan
Y
C
B
O
G
W
RC RH
Hot
24 VAC
120 VAC
Neutral
Reversing Compressor Fan
Valve*
Contactor Relay
Hot
TRANSFORMER
24 VAC
120 VAC
Neutral
Figure 3. Typical wiring diagram for
cool only, 4-wire, single transformer systems
* Reversing valve is energized when the
system switch is in the COOL position
TRANSFORMER
Figure 6. Typical wiring diagram for heat pump
with reversing valve energized in COOL
NOTE
RED jumper wire (provided with thermostat) must be
connected between thermostat RH and RC terminals
for proper thermostat operation with this system.
JUMPER
WIRE
JUMPER
WIRE
JUMPER
WIRE
THERMOSTAT
SYSTEM
THERMOSTAT
SYSTEM
Y
C
B
O
G
W
RC RH
Y
C
B
O
G
W
RC RH
Cooling
System Relay
Fan
Heating
System
Reversing Compressor Fan
Valve*
Contactor Relay
Hot
Hot
24 VAC
120 VAC
Neutral
24 VAC
120 VAC
Neutral
* Reversing valve is energized when the
system switch is in the HEAT position
TRANSFORMER
TRANSFORMER
Figure 7. Typical wiring diagram for heat pump
with reversing valve energized in HEAT
Figure 4. Typical wiring diagram for
heat/cool, 5-wire, single transformer systems
CHECK THERMOSTAT OPERATION
5
This thermostat has a time delay between cooling cycles to allow
the head pressure in the compressor to stabilize. If the tempera-
ture is adjusted to call for cool within 5 minutes of the last cycle the
snowflake icon will blink indicating the thermostat is locked out.
After 3 to 5 minutes, the compressor will start and the snowflake
icon will stop flashing. This helps prevent the compressor from
cycling too quickly and is normal operation for the thermostat.
NOTE
To prevent static discharge problems, touch side of ther-
mostattoreleasestaticbuild-upbeforetouchinganykeys.
If at any time during testing your system does not operate
properly, contact a qualified serviceperson.
Fan Operation
If your system does not have a G terminal connection, skip to
Heating System.
1. Move SYSTEM switch to COOL position.
2. Press
to adjust thermostat setting below room tempera-
ture. The blower should come on immediately on high speed,
followed by cold air circulation
1. Turn on power to the system.
2. Move fan switch to ON position. The blower should begin to
3. Press
to adjust temperature setting above room tem-
operate.
perature. The cooling system should stop operating.
3. Move fan switch to AUTO position. The blower should stop
Heating System
immediately.
1. Move SYSTEM switch to HEAT position. If the heating system
Cooling System
has a standing pilot, be sure to light it.
2. Press
to adjust thermostat setting above room tempera-
ture. The heating system should begin to operate.
CAUTION
!
3. Press
to adjust temperature setting below room tem-
To prevent compressor and/or property damage, if the
outdoortemperatureisbelow50°F, DONOToperatethe
cooling system.
perature. The heating system should stop operating.
CHECK THERMOSTAT OPERATION
CONTINUED FROM THIRD PAGE
5
1
2
Before you begin using your thermostat, you should be familiar
with its features and with the display and the location and
operation of the thermostat buttons. Your thermostat consists of
two parts: the thermostat cover and the base. To remove the
cover, gently pull it straight out from the base. To replace the
cover, line up the cover with the base and press gently until the
cover snaps onto the base.
WHITE-RODGERS
FAN
SYSTEM
The Thermostat Buttons and Switches
ON AUTO COOL OFF HEAT
1
2
3
4
(Up arrow) Raises temperature setting.
(Down arrow) Lowers temperature setting.
3
4
FAN switch (ON, AUTO).
SYSTEM switch (COOL, OFF, HEAT).
The Display
6
7
5
is displayed when the SYSTEM switch is in the HEAT
position.
is displayed (non-flashing) when the SYSTEM
is displayed (flashing)
switch is in the COOL position.
5
when the compressor is in lockout mode.
6
7
Displays current temperature.
Figure 8. Thermostat display, buttons, and switches
Displays currently set temperature (this is blank when
SYSTEM switch is in the OFF position).
CONFIGURATION MENU
Operating Features
6
Now that you are familiar with the thermostat buttons and display,
read the following information to learn about the many features of
the thermostat.
The configuration menu allows you to set certain thermostat oper-
ating characteristics to your system or personal requirements.
• SIMULTANEOUS HEATING/COOLING SETPOINT
STORAGE — You can enter both your heating and cooling
setpoints at the same time. There is no need to re-enter the
thermostat at the beginning of each season.
With the system switch in “OFF” mode, press
at the same time to enter the configuration menu. The display will
show the first item in the configuration menu.
and
keys
The configuration menu table summarizes the configuration
options. An explanation of each option follows.
• TEMPERATURE SETTING — Press
or
until the
display shows the temperature you want. The thermostat will
keep the room temperature at the selected temperature.
Press
and
together momentarily to change to the next
menu item. To exit the menu, change the system switch from OFF
to HEAT or COOL. If no action is taken within fifteen minutes, the
thermostat will revert to normal operation.
• °F/°C CONVERTIBILITY — The factory default setting is
Fahrenheit. If you need Celsius temperature setting, go to
menu mode and change the fifth option to C (see configura-
tion menu, page 5).
2) Select FA or SL (Fast or Slow) Heating Cycle Rate—The
FA setting is frequently used for gas, oil or electric heat. The
SL setting produces a longer heating cycle which is normally
for hot water or steam (hydronic) systems. Both settings
produce very accurate temperature control and can be set to
your personal preference. FA cycles the system just under
1°F and the SL setting cycles at approximately 1.5F°.
• TEMPERATURE DISPLAY ADJUSTMENT — Your new
thermostathasbeenaccuratelysetinourfactory. However,if
you wish, you may adjust your new thermostat temperature
display to match your old thermostat. This can be accom-
plished(withina±4° range)bygoingintothemenumode(see
configuration menu, page 5).
3) Not Available
4) Select Compressor Lockout LOC OFF or ON—Selecting
LOC ON will cause the thermostat to wait 5 minutes before
turning on the compressor if the heating and cooling system
loses power. It will also wait 5 minutes minimum between
cooling cycles. This is intended to help protect the compres-
sor from short cycling. Some newer compressors already
Configuration Menu
Step
Displayed (Factory Default)
Comments
Press Button(s)
Press
or
to select:
1
System switch must be OFF to configure thermostat
Set system switch
to OFF
2
3
4
5
6
7
(FA)
d-L (ON)
LOC (OFF)
0 HI (0)
(F)
Select FA or SL (Fast or Slow) heating cycle rate
N/A
and
and
and
and
and
SL
OFF
ON
Select compressor lockout OFF or ON
Select temperature display adjustment higher or lower
Select temperature display to F or C
Returns to normal operation
4 LO to 4 HI
C
Move system
switch from OFF
to HEAT or COOL
* Press
and
simultaneously to advance to next item
have a time delay built in and do not require this feature. Your
compressor manufacturer can tell you if the feature is already
present in their system. When the compressor time delay
SPECIFICATIONS
ELECTRICAL DATA
7
Electrical Rating:
occurs it will flash the
the compressor.
for about five minutes then turn on
20 to 30 VAC 50/60 Hz.
0.05 to 1.2 Amps (Load per terminal)
1.5 Amps Maximum Total Load (All terminals combined)
5) Select Temperature Display Adjustment 4 LO to 4 HI—
Allows you to adjust the room temperature display 4° higher
or lower. Your thermostat was accurately calibrated at the
factory but you have the option to change the display tem-
perature to match your previous thermostat.
THERMAL DATA
Setpoint Temperature Range: 45°F to 90°F (7°C to 32°C)
Operating Ambient Temperature Range: 32°F to 105°F
Operating Humidity Range: 0 to 90% RH (non-condensing)
Shipping Temperature Range: -40°F to 150°F
6) Select F° or C° Readout—Changes the display readout to
Centigrade or Fahrenheit as required.
TROUBLESHOOTING
8
Symptom
Possible Cause
Corrective Action
No Heat/No Cool/No Fan
(common problems)
1. Blown fuse or tripped circuit breaker.
2. Furnace power switch to OFF.
Replace fuse or reset breaker.
Turn switch to ON.
3. Furnace blower compartment door or
panel loose or not properly installed.
Replace door panel in proper position to engage
safety interlock or door switch.
No Heat
1. Pilot light not lit.
Re-light pilot.
2. System Switch not set to Heat.
Set System Switch to Heat and raise temperature
above room temperature.
3. Loose connection to thermostat or system.
Verify thermostat and system wires are securely
attached.
4. Furnace Lock-Out Condition. Heat may also
be intermittent.
Many furnaces have safety devices that shut down
when a lock-out condition occurs. If the heat works
intermittently contact the furnace manufacturer or
local service person for assistance.
5. Heating system requires service or
thermostat requires replacement.
Diagonistic: Set System Switch to Heat and raise
the setpoint above room temperature. Within a few
seconds the thermostat should make a soft click
sound. This sound usually indicates the thermo-
stat is operating properly. If the thermostat does
not click on, contact your heating and cooling
service person or place of purchase for a
replacement. If the thermostat clicks, contact the
furnace manufacturer or a service person to verify
the heating is operating correctly.
TROUBLESHOOTING
8
Symptom
Possible Cause
Corrective Action
No Cool
1. System Switch not set to Cool.
Set System Switch to Cool and lower temp below
room temp.
2. Loose connection to thermostat or system.
Verify thermostat and system wires are securely
attached.
3. Cooling system requires service or
thermostat requires replacement.
Same procedure as diagnostic for No Heat
condition except set the thermostat to Cool and
lower the setpoint below the room temperature.
There may be up to a five minute delay before the
thermostat clicks in Cooling.
Heat, Cool or Fan Runs Constantly.
1. Possible short in wiring.
Check each wire connection to verify they are not
shorted or touching together. No bare wire should
stick out from under terminal screws. If the
condition persists the manufacturer of your
system or service person can instruct you on how
to test the Heat/Cool system for correct operation.
If the system operates correctly, replace the
thermostat.
2. Possible short in thermostat.
3. Possible short in heat/cool/fan system.
4. Fan Switch set to Fan On.
Furnace Cycles Too Fast or Too Slow
(narrow or wide temperature swing)
1. The location of the thermostat and/or the
size of the Heating System may be
influencing the cycle rate.
Digital thermostats normally provide precise
temperature control and may cycle faster than
some older mechanical models. A faster cycle
rate means the unit turns on and off more
frequently but runs for a shorter time so there is
no increase in energy use. If you would like to
increase the cycle time, go to menu mode as
mentioned in the instructions for Hydronic Heating
Systems. It is not possible to shorten the cycle
time. If an acceptable cycle rate is not achieved as
received or by changing cycle time from FAST to
SLOW on the menu mode contact a local
service person for additional suggestions.
Cooling Cycles Too Fast or Too Slow
(narrow or wide temperature swing)
1. The location of the thermostat and the size
of the Cooling System can influence the
cycle rate.
The cycle rate for cooling is fixed and can not be
adjusted. Contact a local service person for
suggestions.
Thermostat Setting and Thermostat
Thermometer Disagree
1. Thermostat thermometer setting requires
adjustment.
The thermometer can be adjusted +/- 4 degrees.
See Temperature Display Adjustment in the
Operation section.
Blank Display and/or Keypad
Not Responding
1. Thermostat loss of power
2. Voltage spike or static discharge.
Check possible blown fuse or tripped breaker.
Turn the system power off. Wait for 5 minutes and
turn the power on.
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