White Rodgers EMERSON 1.00E+78 User manual

To prevent electrical shock and/or equipment damage,
disconnect electric power to system at main fuse or
circuit breaker box until installation is complete.
Base Back of
Thermostat Body
RC GRH
YO B
W
W904
W905
Mounting
Hole
Mounting
Hole
Figure 1. Thermostat
W904 - clip for Celcius display
W905 - clip for hydronic system
NOTE: Earlier models refer to 37-7006 for jumper locations.
Heating & Air Conditioning
1E78
Non-Programmable Heat Only Thermostat
PART NO. 37-6620B
Replaces 37-6620A
1026
Installation Instructions for
YOUR THERMOSTAT REPLACES
Typical System Compatibility Chart 1E78
Standard Heat Only Two Wire Gas or Oil Fired Systems (24 volt) Yes
Electronic Ignition Heat Only Two Wire Systems (24 volt) Yes
Electronic Ignition Heat Only Gas or Oil Fired Systems (24 volt) Yes
Standard Heat/Cool Systems (24 volt) No
Heat/Cool Systems Electric Heat (24 volt) No
Heat Only Electric Heat Systems (24 volt) No
Cool Only Systems No
Heat Pump Systems (No Aux. or Emergency Heat) No
Hot Water Zone Heat Only (Two Wire) Systems Yes
Hot Water Zone Heat Only (Three Wire) Systems No
Line Voltage Heating or Baseboard 110/240 Volt Systems No
Millivolt Systems Floor or Wall Furnaces Yes
12 VDC Mobile Home Application Yes
Multistage Systems No
Systems Exceeding 30VAC, 1.5 Amp No
Assemble tools required as shown below.
HAND OR POWER
DRILL WITH 3/16 INCH
DRILL BIT, IF NEEDED
FLAT BLADE SCREWDRIVER
WIRE CUTTER/STRIPPER
3
REMOVING OLD THERMOSTAT
1
PREPARATIONS
2
THERMOSTAT DETAILS
Before removing wires from old thermostat’s switching subbase,
label each wire with the terminal designation it was removed
from.
1. Remove OldThermostat: 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.
c. The switching subbase, which is removed by unscrewing
the mounting screws that hold it on the wall or adaptor
plate.
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, remove wall plate from the wall. If the old
thermostat has a wall mounting plate, remove the thermostat
and the wall mounting plate as an assembly.
4. Identify each wire attached to the old thermostat using
the labels enclosed with the new thermostat.
5. Disconnectthewiresfromtheoldthermostatoneata time.
DO NOT LET WIRES FALL BACK INTO THE WALL.
6. Install new thermostat using the following procedures.
CONTENTS
Preparations ................................................ 1
Thermostat Details ...................................... 1
Removing Old Thermostat........................... 1
Mounting and Wiring.................................... 2
Check Thermostat Operation....................... 3
Specifications .............................................. 4
Troubleshooting ........................................... 4
Failure to follow and read all instructions carefully
before installing or operating this control could cause
personal injury and/or property damage.
www.white-rodgers.com
www.emersonclimate.com
CAUTION
!

2
Take care when securing and routing wires so they do
not short to adjacent terminals or rear of thermostat.
Personal injury and/or property damage may occur.
Do not use on circuits exceeding specified voltage.
Higher voltage will damage control and could cause
shock or fire hazard.
Do not short out terminals on gas valve or primary
control to test. Short or incorrect wiring will
damage thermostat and could cause personal injury
and/or property damage.
Thermostat installation and all components of the
system shall conform to Class II circuits per the
NEC code.
RH
24 VAC 120 VAC
Hot
Neutral
THERMOSTAT
SYSTEM
G W
Figure 2. Typical wiring diagram for
heat only, 2-wire, single transformer systems
TRANSFORMER
Heating
System
YRC
JUMPER
WIRE
OB
ATTENTION! This product does not contain mercury. How-
ever, this product may replace a unit which contains mercury.
Do not open mercury cells. If a cell becomes damaged, do
not touch any spilled mercury. Wearing non-absorbent gloves,
take up the spilled mercury and place into a container which
can be sealed. If a cell becomes damaged, the unit should be
discarded.
Mercury must not be discarded in household trash. When the
unit this product is replacing is to be discarded, place in a suit-
able container. Refer to www.white-rodgers.com for location to
send product containing mercury.
WARNING
!
Hydronic (Hot Water or Steam)
Heating Systems
This thermostat is set to operate properly with a forced-air heating
system. If you have a hydronic heating system (a system that
heats with hot water or steam), you must set the thermostat to
operate properly with your system.
The factory default setting is forced air heat. Clipping jumper
W905 on the circuit board will produce a longer heating cycle
which is normally for hot water or steam (hydronic) systems.Both
settings produce a very accurate temperature control and can
be set to your personal preference. As received, the thermostat
cycles the system just under 1°F.With W905 clipped, the system
cycles at approximately 1.5°F.
Attach Thermostat Base to Wall
1. Remove the packing material from the thermostat. Gently
pull the body straight off the base. Forcing or prying on the
thermostat will cause damage to the unit.
2. Connect wires beneath terminal screws on base using ap-
propriate wiring schematic (see fig. 2).
3. Place base over hole in wall and mark mounting hole loca-
tions on wall using base as a template.
4. Move base out of the way. Drill mounting holes.
5. Fasten base loosely to wall, as shown in fig. 1, using two
mounting screws. Adjust until level, and then tighten screws.
(Leveling is for appearance only and will not affect thermostat
operation.) If you are using existing mounting holes, or if holes
drilled are too large and do not allow you to tighten base
snugly, use plastic screw anchors to secure subbase.
6. Push excess wire into wall and plug hole with a fire-resistant
material (such as fiberglass insulation) to prevent drafts from
affecting thermostat operation.
Battery Location
This thermostat requires 2 “AAA” alkaline batteries to operate.
If appears on the display, the batteries are low
and should be replaced with fresh “AAA” Energizer®alkaline
batteries.The batteries are located on the back of the thermostat
body (see fig. 1).
New Thermostat Other Manufacturers’
Terminal Designation Terminal Designation
RH 4 RH M
W W W H
TERMINAL CROSS REFERENCE CHART
CAUTION
!
3
REMOVING OLD THERMOSTAT
continued from first page
4
MOUNTING AND WIRING

3
NOTE
To prevent static discharge problems, touch side of
thermostat to release static build-up before touching
any keys.
If at any time during testing your system does not operate
properly, contact a qualified service person.
Heating System
1. Move SYSTEM switch to HEAT position.If the heating system
has a standing pilot, be sure to light it.
2. Press to adjust thermostat setting above room tem-
perature. The heating system should begin to operate.
3. Press to adjust temperature setting below room tem-
perature. The heating system should stop operating.
Before you begin using your thermostat, you should be familiar
with its features and with the display and the location and op-
eration of the thermostat buttons. Your thermostat consists of
two parts: the thermostat body and the base. To remove the
body, gently pull it straight out from the base. To replace the
body, line up the body with the base and press gently until the
body snaps onto the base.
The Thermostat Buttons and Switches
1
(Up arrow) Raises temperature setting.
2
(Down arrow) Lowers temperature setting.
3
SYSTEM switch (OFF, HEAT).
The Display
4
is displayed when the SYSTEM switch is in the HEAT
position.
5
Displays current temperature.
6
is displayed when the 2 “AAA” batteries are
low and should be replaced. Nothing else will be displayed.
Earlier models display "LO BATTERY". Refer to 37-7006.
7
Displays currently set temperature (this is blank when
SYSTEM switch is in the OFF position).
Operating Features
Now that you are familiar with the thermostat buttons and display,
read the following information to learn about the many features
of the thermostat.
• TEMPERATURE SETTING — Press or until the
display shows the temperature you want.The thermostat will
keep the room temperature at the selected temperature.
• °F/°C CONVERTIBILITY — The factory default setting is
Fahrenheit.Clipping W904 jumper on the circuit board (see
fig. 1) will alter this feature to Celsius temperature setting.
Figure 3. Thermostat display, buttons and switches
• LOW BATTERY INDICATOR — If the 2 “AAA” alkaline bat-
teries are low and should be replaced, the display will be
blank except for .When the batteries are low,
pressing any button will cause the display to operate for ten
seconds.After ten seconds, the display will be blank except
for . After has been displayed
for 4 weeks, the thermostat will drop the temperature 10°
below your setpoint in HEAT mode.You cannot program with
low batteries but you can override setpoint temperature.
• TEMPERATURE DISPLAY ADJUSTMENT — Your new
thermostat has been accurately set in our factory. However,
if you wish, you may adjust your new thermostat temperature
display to match your old thermostat. This can be accom-
plished (within a ±3° range) as follows:
1. Press and at the same time for two seconds
with the SYSTEM switch in OFF position.
2. Press or to adjust the displayed temperature
to your desired setting.
3. Move SYSTEM switch from OFF to exit the feature.
• DISPLAY BACKLIGHT— The display backlight improves
display contrast in low lighting conditions.Selecting backlight
ON will turn the light on for a short period of time after any
button is pressed. Selecting backlight OFF (default) will
keep the light off. Turn the display backlight feature ON as
follows:
1. Press and at the same time for two seconds
with the SYSTEM switch in HEAT position. The display
will alternately show “-L” AND “FF” (off).
2. Press or to change “FF” to “ON”.
3. Move SYSTEM switch to OFF to exit the feature.
Figure 3. Thermostat display buttons and switches
5
CHECK THERMOSTAT OPERATION

4
Symptom Possible Cause Corrective Action
No Heat
(common problems)
Blown fuse or tripped circuit breaker.1.
Furnace power switch to OFF.2.
Furnace blower compartment door or panel3.
loose or not properly installed.
Replace fuse or reset breaker.
Turn switch to ON.
Replace door panel in proper position to engage safety interlock or door switch.
No Heat Pilot light not lit.1.
SYSTEM Switch not set to2. HEAT.
Loose connection to thermostat or system.3.
Furnace Lock-Out Condition. Heat may also be4.
intermittent.
Heating system requires service or thermostat5.
requires replacement.
Re-light pilot.
Set SYSTEM Switch to HEAT and raise temperature above room temperature.
Verify thermostat and system wires are securely attached.
Many furnaces have safety devices that shutdown when a lock-out condition
occurs. If the heat works intermittently contact the furnace manufacturer or local
service person for assistance.
Diagnostic: 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 thermostat is operating properly. If the thermo-
stat does not click, try the reset operation listed above. If the thermostat does not
click after being reset contact your heating and cooling service person or place of
purchase for a replacement. If the thermostat clicks, contact the furnace manufac-
turer or a service person to verify the heating is operating correctly.
Heat, Runs
Constantly
Possible short in wiring.1.
Possible short in thermostat.2.
Possible short in heat system.3.
Check each wire connection to verify they are not shorted or touching together.
No bare wire should stick out from under terminal screws. Try resetting the
thermostat as described above. If the condition persists the manufacturer of your
system or service person can instruct you on how to test the Heat system for
correct operation. If the system operates correctly, replace the thermostat.
Furnace Cycles Too
Fast or Too Slow
(narrow or wide
temperature swing)
The location of the thermostat and/or the1.
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, clip Jumper
W-905 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 clipping W-905 contact a local service person for additional
suggestions.
Thermostat Setting and
Thermostat Thermometer
Disagree
Thermostat thermometer setting requires1.
adjustment.
The thermometer can be adjusted +/- 3 degrees. See Temperature Display
Adjustment in the Operation section.
Blank Display and/or
Keypad Not Responding
Voltage spike or static discharge.1.
Battery change required.2.
Replace batteries and check heat/cool system for proper operation. If a voltage
spike occurs use the Reset Operation listed above.
ELECTRICAL DATA
Electrical Rating:
0 to 30 VAC 50/60 Hz. or D.C.
0.05 to 1.0 Amps (Load per terminal)
1.5 Amps Maximum Total Load (All terminals combined)
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
Reset Operation
If a voltage spike or static discharge blanks out the display or
causes erratic thermostat operation you can reset the thermostat
by pressing and at the same time while moving the
SYSTEM switch from OFF to HEAT.This also resets the factory
defaults. If the thermostat has power, has been reset
and still does not function correctly contact your heating/cooling
service person or place of purchase.
Batteries
For optimum performance, we recommend replacing batteries
once a year with fresh “AAA” Energizer®alkaline batteries.
6
SPECIFICATIONS
7
TROUBLESHOOTING
White-Rodgers is a division
of Emerson Electric Co.
The Emerson logo is a
trademark and service mark
of Emerson Electric Co.
Homeowner Help Line: 1-800-284-2925
www.white-rodgers.com
www.emersonclimate.com