Installation Instructions for
Heating & Air Conditioning
5/2 Day Programmable Thermostat
YOUR THERMOSTAT REPLACES
Typical System Compatibility Chart
Standard Heat Only Two Wire 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)
Heat/Cool Systems Electric Heat (24 volt)
Heat Only Electric Heat Systems (24 volt)
Cool Only Systems (24 volt)
Heat Pump Systems (No Aux or Emergency Heat)
Hot Water Zone Heat Only (Two Wire) Systems
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
Multistage Systems
Systems Exceding 30VAC, 1.5 Amp
2
THERMOSTAT DETAILS
Mounting
Hole
RC
G
RH
W
Y
O
B
Mounting
Base
W903 - clip to disable EMR feature
W904 - clip for Celcius display
W905 - clip for hydronic system
Figure 1. Thermostat
1E78
1E78
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Yes
Yes
No
No
ELEC
GAS
Elec/Gas
Back of
Hole
Thermostat Body
White-Rodgers is a division
of Emerson Electric Co.
CONTENTS
Preparations .................................................. 1
Thermostat Details ........................................ 1
Removing Old Thermostat ............................ 1
Mounting and Wiring ..................................... 2
Check Thermostat Operation ........................ 3
Programming your Thermostat ..................... 4
Specifications ................................................ 6
Troubleshooting ............................................ 6
1
PREPARATIONS
Assemble tools required as shown below.
HAND OR POWER
DRILL WITH 3/16 INCH
DRILL BIT, IF NEEDED
Failure to follow and read all instructions carefully
before installing or operating this control could cause
personal injury and/or property damage
3
REMOVING OLD THERMOSTAT
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.
W905
W904
1. Remove Old Thermostat: A standard heat/cool thermostat
W903
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.
Switch
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.
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.
www.white-rodgers.com
FLAT BLADE SCREWDRIVER
WIRE CUTTER/STRIPPER
CAUTION
!
PART NO. 37-6542B
Replaces 37-6542A
0434
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