Installation Instructions for
Heating & Air Conditioning
Non-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 Exceeding 30VAC, 1.5 Amp
2
THERMOSTAT DETAILS
Mounting
Hole
RC
G
RH
W
Y
O
B
Mounting
Base
Hole
W904 - clip for Celcius display
W905 - clip for hydronic system
NOTE: Earlier models refer to 37-7006 for jumper locations.
Figure 1. Thermostat
1E78
Back of
Thermostat Body
CONTENTS
Preparations .................................................. 1
1
PREPARATIONS
1E78
Yes
Assemble tools required as shown below.
Yes
Yes
Yes
Yes
Yes
HAND OR POWER
Yes
DRILL WITH 3/16 INCH
DRILL BIT, IF NEEDED
Yes
Yes
No
No
Yes
Failure to follow and read all instructions carefully
Yes
before installing or operating this control could cause
No
personal injury and/or property damage
No
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.
1. Remove Old Thermostat: A standard heat/cool thermostat
W904
consists of three basic parts:
a. The cover, which may be either a snap-on or hinge type.
W905
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 com-
plete. 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. 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.
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FLAT BLADE SCREWDRIVER
WIRE CUTTER/STRIPPER
CAUTION
!
PART NO. 37-6599B
Replaces 37-6599A
1026