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
-
W903
Clip to
Disable
EMR
Feature
Mounting
hole
W903
W9 4
0
W9 5
0
W905
Clip for
Hydronic
System
W904
Clip for
Celsius Display
Figure 1. Thermostat base
Figure 1. Thermostat base
1F78
1F78
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Yes
Yes
No
No
Mounting
hole
-
+
+
W
RH
B
RC
G
Y
O
ELEC
GAS
Electric/Gas
Switch
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 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.
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.
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.
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. 37-6614B
Replaces 37-6614A
0731
Need help?
Do you have a question about the 1F78 and is the answer not in the manual?
Questions and answers
I have two 1F78-144, both are wired the same way. One unit works fine in cool and heat. The other unit works on cool, but does not work on heat. Only the **** comes on in heat mode. The installer of my heat pump says it is a faulty Thermostat. However after replacing with a new one I still have the same problem. Can you help?
Possible causes for one White Rodgers 1F78-144 thermostat not working in heat mode while another functions properly include:
1. System Switch Not Set to Heat: Ensure the SYSTEM switch is set to HEAT and the setpoint temperature is higher than the room temperature.
2. Loose Connections: Verify that the thermostat and system wires are securely connected and not loose.
3. Wiring Issues: Check for possible shorts in the thermostat wiring. Ensure no bare wires are exposed or touching each other.
4. Thermostat Issue: The thermostat might be faulty and require resetting or replacement.
5. Heating System Problem: The heating system itself may require servicing. Contact a technician to inspect the furnace or heating unit.
6. Configuration Settings: If the system is hydronic (hot water or steam), ensure the thermostat is configured correctly for this type of system. Adjust settings as outlined in the configuration menu.
7. Battery Issue: If the thermostat displays "LO BATT," replace the batteries with fresh “AAA” alkaline batteries.
8. Delay in Operation: Some systems can have a delay before the thermostat activates the heat. Wait a few minutes to see if the system responds.
This answer is automatically generated