Emerson 1E78-144 - User Manual

Installation Instructions for

Heating & Air Conditioning

1E78

5/2 Day Programmable Thermostat

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

2

THERMOSTAT DETAILS

3

REMOVING OLD THERMOSTAT

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 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.

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.

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.

PART NO. 37-6542C

Replaces 37-6542B

1026

Failure to follow and read all instructions carefully
before installing or operating this control could cause
personal injury and/or property damage

Assemble tools required as shown below.

WIRE CUTTER/STRIPPER

HAND OR POWER
DRILL WITH 3/16 INCH
DRILL BIT, IF NEEDED

FLAT BLADE SCREWDRIVER

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)

Yes

Heat/Cool Systems Electric Heat (24 volt)

Yes

Heat Only Electric Heat Systems (24 volt)

Yes

Cool Only Systems (24 volt)

Yes

Heat Pump Systems (No Aux. or Emergency Heat)

Yes

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

CAUTION

!

Base

Back of

Thermostat Body

RC

ELEC

GAS

G

RH

Y

O

B

W

W903

W904

W905

Elec/Gas

Switch

Mounting

Hole

Mounting

Hole

Figure 1. Thermostat

W903 - clip to disable EMR feature
W904 - clip for Celcius display
W905 - clip for hydronic system

NOTE:

Earlier models refer to 37-7006 for jumper locations.

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