Installation
TURN OFF POWER TO THE SYSTEM AT THE MAIN POWER
PANEL TO AVOID ELECTRICAL SHOCK
Installation should be carried out by an electrician or a qualified
technician.
1.1
Find a Location for the Thermostat
• For a new installation, choose a location about 5 ft. (1.5 m) above
the floor and on an inside wall.
• Avoid locations where there are air drafts (top of staircase, air out-
let), dead air spots (behind a door), direct sunlight, concealed
chimneys or pipes, or air diffusers.
Terminals
1H1C
Geothermal
R
C
W
Y
Y1
Y2
G
O/B
Fault
REM
Vcc (1)
Tx/Rx (2)
Gnd (3)
a.
For 2H1C & 3H2C models, the AC144-02 is required to use the balance point option (compressor cut-off).
TH144
.
TABLE 1: Wiring Terminals
OUTPUT CONFIGURATION (MODEL)
2H2C
2H1C
Geothermal
Unoccupied input (optional) - see 1.3
AC144-02 Remote Indoor and Outdoor
Temperature Interface - see 1.4
FIGURE 1: Typical Wiring Diagram (model shown TH144-3H2C)
1.2
Prepare and Connect the Thermostat
1.
Loosen the captive screw
holding the base to the
module.
3H2C
Installation and User Guide
Electronic Thermostat for a Heat Pump
Gently lift the lower part of
Secure the base using the
the module to remove it
wall anchors & screws.
from the base.
Wire the thermostat.
Connect to...
Supply 24 VAC
Common
Auxiliary heat relay
Compressor relay
First compressor relay
Second compressor relay
Fan relay
Reversing valve
Heat pump fault output
CT240/CT241/timer
a
AC144-02
400-144-003-C
2008-02-08
TH144
1/6