RTH1120
69-1876ES-1 29/11/06 3/4
3.1 System Operating Mode
Use the selector switch to place the system in Heating
mode (HEAT) or Cooling mode (COOL), or to turn the
system off.
Note
: When you place the thermostat in Cooling mode, you might
need to wait up to five minutes before cooling can start. This is a
safety feature for the compressor. will flash on the screen until
cooling can start again.
3.2 Fan Operating Mode
Use the selector switch to set the fan to automatic
mode (AUTO) or continuous mode (ON).
Note
: This switch is not used if you have a 2-wire
installation as the fan is not connected to the thermo-
stat.
3.3 Displaying the Temperature
The actual temperature is normally displayed. To view the setpoint,
press once on either of the
buttons. The setpoint is displayed
for 5 seconds along with the icon.
Note
: Pressing any of the
buttons more than once will change
the setpoint.
3.4 Setting the Temperature
Press one of the
buttons until the desired temperature is dis-
played.
3.5 Backlight
The display illuminates for 12 seconds when the backlight button or
either of the
buttons is pressed.
3.6 Battery Replacement Indicator
An icon appears when the batteries need replacement.
This icon will flash for 120 days, then the thermostat
will cut power to the heating/cooling unit. The icon dis-
appears once the batteries are replaced. The tempera-
ture settings are saved and do not need to be re-entered.
Warning
: Before removing the batteries, place the
system switch on the thermostat to Off. Otherwise, the
heating/cooling unit might still be running even after
the batteries are removed.
n
To access the configuration menu, press the backlight button
for 3 seconds.
o
To go to the next parameter (menu item), briefly press the back-
light button.
p
To modify a parameter, press
.
q
Repeat steps 2 and 3 if necessary.
r
Press the backlight button for 3 seconds to exit the configura-
tion menu.
Power supply: 2 AA batteries
Maximum load: 1 A @ 24 Vac per output
Setpoint range (heating): 41 to 82°F (5 to 28°C)
Setpoint range (cooling): 59 to 95°F (15 to 35°C)
Display range: 23 to 122°F (-5 to 50°C)
Storage temperature: -2 to 122°F (-20 to 50°C)
Temperature display resolution: 1°F (0.5°C)
Accuracy: ± 1°F (0.5°C)
Heating/cooling cycle lengths: 10, 12, 15, 20 or 30 minutes (pro-
grammable)
Compressor short-cycle protection (minimum off time): 5 minutes
Data memory: non-volatile
Dimensions: 5 in. x 3 in. x 1 in. (127 mm x 75 mm x 28 mm)
3. Basic Functions
AUTO
The fan operates only when the heating or cooling sys-
tem is On (typical setting).
ON
The fan operates continuously. Use this setting to
improve air circulation and air cleaning.
4. Configuration Menu
DISPLAY
DESCRIPTION
DEFAULT
SETTINGS
Temperature
display
°F
°C or °F
Heating cycles
per hour
1
4
2, 3, 4, 5 or 6
2
Cooling cycles
per hour
1
4
2, 3, 4, 5 or 6
3
1
When either the heating or cooling parameter is displayed, use
the system mode selector switch to alternate between the two
parameters.
2
For optimal heating control, use the setting that matches your
system as follows: 2=30 min (steam or gravity), 3=20 min (hot
water or 90%+ high-efficiency furnace),
4=15 min (gas or oil), 5=12 min (alternate setting for gas or oil),
6=10 min (electric).
3
The corresponding cooling cycle lengths are as follows: 2=30
min, 3=20 min, 4=15 min, 5=12 min, 6=10 min.
5. Technical Specifications
400-147-034-B TH148LE (69-1876ES-1 Honeywell RTH1120) ENG.fm Page 3 Wednesday, November 29, 2006 3:58 PM
