10
◆ Changing Fahrenheit (F) to Celsius (C),
Temperature Differential, Deadband,
and Residual Cool
The temperature differential is factory set at 1°F (0.5°C). The deadband for
auto changeover is set at 3°F (1.5°C). To change settings:
1. The thermostat is preset to display the temperature in degrees
Fahrenheit (US models) or degrees Celsius (Canadian models). The
temperature display can be changed.
2. Press and hold both the ٚ and
ٙ
buttons for three seconds. The
display will read F or C. Release the buttons. Press the ٚ or
ٙ
but-
ton to switch the display.
3. After three seconds the display will switch to the differential setting.
The display will read DIFFERENTIAL 1st.
4. The temperature differential is factory set at 1°F (0.5°C). Press the
ٚ or
ٙ
to adjust the differential up or down.
5. Either wait three seconds or press the button. The display will
indicate: AUTOCHANGE DEADBAND.
6. Press either the ٚ or
ٙ
button to adjust the deadband between
2.0°F - 8.0°F (1.0°C - 4.5°C).
7. Either wait five seconds or press the button. The fan icon and
ON will be displayed.
8. Press either the ٚ or
ٙ
button to adjust the residual cool fan delay
between 0, 30, 60, or 90 seconds.
9. The display will return to the original room temperature display after
a few seconds.
◆ LED Indicators
The Robertshaw 9550 uses three LED indicators (in addition to icons
on the LCD display) to indicate functionality of the thermostat. When
illuminated, the right orange LED indicates that the thermostat is calling
for heat. The left green LED indicates a call for cool. The middle amber
LED indicates the fan is running.
