Led Indicators; Troubleshooting; Changing Fahrenheit (F) To Celsius (C) - Robertshaw 9520 User Manual

Changing Fahrenheit (F) to Celsius (C)

The thermostat is preset to display the temperature in degrees Fahrenheit.
You may change the display readout to Celsius if desired.
1. Move the manual switch marked "F" (Fahrenheit) and "C" (Celsius)
located at the top center of the circuit board to the desired setting.
(see page 5)
2. Press RESET button located lust below the LCD display to register
the change.
The display will change to show the temperature in your desired tempera-
ture scale. To return the thermostat to its original setting, repeat steps 1
and 2 above.

LED Indicators

The LED indicators are used to indicate system activity. The AUX indicator
illuminates during a call for second stage heating. The auxiliary stages are
used to maintain comfort during extremes in weather conditions. If the
AUX LED is illuminated too frequently during periods of moderate temper-
ature, check the differential settings (page 6).
The CHECK indicator is used to monitor system status. If the CHECK indi-
cator is illuminated, call your local HVAC service provider.
The EMER indicator is illuminated only when the system switch is moved
to the EM, emergency heat position. The EM position is used only when
the primary stage of heat is not functioning or requires service.

Troubleshooting

Symptom
Thermostat does not turn
on system
Thermostat turns on and
off too frequently.
Display is blank, flashing
or constant "LO BAT".
System fan does not
operate properly.
Thermostat does not display
proper room temperature.
Check Wiring
(See "INSTALLATION")
Check fuse. Replace with 2 amp
fuse if fuse has opened.
Increase Temperature Differential
(See "DIFFERENTIAL).
Replace batteries.
Move fan option switch to either
gas or electric, to match system.
(See Installation).
Check "F" Fahrenheit/"C" Celsius
switch located at top center of cir-
cuit board for proper position. If a
new selection is made, press
"RESET" button located directly
below LCD display.
8
Remedy