Thermostat
CHS-SVN011C-EN
19
(F1) Units
The PENN A421 electronic temperature control is a 120v
SPDT thermostat with a simple on/off setpoint of -40° to
212°F and a built in anti-short cycle delay that is factory set
at “0” (disabled). The temperature sensor is mounted in
the return filter door. The touch pad has three buttons for
setup and adjustments. The basic menu allows for quick
adjustment of ON and OFF temperature values, as well as
the Sensor Failure mode (SF) and Anti-Short Cycle Delay
(ASd) value.
Table 3.
Fault codes defined
Fault Code
Definition
System Status
Solution
SF flashing alternately with OP
Open temperature sensor
or sensor wiring
Output functions according to the
selected sensor failure mode (SF)
See Troubleshooting Procedure. Cycle
power to reset the control.
SF flashing alternately with SH
Shorted temperature
sensor or sensor wiring
Output functions according to the
selected sensor failure mode (SF)
See Troubleshooting Procedure. Cycle
power to reset the control.
EE
Program failure
Output is off
Reset control by pressing the
MENU
button. If problems persist, replace the
control.
To change the temperature setpoint
Press MENU button until the LCD displays “OFF”, press
MENU again, the LCD now displays the “OFF” setpoint
temperature, press or to change the value (“OFF”
temperature is the desired room temperature). When the
desired value is reached press MENU, this stores the
value. The LCD will now display “On”, press MENU, the
LCD now displays the on setpoint temperature. Press or to
change to the desired value and press MENU to save. After
30 seconds the controller will divert back to the home
screen, displaying the room temperature.
Note:
When the green relay status LED is illuminated
the thermostat is calling for cooling (a
snowflake symbol will also appear).
EXAMPLE:
To maintain room temperature of 5° F, set
the “OFF” to 4° and set the “On” to 5°
