Henny Penny FlexFusion FPG-221 Service Instructions Manual page 29

Step 9 (temperature control)
1. Check of temperature control.
The temperature in the cooking chamber must reach 140 °C
(284 °F) within the time specified.
Display switches to green = test successful.
Display switches to red = test not successful.
Check region around cooking chamber sensor for soiling.
Check temperatures via calibration in the service menu.
If necessary, replace cooking chamber sensor or control board.
Service-instructions
Service menu - appliance test
29