The tank alarm is designed to go off only if one of two conditions occur:
1 - The tank is to full due to
blockage or failed pump.
2 - The tank is too empty due
to failed float or pump.
Septic Tank Control Panel
Silencing the alarm by pressing the red button is the first step once its gone off. Next, the tank lids must be removed so the cause of alarm can be determined. Many times the alarm will go off after the tank has been pumped. This happens because the float's level has been altered by a source other than its own pump & is not necessarily a sign of failure.
Three Chambered Septic Tank With Pump
Two Tank Septic System With Pump