How to Troubleshoot Septic Float Switches

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If your septic system uses a pump to remove wastewater from the tank to a drain field, your system will include a septic tank alarm and float switch. When the float rises to an unacceptable level, it sets off an alarm to warn you that your tank may be about to overflow. At times the float switch will malfunction and sound the alarm when the tank isn't overflowing. Before calling a service technician, try troubleshooting the problem first. Refer to your specific float switch user manual for instructions on the location of parts.


Step 1

Turn off the alarm switch for the float if the alarm is ringing. This indicates there is an overflow in the system, or that the float is malfunctioning.

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Step 2

Stop running anything plumbing-related in your house that puts water into the septic system, including the washing machine and dishwasher.


Step 3

Turn the alarm switch back on. Wait six to eight hours before turning on your water. If the alarm doesn't ring again after this period of time, the problem is likely something other than an overflow.

Step 4

Check the circuit breaker or the GFCI plug (Ground Fault Circuit Interrupter) for the float switch to make sure it hasn't tripped. The GFCI plug will trip if moisture gets into the outlet. A light will come on that indicates the circuit has tripped. Try pushing the button on the GFCI plug to reset it, or flip the switch for the circuit breaker to reset it. If the circuit breaker or GFCI outlet turns off again, this indicates you may have a wiring issue or moisture in the circuit.


Step 5

Check the on/off switch on the float switch to see if it turns on the pump. If it doesn't, you may have either a dead switch or a malfunctioning pump.

Step 6

Inspect all exposed cables or wires to see if they're damaged.



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