Septic Alarm Going Off? What to Do

Routine Maintenance

This page covers regular POWTS pumping and upkeep, not a real estate transaction.

A septic alarm only exists on systems with a pump chamber, a mound, at-grade, or aerobic system, and it means something specific: the pump is not keeping up with the water coming into that chamber.

What the alarm is actually telling you

The alarm is triggered by a float switch sensing a high-water level in the pump chamber. That can mean the pump has failed, the float itself is stuck or fouled, a circuit tripped, or the household is simply using more water than the pump chamber can currently keep up with. See mound system maintenance in Wisconsin and aerobic treatment unit systems in Wisconsin for how each system type uses this same kind of alarm.

What to do right now

Check the electrical panel for a tripped breaker feeding the pump, a simple reset sometimes clears it.
Cut back on water use immediately, laundry, long showers, and dishwasher runs, until the alarm clears or a professional has looked at it.
Note whether the alarm is a steady light, a flashing light, or an audible horn, and whether it clears on its own.
Do not silence the alarm and ignore it. Silencing a horn without fixing the underlying issue just removes your own warning.

When to call now versus wait for a scheduled visit

SPS 383.53Verified Sep 2026

Electromechanical POWTS components, including pump chambers and aerobic units, are required to have a maintenance contract with a certified maintainer. That maintainer is the right first call for an active alarm, not a general plumber unfamiliar with POWTS equipment.

Read the code at docs.legis.wisconsin.gov

Call your maintainer the same day if the alarm is steady and does not clear after cutting back water use, or if you notice sewage odor, wet ground near the mound, or slow drains alongside it, see signs your septic system is failing. If the alarm clears after a brief high-use period, a heavy laundry day, for instance, it may still be worth a call to confirm the system is functioning normally.

Preventing repeat alarms

Spread out heavy water use rather than running several loads back to back, keep the maintenance contract current so a maintainer catches a failing float or pump before it triggers an alarm, and test the alarm periodically per the manufacturer’s recommendation if your system has that feature.

Frequently asked questions

Is a septic alarm an emergency: Treat a steady alarm that does not clear as urgent, even if it is not always a full emergency. Call your maintainer promptly rather than waiting for a scheduled visit.
Can I just unplug or silence the alarm: No. That removes your warning of a real problem without fixing anything, and it can let a small issue turn into a costly failure.
Does every septic system have an alarm: No, a basic gravity-fed conventional system typically does not. Alarms are on systems with a pump chamber or aerobic treatment equipment.