Septic alarm going off: what to do

Short answer: A septic alarm usually means the water level in the pump tank is too high: the pump is not running, the pump's float is stuck, the pump circuit has lost power, or an unusual amount of water went in. Silence the alarm, stop using water as much as you can, check the pump breaker, and call a septic professional if the alarm does not clear.

Safety: Never enter or lean into a septic tank; gases in tanks can kill. Keep lids secured. Do not open control panels or work on pump wiring; many areas require licensed septic or electrical professionals.

Step by step

1. Silence the horn. Most alarm panels have a silence or test/silence button. The light usually stays on until the level drops.
2. Cut water use. Avoid laundry, showers, the dishwasher and extra flushing so the tank does not overflow or back up.
3. Check the pump circuit. Look at the breaker for the pump (often separate from the alarm) and reset it once if tripped. If it trips again, stop and call a pro.
4. Give it time. If heavy use or rain caused it and the pump is working, the alarm often clears within hours as the pump catches up.
5. Call a professional. If the alarm stays on, the pump or float likely needs service.

Septic alarms and floats

• Sump Alarm "2L" High Water Alarm with Power Indicator With Sludge Boss Float Switch — 120 / 100 — $421.86
• Sump Alarm "2L" High Water Alarm with Power Indicator With Sludge Boss Float Switch — 120 / 16 — $247.95
• Original Sump Alarm with SludgeBoss Float Switch — 100 — $421.86
• Grinder Pump Control Panel — WiFi alerts — $670.61
• "Sludge Boss Piggyback" Heavy Duty Float Switch for Suspended Solids (3120 Series) — 20 Foot — $120.28
• "Sludge Boss" Heavy Duty Float Switch for Septic and Sewage — 100 Foot — $258.96

Common questions

Can I just turn the septic alarm off?

You can silence the horn, but do not unplug or disconnect the alarm. It is your warning before a backup.

Why does my septic alarm go off when it rains?

Groundwater or surface water may be getting into the tank, or the system may be overloaded. A professional can check risers, lids and seals.

How much does a new septic alarm cost?

See the prices on the alarm listings below. Indoor/outdoor alarms come with different float cord lengths and options such as Wi-Fi alerts.

Shop septic parts Sump and septic alarm buying guide

Related categories: Septic & Wastewater Parts · Sump & Effluent Pumps & Alarms. General information only; follow the equipment maker's instructions and local codes. Updated 2026-11-14.