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My septic alarm is going off. What do I do?

This page is for systems with a pump chamber, such as mound systems. The steps come from Washington State's mound-system guide, and your system's own manual comes first. There, the high-water alarm (a buzzer and light) means the effluent in the pump chamber has risen too high. Washington's guide gives the causes as a faulty pump, float or circuit, excessive water use, or other reasons (Washington Dept. of Health, January 2025). Cut your water use right away: no laundry, baths or showers. The chamber has reserve space to buy you time while you find the problem (Washington Dept. of Health, January 2025).

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Right now: four steps

• Stop using water. Avoid baths, showers and clothes washing. The pump chamber's reserve storage should give you time to get it fixed (Washington Dept. of Health, January 2025).
• Silence the alarm. Washington's guide says to push the reset light on the alarm panel to silence it (Washington Dept. of Health, January 2025). Silencing it doesn't fix anything.
• Never enter the pump chamber. Gases inside pump chambers are poisonous and the lack of oxygen can be fatal (Washington Dept. of Health, January 2025).
• Run the simple checks below, then call for service if they don't find it.

Simple checks before you call

Washington State's Department of Health lists what to rule out before calling for service (Washington Dept. of Health, January 2025):

• A tripped breaker or blown fuse. The pump should be on its own circuit; if it shares one, other equipment can trip it.
• An unplugged cord. If the pump and float switch plug in, make sure both plugs are seated firmly in the outlet.
• Tangled floats. Floats caught on the power cord, lifting rope or pump screen can't move freely.
• Debris on the floats or their support cable, which can switch the pump off.

For the float checks, Washington's guide says to turn off the power at the circuit breaker and unplug all power cords before handling the pump or floats (Washington Dept. of Health, January 2025). If you're not comfortable doing that, leave it to the service provider. Excessive water use is one of the causes the guide lists (Washington Dept. of Health, January 2025), so an alarm after unusually heavy use may be that. Have it checked if it happens again.

When to call (and what it may cost)

If the checks don't find it, call your pump service provider or septic contractor. Washington's Department of Health says pump and electrical service must be done by a licensed professional (Washington Dept. of Health, January 2025); check your own state's rules. If the fix is a part, HomeAdvisor's ranges (HomeAdvisor, June 19, 2026):

Don't keep using water heavily while you wait: once the reserve storage is used up, the plumbing can back up into the house. See septic repair costs.

Prevent the next one

• Test the alarm: if the panel has a push-to-test button, check it regularly (Washington Dept. of Health, January 2025).
• Keep the effluent filter or pump screen clean. It stops solids from clogging the pump (Washington Dept. of Health, January 2025).
• Spread out heavy water use, and fix leaky fixtures. One running toilet can add up to 200 gallons a day (EPA, August 17, 2026).
• Know your pump's age: EPA says many pumps and controls need replacing every 10 to 20 years (EPA, March 11, 2026).
• EPA says alternative systems with pumps, float switches or mechanical components should be inspected more often, generally once a year (EPA, August 17, 2026).

Related questions

Sources

1. Washington State Dept. of Health, publication 337-088, January 2025.
2. HomeAdvisor, Septic Tank Repair Cost, updated June 19, 2026.
3. U.S. EPA, How to Care for Your Septic System, last updated August 17, 2026.
4. U.S. EPA, Frequent Questions on Septic Systems, last updated March 11, 2026.