Septic Alarm Going Off: Float Fix $100 to $300 (HomeGuide)

National figures. Many alarms clear on their own once water use drops; these are the prices when a part has failed.

Is a septic alarm an emergency?

The University of Minnesota's septic program says alarms on pumps and filters must be attended to immediately, though that does not always mean a truck tonight. Two safety rules come first, both from Washington's Department of Health: never enter the pump chamber, because the gases are poisonous and the lack of oxygen can be fatal, and turn off the power at the circuit breaker and unplug every cord before touching the pump or floats.

• Call now: the alarm is on and sewage is backing up into a drain or there is a sewage smell in the house (Angi). See septic backing up into the house.
• Call today: the alarm keeps sounding after you have silenced it, checked the breaker and cut water use for about 10 hours, the window Angi and HomeServe give the pump to catch up.
• Book a check this week: the alarm went off during heavy water use and the light went out on its own. Something let the level rise, and Washington's Department of Health says to check the pump chamber, pump and floats every year anyway.

What does a septic alarm mean?

Washington's Department of Health says an alarm float turns on a light and a buzzer if the effluent level inside the pump chamber gets too high, and that the cause could be a faulty pump, float or circuit, excessive water use, or other reasons. NC State's owner guide describes the same thing as a flashing red light or beeping alarm that can mean the pump is not working or the water level in the pump tank is near failure.

SJE Rhombus, which makes these alarms, says the alarm is tied to float position: a rising high-level float, or a dropping low-level float, triggers it. Washington's guide adds that the alarm should be on an electrical circuit separate from the pump, which is why the alarm can still sound when the pump has lost power.

Why is my septic alarm going off? The common causes

Causes as listed by each source. Several can happen at once, such as rain on a field that was already slow.

How to silence and reset a septic alarm

Press the red button on the alarm box. Angi says it stops the noise, not the problem, and Washington's Department of Health says to push the reset light on the alarm panel to silence it. HomeServe says the light typically stays on until the level returns to normal, so a red light that stays lit after the horn stops is expected for a while.

To check that the alarm itself works, SJE Rhombus says to push the test button: the horn and red light should come on. Its troubleshooting guide is clear that the test button checks the alarm, not the whole system.

Septic alarm going off after heavy rain

Roto-Rooter says heavy rain or flooding can push groundwater into the system, and HomeServe lists groundwater entering the tank as a cause on its own. EPA and Penn State Extension both say to cut water use while the soil is saturated, and Penn State says to turn off power to pumps during a flood. If the alarm comes back after every storm, groundwater may be getting into the tank, as HomeServe describes, or the field may be failing; drain field repair covers the second.

Septic alarm after a power outage

Roto-Rooter says a power outage or a tripped breaker can shut off the septic pump. Washington's Department of Health gives a procedure when the float controls have been off for more than 6 hours: cut water use, turn the pump off at the panel, and once power is back run it manually for up to 5 minutes every 6 hours. If your panel has no manual setting, call the company that services the system.

Aerobic septic system alarm

Aerobic treatment units have an air pump and other mechanical parts, and none of the sources we checked describes their alarm codes or what each light means, so start with the company on your service contract. EPA says regular lifetime maintenance should be expected for these units, that systems with mechanical parts generally need a check once a year, and it recommends a service contract. If the aerator has failed, HomeGuide prices a new one at $300 to $900 installed, or $200 to $600 for the unit alone.

If the alarm belongs to a basement grinder or ejector basin rather than an outdoor pump tank, the pump prices are on the septic, ejector and grinder pump replacement page.

What it costs to fix a septic alarm problem

Installing new tank floats costs $100 to $300 in HomeGuide's septic repair guide, and Fixr puts float replacement at $150 to $500. HomeGuide prices a control panel replacement at $300 to $500 and a pump repair at $250 to $400.

• Pump replacement: $500 to $1,300 in HomeGuide's guide; Fixr's $250 to $500 is well below the other guides. Full detail is on the septic pump replacement cost page.
• Pump repair: Fixr's range is wider at $250 to $1,500.
• Age matters: EPA says many pumps and controls need replacing every 10 to 20 years.
• A clogged filter or a full tank is a service call, not a part; see septic tank repair costs and septic tank pumping.

What the septic company checks on an alarm call

SJE Rhombus tells technicians to check the float for proper position, tether length, and anything that may have caused it to hang up, and lists a pump that does not run as either wired wrong or failed. Washington's Department of Health says pump and electrical repairs must be done by a licensed professional, and NC State says not to attempt the repair yourself. Ask the tech to test the pump, the floats and the panel, and to look at the effluent filter and sludge level while the lid is off. If the system has never been checked end to end, ask for a septic inspection price too.

Questions to ask before you book an alarm call

• Is there a service call fee, and is it credited toward the repair?
• Float, pump or panel? Ask what failed and see the old part.
• Repair or replace the pump? HomeGuide puts the gap at $250 to $400 against $500 to $1,300.
• Should the tank be pumped while the lid is open?
• License and insurance. Ask for the license number for pump and electrical work where your state requires one, and for proof of insurance.

Septic alarm going off: what to do, step by step

1. Silence it. Push the red button or reset light on the alarm panel (Angi, Washington DOH).
2. Cut the water. Washington's Department of Health says to avoid baths, showers and clothes washing as much as possible; the reserve space in the pump chamber is meant to give you time to fix the problem.
3. Check the power. Look for a tripped breaker or blown fuse and an unplugged cord (Washington DOH).
4. Look outside. Angi says to check for standing water around the tank.
5. Wait about 10 hours. Angi says conserving water for 10 or more hours lets the pump catch up; HomeServe gives the same window for the light to go out.
6. Call if it comes back or there are backups or odors (Angi). Washington DOH says to call your pump service provider if the basic checks do not fix it.

More septic help: septic backup, septic inspection cost and septic tank installation cost. Calls go to an independent company that serves your area and takes this kind of job; hours vary. How calls work.