Guide

What Your Septic System Alarm Lights and Beeps Actually Mean

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If your AWTS or septic system control panel has a light on or is beeping, it means the system has detected something outside its normal operating parameters. Many property owners ignore alarms for days or weeks, some even tape over the panel light to stop the visual annoyance. This is one of the most damaging things you can do to your system and your Council compliance record.

This guide explains what the common alarm states mean across most AWTS brands used in the Port Macquarie and Mid North Coast region, and what action to take for each.


A Note on Alarm Panel Variation

AWTS brands vary in how they present alarm states on their control panels. Common brands in the Port Macquarie area include Envirocycle, Biocycle, Orenco, Aquafast, BioMaxx, and Fuji Clean. Each has its own panel design, but the underlying alarm categories are consistent:

  • Power supply alarms
  • High water level alarms
  • Motor / aerator alarms
  • Pump alarms
  • Disinfection alarms (UV or chlorine)
  • General fault alarms

Your system’s user manual (usually clipped inside the control panel lid) will have the specific meanings for your model. If you don’t have the manual, the manufacturer’s website usually has downloadable copies, or contact your service provider.


Common Alarm States and What They Mean

Green Light Only, Normal Operation

A solid green light (or green LED) on most AWTS panels indicates the system is powered and operating normally. No action required. Check that the green light is on during your regular visual inspection of the panel, if it’s never on, you have a power problem.

No Lights at All, Power Loss

If the panel is completely dark, the AWTS has no power. This happens due to:

  • Circuit breaker tripped at the switchboard
  • Power outage to the property
  • Damaged power cable to the unit
  • Failed power supply board in the unit

What to do:

  1. Check your main switchboard for a tripped breaker. If there is a breaker labelled “Septic,” “AWTS,” or “Pumps” that is tripped, reset it.
  2. If the breaker trips again immediately, there is a short circuit or overload in the AWTS wiring, call your service provider.
  3. If there is no property-wide power outage and no tripped breaker, call for service.

Important: A power outage lasting more than 24-48 hours allows the AWTS aeration chamber to go anaerobic, reducing treatment quality. Notify your service provider after any extended power outage so they can assess whether the system has recovered.

Red Light + Alarm Beeping, High Water Level

The most common alarm situation. A float switch in the AWTS triggers when the water level in one of the chambers rises above its normal operating range. This alarm means the system is accumulating liquid faster than it can process and discharge it.

Common causes:

  • Oversaturated irrigation area: After heavy rain, the drip irrigation area cannot accept more liquid. The system backs up. Very common on coastal properties in the Port Macquarie area after rain events.
  • Pump failure: The pump that sends treated effluent to the irrigation area has failed. Liquid accumulates.
  • Blocked irrigation lines: Blocked emitters prevent effluent from reaching the soil.
  • High wastewater input: Holiday rental overload, extra guests, or a water leak allowing large volumes into the system.

What to do:

  1. Reduce water use immediately, no laundry, short showers, minimal toilet flushing.
  2. Check the irrigation area, is it visually wet or saturated? Is there rain forecast?
  3. If it’s post-rain and the ground is saturated, the alarm may clear within 24-48 hours as the ground drains. Continue to minimise water use.
  4. If the alarm persists beyond 48 hours of dry weather, or if effluent is surfacing in the yard, call for service.
  5. If sewage appears to be backing up toward the house, call immediately for emergency service.

Red Light, Aerator / Motor Fault

This alarm indicates the aerator motor (air compressor) has failed or is drawing the wrong current. The aerator is the core of the AWTS, without it, the system rapidly goes anaerobic and effluent quality drops.

What to do:

  • Call your service provider. This is not something to monitor, an aerator failure requires prompt attention.
  • Minimise wastewater input to the system while awaiting the service call.
  • A replacement aerator is typically $250 to $600 parts and labour.

Yellow / Amber Light, Chlorine Low or UV Lamp Alert

On systems with a chlorine disinfection stage, a yellow or amber light often indicates the chlorine tablet supply is depleted or very low. On UV disinfection systems, it may indicate the UV lamp is nearing end of life or has failed.

What to do:

  • For chlorine systems: check the chlorine tube at the next reasonable opportunity. Your service provider restocks this at every quarterly service, if you’re seeing this between services, either there was unusually high demand or the last service was missed. Call your provider to arrange a mid-cycle refill.
  • For UV systems: call your service provider. UV lamp replacement is typically done annually and should not be delayed.

Why it matters: Without disinfection, the effluent from the AWTS does not meet the pathogen reduction requirements specified in your Council approval. You are producing substandard effluent.

Flashing Green / Alternating Lights, Pump Running Indicator

On some models, a flashing green or alternating indicator simply means the dosing pump is in operation (pumping effluent to the irrigation area). This is normal operation, not an alarm. If you notice the pump seems to be running continuously without stopping, this may indicate a stuck timer or controller issue, check with your service provider at the next service.

All Lights On Simultaneously

Indicates a controller or logic board fault on some models. Cycle the power off and back on (wait 30 seconds with power off). If the condition persists, call for service.


Alarm Response Quick Reference

Alarm ConditionLikely CauseAction
No lights at allNo powerCheck breaker, call if persists
Red light + beepingHigh water level in chamberReduce use, check irrigation, call if persists 48 hrs
Red light (no beeping)Motor/aerator faultCall service provider
Amber/yellow lightLow chlorine or UV faultSchedule mid-cycle visit
Alarm after heavy rainSaturated irrigation areaReduce use, wait for ground to drain
Alarm after power outageAWTS going anaerobicNotify service provider

What NOT to Do When an Alarm Is Active

Don’t reset and ignore: If your panel has a “silence” or “reset” button, pressing it stops the beeping but does not fix the underlying problem. The alarm light usually stays on. Silencing the alarm without investigating the cause means the system continues to operate incorrectly.

Don’t tape over the light: Obscuring the indicator does not clear the alarm condition.

Don’t continue normal water use: If the alarm is a high-level warning, running the washing machine, having a bath, or running the dishwasher pushes more liquid into an already overwhelmed system.

Don’t wait until the next quarterly service to report it: Many faults caught early are minor repairs. Faults ignored for three months become major failures.


Alarms After Guest Departures or High-Use Periods

If you operate a holiday rental or have had guests, AWTS alarms after high-use periods are not uncommon. A full house with guests using laundry, multiple showers, and the dishwasher multiple times per day can load a system to its design limits. If the system was already borderline on capacity or the irrigation area was already moist, this tips it over.

See our full guide on managing septic systems in holiday rental properties for preventive strategies.


When to Call for Emergency Assistance

Call for emergency service, not just the next business day, when:

  • Sewage is backing up inside the house
  • Sewage or foul water is pooling in the yard above the irrigation area
  • You cannot safely contain the situation by reducing water use
  • The alarm has been active for more than 48 hours with no improvement
  • The AWTS was submerged in floodwater

Urgent enquiries for emergency septic and AWTS pump-outs come from across Port Macquarie, Wauchope, Lake Cathie, Camden Haven, and surrounding areas.


FAQ

My AWTS alarm has been going off for a week, is that a serious problem? Yes. A sustained alarm indicates an ongoing system malfunction. A week of incorrect operation has likely compromised effluent quality and is building toward a more serious failure. Call your service provider today.

The alarm went off after heavy rain and then cleared, do I need to report it? Brief alarms during rain events that self-clear once the ground drains are common on coastal properties with high water tables. You should note the event in your own records. At the next quarterly service, tell your provider it occurred, they can assess whether the irrigation area needs attention to improve wet-season performance.

Is it safe to use the system while the alarm is on? With caution. If the alarm is a high-level alarm, minimise water use. If the alarm is a motor or disinfection fault, the system is producing lower-quality effluent, the treated effluent reaching your irrigation area may not be meeting its design quality standard. Limit use and get it fixed as quickly as possible.

My AWTS has no visible alarm at all, how do I know if it’s working? Your system should have a high-level alarm at minimum, either a panel indicator or a separate external buzzer. If you cannot identify an alarm system on your installation, ask your next quarterly service provider to check that alarms are functional. All compliant AWTS installations are required to have working alarm systems.


Alarm light on and not sure what to do? See our emergency septic page; AWTS servicing, urgent pump-out and repair enquiries come from across the Port Macquarie and Hastings region.

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