Your Pump Station Alarm Is Going Off. Here's What It Means
A pump station alarm means the liquid in the tank has risen past the high level float, which sits above the level the pump is supposed to switch on at. In plain terms: waste is going in faster than it is going out, or it is not going out at all. The tank is not full yet. You have some room left, and that room is exactly what the alarm was installed to buy you.
Not sure what size you need? Try our pump station size calculator. It works out the tank size, pump head and the packaged stations that fit your job.
So stop reading for a second and do this first. Stop using water. No toilets, no showers, no washing machine, no dishwasher. Every litre you send down there from now on eats into the only buffer you have.
Right. Now we can work out what is actually wrong.
What the alarm is actually measuring
The alarm is triggered by a separate high level float, wired to the control panel independently of the pump. That independence is the whole point. If the pump circuit is dead, tripped or switched off, the alarm still works, because it runs on its own circuit. A buzzer sounds and a light comes on at the panel.
Packaged stations like the Kwikflo 250L sewer pump station package and the REEFE 250L sewer pump station package ship with this wired in from the factory. That is a large part of what you pay for when you buy a package instead of a tank and a pump separately.
The float order inside the tank, bottom to top, is stop, then start, then alarm. The pump should have kicked in well before the alarm float ever got wet. The fact that it did not is the information you are being handed.
Stop using water, then check the obvious three
Before anyone gets a torch out, check power, check the panel and listen. Those three take under a minute between them and they resolve a good share of alarm calls.
Power first. Go to the switchboard and look for a tripped breaker or RCD on the pump circuit. A grinder pump that has jammed will draw hard and trip out, and the alarm is the downstream symptom, not the fault.
Panel second. Most panels have a mute button and some have a reset. Muting is not resetting. If the fault light stays on after you mute, the fault is still live.
Listen third. Stand near the lid. A pump that hums but does not move anything is jammed. A pump that runs continuously and never satisfies is pumping against a blockage or a stuck valve. A pump that makes no sound at all is not getting power.
The five things that set a pump station alarm off
Nearly every high level alarm traces back to one of five causes. Here they are in the order we actually see them.
| Cause | What you notice | Who fixes it |
|---|---|---|
| Blocked impeller or cutter | Pump hums, trips the breaker, nothing shifts | Licensed plumber |
| Float switch jammed or tangled | Pump never starts, tank keeps filling, no noise | Licensed plumber |
| Power lost or breaker tripped | Panel dead, pump silent, alarm still sounding | Licensed electrician |
| Non return valve or discharge blocked | Pump runs and runs, level barely drops | Licensed plumber |
| Inflow beating the pump | Only alarms during heavy use or heavy rain | Sizing problem, not a fault |
Blocked impeller or cutter
Wipes. It is almost always wipes. Flushable is a marketing word, not an engineering one, and the ones labelled flushable are the worst offenders because people believe them. Cotton buds, sanitary products, dental floss and rags do the same job.
A grinder pump such as the REEFE RGS11A automatic sewage grinder pump is built to cut solids before they reach the impeller, and it handles a great deal more than a plain drainage pump will. It is still not a woodchipper. If you are unclear on why pump type matters here, we covered it in grinder pump vs drainage pump.
Float switch jammed or tangled
A float switch that cannot swing cannot tell the pump to start. Cables get wrapped around the discharge pipe, floats catch on the guide rail, and fats and rags build up on the tether until the float is effectively tied down.
This one is cheap and infuriating in equal measure. The pump is perfectly healthy. It simply never got the message.
Power lost or breaker tripped
No power to the pump means no pumping, and the alarm float is often the first anyone hears of it. Check whether the RCD went out with something else in the house, which points at a fault elsewhere, or whether it went on its own, which points at the pump.
Do not keep resetting a breaker that keeps tripping. It is tripping for a reason and the reason is usually a pump drawing current it should not be. That is an electrician's call, not a homeowner's.
Non return valve or discharge blocked
A stuck non return valve means the pump lifts the same water over and over. It runs, the level drops slightly, then the column falls straight back down the rising main. You get a pump that never stops and a tank that never empties.
Fats are the usual culprit in a domestic line, silt and gravel in a stormwater one. Long rising mains and high lifts make it worse, which is one reason head height matters so much at the design stage. Our guide to calculating head height for a pump station covers that side of it.
Inflow beating the pump
If the alarm only ever sounds during peak use, the station is undersized rather than broken. Four people showering back to back, plus a washing machine cycle, will out pace a small pump on a long lift.
The fix is not a bigger tank on its own. It is more pump, or a second pump. A dual pump Kwikflo station alternates duty between two pumps and can run both together when the level climbs, which is why they turn up on larger homes and small commercial sites. Compare the tiers in 250L vs 900L vs 1200L if you suspect this is the problem.
How long you have before it overflows
Assume you have minutes of normal household use, not hours, and act accordingly. The exact reserve between the alarm float and the inlet depends on tank size and how high the inlet sits, so there is no universal number, but the input side is simple arithmetic and ordinary fixtures eat that reserve faster than people expect.
| Fixture | Roughly what it adds |
|---|---|
| Toilet, one full flush | 4.5 litres |
| Shower, water efficient head, 8 minutes | About 60 litres |
| Front load washing machine, one cycle | 50 to 80 litres |
| Dishwasher, one cycle | About 15 litres |
| Bath | 150 litres or more |
One load of washing can be the difference between an alarm and a mess. That is why the first instruction is always stop using water, and why it comes before diagnosis.
What you can safely check yourself
Homeowners can check the switchboard, look at the control panel and listen at the lid. That is the list.
Opening a sewer pump station lid is not a homeowner job. The chamber holds sewage, it can hold gases that displace oxygen, and the equipment inside is live. Confined space entry is regulated work in Australia for good reason. Reaching in to free a float is how people get hurt.
Anything past the switchboard and the panel goes to your licensed plumber, and anything electrical goes to a licensed electrician. Call them, tell them the alarm is on and that you have stopped using water, and let them handle it.
Silencing the alarm is not fixing the alarm
Muting the buzzer stops the noise and changes nothing else. The float is still wet, the pump is still not clearing the tank, and the fault is still there.
We hear from people whose alarm has been muted for a fortnight because the beeping was annoying. By the time they call, it is not a service call any more. Mute it if you need to sleep. Book the plumber the same day.
How to stop it happening again
Most repeat alarms come down to what is being flushed and how long since anyone looked at the station. Both are fixable.
Get the station serviced yearly. A plumber pulls the pump, clears the cutter, checks the floats swing freely, tests the alarm circuit and confirms the non return valve seats properly. It is a short visit and it costs a fraction of an emergency callout.
Put a sign in the bathroom if the property is a rental or a granny flat. Three things go down the toilet: waste, water and paper. Nothing else. Tenants are not being difficult, they just do not know there is a pump out there.
Test the alarm at every service by lifting the alarm float by hand, so you find a dead buzzer on a quiet Tuesday instead of during a blockage.
If the station is past saving
A pump that has been run dry, run jammed or run for years without service is often cheaper to replace than to keep patching. Pumps are the wear item in a station. Tanks outlast them comfortably.
We stock replacement packages across the range: 250L at $3,199, 900L at $4,699 and 1200L at $4,999, all pre assembled with the alarm wired in. Prices current as of August 2026. Browse the full packaged pump station range or the wider sewer and stormwater pump station catalogue.
Plumbers and builders buying regularly should be on trade pricing. If you want a station specified properly for the site rather than guessed at, send us the details through the pump station quote form.
Frequently asked questions
Why is my pump station alarm going off?
A pump station alarm sounds because the liquid level has risen past the high level float, meaning the pump is not clearing the tank. The five usual causes are a blocked impeller, a jammed float switch, lost power at the breaker, a stuck non return valve, and inflow that exceeds what the pump can move.
Can I turn off a pump station alarm?
Most control panels have a mute button that silences the buzzer while leaving the fault light on, and muting it does not fix anything. The tank is still above the alarm level. Mute it if you must, then call a licensed plumber the same day.
How long before a pump station overflows after the alarm sounds?
Assume minutes of normal household use, not hours. The reserve between the alarm float and the inlet is limited, so if you stop using water immediately it can hold for hours, but a bath and a washing machine can consume the lot in one go.
Does a pump station alarm mean the pump is broken?
No, a pump station alarm often means the pump never started rather than that it failed. A tangled float switch or a tripped breaker leaves a perfectly good pump sitting idle. Diagnosis has to come before anyone quotes a replacement pump.
Who do I call when a sewer pump station alarm goes off in Australia?
Call a licensed plumber for anything inside the tank and a licensed electrician for anything at the switchboard or the control panel. Sewer pump stations are confined spaces with live equipment, so lid removal and float work are not homeowner tasks.
Not sure what you are looking at? Send us a photo
Send through a photo of your control panel and the make of the station, and we will tell you what the light is telling you and what it usually costs to sort out.
This guide is general information for Australian conditions and isn't a substitute for advice from a licensed plumber. Pump station work, sewer connection and electrical work are regulated, and requirements differ between states and water authorities. Have your plumber and electrician confirm any fault, repair or replacement before you act.