Quick Answer: How to Tell If Your Water Pressure Is Too High
You can pick high pressure without a gauge. Watch for these:
- Loud banging in the pipes when the washing machine stops filling or you turn off a tap fast
- Taps that drip within weeks of a washer repair, then drip again after the next one
- Flexi hoses that look swollen or blistered behind the machine or under the sink
- Cisterns that whine, hiss, or run on after a flush
- The hot water relief valve dribbling out the overflow pipe on the side of your house
- Taps and showerheads that spray everywhere even when barely opened
Two or more of those ticked off? Get a plumber to put a gauge on it. EKORP Plumbing carries calibrated test equipment and can check your Sydney home the same day you call.
Signs of High Water Pressure
Most people live with the symptoms for months before they connect the dots back to pressure. Here is what each one looks like in practice.
Banging and Knocking Pipes (Water Hammer)
That thud or clang you hear when the dishwasher clicks off mid-cycle is moving water hitting a shut valve at full pace. The higher your supply pressure, the harder that slam. Pipes that knock on every appliance cycle or every time you close a tap briskly are telling you the pressure behind the water is far too high.
Dripping Taps That Won’t Stay Fixed
A new washer should hold a tap shut for years. If yours lasts a few weeks before the drip returns, the fault is not the washer and it is not the plumber who fitted it. Excess force is squeezing water past the seal even with the tap fully off. The seal deforms, the drip comes back, and the cycle repeats until you deal with the actual problem.
Noisy Toilet Fill Valves
A cistern refilling quietly is normal. One that shrieks, vibrates, or lets the toilet ghost-flush hours later is not. The fill valve internals are rated for a normal pressure window. Push them past it and they fail sooner, make more noise doing it, and can leave the toilet running water continuously.
Burst or Ballooning Flexible Hoses
Braided flexi hoses are built for the pressures you find inside most homes. Push past that and the rubber core starts to stretch inside the braid. The outside may look fine right up to the point it lets go. When a flexi hose bursts it can dump hundreds of litres in minutes, often while you are out. Swelling, kinking, or rust on the fittings are your warning shot.
Hot Water System Relief Valve Discharge
The temperature and pressure relief valve on your hot water unit is a safety device. It opens when conditions inside the tank get dangerous. Frequent or constant dripping from that valve means either the tank temperature is wrong, the incoming pressure is too high, or both. In a closed-system home with check valves fitted, heated water that expands has nowhere to go, so the relief valve cops it repeatedly.
Why High Pressure Damages Your Home
It is not just an annoyance. High water pressure is quietly working through your plumbing from the meter to every fixture in the house.
Shortens the Life of Taps, Valves, and Fixtures
Seals, springs, and solenoids are all rated for a pressure range. Run them above that range every hour of every day and they wear out in months rather than years. The money you spend replacing washers, cartridges, and fill valves adds up fast, and none of those repairs fix the underlying cause.
Increases the Chance of Leaks and Sudden Bursts
Pipe joints, solder connections, and fittings are all under constant mechanical stress at high pressure. Weak points that would hold for decades under normal conditions can open up far sooner. Flexi hoses are the most vulnerable point in most homes. A burst at 2am on a Thursday is the kind of plumbing story nobody wants to tell.
Water Damage and Insurance Implications
Flood damage from a plumbing failure runs into the thousands before you factor in flooring, walls, cabinetry, and personal property. Insurers are asking harder questions about preventable failures. If the assessor finds you had obvious warning signs, like repeated bursts and no pressure limiting valve fitted, your claim can be cut back or knocked back entirely. A pressure test and a valve costs a fraction of what a flood costs.
What Causes High Water Pressure in Sydney Homes?
A few different things can push your pressure into the danger zone, often in combination.
Supply Pressure Variability
Sydney Water aims to keep mains pressure between 200 kPa and 500 kPa, but properties at lower elevations or close to trunk mains can sit well above 500 kPa during peak supply periods. Your neighbour’s pressure and yours can differ meaningfully even on the same street.
Failed or Absent Pressure Limiting Valve
A pressure limiting valve, or PLV, steps the mains supply down to around 350 to 400 kPa before it enters your home. Many older Sydney properties never had one fitted. In others, the valve was installed years ago and has since seized open, clogged with debris, or simply worn out. An absent or dead PLV means whatever the main is running at comes straight through to your taps.
Renovations and Plumbing Changes
Replacing old galvanised pipes with copper or PEX is a genuine improvement for flow, but if supply pressure was already borderline, the new pipework can make the symptoms more pronounced. Adding backflow prevention or check valves as part of a reno also changes how the system behaves, sometimes tipping a borderline situation into a problem.
Thermal Expansion in Closed Systems
Homes with check valves or backflow preventers on the main are effectively sealed once water passes the meter. When the hot water system heats a tank of water, that water expands. In an open system it pushes back toward the street. In a closed system it pushes against everything downstream instead, spiking pressure with every heating cycle.
How Plumbers Fix High Water Pressure
There are no safe shortcuts here. Pressure control is licensed plumbing work, and the right fix is done in a logical order.
Pressure Testing
A licensed plumber starts by fitting a calibrated gauge to the system, usually at the meter and at one or two internal points. This gives a real reading rather than a guess. Safe household pressure sits between 250 kPa and 500 kPa. Above 500 kPa consistently is the point where a PLV is needed. EKORP Plumbing carries test gauges on every van.
Install or Replace a Pressure Limiting Valve (PLV)
The PLV goes in on the main line, typically right after the meter or at the boundary. It sets a ceiling on the pressure entering your home, normally around 350 to 400 kPa, and holds it there automatically regardless of what the street main is doing. A quality unit lasts ten to twenty years with no attention. If your home already has one but it has seized or drifted, we swap it out for a new one at the same time.
Add Water Hammer Arrestors Where Needed
In homes with quick-shutting solenoid valves on the washing machine or dishwasher, even a corrected pressure level can leave some residual banging. Hammer arrestors are shock absorbers plumbed in close to the problem appliance. They are a secondary fix, used alongside the PLV rather than instead of it.
Verify Safe Operation of Key Valves and Fixtures
After the PLV is commissioned, we recheck pressure at multiple points and run through taps, toilets, and appliances to confirm everything is behaving correctly at the new set point. If high pressure has already knocked out a fill valve or blown a washer, we flag those for repair so you do not start fresh with a leaking fitting.
DIY Checks You Can Do Safely (and What Not to Touch)
You can gather useful information yourself before calling us.
Listen for Water Hammer
Run the washing machine and stand near the laundry pipes when it finishes filling. Turn a tap off quickly and listen for a bang or a thud. Note how often it happens and which appliances set it off.
Check for Dripping Taps
Go around the house with a dry finger and check every tap outlet. If three taps are dripping, or a tap you had fixed last month is already dripping again, write it down. That pattern matters.
Inspect Flexible Hoses
Pull the washing machine out a few centimetres and look at the hoses front on. Check under bathroom and kitchen vanities too. Any puffiness in the rubber, corrosion on the fittings, or staining on the wall behind counts as a red flag worth mentioning to your plumber.
Note How Taps Feel
A tap that blasts water with the handle barely cracked open, or a showerhead that sprays off the walls at the lowest setting, is showing you what high pressure feels like day to day. It is not normal.
What Not to Touch
Do not adjust, bypass, or try to install a PLV yourself. Do not loosen fittings on the meter or tamper with backflow prevention devices. In NSW, pressure control work must be done by a licensed plumber. Getting it wrong can make things worse and puts you offside with building regulations.
When High Pressure Becomes an Emergency
Most pressure problems build slowly, but some tip into an emergency fast. Call EKORP Plumbing’s 24/7 emergency line immediately if:
- A flexi hose or pipe has burst and water is spreading across the floor
- Your hot water unit is pouring water continuously from the relief valve
- Several taps or fittings have suddenly started leaking at once
- You hear a loud bang in the pipes followed by water noise that will not stop
Turn off the main stopcock first to stop the flow, then call us. EKORP Plumbing carries pressure gear and replacement parts on every van for a same-day fix across Sydney.
FAQs
What Are the Symptoms of High Water Pressure?
The key signs are: banging pipes when taps or appliances shut off, taps dripping repeatedly after washers are replaced, flexi hoses swelling or bursting, noisy or constantly running toilets, hot water relief valves dripping regularly, and fixtures wearing out well before they should.
Can High Pressure Cause a Hot Water System to Leak?
Yes. High incoming pressure pushes the relief valve beyond its normal operating range, causing it to weep or run constantly. It also stresses tank connections and internal fittings. In closed-system homes, thermal expansion on top of already-high pressure can spike the tank pressure dangerously. If your relief valve is dripping regularly, get a plumber to test the supply pressure straight away.
Why Do My Taps Keep Dripping After Repairs?
Because the repair is not the problem. The washer or cartridge fails again because the pressure forcing water against the closed seat is too high for the seal to hold. No number of washer replacements will fix it permanently. Bring the pressure down with a PLV and the next washer will last years, not weeks.
What Is a Pressure Limiting Valve and Do I Need One?
A PLV is a valve fitted to your main water line that knocks incoming mains pressure down to a safe household level, typically 350 to 400 kPa. If you have any of the symptoms above, you almost certainly need one. Even without obvious symptoms, a supply pressure above 500 kPa is reason enough to fit one before something fails.
What Causes Water Hammer?
Moving water stopped suddenly creates a pressure wave that slams back through the pipes. High supply pressure means the water is moving faster and hits harder when it stops. Washing machines and dishwashers are common triggers because their inlet valves close instantly. A PLV reduces the energy behind that wave, and hammer arrestors absorb what remains.
How Quickly Can High Pressure Damage Flexi Hoses?
Faster than most people expect. Exposure to pressure above the hose’s rated threshold weakens the inner lining over weeks and months. The outer braid can hide the damage right up to the point the hose lets go, sometimes without any visible warning. Because failures can happen when you are not home, the flood runs unchecked until someone notices. Do not wait for visible damage before taking action.
Is High Pressure Worse in Apartments vs Houses?
Both property types are affected. Apartment buildings often have building-wide pressure control, but individual units can still run high if the system is old or poorly maintained. If you are in a strata property, report symptoms to your building manager as the fix may sit with the owners corporation. In a freestanding house, a PLV at the boundary usually solves it cleanly. Either way, a licensed plumber can diagnose which side of the equation the problem sits on.
Conclusion
High water pressure is one of the most common plumbing problems in Sydney homes, and one of the most overlooked. Banging pipes, washers that fail repeatedly, flexi hoses that blow without warning, these are not random bad luck. They are the system telling you the pressure is too high. A PLV fitted by a licensed plumber stops the damage at the source and protects every fitting, appliance, and hose in the house from that point forward.
EKORP Plumbing has been fitting pressure limiting valves across Sydney for years. We test pressure on arrival, install quality PLVs set to the correct range, and verify the whole system before we leave. The cost of a pressure test and PLV installation is nothing compared to cleaning up after a burst hose.
Call EKORP Plumbing on (02) 8074 5786 to book a pressure test today. Same-day appointments available across Sydney.
