What's causing low water pressure in your home?

By: Ryan Suckling

But it’s also important to take note of any significant changes in water pressure as this could indicate a related issue somewhere in your plumbing system, including water leaks that need repair or faulty valves that must be replaced.

Signs to look out for

One obvious sign to look out for is low water pressure from showerheads and taps when water is not being used elsewhere in the home. You may even experience a noticeable delay between when you turn the tap on and the release of water.

This could be caused by water leaks somewhere in your plumbing system. Look out for dampness on walls, floors and other surfaces. Some are much harder to spot, such as leaks under the driveway or buried beneath grassed areas if you have reticulation. If it’s a big leak, you’re likely to hear it coming through the plumbing in your house.

Flaking wall paint and tile grout also indicate you could have a plumbing leak. As plumber Ben Talbot from Beta Plumbing & Gas tells us, “For tiny pin-hole leaks, you won’t know about it until you start seeing damage to brickwork or behind tiles. These leaks are often difficult to locate and repair, so it’s best to contact a plumber immediately.”

To gauge if there is a problem somewhere in your plumbing system, there is a simple test you can carry out.

Testing water pressure

The Water Corporation is required to provide at least 20 litres of water per minute.

To test this, turn off all taps and water-using appliances. Locate your water meter and record the numbers or take a photo with your phone. Then, to determine your per litre output, run a garden tap for 60 seconds.

Once the minute is up, turn off the tap and return to the water meter and again record the numbers. Simply subtract the original reading from the second and you’ll know approximately how many litres you’re getting per minute.

Keep in mind the calculation is not completely accurate as a lot depends on the location of water outlets across your property. But it will give you an estimate to see if further action should be taken.

Plumber Ben Talbot says he places a gauge device on the garden tap to get a more accurate reading. “Once all taps and water-using appliances are off and I’ve measured the water pressure, I can then determine if it’s too low or high and meets Australian standards.”

The Australian standard for water pressure sits at 500 kPa, or kilopascals, which is widely used as a unit measurement for water pressure. A plumber will be able to quickly tell if the pressure is low. But if the pressure should exceed that limit, the plumber would need to install a pressure limiting valve (PLV) to protect the pipes and fittings.

Talbot also stresses that any damage to new fixtures or appliances caused by high water pressure is not covered under warranty.

If water pressure should fall below the minimum requirements, these are some of the most common causes to consider.

Common causes

Water outage

The first thing to rule out is whether there is maintenance work being carried out to the water supply in your area. In this case, you may temporarily experience a drop in water pressure throughout your home. Residents are generally alerted prior to such work being carried out, but if you’re unsure, see if your neighbours are experiencing the same issue.

To look up water outages possibly affecting your area, enter your home address on the Water Corporation’s outages and works page.

Corroded and blocked pipes

Over time, the pipes in your home can deteriorate. Copper, a common material used for pipes, is susceptible to corrosion.

For the most part, you can expect copper pipes to last for up to 50 years. But in older houses especially, it’s worth ruling out if rusted pipes are adversely affecting water pressure.

In that case, you’ll need to contact a professional plumber to carry out repairs.

Build-up of minerals and other debris can also reduce the diameter of water pipes and impede water pressure. A plumber should be able to locate any blockages.

In the case of fixtures, blockages can be identified at the basin, including the aerator at the end of the tap where build-up can often occur. A plumber will also check the flexi hoses under the sink to make sure nothing is lodged inside.

Water shut-off valves

Water valves are key to supplying your home with water at the right pressure. First, you’ll want to check that the shut-off valve at the water meter is fully open. If the Water Corporation has recently carried out maintenance work in your area, the valve might only be partially open. Simply turn the handle so that it is completely open.

Hot water valves

There are different valves on hot water services. If one or more should become blocked or damaged, that would have a noticeable effect on water pressure in the home. Also, there are strainers in some valves that can get blocked up and require replacement.

You wouldn’t know by looking for yourself whether these valves are blocked or damaged, which is why a plumber will need to take it apart and inspect the system.