Skip to main content

Poor Water Pressure

The following topics are discussed:



Poor water pressure can affect us in several ways and can be especially frustrating when the pressures around our homes fluctuate, depending on what time of the day it is. Most water pressure problems are easily fixed with little cost.


Common causes of poor water pressure

The table below identifies the reasons for poor water pressure and identifies a solution. These causes are not in any order or frequency.


Cause of poor water pressure Solution for fixing the problem
Grit in the mixer tap aerator The aerator is located at the end of the mixer tap spout. This needs to be unscrewed and the grit washed out and then reinserted back into the spout. Grit in the aerator can cause a complete water blockage.
Grit in the tempering valve strainer The water supply will need to be turned off and the pressure released through a hot tap. The tempering valve can then be taken apart and the strainers cleaned and then put back together.
Degraded tap washer Low water pressure only in the shower?  Replacing the tap washer in most cases will fix this problem. Limescale build up in the shower head can also cause poor water pressure.
Blocked water filter Over time, the water filter will become overused if not changed. Make sure you change the water filter periodically.
Leaking water pipe (house pipe) Find the leak and repair.
Council leak water main Very occasionally, you may experience poor water pressure due to a burst water main. Normally the utility company will send out a group email or text when this happens.
Faulty pressure limiting valve This valve is normally located just before the water enters the house. If it is adjustable, then try and increase the pressure. If not, then the valve needs to be replaced.
The line strainer before the hot water system is full of debris Undo the strainer nut and wash out the debris.
Galvanised water entry pipe to your home Replace the mains. Not only does the galvanised internal diameter get much smaller with time, but also it can be quite dangerous due to leaching chemicals.
Old Pipes (Smaller) Old pipes were run in smaller pipe sizes. If your pipes are all ½ inch, then it may be time to upgrade your pipe size.
Pipe sizes are incorrectly sized Quite often plumbers just install a standard ½ inch for hot water and ¾ inch for the cold. If you live in a big house, then these sizes may not be adequate. Call a plumber to resize your pipes to see if they do need upsizing.
New water fixtures are more water efficient You may sometimes notice that when you go from an old to a new fixture the pressure changes. This does not mean that something is wrong; the new water fixtures are just more regulated and are constrained to stricter water efficiency standards.


Locating the source of your poor pressure

If you know what you are doing, then you may be able to skip a few of the following steps:

  • We first need to check to make sure that the property doesn’t have a significant leak. We do this by turning off all the fixtures in the house and taking a water meter reading. After one hour, go back to the water meter to see if the reading has changed. If it is the same, you have no leak. A small change means a small leak and a major change means a major leak and this may be the cause of your pressure problem. Time to find the leak and call a plumber.
  • Put a test gauge on the nearest hose to your water meter to identify the pressure of water coming into your property. If this pressure is 400kpa or more, then your pressure is ok. The maximum allowable in your home is 500kpa – this is not your problem area.
  • Put a test gauge on the furthest hose tap from the water meter. Turn off one tap in the house and see if the pressure drops on the gauge. Repeat this process for 2 taps and 3 taps turned on and record the pressures. What you want to see here is as little pressure drop as possible. 0 to 50kpa pressure would be ideal; anything more than this could be pointing towards the pipe size in parts of your property being incorrect.

If all the above is checked out, then it is time to assess each individual fixture independent of each other.

  • Showers – Remove the shower head and check the strainer inside. Quite often, the strainer gets full of grit. You need to wash out the grit and let the water run through the open outlet for 30 seconds just in case there is any more grit in the pipe. Check the pressure with a gauge too. You do this by attaching a gauge to the water outlet and turning the water on. The water pressure should be similar to the one at the water meter. Repeat this process for all the showers at your property.

Low Water pressure only in the shower? We first need to check and replace the tap washers. In 95% of cases, this will be the cause of a shower’s pressure problems.

  • Taps (Sink, Laundry, Basin) – Remove the aerator from each tap and remove any grit from the strainers. On removing the grit, you should notice a dramatic improvement in the tap flow.
  • The poor pressure is only on the hot side – Locate the tempering valve and clean out the strainer on the hot and cold water. This should fix your problem.


Future Projects

As a previous client, you can now enjoy the benefits of being a Yates Plumbing and Gas VIP Member.

To view member benefits, go to our home page.



  • All our plumbing and gas customers will receive
    • 10% off all future work
    • and one free hot water system check