Water Pressure


Most new homes today are built using mains water pressure for hot and cold water, a large number of existing homes operate with unequal water pressure. However, there are also equal low pressure situations in NZ as well. Identifying what type of water pressure you have in your home is vital when deciding on tapware and showers. It is important to check every time so you don’t end up with the wrong product – using tapware designed for mains pressure on your unequal pressure system will leave you disappointed with your choice, since they will not perform satisfactorily. This is a basic guide only to the 3 most common types of water pressure in NZ. All hot water cylinders should be labelled.

Mains Pressure (High)

Both hot and cold are supplied at high pressure.

Cold water is town supply. Hot water is from a high/mains pressure cylinder or gas infinity.

Unequal Pressure

Cold supply comes directly from town or tank pump (approximately 500kPa).

Hot supply from low pressure hot water cylinder (exhaust vent pipe through roof).

Low Pressure (equal low)

Both hot and cold are from the same water source at low pressure (eg: header tank/gravtiy feed).

NOTE: If you have a hot water cylinder with a metal pipe protruding out the roof, then you have low pressure hot water.

The Easy Test:

Turn on the hot to full, turn on the cold to full. Was the cold a lot more than the hot or even?



Please check that you are buying the right taps or showers.  Greens have a solution for all water pressure situations.  It pays to check every time so you don’t buy the wrong tapware.

Alongside each Greens product you will find one of these symbols. This denotes the performance of the product in various pressure environments.  Look for the symbols to make it easy for you to identify which one best suits your requirements.


Products are suitable for mains pressure only (high pressure)


Products are suitable for all pressures (from 35kPa)


FloBOOST Technology for Shower Mixers only. Suitable for all pressures (min 10kPa unequal | 20kPa equal)