Gas continuous flow

Gas continuous hot water systems heat the water as you need it, so you’ll never run out.


  • Gas continuous hot water is more efficient than gas hot water cylinders.

  • Condensing gas continuous flow systems are more efficient than conventional gas continuous flow systems.
  • Provide ‘unlimited' hot water.

  • Free up storage space in your house if the cylinder is removed.

  • Digital controllers on gas continuous hot water systems allow specific water temperature to be selected, for example to fill a bath without adding cold water.

Keep in mind

  • You will have to pay a fixed charge for reticulated gas supply (if you don't already).
  • Running costs are high if you use LPG bottles.
  • While burning gas is relatively clean, the greenhouse gas emissions contribute to climate change.
  • This type of system tends to waste more water than other types while you wait for the water to get hot. This may be important to you, particularly if you are on tank water supply or metered water.

  • As most require an electrical supply, you won't have hot water during power cuts (though power backup systems are available).

  • Though the hot water never runs out, using more than you need is a waste of money, water and energy.

  • Use our water heating tool?to compare the upfront and ongoing costs of different water heating options for your situation.

?Water heating tool

How they work

Gas continuous flow systems burn gas to heat water as it runs through them. They can run on natural gas or LPG.