Saving Gas

If your hot water is heated by gas, it is usually either Reticulated (town supply) or LP (Bottled) Gas. You would likely have either an instantaneous heater or a hot water storage system.

The storage type of heater is sometimes located above the ceiling of the house. Some of these rely on gravity to feed the hot water to the shower. We do not recommend fitting Showertimer in this case unless the cold water is also gravity fed.

Gas saving potential varies according to the cost of supply and, to a lesser extent, which type of heater. It is related to the amount of water to be heated and to the cold water temperature. Saving gas with Shower Timer is achieved by using less water.

To determine your supply cost (cents per megajoule), consult your gas account or call the gas supply authority. If you have bottled gas (LPG), the cost per Kg or per Litre can easily be converted to Cents per MegaJoule. See our shower savings calculator which you can download to easily calculate your potential gas saving.

The following shows the approximate cost of a 12 minute gas heated shower:


Cost of showerEach Shower5 Showers  aDayAnnual Cost
Reticulated Gas$0.55$2.75$1.004
LP$0.95$4.75$1,734

These costings are based on a cold water temperature of 15°C and a shower flow rate of 12 litres per minute at a comfortable temperature. Tariffs used are 1.6¢ per megajoule (reticulated gas), $1.60 per Kg or 80¢ per Litre (LPG) and 90¢ per kilolitre (water supply).

By fitting our Shower Timer set to 6 minutes, your annual gas saving will be half the annual cost. The cost of a Shower Timer will be recovered in a matter of months.