Increase your swimming season and the value of your investment

The ideal pool temperature is around 25 to 28 degrees celsius, but this is very rarely achieved naturally.

The average unheated water temperature in most of Victoria is 13 degrees and only reaches 18 – 20 degrees for short periods during the swimming season. Gas heating can quickly and efficiently heat your pool to a comfortable temperature at any time.

Your swimming season can be as long as you like, and the value gained from your substantial investment in your pool will be much greater.

Increased availability of natural gas and LPG has made it a popular form of swimming pool heating. It’s always available and can be closely regulated so it’s ideal for use on both pools and spas.


The gas energy consumed by a gas heater is measured in Megajoules (MJ) and the energy output rating is in Kilowatts (kW).

Smaller heaters are in the range of 60 to 100MJ and range through 250 up to 500MJ. The output ranges from 15 to 110kW.


Selecting the right heater depends on a number of factors. You need to consider the size of your pool or spa, the maximum temperature you would like to reach and how long you are willing to wait for it to heat up.

If you have a pool and spa combination, remember to consider both when deciding. Spas usually need to be heated more quickly and to a much higher temperature than pools, so select a heater with this in mind. If only a pool is being heated, it is not as critical to heat it quickly, so perhaps a smaller heater could be considered.


All gas heaters are fitted with thermostatic controls. These range from simple mechanical thermostats to sophisticated digital controls with temperature and status read out. Heaters connected to pools and spas must have a safety high limit thermostatic control with a maximum set temperature of 42 degrees.

Controls range from the basic to the very sophisticated. Seek expert advice and consider your budget, lifestyle and most importantly, what will best match the way you want to use your pool or spa.


Heaters can be installed indoors but require special fluing and may require additional ventilation specifically designed to suit the size and type of heater to be used. Never install a heater designed for outdoors inside unless the appropriate flue is fitted in accordance with the manufacturer’s instructions.

Heaters should always be installed on a stable, non-combustible base, preferably a minimum of 50mm above ground level.

Spa blowers must be located a minimum of 1.5m from outdoor gas heaters, and never in the same plant room as indoor gas heaters unless separate ventilation is provided.


Gas pool and spa heaters are very cost efficient. Running costs are relatively inexpensive. On pools, these can be further reduced in summer by incorporating a solar heating system and all year round by using a pool blanket to stop overnight heat loss.

See SPASA Victoria Fact Sheet 14 on Covers & Blankets.

Download Fact Sheet 11 - Gas Pool Heating