For a standard three-bedroom household in Australia, installing a 250-litre hot water heater should meet peak demand.

The two main factors influencing cost are capacity and power. Capacity refers to how much hot water can be stored in litres, while power relates to how fast the tank heats up again after being drained down, usually quoted in litres per minute.

Estimated prices for electric hot water heaters

  • 250 litre Electric Hot Water Heater supply and install $1,500.

  • 250 litre Electric Hot Water Heater supply $1,100.

What hot water system should I get?

The two main factors influencing cost are capacity and power.

Capacity refers to how much hot water can be stored in litres, while power relates to how fast the tank heats up again after being drained down, usually quoted in litres per minute.

In addition, if you have a pump for your gravity feed system, consider its amperage draw as well as the price of any accessories that may come with your unit such as a timer or spa setting controller, they all drive up capital costs.

Sometimes pumps are sold separately from heating systems though it is more usual for them to be included as part of a package deal where the heats exchanger, temperature controls and all other required parts.

What types of hot water system can I get?

There are two main types of hot water systems: tankless and storage tanks.

Tanks can go up to 400 litres or more. The average family-of-four needs at least a 150-litre model while larger households may need several tanks connected together so multiple showers can operate simultaneously with no wait time. That's called stacking.

What are the different types of hot water heaters?

There main types of hot water heaters are electric, gas and solar. Which type of hot water heater you have largely depends on you or existing infrastructure. There are also tankless or 'instant' hot water heaters, but these are not so common at the moment.

Electric water heaters

An electric water heater uses electricity to heats up the suitable water inside it. These usually consist of a large steel tank that sits inside your house, with an element wrapped around the outside to transfer hotness into the cold water that flows through it and they are highly recommended.

There are many types of warranty conditions for these type of electric water heaters. By being located indoors, they're safe from freezing outdoors and won't be affected by cold weather either. Electric storage tanks use between 4-8 kWhs of energy per day and they also have a labour warranty.

This can easily be supply and install from local shops. The warranty conditions apply automatically when you brought the electric hot water system.

Electric water heaters are the most widely used heaters in the Australian household. Plus, since it uses electricity, you don't need to worry much about installations.

Gas water heaters

A gas hot water heater consists of a large tank that is usually installed just outside your house, heated by either natural gas, liquefied petroleum gas (LPG), butane or you can also use a home delivery cylinder for it. Your professional warranty conditions apply as soon as you buy the gas water heater. When you turn the hot tap on, cold water enters at the bottom of the tank and flushes through to the top where it's heated to over 60°C before being pumped back down again to the mains pressure. They are less expensive to operate than electric storage tanks, using around 2-3 kWh of energy per day on average. Installation of gas water heaters is a free plumbing service.

Solar water heaters

A solar water heater uses energy from the sun to heat up water and send it into your house. These systems usually have a tank that stores hot water, with tubes running from the tank to panels on the roof that collect solar energy.

Solar water heaters can be used in combination with other types of water heaters, such as gas or electric, or they can be used as a standalone system. They come in two main varieties: active and passive.

Using solar energy makes these systems extremely cheap to operate, using no more than 1 kWh of energy per day.

What size hot water system should I get?

If you have a large family or like to take long showers, you'll need a larger system that can handle more demand. If you don't use a lot of hot water, then a small system may be all you need. The larger your family, the bigger your hot water system should be. For larger families or households where several people use the shower at once, a 200- to 250-litre storage tank might be a better option. And if everyone in your household likes a long hot shower, opting for a high-capacity 300+ litre model will ensure no one has to wait their turn. That said, it's important to get the right size water heater for your home. If your tank is too small, you might run out of hot water; if it's too big for your household's needs, it could be unnecessarily heating up and wasting energy. To avoid running out of hot water or spending more than necessary on energy bills, we suggest getting a system that can comfortably handle the highest demand in the busiest hours, usually early evening, and still have enough capacity to meet daily and weekly fluctuations in use.

  • Five members: 240-litre storage tank.

  • Two teenagers who like long showers: 220-litre storage tank.

  • One person taking a quick shower: 125-litre storage tank.

It's important to remember that not all hot water systems are created equal. Cheaper units might be less efficient and could end up costing you more over time.

Which hot water system is cheapest to run?

An electric storage tank. Electric storage units are by far the cheapest type of hot water system to run, using up to 4 kWh of energy per day.

This is due to new technologies that have made hot pumps more efficient and improved insulation in tanks, meaning less heat is lost before it gets into your house. For large families or households where several people shower at once, an electric system will be cheaper than gas or the solar option.

Gas systems aren't too far behind, running on average between 2-3 kWhs per day, and they're often cheaper than solar hot water systems as well, which can use around 1 kWh/day on average (or even less with modern technology). The biggest downside for gas and electric hot water is that you need to factor in the cost of installing a new hot water system.

For more information on energy efficient hot water systems, take a look at Energy.gov.au.