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Which hot water system is right for you?

When it comes to buying water heaters – there are four main considerations:

Storage hot water systems

As the name suggests, these systems store hot water in a tank. They get a supply of cold water and heat the water when the unit is on. Tanks are usually insulated so there is minimal heat loss and can be installed outside or inside.

  • The storage hot water systems are available in all types – solar, electric, gas and heat pump.
  • The tanks are made of different materials – steel, vitreous enamel, or copper.
  • The steel tanks are expensive, however, they have high resistance to corrosion, need less maintenance and last longer (around 10 years). Vitreous enamel tanks are prone to corrosion and might last for 5 -10 years whereas copper tanks last for 7 years approximately.
  • The life expectancy of the hot water tank depends on many factors including the quality of water and maintenance carried out.
  • The tanks require regular maintenance as their internal components are prone to wear and tear. For example, the sacrificial anode rod in the tank is designed to attract any corrosive materials preventing tank corrosion. It usually needs to be replaced as per the manufacturer’s instructions or every 5 years. However, it might need to be replaced before this time period if it develops any faults.
  • The required size of the storage hot water system will depend on the size of your household and its hot water requirements.
  • Storage hot water systems can last for 10-15 years. Some systems have a lifespan of 8-12 years.
  • Many manufacturers offer a warranty of 5-10 years for storage hot water systems.
electric hot water

Electric Hot Water System

Continuous hot water systems

How does an instant water heater work?

The cold water flows through the water heater when the tap is turned ON. The cold water is heated using the heating element present in the electric system or using a gas burner in case of an instant gas system. They can deliver a constant supply of hot water but there might be a lag in hot water supply during periods of higher demand.

  • The instant hot water systems are available in electric and gas variants.
  • Tankless systems can last for 20 years and the parts are easily replaceable so your system might last longer.
  • The size of your instant HWS depends on the number of hot water outlets. You will also need to coordinate your use of different appliances like a washing machine or dishwasher and showers. The supply of hot water will decrease if multiple taps are open at the same time.
  • Cheaper to run than storage hot water systems
  • They are compact and can be fixed on a wall

Know more about how the different types of instant hot water systems work here:

Electric vs gas continuous hot water systems

The gas-powered continuous system offers more efficiency and is more common in Australian households. Gas is also cheaper than electricity so you can save more by opting for a gas system.

Rinnai Instant

Rinnai Instant

The energy efficiency of hot water systems

The instant hot water systems are energy-efficient and often have up to 6 or 7-star energy ratings. They are more energy-efficient than storage systems (most of the storage systems have an energy rating of 3,4 or 5 stars).  For example, Rheem Infinity 26 Continuous Flow system has a rating of 6-star while Rheem Stellar Gas Hot Water Heater has a 5-star rating.

Pros and cons of hot water systems

Instant Hot Water Systems


  • They offer a continuous supply of hot water.
  • Last longer nearly 20 years.
  • More energy-efficient and reduced operating costs.
  • Require less space and don’t hamper the aesthetics of your house.
  • The water doesn’t need to be maintained above 60 degrees Celsius to prevent the growth of bacteria and Legionnaires’ disease.
  • No issue of rust and frequent maintenance.
  • Lower greenhouse gas emissions.


  • In the case of higher demand, these systems will take more time to supply hot water.
  • The upfront cost is higher than the storage systems.
  • Water supply can be affected if you have low-flow showerheads.

Storage hot water system


  • The hot water is stored ready to go and will be used when you need it.
  • Low upfront cost.
  • Solar style storage hot water systems are highly efficient, have low operating costs and can significantly reduce your power bills.


  • The storage capacity is limited and it takes time to heat cold water if the tank hot water capacity is depleted.
  • Energy efficiency is low.
  • Electric and Gas storage style have higher operating costs and energy bills compared to their instant counterparts.
  • For larger households, the storage capacity required would be higher and it would be more expensive to purchase the unit.
  • The hot water needs to be maintained above 60 degrees Celsius to prevent the growth of bacteria and requires more energy to maintain this consistent temperature.
  • The water tank requires a lot of space for its installation.

Choosing the best hot water system

Choosing the best hot water system depends on your budget and hot water requirements. Think about your preferences and water demand. Consider things like – do you take showers or baths, if you use hot water for your appliances and the number of people in your household. A specialist assessment will help you choose the right system for your needs, reducing the risk of regretting your decision later on.

Talk to the expert plumbers at Brisbane Plumbing and Drainage, we can help you find the right hot water system to meet your needs. Our licensed plumbers can install, repair and maintain hot water systems of all types. Contact us at 1300 616 203 or complete our online booking form.