Expert advice on the best hot water systems from a professional plumber

hot water systems - best hot water systems

How to choose the best hot water system for your home?

Are you in the market for a new hot water system and wondering which one might be best? You’re not alone—there are so many options available that it can be hard to know which one is right for you. 

While researching different systems, ask yourself what your needs are, what your budget is, and if there are any local regulations on installation. To help give you more insight into deciding on the ideal hot water system for your home or business we asked Kris, from Ironclad Plumbing Blue Mountains to rate their favourite types of systems and explain their personal experience working with them. Let’s take a closer look at some of the top-rated hot water systems in Australia.

The two basic kinds of water heaters are storage and heat pumps. The less popular continuous-flow heat pumps don’t require a tank but are costly to install and maintain. The more traditional storage systems of gas, electric and solar, which hold hot water in a storage unit, are widely made by a number of top brands. The expert tradie will look at a number of features to find the perfect gas, electric or solar heating system for you, no matter what make or model.

A hot water system, also known as a storage water heater, is a tank of heated water that can range from 25 litres to 400 litres in size. The water is heated to between 60 degrees to 83 degrees, either by electric, gas or solar means and sent through the home via pipes and fixtures. The heater allows for constant hot water from tank to tap and must store water at a temperature of at least 60 degrees Celsius. This stops any growth of bacteria.

Why have the right hot water system?

The right hot water system depends on fuel source, size, cost, placement, and demand for hot water. A plumber would tell you to consider the following when choosing your hot water –

The primary power source of your hot water system

There are four types of hot water systems you can choose from. They are:

  • Electric hot water systems are the most sought after with around 44 percent of Australian households using this. The unit is plugged into a power outlet and an element in the storage tank heats the water with electricity. It is pricey to install but very efficient.
  • Gas hot water systems use a burner under the tank that is always lit. 37 percent of households use gas systems which cost more to fit in at the start but are very efficient in the long run.
  • Solar systems use panels on the roof to absorb the sun’s rays and heat the water. It is cost effective in the long run and green conscious but can be less effective at heating. About 11 percent of Australians use solar hot water.
  • A continuous flow heat pump is newer costly technology and not as popular as better-known heating systems. It heats water directly at the pipe and does not use a tank.

How many people will use the system?

The size of your storage water unit should depend on the number of people using it, and how often. If you are alone, or a couple, or a large family, then choosing the right size system is important. If the unit is too small, you’ll always run out of hot water which brings high bills. If it is too large, then excess hot water will be wasted and costs will be high.

How much can you afford?

Starting with a new hot water system can range between $500 to $9000. This takes into account make and model, labour costs, delivery and quote. The system you choose should fit in your budget while still being highly effective and efficient.

Where are you going to install it?

The best place to put your system depends on the space that is there. Some systems can be quite large and need to be placed in a spot that has enough space but is not obvious. Heating systems can be external or internal with more wear and tear if placed outside but taking up more space if inside. The choice depends on residence. For instance, an apartment has less space than a house so a smaller unit would be required indoors. A house with a laundry could fit a large hot water system indoors or outdoors in the backyard.

Top systems - the Plumber’s Pick

When we think about cost and value, plumbers will recommend either a Rheem, Rinnai, or Thermann brand of hot water system. These are most suitable for Australian conditions and preference. Each brand has its own high points. Let’s take a look at each one.


Rheem has been around for 97 years with a brand name for quality. These systems are also perfectly suited to Australia’s sometimes extreme conditions. Rheem covers the full range of heating systems but has the biggest range of gas systems on the market.  

Rheem has its Stellar (top-line), 5-star, 4-star, Rheem Plus, and internal gas heating systems with 130 litre to 170 litre tanks. Rheem gas heater systems are made of durable steel design and are easy to use and maintain.  

Rheem’s electric systems also come in the above lines all with sacrificial anode but has a greater range of tank capacity from 25 litres to 412 litres. This allows for the choice of a perfect fit of system to home space.

Rheem also has a solar hot water range in a Hiline and Loline range. The Hiline has two solar panels mounted on the roof which heat water and circulate it back into the system. The Loline range mounts the tank on the ground and is better for smaller or average homes. The sizes go from 160 litres to 305 litres. Every type of Rheem system has a warranty from either 5 years up to 10 years. A government rebate is available for most Rheem solar systems.

Rheem also has continuous flow systems which can be mounted on the wall and have a size of 12 litres, 20 litres and 27 litres. This system is better for apartments with little space.

The cheapest unit in its entire line-up starts from around $480 for supply only. Rheem’s most expensive system tops out at around $1980 supply only.


Rinnai is an international brand that has been around for nearly 100 years. Rinnai’s gas storage units come in two sizes within its Hotflo line. The moderate 135 litre unit provides great first hour hot water and is suitable for high usage. So too, the larger 170 litre unit.

Rinnai has a huge range of electric water systems from sizes of 25 litres up to 400 litres. All types have a sacrificial anode and an enamel lined tank for durability.

Rinnai solar systems come in the Prestige line and hold from 180 to 300 litre size. They have roof and ground mounted tanks and the system is frost resistant so perfect for colder places. Rinnai offer enhanced solar systems with their Sunmaster range.

Rinnai produced the first continuous flow hot water system and is at the top of the field. 10 models range in size from 16 litres up to 32 litres. All Rinnai types from gas, to electric to solar and continuous, have energy ratings from 4.7 to 7-star efficiency. The cheapest unit starts at around $410 supply and the most expensive tops out at $2400 supply only.


Thermann is a wholly Australian company started in 2012 and is a plumber’s choice because of their simple design and great value for money. They provide the full range of storage heating types with over 500, 000 units installed in Australia. Their electric storage tanks go from 25 litres up to 400 litres in small and large sizes. They include the latest technology including sacrificial anode and durable design.

Their gas hot water units go from 135 litres to 170 litres and also include the newest technologies. Thermann also have solar units that use evacuated tube technology to heat the water with the panels and keep it in the tank.

The solar units range from 250 litres to 400 litres. The units can either be gas-boosted or electric boosted for the times when there is not much sun around.

The cheapest unit in its entire range is around $500 supply with the most expensive topping out at $2148 supply.

How to choose the right hot water system?

As stated above, choosing the right hot water system depends on:


  • Size – A hot water system that is too small will not supply enough hot water at peak times. It will also run up a high energy bill from refilling the unit. A hot water system that is too large is not needed for a single or couple in a home, but is needed for a large family. Sizes can also be found that fit perfectly in that space under the stairs, or in the laundry, or beside the garage. When picking by size, the number of people using hot water, the number of times used, the size of the residence, and the space available should all be taken into account.
  • Fuel-type – Electric systems are the most popular because of their ease of connection. However, gas systems are popular in the southern states where there are gas mains to the house. Gas systems cost more to install but are very efficient in the long run. Solar systems are great for green conservation but sometimes need an electric or gas booster in case of cloudy weather. Solar units are great for those places that receive plenty of sunny days.
  • Location – Colder, wetter locations would be better with gas or electric rather than solar.
  • Cost – The cost of the unit is important and depends on your budget. A high installation cost can be offset with high value in the long run, where a lower install cost might run into problems of upkeep and quality later down the road.

Common mistakes when choosing a hot water system

By far, the most common mistake is to choose the wrong size hot water system. If it is too small then there won’t be enough hot water with higher running costs. Too large and hot water will be wasted. There will also be space problems in or around the house.

The other main problem is to not factor in the start-up cost to install a hot water system. The labour and shipping can cost more than the heater itself. There is also the cost of routine checks on a hard-to-use system when a plumber is called. Choosing a top brand that gives best value in the long run is the way to go.

Benefits of the right system

Take your time and be careful about choosing a new hot water system. The benefits will happen in the long run with

  • cheaper household bills when the system is in peak function
  • best support of your lifestyle with on-demand hot water
  • long-life hot water system when the design is quality parts
  • low upkeep with a quality system
  • improved comfort and quality of life with the latest methodologies in hot water heating.

The best and right hot water system is waiting for you. Get advice from a hot water expert today and find the right choice of either gas, electric, solar or continuous flow hot water system for your home.  Your hot water system is a most valuable asset to your home and life. Choose it well.

To book hot water service in Blue Mountains, Lithgow or Penrith, call our team today! We’ll be happy to help!

Or fill in the form below and we’ll call you back.

    Fill in the form and we'll call you back.