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#7 Choosing the right hot water system

#7 Choosing the right hot water system

Many of us take hot water for granted. This isn’t surprising as it always seems to be always there when we want it.

In this blog, I will provide information on factors that contribute to making the best decision when choosing a hot water system for your home.


When in need of a new hot water system, figuring what it will cost you is the first and most important question you will ask.

If you are sure you can’t afford the best 300 litre hot water system but this is the size you need in your home, it is wise to look at how you can make it work rather than down sizing (to a 250 litre for example). This is likely to result in you running out of water at some point and affecting how hot water is used in your home.

If this situation happens, you have a few different options:

Option 1: Purchase the hot water system on finance. A large percentage of plumbing companies now offer finance as an option and allow you approximately 6 months to pay the hot water system off.

Option 2: Talk to your plumber and ask if they can recommend you a cheaper storage hot water system brand. Bunnings have a great range of cheaper hot water systems and they are all Australian approved with a water mark.

There are many online stores which offer free delivery hot water systems at a reasonable price. In saying this, I recommend you do your homework before purchasing, make sure the company is reputable, check all products have good warranty periods, and read through website reviews too.

As plumbers we get used to a brand and stick with it, however there are many other good options out there available. I come across new items daily which are great and have been around for years. It pays to keep looking and have an open mind.

Option 3: Look at a continuous flow style hot water system. These are slightly cheaper to buy and install, yet provide a never-ending supply of hot water. They typically provide around 26 litres of hot water per minute, with the largest unit providing 32 litres – this would cope with three showers running at once.

Natural gas is a preferable source over LPG here as they do not chew through gas when in operation but no gas consumption when dormant.

Family size and family age ranges

The bigger the family = the bigger the daily hot water usage.

Looking at ages in the family is also very important. Despite the common belief that females take longer showers, a comprehensive study out of the UK proved this to be incorrect. There is very little difference between the sexes, with the average shower being between 7-8 mins.

Let’s have a look at why this is important…

If we take a family of five for example with two adults with three young kids, it is unlikely the kids will shower in the morning but the adults probably will. Whereas if you get a family if five with three kids over 12, it is more likely that the showers will be running both morning and night consistently through the week. This means the showers will be used approx 490 minutes over the week compared to 343 mins for the family of five with younger kids.

Obviously, every family is different, this is why understanding the clients water habits are essential. For example, my kids can spend 30 minutes in the shower playing on a cold day.

The table below can be used as a guide to help you give your plumber an idea of your situation.

House type

Do you live in a unit? Or do you live in a house with one or two levels with lots of roof space? These are important areas to look at to help you narrow down your options when choosing a hot water system.

If you have a low-set home with lots of room and roof space, your options are nearly limitless. If you live in the CBD in a small unit with one bed and no balcony, you are a lot more limited in your options.

House size

If you have a larger house with multiple bathrooms, the location of your hot water system is paramount. Poor location can mean a huge amount of wasted water while you wait for the hot water to come through. Quite a few houses are now installing several hot water systems to combat this. This design decreasing water waste and allows you to install smaller hot water systems as they are only serving possibly one bathroom or sink each.

Fuel Type

We have a choice of:

1. Natural Gas

2. LPG

3. Electric

4. Heat Pump

5. Solar

This is where your personal circumstances come into play.

If your budget is not a constraint then Solar is a great possible option. It costs a little extra to purchase and install but the savings throughout the life of the system are great, especially as they generally provide a good warranty length.

These different options all have their own merits and should definitely be considered against your own personal circumstances.

The graph below should help give you an idea of what other residents in your state are doing:

Like for like but modern

If you replace an old hot water system with the exact or very similar model then the installation costs will be far cheaper than something completely different.

This means if you happy with your old hot water system and aren’t fussed about upgrading to a newer model, you have the option of getting your plumber to install a “like for like” hot water system which could save you a few hundred dollars.

However, if you are willing to do a bit of research and look for a better hot water system while still on a budget, make sure the cold water inlet and hot water outlet are similar to the one you are removing. This will help your plumber and save you money in the process.

In saying this, a plumber should be able to drain your old hot water system and install a new one in around three hours. This is based on the hot water system being in the same location, with the drainage and power all correct and available to connect to.

When things go well, you can be in and out within the hour. However, other jobs have taken longer especially when drains are not close by and the previous pipe work was installed incorrectly.

Open to different set up type

Are you open minded about the type of hot water system you are willing to install?

I have personally been a storage hot water systems all my adult life however, recently I went to the Brisbane Plumbing and Gas expo where I was introduced to an instantaneous hot water system. It is Bluetooth compatible to my iPhone and can be used to set temperatures for each person individually. It also can tell you your hot water usage for different times of day. After being shown this system, I decided I am going to purchase this system when mine dies in the next year or two.

Would you be open to change?

Google Home also has voice-activated showers with hot water voice control!

Hot water tariff

Your power provider will have a tariff which will only heat your hot water system during an off-peak period. This really only applies to electric storage type hot water systems, but can save you hundreds per year.

A problem I have come across with this tariff is if you have a big day of hot water usage (showers and washing laundry etc.), it is possible to run out of hot water which will not be heated until the off-peak, tariff time kicks in.

Peak period usage

One of the most critical factors in determining your hot water system size is how much hot water are you likely to use during the busiest hour of the day.

For example a larger family may have two showers running for 30 minutes each night. If we allow approx. 5- 6 litres of hot water per min, per shower – this equates to between 300 – 360 litres of hot water for the peak 30 mins of the day.

A 315 litre hot water system would have enough recovery over the 30 mins to ensure the hot water did not run out, although this is where an off-peak tariff may catch us out.

An instantaneous style hot water system is becoming more and more popular as one unit has the ability to deliver up to 32 litres of hot water (certain models only), and it provides an ever ending supply of hot water.

A hot water system needs to installed by a licensed plumber but inevitably the type of hot water system placed in your home is completely your choice.

Please see the table below as a guide only. This chart only uses a few factors but hopefully gives you an idea of how to start choosing the right hot water system for you and your family.

If you need any further assistance, feel free to reach out to Yates Plumbing and Gas. We are local Brisbane plumbers, with a passion for excellence. Our friendly qualified team can help you with all of your plumbing and gas needs.

If you require more information or would like to book our service, please email on or call us on 0437 827 502

We service the following areas:
Birkdale – Wellington Point- Alexandra hills- Capalaba – Wynnum – Thorneside – Lota- Manly – Cleveland- Ormiston – Morningside – Cannon Hill- Camp Hill- Chandler – Carindale – Gumdale – Wakerley – Bulimba – Belmont – Tingalpa