Choosing The Best Hot Water Cylinder

shower with flowing water

When it comes to choosing a hot water cylinder, the first decision needs to be determining what type of system you need. Most systems are either electric or gas. Although solar only and heat pumps are also available.

Before making any decision, some important information should always be collected first so you can make an informed product purchase. Think about your usage as this will help to determine the size of the hot water cylinder you need to acquire. Also consider your budget, as this can affect your accessibility in purchasing modern models. Many units out there also save energy and money being kinder to the environment.

Electric units are usually the cheapest systems to buy and install. However, it is usually the most expensive to run especially if its on all the time. Meaning that in the long run, initial investment savings will be eaten away with the higher everyday use costs. To reduce this problem, any running costs can be offset with solar panels.

With improvements over time, electric systems can either be instantaneous, heating up when needed, or continuous, meaning it constantly heats the liquid. Other sophisticated systems time their electricity use for periods with less expensive off-peak running costs. Although not every home will run on off-peak electricity.

The number of household members relates to product size as more people means more usage. Generally speaking, a four-person household will roughly need a 150L tank for a continuous electric unit, or a 300L tank for off-peak. Electric units can either be installed outdoors or indoors. Modern systems have also been designed to run completely off solar energy.

Natural gas is a really great option especially if you have connection to it. Gas is a lot cheaper than electricity. Although prices have been rising a bit recently, but gas rates also do not change through the day. So, gas hot water cylinders can heat on demand when needed. Because of the venting requirements of these hot water cylinders, they are usually installed outside but can also be installed inside with an exhaust duct. Because gas units heat on demand, smaller hot water cylinders can be used to output large volumes. If deciding on a gas unit, energy efficiency star ratings are supplied to help assist your purchase decision.

As seen from above, once a heating method has been selected, options over whether a storage tank or continuous flow model is chosen is the next step. Hot water cylinders made from steel can corrode overtime. Especially with storage tanks that constantly retain liquid. Regular maintenance every few years will help to prevent this. Once purchased, models usually come with five- or ten-year warranties.

The biggest benefit of continuous flow system is in using resources efficiently. It only heats as much liquid as you need. It is not instantaneous in the true sense as it will still take a few seconds before the heated liquid starts to flow from the tap. This also causes less heat loss with any water stored in the tank. So continuous flow is often cheaper to run than storage systems.


The hot water cylinder size and resulting flow rate, will depend on the number of outlets the heater access. Flow rate is measure in terms of litres per minute. Correctly positing the unit in a central location is also important. This is because heat dissipates as it travels through the pipes. But also, because it will take time for the hot water to get to the outlet.

Of course, when evaluating during the above information, consideration with regard to which hot water cylinder brand must also be made.