A hot water system represents a significant investment and it’s important you make sure you are getting the most value from your money by buying a hot water system that will last a long time. But that then begs the question: how long should a hot water system last?

Well, a hot water system lifespan depends on a number of different factors. Here, we will take you through the variables that will make a hot water system last longer than others.

Primary factors for how long a hot water system lasts

There are five main factors that will go into determining how long any given hot water system will last. These factors are: quality, material, type, usage, and water quality. We will now go through each of them in detail.


This is the most straightforward factor and you were probably already aware of it yourself. As with most things, paying more for your hot water system will generally translate into a higher quality product that is going to last longer. The most common reason a hot water system needs to be replaced is that the water tank corrodes from holding water over time. Buying a better quality tank may increase the lifespan of your hot water system by a matter of years.


Since tank corrosion is the number one cause of hot water system failure, the material from which the tank is constructed is very important. Here are some rough guidelines for what you can expect from tanks made of different materials:

Copper tanks low pressure gravity fed: approximately 25 + years

Glass-lined or enamel-lined tanks: between 5 and 10 + years

Stainless steel tanks: between 8 and 12 + years

Heat pump: approximately 10 + years

These numbers are conservative – with some particular models you can expect the tank to last for 15 years or more.

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We can’t judge all hot water systems according to the same guidelines. Whether a hot water system is gas, electric, instantaneous, solar etc. is going to change the expected time for which it will continue to function.

Hot water systems that use tank storage are likely to have a shorter lifespan, since the stored water will corrode the tank over time. On the other hand, an instant hot water system is likely to last much longer, since it employs a very simple mechanism and stores no water over time.

How long do electric hot water systems last?

You can expect an electric hot water system to last on average between 10 and 15 years.

How long do gas hot water systems last?

Gas systems have slightly shorter life expectancies at around 8-12 years.

Remember, the age of a gas or electric system depends not just on the length of time that a tank will last (see above). Gas and electric systems also place different levels of stress on the heating components of the system.


As with any machine, heavier usage will cause the elements of the system to undergo more strain. The materials used in a hot water system are obviously built to withstand significant changes in temperature. However, there is always a limit to what a machine can handle over time. Unfortunately you can’t really control this factor and you may not even know that it is affecting your hot water system.

Water quality

A little known fact is that a hot water system’s lifespan can be significantly affected by the water that passes through it. In some areas, water quality is poorer – hot water technicians call this ‘hard water’. When your system is processing hard water day in and day out, it can cause corrosion to occur on your tank much more quickly. This may significantly reduce the lifespan of your tank. However, you can extend the life of a tank that uses hard water by getting it regular maintenance.

So, how long do hot water tanks last?

Taking into consideration the above information, you can expect your hot water tank to last, on average, for about 7 to 15 years. However, if you go for a tank-less (or instant) hot water system, you can expect to add at least a few years onto that.

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How do I make my hot water system last longer?

Once you install your hot water system, you should make sure that you get it checked regularly. Often, if an expert technician looks over your hot water heater, they may be able to detect an issue before it causes your system to fail completely. For example, replacing the anodes in your hot water tank can ward off corrosion and add a few years to the life of your tank.

For all of your hot water system repairs and maintenance, make sure you get in contact with Australian Hot Water. Our fully certified technicians are used to working with all of the hot water system brands on the market and will keep your system going for years to come.

How do I know if my hot water heater needs replacing?

If you are wondering whether your hot water heater needs to be replaced, there are some common signs that it might be time. Consider the following:

  • The water is not as hot as normal or the hot water runs out faster than normal
    • (you should also check that this is not simply an issue with the thermostat or a broken heating element)
  • The tank has become noisy
    • Hissing and sizzling sounds are the most common noises that aging hot water heaters make
    • (you should also check this is not being caused by a faulty relief valve)
  • Rust and sludge accumulating on the tank
    • This is a surer sign that the tank is reaching the end of its lifespan as it usually indicates corrosion

If you are unsure whether your hot water heater is acting the way it should, you should get in touch with Australian Hot Water. Our expert technicians can help you out with identifying the issue. It may just be that an individual part of the machine is failing and needs to be replaced. Don’t jump to the conclusion that your hot water system is dying!



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