6 Signs You Need Hot Water System Replacement

From the morning shower to the evening post-dinner dishes clean-up, the home hot water system is one of the true workhorses of the house.

Depending on the type of system you have, it will typically provide you with between 8 and 15 years of service. Therefore, it helps to understand the signs that a hot water system replacement is imminent.

There are many types and sizes of hot water systems in homes all across Australia. When your hot water system is having problems, it can become a serious inconvenience to your life.

Look out for these six warning signs that a hot water system replacement might be on the cards for you sooner than you expect.

Average Lifespans of Common Hot Water Systems

Before we look at some of the common tell-tale signs that you need a hot water system replacement, let’s first understand how long you should be able to get from your existing water heater.

  • Gas or electric storage tank systems should give you a good 8 to 12 years of service.
  • Instantaneous / continuous flow water heaters have a lifespan of 10 to 15 years.
  • Heat pump hot water systems also typically last between 10 and 15 years.
  • Solar hot water systems should work for between 15 and 20 years, depending on climate conditions and the quality of maintenance they receive.

With these average lifespans in mind, you’ll have a good idea of when to expect your hot water system will show signs of being on its way out. Here are 6 of the more common signs to be aware of.

hot water system replacement

1. Your Existing Hot Water System Only Gives Warm Water at Best

When a hot water system’s only job is to create hot water, it’s an obvious warning sign if it simply isn’t doing that. You may find mildly warm or even straight-up cold water flowing from your taps. The reason it may be doing this could be one of many.

There may simply be an issue with the natural gas or electricity supply that feeds it, but this is rare. It usually comes down to faulty, defective or simply worn-out heating elements or thermostats. Often, parts for hot water systems can be pricey. Depending on the age of the unit, a full hot water system replacement is usually the best course of action.

2. Your Hot Water System is Nearing the End of Its Life

This is an obvious one. Like any household appliance, hot water systems have a limit as to how long they can last. Most units from top brands in Australia will outlive their warranty, but it depends on many factors. Climate, usage, hot water heater quality and location all factor into how long a unit can produce hot water reliably.

Most units have a warranty between 5-10 years, depending on the brand, model and size. This is a good general ballpark figure, however, it shouldn’t be taken as gospel.

3. Noise

No one likes a noisy home appliance. It can disturb your peace, as well as that of the neighbours, and hot water systems are no exception. The most common cause of a noisy hot water system is simply loose or worn-out parts.

It could be rattling, hissing, screeching, or banging, there are a whole lot of noises a machine can make. They aren’t designed to be whisper quiet by nature, but if it’s creating a serious disturbance to your life every time you turn on the hot water tap, get a professional in to look at it, because you may need a new system.

4. Rust and Corrosion

This is possibly the most damning sign that your system needs replacing. You can’t fix a rusty or corroded system.

Rust and corrosion are most commonly caused by factors like the climate conditions of the area and the quality of the water in your system. Each causes parts and fittings to crack and begin to leak, allowing rust to enter your water. This can be dangerous for your health.

If you notice your water is a brownish, reddish colour, stop using it completely. Rusty components generally aren’t replaceable, so call a plumber ASAP to arrange a full hot water system replacement.

5. Leaks

Many homeowners dismiss water leaks as a non-issue. A little drip here, a little drop there won’t hurt, right? But think about how each of those drips and drops adds up. You’re paying for that water, and if you let those leaks continue, you could be adding hundreds of avoidable dollars each year to your water bill. As it happens, leaky hot water systems are a common perpetrator.

Faulty parts and fittings are common causes of hot water system leaks. If yours is leaking excessively, it may be time to move on to a new hot water system.

leaking storage hot water system

6. Increased Demand

Have you been adding to the family? Maybe your 12L continuous flow efficient hot water system was adequate when it was maybe just you and your partner. But once kids come along, you’ll need to revise just how much hot water you need, and your existing hot water system might not meet that added demand.

If you find that doing the dishes while your kids shower and the washing machine is on leaves you with very low water pressure and lukewarm water, your hot water system isn’t fit for the job anymore. You can upgrade to bigger sizes with ease, with continuous flow models going up to even 30L, nearly tripling your hot water delivery.

 

So, What System Should I Get Then?

When you need to consider a hot water system replacement, you effectively need to consider what will be the right hot water system for your home, your family and your household budget. You have some options up your sleeve.

Gas Hot Water Systems

When considering a new hot water system, many Australian homeowners look towards a gas hot water heater as a reliable option. Here’s what to keep in mind:

  • Gas hot water systems heat water quickly and are more energy-efficient than electric models, leading to potential cost savings.
  • However, they can be expensive to install, especially if your home needs a new gas connection.
  • The environmental impact of a gas-powered system can also be higher compared to renewable energy systems, which is an important factor in today’s climate-aware society.

It’s clear that while a gas hot water system is efficient and effective, the initial setup costs and environmental considerations are important drawbacks that you should bear in mind.

Electric Hot Water Systems

For a straightforward and often economical installation, many homeowners look to electric hot water systems for their homes. Here are the details:

  • An electric hot water system is less expensive upfront and offers great installation flexibility.
  • They are an excellent choice in areas without access to natural gas.
  • On the downside, running costs can be significantly higher over time due to higher electricity costs. They can also be less environmentally friendly.

Despite these potential drawbacks, electric systems remain a popular choice due to their initial affordability and ease of installation.

Solar Hot Water System

Solar power is highly regarded in the realm of sustainable living and for good reason. If you’re leaning towards a greener lifestyle, here’s what solar hot water systems offer:

  • Solar water heaters use renewable energy, which can dramatically lower your household’s carbon emissions and energy bills.
  • Potential government rebates can offset the high initial investment required for these systems.
  • The efficiency of solar systems, however, does depend on the weather. They also require significant space for installation.

Solar hot water systems are an excellent long-term investment, especially for those committed to eco-friendly living, but they do come with considerations regarding cost, weather, and space.

solar hot water heater

Heat Pump Hot Water Heaters

Heat pump hot water systems are gaining traction as an energy-efficient alternative. Here’s why they might be the right choice for your home:

  • Heat pumps power a much more efficient hot water system than traditional electric heaters, extracting heat from the air around them.
  • They’re versatile across various Australian climates and often come with enticing government rebates for their eco-friendly nature.
  • The initial cost and potential for decreased efficiency in colder weather are notable concerns, as is the operational noise level.

While the efficiency and environmental benefits of heat pump systems are appealing, the higher upfront cost and performance in cold weather are factors you’ll certainly need to consider.

Storage Heater vs Continuous Flow Systems

Another key factor to consider when it comes to a new hot water service is whether you choose a continuous flow system or opt for a storage tank hot water system installation. So how do each of these systems differ?

Storage tank hot water systems keep a consistent supply of hot water ready for use in an insulated tank. They can be quite convenient for high-usage periods. Due to their heat loss, however, they can be less energy-efficient.

Continuous flow systems, also known as a tankless or instantaneous system, heat water on demand. They provide an endless hot water supply without the standby energy losses associated with storage tanks. This makes them more energy-efficient and space-saving. However, they may struggle to supply sufficient hot water during peak times to multiple outlets simultaneously.

Ultimately, the choice between the two depends on household hot water usage patterns, space considerations, and energy efficiency priorities.

Speak to Your Trusted Metropolitan Hot Water Specialist

If you need help deciding on the right hot water system to upgrade to, your friendly Metropolitan Plumbing local expert is always around the corner to help. Whether you’re looking at electric instantaneous water heaters, gas storage systems, heat pumps or solar panels, we’re here to help. We can give you the full lowdown on the hot water system brands we carry, and ultimately help you with your hot water system replacement needs.

Please note: This information is provided for advice purposes only. Regulations differ from state to state, so please consult your local authorities or an industry professional before proceeding with any work. See our Terms & Conditions here.

The right size depends on the number of people in your household and your hot water usage habits. A family of four might need a 160–250L storage system or a 20–26L/min continuous flow unit. Overestimating can waste energy; underestimating causes cold showers.
Yes, but it may involve significant changes, such as installing solar collectors, gas plumbing, or new electrical circuits. Check eligibility for rebates to offset upgrade costs, especially when switching to solar or heat pump systems.
Yes. The Australian Government offers incentives under the Small-scale Renewable Energy Scheme (SRES) for solar and heat pump systems to eligible homeowners. State-level schemes (like Victoria’s Solar Homes) may offer further rebates.
It depends on the age and condition of the unit. If your system is over 8–10 years old and showing multiple signs of failure (e.g. leaks, rust, poor performance), replacement is usually more cost-effective than repairs.

Published: 2025-04-08

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