Imagine your alarm clock buzzes early on a cold winter morning, you groggily make your way to the bathroom and turn the hot tap only to be met with an icy stream. Or, you’ve just completed a rigorous workout and are looking forward to a soothing hot shower only to realise there’s not enough hot water. Both instances are examples of a hot water system that’s not the right size for your needs. A hot water system that’s too small struggles to keep up with demand, while a system that’s too large can lead to wastefulness and unnecessary costs.

But how do you make sure you get it just right? You turn to the experts! At Hot Water Now, we know hot water systems inside and out, and we can help you find the perfect fit for your home or business. Let’s break it down.

Quick Summary

The correct size of your hot water system hinges on your household’s hot water consumption, the number of occupants, and your preferred type of system (gas, electric, solar or heat pump). Professional advice and assessment can ensure you get the most efficient solution.

Understanding Your Hot Water Needs

Firstly, you need to understand your hot water usage. This is usually measured in litres per day. The average person uses about 50 litres of hot water each day, but this can vary greatly based on habits and lifestyle. Consider the number of people in your household and their daily hot water usage, including number of showers, washing up and laundry.

Also consider ‘peak hour demand’. This is the time when you require the most hot water. For instance, in the morning when everyone is getting ready for work or school or in the evening when meals are cooked and dishes are washed. If you see that your hot water runs out during these peak times, it’s likely you could benefit from a larger system.

Selecting Your Hot Water System Type

Once you have an idea of your average hot water consumption, it’s time to select the type of hot water system that best suits your needs. Each type, whether it’s electric, gas, solar, or heat pump, is sized differently. An experienced hot water plumber can help you make the right decision based on consumption, energy efficiency, upfront costs, and environmental impacts.

For instance, while a solar hot water system might have higher upfront costs, it can result in major savings in the long run due to lower operating costs. However, if your home doesn’t receive a lot of sunlight, a solar system might be less efficient. These are the types of things to take into account when choosing a system type.

Hot Water System Size Guide

Generally, the hot water system sizes are usually referenced in terms of the number of people they can cater to. Here’s a quick guide:

  • Small (1–2 people) – electric: 25–50 litres, gas: 90–135 litres
  • Medium (3–4 people) – electric: 80–315 litres, gas: 135–170 litres
  • Large (5+ people) – electric: 315+ litres, gas: 170+ litres

Note: This is a general guideline and individual needs may vary. For a more accurate assessment, consult with hot water experts like us at Hot Water Now.

Considering Future Needs

Your hot water needs today may not necessarily be your hot water needs in five years. Future changes such as extending your family, installing a new appliance or adding a bathroom can all impact hot water use. Planning for these potential changes when choosing your hot water system will ensure you don’t fall short on your hot water needs in the future.

If you’re not sure where to start, a professional hot water system repair and installation service can conduct a thorough assessment of your current and future needs, ensuring a system that matches your lifestyle for years to come.


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When it comes to answering the question ‘What size hot water system do I need?’, there’s no one-size-fits-all solution. It requires a thorough understanding of your daily hot water usage, your preferred system type and consideration of future needs in line with your lifestyle. But you don’t need to navigate these waters alone. Let Brisbane’s hot water system installation experts at Hot Water Now guide you towards the perfect hot water system for your home.

Ready to ensure a warm and comforting shower whenever you need it? Contact Hot Water Now for a customised quote tailored to your needs.

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