How to Calculate Your Hot Water Usage

  • By Hot Water Boss

Published: Monday, February 8, 2024

How to Calculate our Hot Water Usage...

Choosing the right hot water system for your home starts with understanding how much hot water your household actually uses. Every family is different, and factors such as lifestyle, appliances, and plumbing setup will all affect your daily demand. By calculating your hot water usage, you can make sure you select a system that’s reliable, efficient, and cost-effective.

Step One: Who's Using the Hot Water?

The number of people living in your home full-time is the biggest factor in hot water demand. Don’t forget to factor in regular visitors or guests who stay overnight - they’ll contribute to your overall water consumption, too.

Step Two: How Many Showers and Outlets?

Count the number of showers, taps, and appliances connected to your hot water supply. For example:

- A home with one shower may only need a smaller system, as the unit generally has time to reheat between uses.

- Multiple bathrooms, frequent showers, and connected appliances will require a larger hot water system to avoid running out.

Step Three: The Impact of Shower Heads

Your choice of shower head can significantly influence hot water usage:

Older shower heads: up to 20 litres per minute (a 10-minute shower could use 200 litres per person).

Water-saving shower heads: around 9 litres per minute (cutting usage - and water bills - by more than half).

Upgrading to a water-efficient shower head is a simple way to reduce both your hot water usage and your household costs.

Step Four: Showers vs Baths

Bathing preferences also matter. On average in Australia:

- A bath uses about 95 litres of water.

- A 10-minute shower with a water-saving head uses about the same.

- A standard shower with an older shower head can use double the amount of water.

Step Five: Dishwashing Habits

- Hand washing dishes: roughly 10.5 litres per person, per day.

- Dishwasher: about 15 litres per cycle.

If you have a busy household, a modern, efficient dishwasher could use less hot water overall.

Step Six: Laundry Considerations

Many modern washing machines are cold-water-only, meaning they don’t draw from your hot water system at all. However, if your washing machine is connected to hot water and you wash frequently, this will increase your overall demand.

Choosing the Right Hot Water System

Once you’ve estimated your hot water usage, you’ll be in a much better position to select the right system for your home. Located in Jimboomba, at Hot Water Boss, we supply and install a wide range of hot water systems throughout Australia, along with accessories, fittings, and valves tailored to suit every household. If you are located within 50km of Jimboomba, including throughout Logan, the Scenic Rim, Ipswich, Brisbane, and Redlands, we offer installation on your new hot water system. 

 

👉 Explore our range of Hot Water Systems or request a free online quote today.

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Frequently Asked Questions

What size hot water system do I need?

While the size of the hot water system will more than likely vary depending on your specific needs, the average 4-person Australian home will need at least a 160 litre tank for a continuous electric system, or a 250-315 litre off-peak system. If you’re in the market for a gas tank, a 4-person house averages a 170 litre tank. 270-315 litre tank should be sufficient for heat-pump users. 

Why is the right size hot water system so important?

If your hot water heater is too small for your needs, you will find yourself continually run out of water. On the other hand, if your hot water system is too large for your needs, you are going to spend an unnecessary amount of energy (and therefore money) heating it. This is because your hot water system will keep maintaining the heat of your water, even when you are not using it.

Can I install the system myself?

You will need a licensed plumber to install your new hot water system.

I'm not in SEQLD - how do I choose a plumber?

It's important to ensure you choose the right plumber to install your hot water system. The last thing you want is a non compliant install on your brand new hot water system, which could shorten the life of the new hot water system and even void the warranty. We are often asked if a customer can install a hot water system...in all honesty the risks aren't worth it - and it's illegal! Best to call a licensed plumber to ensure it's done right.

How do I calculate my hot water usage?

The first step to take in choosing a new hot water system is to calculate the hot water usage in your home. The amount of hot water each household uses will vary depending on lifestyle, appliances, and water fixtures throughout the house. 

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