Gas Hot Water Service Tips

What Size Hot Water System Do You Need?

If you’re wondering what size hot water system will best suit your needs, you’ve come to the right place.

In this article, we’ll discuss the answer to the question: the range of sizes hot water systems are available in for household usage, if there is a particular size hot water system you need for a certain amount of people,  and the factors you need to consider to ensure you choose the right size hot water system for your home.

Sizes of Hot Water Systems

Hot water systems aren’t one size fits all. There are a variety of sizes available for residential use ranging from 25L to 400L.

Recommendations on Size

Generally speaking, there are recommendations and guidelines you can follow when deciding on what size hot water tank would suit your needs.

For instance, a household of two to four people often requires a system between 125L to 160L, whereas if there are three to six people living in the same household, you may need a tank holding capacity of between 160L and 315L. That number increases to between 250L and 400L when you have six to eight people sharing a house.

That said, this guide is just that. It’s a guide, and there are a number of factors you need to consider when choosing the right size hot water system for you and your family.

Things to Consider When Choosing Your Hot Water Tank’s Capacity

There are several factors you need to take into account when deciding which size hot water tank is best for you. Some of the most important – apart from number of residents living in the house – are:

Peak Times

Peak times is a phrase you probably will encounter a fair bit when researching water tanks. Just like traffic, peak times refer to the times that your hot water system is used.

For example, if everyone in your household showers in the morning, your peak times may be between 7am and 9am. You may also find you have another peak time, which may be when you wash dishes after dinner or put the washing machine on when getting home from work.

Washing Machines & Dishwashers

Speaking of washing machines and dishwashers, your usage of them, whether the former appliance runs on hot or cold water will impact the size of hot water system you need.

If you use more energy efficient appliances in your household, you may find you can make do with a smaller system, but this is not always the case.


While it’s not strictly one  of the main factors you need to consider, budget is important. This is because larger systems are usually more expensive, so your budget may have an influence on not necessarily the size system you need, but the one you can afford.

Type of Hot Water System

The type of hot water system will definitely impact the size you need. Gas hot water systems, for instance, require less time to heat up than electrical.

As such, the amount of water – or how long you need to let the water run before it reaches your preferred temperature – may be less, meaning you could possibly get away with a smaller tank.

How to Choose What Size Hot Water Tank You Need

Choosing hot water tanks and the size you need to sustain your household can be a little tricky, even with the above information on hand.

If you need assistance with choosing the right size for your system, or simply want an expert opinion, contact RPG Plumbing.

To find out more about the factors to consider when choosing your hot water tank size, get in touch with our expert team today.

What Size Hot Water System Do You Need?