The best hot water system for a family of 4 or 5

A family of four or five puts real pressure on a hot water system, and the classic sign it is wrong is the last person in the morning getting a cold shower. Getting it right is less about the brand on the box and more about matching the system to how a busy household actually uses hot water. Terry has sized systems for hundreds of Western Sydney families since 1986, and it always starts with one number.

The number that matters is peak demand

Households do not use hot water evenly through the day. They use it in a rush: two showers running, the kitchen tap going, maybe the washing machine filling, all inside the same half hour before school and work. That morning peak, not the daily total, is what a system has to cope with. A unit that looks big enough on paper can still run cold if three hot taps open at once, which is why Terry sizes for the busiest moment, then adds a little headroom.

Sizing a storage tank for four or five people

With a tank, the figure is litres of stored hot water. As a rule:

• 250 to 315L suits a family of three or four.
• 315 to 400L is the safer choice for five or more, or for a four-person home with two bathrooms and long showers.

Go too small and the tank empties mid-morning and cannot reheat fast enough. On an off-peak or controlled load electric tariff, a slightly larger tank is worth it, because the extra litres are heated overnight on cheaper power and see you through the morning.

Sizing a continuous flow unit

A gas continuous flow system never empties, so the figure here is flow rate in litres per minute, which sets how many taps it can feed at once. For a family home:

• 24 to 26 L/min comfortably runs two bathrooms.
• 32 L/min is the pick for three or more bathrooms, or a busy five-person household.

This is why Terry often steers larger families toward continuous flow. There is no tank to run dry, so back-to-back showers stay hot as long as anyone needs.

The best pick by connection type

What suits your family comes down to what the home is connected to:

• Gas connected: a 24 to 26 or 32 L/min continuous flow unit is usually the best all-rounder, roughly $1,900 to $3,500 fitted and good for 15 to 20 years. A 315L-plus gas storage tank is a simpler like-for-like swap at around $1,800 to $3,000.
• No gas: a heat pump sized for a family is the cheapest to run, using about a third of the power of an electric element, and NSW rebates can knock roughly $1,000 to $2,500 off the up-front price. A 315 to 400L electric tank on controlled load is the lower-cost alternative if a heat pump is out of budget.

Terry is brand-independent, so he will size and recommend based on your actual household and connection rather than whatever is on special. He also rates parts availability highly, favouring makes like Rheem and Rinnai whose parts are easy to get in Sydney, so a future repair is quick rather than a week without hot water. Hot water and gas work must be done by a licensed plumber and gas fitter, so leave the install to a professional. For a system sized properly to your family, call Terry on 0415 274 542 for a fixed quote before any work starts.