Free delivery to every capital city except Darwin Genuine Stiebel Eltron, Australian stock Heating engineers since 1992
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Calculator

How many kilowatts does your instantaneous heater need?

Tick the taps you run at the same time, pick your city and your power supply. You get the kilowatts, the arithmetic, and the model that fits.

1. What runs at the same time?

Tick everything that might be on at once.

2. Where is the home?
3. Which power supply do you have?
FAQ

About the calculation

Where do the flow rates come from?

A water-efficient (3-star) shower uses up to 9 litres a minute. We use typical figures for the other outlets. If your shower head uses more, the heater needs more power.

Why does the city matter?

The heater has to lift the water from the temperature it arrives at. In a Canberra winter the mains water is much colder than in Brisbane, so the same shower needs more kilowatts. Our winter water temperatures are approximate.

What if I only have single-phase power?

Single-phase heaters top out at about 9.5 kW: enough for one basin or sink, not a shower. For a shower on single-phase power, a heat pump with a tank is the practical choice.