Hotflo Electric Storage 400L

As a general guide, you’ll need about 50 litres of hot water per person, plus an extra 50 litres to cover those busy times when everyone’s using hot water at once.

For example:

1–2 people → around 125L
3–4 people → around 250L
5 or more people → 315L or larger

Everyone’s usage is a bit different, so think about things like how long your showers are, what time of the day showers are taken, how often you use the washing machine or dishwasher, and whether you have guests staying often.

The difference between single and twin element hot water storage tanks lies in how many electric heating elements are built into the tank, and how that affects heating performance, control, and efficiency.

Single element system

• Contains one heating element, usually located near the bottom of the tank.

• Heats the entire tank from the bottom up.

• Slower recovery time, especially during periods of high hot water usage.

• More energy-efficient for smaller households or low-demand situations.

Twin element system

• Contains two heating elements - one at the top and one at the bottom.

• The top element is typically connected to continuous power, allowing it to quickly heat the upper portion of the tank when hot water is used.

• The bottom element is usually connected to an off-peak tariff, heating the full tank overnight when electricity is cheaper.

• Provides faster recovery, ideal for larger households or homes with higher hot water demand.

• May use more energy but offers better performance during peak usage times.

Single element systems: have one heating element located at the bottom of the tank. They typically operate overnight during off-peak electricity periods, making them cost-effective while still providing a reliable hot water supply.

Twin or dual element systems: feature two heating elements - one at the top and one at the bottom of the tank. This setup heats water more evenly and efficiently, ensuring hot water is readily available throughout the tank. While dual element systems offer improved performance, they generally come with higher installation costs.

The reheating time depends mainly on the size and power rating of the heating element. The larger the element (in kilowatts), the faster it can heat the water.

Estimated Heating Rates (for a 50°C temperature rise):

• 1.2kW element → heats approx. 20.6 litres/hour.

• 2.4kW element → heats approx. 41.2 litres/hour.

• 3.6kW element → heats approx. 61.9 litres/hour.

• 4.8kW element → heats approx. 82.5 litres/hour.

Note: These figures are estimates.

Actual recovery rates may vary depending on:

• Incoming cold water temperature.

• Tank insulation and condition.

• Thermostat settings.

• Power supply type (e.g., continuous or off-peak).

If your system is taking longer than expected to reheat, it may be worth having an Electrician check the element and thermostat settings.