Choosing a water heater

This table approximately shows what capacity water heater serves what purpose.

Number of persons






Wash basin

5 ltr

10 ltr

15 ltr

30 ltr

30 ltr


30 ltr

50 ltr

80 ltr

100 ltr

120 ltr

Washbasin plus shower

50 ltr

80 ltr

100 ltr

120 ltr

120 ltr


100 ltr

120 ltr

120 ltr

140 ltr

140 ltr


*based on an average shower time of 5 minutes with a standard shower head

The following link provides some information on how much water (note: not just hot water) a household uses daily.

Help avoid a cold shower by using the table above as an indication of what capacity water heater you would probably require for your daily use. We advise you to always go for overcapacity when choosing a water heater. Please note: This is pure advisory and is not a binding opinion from our part what size water heater would suit your needs.   

Water heater usage for your bathroom

What capacity water heater you require depends on your daily usage. Below is the watervolume in litres you will approximately require daily for a bath, a shower and using the faucet. It is always better to have overcapacity. It would be shame having to buy a new water heater if you use more water than you thought, your family grows or if you have grandchildren visiting.  

Drawing a bath

For a bath you approximately require 120 litres of warm water. For a bath and a shower you require approximately 170 litres of warm water.

Taking a shower

For a shower you require approximately 40 litre of warm water. A long shower requires 70 litres of water.


7 to 10 litre per use.

To calculate your daily water usage take the capacity of the water heater and multiply it by 1.7, because warm water is hot water mixed with cold water to reach an comfortable 37 degrees celsius. For 130 litres of warm water you would need an electric water heater with an 80 litre capacity.

Please note: To roughly calculate what capacity you require divide the litres of warm water (37 degrees celsius) you require a day by 1,7. So in case you require 200 litres of warm water you will roughly need an 117 litre capacity water heater.

Capacity electric water heater in litres

Te be sure you have sufficient hot water always choose some overcapacity. A larger size water heater does take up more space, however. Please keep that in mind as we regularly get customers returning their water heater simply because it didn’t fit where they wanted to install it.

electric water heaters are available in the following sizes:

  • electric water heater 5 litre;

  • electric water heater 10 litre;

  • electric water heater 30 litre:

  • electric water heater 50 litre:

  • electric water heater 60 litre;

  • electric water heater 80 litre,:

  • electric water heater 100 litre;

  • electric water heater 120 litre;

  • electric water heater 150 litre;.

  • electric water heater from 200 litre;

  • electric water heater with 1 coil;

  • electric water heater with 2 coils;

  • General Terms & Conditions

  • Returns-revocation rights

  • Shipping procedure/ guarantee

  • Contact

  • Downloads

  • Manual replacing a water heater

  • What electric water heater to order

  • Electric heater calculator

  • Choosing an instant water heater

  • Choosing an electric central heating boiler

  • Calculate required power and warm-up time

  • An overview of the differences in water heaters

Disclaimer: All information on this page is for informational purposes only and not binding advice on what product you should choose. The final choice is always up to you.