An instantaneous water heater<\/strong> heats water at the moment of use. It is compact but needs a lot of power: 6-8 kW for one tap and more for a shower. For a typical apartment electrical supply this is often too much.<\/p>\n\n\n\n A storage water heater<\/strong> heats water in advance and keeps it in a tank. Its power is 1.5-2.5 kW, suitable for a standard socket on a dedicated circuit. It provides a stable temperature and good water pressure.<\/p>\n\n\n\n For an apartment or a house without gas, a storage water heater is the most practical option.<\/p>\n\n\n\n The water in the tank is hotter than needed for a shower and is mixed with cold water. 80 l of water at 75 \u00b0C gives about 190 l of water at a comfortable 40 \u00b0C.<\/p>\n\n\n\n Most household models draw 1.5-2.5 kW. Heating time can be estimated as follows:<\/p>\n\n\n\n Time (h) = volume (l) \u00d7 temperature rise (\u00b0C) \/ (860 \u00d7 power, kW).<\/strong><\/p>\n\n\n\n An 80 l, 2 kW water heater will heat water from 15 to 60 \u00b0C in about 2 hours. A 100 l model takes about 2.5 hours.<\/p>\n\n\n\n A vertical model heats more efficiently: hot water collects at the top, cold water stays at the bottom and they hardly mix. A horizontal one is needed when height is limited: above a door, under the ceiling, in a niche.<\/p>\n\n\n\nHow many litres you need<\/h2>\n\n\n\n
Who uses it<\/th> Volume<\/th><\/tr><\/thead> Kitchen, washing up<\/td> 10-30 l<\/td><\/tr> 1-2 people, shower<\/td> 50 l<\/td><\/tr> 2-3 people, shower<\/td> 80 l<\/td><\/tr> 3-4 people, bathtub<\/td> 100 l<\/td><\/tr> Large family, 2 bathrooms<\/td> 150 l or more<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n How many watts and how fast it heats<\/h2>\n\n\n\n
Vertical or horizontal<\/h2>\n\n\n\n
What to look for when choosing<\/h2>\n\n\n\n