Like all appliances that comes in contact with water, if you live in a hard water area, you will need to descale your hot water dispenser regularly. You can find out more about these products and how they compare in Quookers and boiling water taps - are they worth it? More-expensive models allow more control over how much water is dispensed each time, rather than having one or two standard cup measurements.

But while some will consistently give you the right amount of water at the right temperature, others spit water everywhere and dispense a less predictable amount. These taps need to be permanently installed, and as such are are different from the hot water dispensers we've tested, which are much cheaper and simply need to be plugged in. This is a safety feature that stops the hot water dispenser from working, and turns it off, if the water tank doesn’t contain enough water.The water tank can't be removed separately from the dispenser, like on a coffee machine, but the water tank and dispenser can be removed from the base of the appliance (like a kettle). Easy to fill, using a large jug, and when you need the water just press and hold the dispense button, perfect for adding water to your coffee cup, hot water bottle or saucepan. This is a handy feature to have in case you change your mind halfway through dispensing, or you realise your mug is going to overflow. Some hot water dispensers have a variable water setting, which means you can alter the amount of water that’s dispensed, but generally they dispense between 150ml (equivalent to a cup or small mug) and 350ml (a large mug).

If I am not mistaken, you press the rocker switch to ON position then press down the On (green light) button to dispense water.Heat can be lost between boiling and travelling through these pipes, so by the time the water has dispensed it has cooled by a few degrees. It's easy to fill, keeps water at your chosen temperature and dispenses without the danger of scalding. There are multiple buttons at the top of the control panel and the clear LCD display allows you to use it with ease. You can use this safe electric hot pot kettle at night because of the night light and visible water level gauge.

You can consult your water company but the quickest way to know the hardness of the water you are getting is to test it yourself with cost effective off the shelf test kit. This allows you to change the amount of water which is dispensed - handy if you want to use several different sizes of mug. HOT WATER ON DEMAND - Instant hot water on tap all day at a fraction of the running cost of a kettle.They’re not suitable for boiling large quantities of water, or for making lots of cups of tea in a row.