Built-in hot water dispensers consist of a small heating tank that you have to install under the kitchen sink and the faucet that can withstand the pressure of boiling water. The tank temperature stays near 200°F as long as you keep the unit plugged in and do not change the settings on the unit. This is much hotter than anything you can get from your regular water heater and is just as hot as the water in coffee pots. People install these because of the benefits they offer.
There are a number of benefits to having a hot water dispenser under the sink. First, under-sink hot water dispensers give you what you need instantly so you don’t have to stop in the middle of something and wait for the water to boil. This is a great advantage for those who spend a lot of time working in the kitchen. Then, contrary to the belief that keeping hot water in tanks is inefficient, built-in instant hot water dispensers actually waste less energy than other means of producing boiling water. For example, with a kettle, often more water has to be heated than is needed and the water that is not used ends up getting cold because there is little insulation. On the other hand, under-sink tanks have decent insulation, so there’s very little standby heat loss. Finally, under-sink kettles don’t take up space on the kitchen counter, while kettles or countertop hot water dispensers can be annoying.
With all the comfort they offer, hot water dispenser tanks can also cause some problems if care is not taken with them. For example, some cheap units can leak due to the immense pressure and corrosive effects of the constantly boiling water inside. If they fail when you are away from home, there could be serious damage to your property. To avoid these types of accidents, you would do well to drain and unplug any boiling water dispensers in your home if you plan to be away for more than a day. A more dangerous problem with these devices is the risk of burns. Liquids at 140°F can cause full thickness injuries in just a few seconds and what comes out of an instant hot water faucet is much hotter than that. Anyone who puts a hand under that faucet will be seriously injured and this is especially a problem for people who may not fully understand the risks. If you want to use these systems in homes with the elderly or small children, you should lower the temperature of the unit to reduce the risk.
In conclusion, under sink hot water dispensers are useful gadgets, but you need to make sure they are suitable for your lifestyle before getting one and you need to be careful when using them.