Expert guide to buying the best kitchen instant hot water dispenser, including recommendations of makes and a description of how they work.
For today’s fast-paced, dinner-in-an-hour kitchen, an instant hot water dispenser is the epitome of convenience, accelerating all kinds of kitchen tasks: preparing hot drinks, soups, gelatins, sauces, and cereals; thawing juices; pre-heating water for cooking; warming baby bottles; even melting wax or purging berry stains from clothing. Instant hot water dispensers take the lag time and the hassle out of these and many other tasks that would otherwise require boiling water on the stove.
Hot water dispensers come in two main types:
• Instant hot water tank-style dispensers with sink-top spouts
• Countertop electric kettles and dispensers
These point-of-use water heaters consist essentially of a miniature electric water heater and storage tank mounted beneath the sink and connected to a small sink-top spout. Many instant hot water dispensers also connect to a water filter, and some models deliver both hot and cold water at the sink.
A tank-style instant hot water dispenser is one of those items that you might as well buy online—appearance doesn’t really matter much because the tank is hidden under the sink, and it’s easy to quickly compare specifications online. Furthermore, online prices tend to be significantly lower than retail store prices, and you can save a trip to the home center by having the small appliance delivered. On this page, you’ll find links to Amazon, where you’re likely to find some of the best prices.
Products sold by different manufacturers are very similar. They have an interior tank that holds water, and a heating element that heats the water. Types with a stainless steel interior tank will last longer than those with a rubber bladder tank (lowest price models).
A control dial allows you to tweak the temperature. They have a thermostat that automatically shuts off the heating element when the water in the tank reaches the set temperature. For more about how they work, see How a Hot Water Dispenser Works, below.
The most common part to fail is the thermostat. If it goes out, fixing the problem is more hassle than it’s worth, so you’re better off just replacing the water dispenser if or when this happens. Thanks to quick-connect couplings, you can usually change-out an instant hot water dispenser tank in less than an hour.
How much does it cost to keep the hot water ready and waiting? The usage is a little more than 1/2 kilowatt hour per 24 hours, which, depending on your local electricity rates, equates to about 6 or 7 cents a day.
Water Dispenser Tank Size
Tanks vary in size and by the heating elements’ wattage. Most are 1/3- or 1/2- gallon and range from 500 to 1,300 watts. A 750-watt, 1/2-gallon tank will produce up to 60 cups of hot water per hour. Higher wattage tanks can deliver up to 100 cups. Most makes have a dial for fine-tuning the temperature up to 190 degrees F, and must be plugged into a 120-volt electrical receptacle.
Shopping for a Dispenser Online
Given the similarity of products, when shopping for a new instant hot water dispenser, focus on price, availability, and warranty. Note that the price often does not include the sink-top spout.
A best seller is the InSinkErator HWT-F1000S (shown above), which has a stainless steel tank and also a filter that connects to the faucet. Tank warranty is for 3 years.
Sink-Top Spouts and Grips
Many styles of sink-top spouts are available, from low spouts with handles you twist to tall, gooseneck units that allow plenty of room for filling tall cups and kettles. As a result, chances are good that you can find a dispenser to match the look of your sink fixtures. Typical finishes include white, black, almond, chrome, satin nickel, and brass.
Some units, such as KitchenAid’s and Whirlaway’s, have a twist grip that releases water with a quarter turn. In contrast, others, such as InSinkErator’s, have a lever release. Elkay’s spouts, which tout “no lead” construction, have a button on top. Franke makes the smartly styled Little Butler, which has a tall, L-shaped spout and a lever handle.
Some manufacturers—Franke and InSinkErator to name two—offer models that dispense both hot and cold water through one faucet. The cold water side can be connected to a chiller, or both supplies can be hooked up to a water treatment system. This type of faucet eliminates the need for yet another spout—the purified cold water spout—at the sink.
For sinks that don’t have the needed mounting hole for a new faucet, replacing a purifier spout with one of these is the perfect solution.
To install one of these yourself, see How to Install a Hot-Water Dispenser.
If you want instant hot water but you don’t want to mess with the plumbing, see Countertop Instant Hot Water Kettles & Appliances.
Instant hot water dispensers are simply miniature electric water heaters that serve a single faucet. A small, under-sink tank heats and holds nearly boiling water, ready for steamy delivery through a sink-top spout that’s separate from the main tap.
Unlike a conventional water heater, however, the tank never becomes pressurized. The system hooks up directly to a cold water pipe under the sink; incoming water travels through the body of the spout and into the tank, where it’s heated by an electric coil.
The heated water expands, filling an expansion chamber in the upper part of the tank. When the faucet is turned on, more cold water is released into the bottom of the storage tank, displacing hot water in the tank and expansion chamber and forcing the heated water up through the faucet.
The spout delivers water more slowly than a typical faucet does, and the water is much hotter than a standard hot water tap’s—about 190 degrees F. instead of 120 degrees. The heated water arrives immediately; you don’t have to wait for it to warm up.
An adjustable thermostat controls water temperature with most models. Adjustment is needed only if the water is too cool or if it’s so hot that it boils away, causing the tank to overheat. (To prevent damage, the tank should be protected from overheating by a replaceable thermal fuse.) Noteworthy: It’s a good idea to turn down the dial or unplug the unit when you go on vacation.
Tanks vary in size and by the heating elements’ wattage. Most are 1/3- or 1/2- gallon and range from 500 to 1,300 watts. A 750-watt, 1/2-gallon tank will produce up to 60 cups of hot water per hour. Higher wattage tanks can deliver up to 100 cups.
As with any water heater, hot water dispensers may accumulate scale in regions of the country that have hard water. Some units have drain plugs at the bottom to allow you to drain the tank once or twice a year.
Next See: How to Install a Hot-Water Dispenser