Tankless / Instant water heaters have been used in Europe and other parts of the world where energy prices are steep.
The happy surprise is that, compared to conventional water heaters, these on-demand water heaters can save energy and money and deliver an endless flow of hot water.
The familiar tank-style water heater is basically a large container with a heater. It stores a lot of water (typically 40 to 80 gallons), heats the water, and keeps it hot until it's needed at a hot-water tap or appliance.
When hot water leaves the tank to serve a faucet or appliance, it is replaced by cold water. This cycle repeats over and over.
The obvious downside of a conventional water heater is that it wastes considerable energy keeping water hot 24 hours a day, 7 days a week, whether or not hot water is wanted.
A tankless / instant water heater, as its name implies, doesn't have a tank. Instead of storing hot water, it circulates incoming water through a series of electric coils or gas burners that heat up automatically when you turn on a hot-water tap or appliance. When you turn off the faucet, the elements or burners turn off.
Tankless / Instant water heaters are sold in several varieties, from small electric point-of-use models to larger gas appliances that supply the whole house.
If you want to replace a conventional water heater, you'll need a whole-house tankless / instant water heater. If you just want to provide hot water quickly and efficiently at a single fixture, such as a bathroom sink, a point-of-use water heater may be the better choice.
If you simply want instant hot water at the kitchen sink, a hot-water dispenser is the appliance for you.
TANKLESS / INSTANT WATER HEATER FEATURES
You will need to select between an Electric Tankless / Instant Water Heater or a Gas-Fired Tankless / Instant Water Heater.
For electric tankless / instant water heater, you will need to consider:
For gas tankless / instant water heater you will need to consider:
Natural Gas or Propane
Location, Size, and Demand
When deciding which Tankless / Instant Water Heater to purchase, you will also need to consider where you will need hot water. Are you looking for a unit that will heat the water at one bathroom sink (single point application), an entire bathroom (multipoint application), or an entire house, apartment, or condo? It is important to recognize the number of fixtures that will require hot water. Each fixture will have its own requirements.
Some examples of functionality are:
Single Point Application - A single point application is one where only one fixture will require an Electric Tankless / Instant Water Heater.
Controlled Flow - These serve two or more points, like two sinks, in close proximity.
Thermostatic - The Thermostatic Tankless / Instant Water Heater serves as a booster for temperature loss from long pipe runs, dishwashers and sanitation. These are good where precise temperature control is needed.
Whole House Indoor Use - Larger Whole House units are designed to serve an entire house or apartment where multiple points of use will exist.
Whole House Outdoor Use - Larger Whole House units are designed to serve an entire house or apartment where multiple points of use will exist. These generally will have uses for swimming pools or gardens and similar such external needs.