What are Hot Water Heaters?

Sometimes it’s good to be in hot water.

Unless you’ve chosen to live in a cave or a tent, it’s a sure bet your home or apartment is equipped with a hot water heater. They have become an indispensable part of daily life, providing necessary hot water for showers, washing machines, dishwashers, and other appliances.

But not all hot water heaters are created equal. There are a number of different designs, all powered by various sources of energy. Hot water heaters can be operated via solar or geothermal power, electricity, propane, natural gas, or wood-burning boilers. However, the two most common types, found in the vast majority of residences, are of either the tank or tankless variety. As a rule, their energy source is electricity, propane, or natural gas.

By far, the most prevalent hot water heaters are of the tank or storage version. These units, whether powered by electricity, propane, or natural gas, usually store between 20 to 100 US gallons (76 to 379 liters) of water, which is kept hot via heating elements. These units are not terribly efficient, as continuous energy is needed to warm the water in the tank. Turning down the thermostat on a tank-style heater can save energy, and the manual dial generally allows a range of between 120 and 180 degrees Fahrenheit (49 to 82 degrees Celsius).

Turning down the thermostat on tank-style heaters will lower your utility bill. But it also means you will experience short showers that quickly go from lukewarm to cold. Also, your dishes and clothes will not reach optimum cleanliness if the tank’s thermostat is turned to its lowest setting. In terms of cost, natural gas or propane water heaters are less expensive to operate than their electric cousins. This is because electric models have two heating elements, whereas gas and propane require only one. Money can also be saved by wrapping tank-style, hot water heaters with an external blanket of fiberglass insulation.

Gaining quickly in popularity are tankless hot water heaters. These innovative devices do not store any water. Instead, water is piped directly into the unit and run through pipes. By virtue of a heat exchanger, it reaches the desired temperature almost instantaneously. Tankless heaters are far more energy efficient than tank-style, due to the fact that energy is used only when water is needed. Also, a tankless heater has a much longer lifespan than a tank-style heater, which will eventually rust through and need to be replaced. Expect utility bills to drop dramatically if you install a tankless heater, and in the long run, the unit will pay for itself. This is important to keep in mind, because the retail price of tankless hot water heaters is roughly three times that of tank-style models.