Everything You Need to Know About Water Heaters

This guide highlights the most important aspects of water heater functionality, some key maintenance tips and tricks and noteworthy upgrades to improve efficiency.

Electric water heaters rely on electricity to heat coils that in turn warm up water. Cold water enters the water heater through a pipe called a dip tube, which channels the unheated water to the base of the tank.

At various locations in the tank, depending largely on the make and model of the water heater, electric heating elements warm the water. Homeowners can set the temperature of the water heater on the thermostat, which controls how much electricity the heater draws to heat up the water inside.

As the cool water at the base of the tank heats up, it rises, providing room for more cool water to become warm. When someone in the home needs to use hot water, the heat-out pipe at the top of the tank carries the heated water into the house as more cool water rushes in to displace it.

If the pressure in the tank ever becomes too high, water can escape through a temperature and pressure relief (TPR) valve.

At least once per year, homeowners should use the drain valve at the base of the tank to release all the water within the tank and clean out any sediment trapped inside. This will prevent that sediment from blocking any of the pipes and keep the water heater working longer.

Additionally, every one to two years, homeowners should replace the anode rod, which is a sacrificial piece of metal that rusts to prevent the water tank from corroding and creating leaks.

Homeowners should always be on the lookout for water leaks around their water heater, as these indicate that the heater is damaged or malfunctioning in some crucial way. Because electric water heaters are plugged in, leaks can be especially dangerous and should be dealt with swiftly.

As one should expect, a gas water heater relies on natural gas to heat water for the home. As with electric heaters, cool water is channeled into the tank through a long pipe, so it can reach the tank’s base.

There, the water is heated with a gas burner — a gas-powered flame that heats the metal surface at the base of the water tank. Thermostats on gas water heaters control how much gas is released and burned.

The air heated by the flame is sent up a chimney that goes through the middle of the tank, relieving pressure that might otherwise cause a dangerous explosion, funneling away toxic emissions and using that hot air to maintain heat in the water, as well. Like the chimney, the TPR valve is another protective measure to ensure the water heater doesn’t explode.

Because gas water heaters also rely on tanks, much of the maintenance required by electric heaters is the same in gas heaters, such as replacing the anode rod, draining the water and watching for leaks. However, gas water heaters come with unique maintenance chores in addition to these.

For example, homeowners should frequently check that the flame is lit; otherwise, natural gas could fill the home, priming it for a dangerous explosion. If the flame ever does go out, homeowners should promptly relight it.

Tank water heaters have been the standard for well over a century, but recently homeowners have chosen to install tankless water heaters to increase energy efficiency.

As the name suggests tankless water heaters do not have a large, bulky tank of water to keep warm; instead, they quickly heat water as it is needed, meaning they are running for less time and consuming fewer resources.

Tankless heaters function in a similar way to the old-fashioned styles: Cold water passes over some type of heating element to transform into hot water. There are both electric and gas tankless heaters, so homeowners can replace their current water heater with a similar tankless style.

However, it is important to note that a tankless water heater’s output is limited by its flow rate, which is typically 2-5 gallons per minute — not enough for simultaneous uses of hot water in a household. Some homes might need two or more tankless heaters to keep up with demand.

A functional water heater is a necessity in a modern home, so the sooner homeowners learn how to maintain their water heaters, the better. Upgrades like extra insulation and tankless models are great, but most important is understanding the appliance’s maintenance needs and meeting them for a continuous and efficient supply of hot water.