Learn How a Hot Water Heater Works

The invention of the hot water heater is a blessing that is seldom realized.

You come to know its worth when you are in the middle of your bath or shower and the hot water suddenly stops coming through the shower! You might begin to think how a hot water heater works when you have to wash the dishes with the cold water because your heater isn’t working.

Have you ever wondered which components are present inside the water heaters that play a role in heating the water? This article explains how a hot water heater works because the working of a heater is something that most people don’t understand.

Learning how a hot water heater works is not difficult. If you are curious and want to learn about the mechanism, you have come to the right place!

Let’s take a quick look at the parts and materials of a hot water heater.

The Components of a Water Heater and How a Hot Water Heater Works

Hot Water Tank

The tank is where all the water is collected for heating purposes. A regular sized water heater can hold 40 to 60 gallons of water.

Dib Tube

The water enters the tank through the dip tube at the top. From there, the water reaches to the bottom of the heater.

Shut-off Valve

This valve controls the flow of the water into the tanks and shuts off the water supply when the water tank is already full.

Heat-out Pipe

Located at the top of the tank’s interior, it allows the heated water to travel to other pipes of a house.


The thermostat regulates the temperature of the water heater. Some water heaters have a single thermostat while others have separate thermostats for different purposes.

Heating Mechanism

All the heaters work through a different mechanism to heat up the water. In the electrical one, a suspended electrical rod is used, and in the gas heater, natural gas and fire are used.

Pressure Relief Valve

This valve regulates the pressure inside the water tank.

Anode Rod

It is made of either aluminum or magnesium. It has a steel core that helps to prevent corrosion in the water tank.

How a Hot Water Heater Works?

The knowledge about the mechanism of the hot heater is important if you really want to know how a hot water heater works. Before you look into the mechanism, you must know whether you are using an electric or a gas heater. Let’s see how a hot water heater works on electric and gas supply.

Electrical Heaters

Electrical heaters have a thermostat mounted on the inside of the tank.  The thermostat keeps a check on the water temperature. When it senses that the temperature has fallen, it triggers a switch that allows the electricity to flow through the heating elements. When the temperature reaches the desired level, the thermostat turns off the power.

Gas Heaters

In gas heaters, there are two sensors: a thermocouple that checks the gas lighting in the pilot setting and a thermostat that has a tube like a sensor with a mercury tip. When the thermostat senses that the water temperature has dropped down various degrees, it signals the gas valve. The gas valve then checks the thermocouple to ensure that the pilot light is burning. After ensuring the light, the gas value opens up the gas supply which burns and heats up the water. When the water becomes hot, the thermostat signals the gas valve to cut off the gas supply.

Now that you’ve learned how a hot water heater works, you can fix minor problems on your own. The water heaters aren’t just limited to these two types as there are tankless and solar water heaters as well. The former works by following a hot water recirculation system, and the latter follows a natural water circulation system that is heated by the sunlight.  If you wish to know how a hot water heater works, you must know the type of your heater.

All in all, learning how a hot water heater works are also important because calling a plumber to fix minor problems can be costly, but with a little know-how of the water heater components, you can maintain the heater by yourself.

Visit our home page to learn more about hot water heaters.

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