How Does A Water Heater Work: All You Need To Know

Water heaters have become a primary household object for ages now, but people don’t usually have an idea on how they work. From needing them for hot showers, to washing the dishes in your home, water heaters serve a very important purpose in every household, so we’re going to use this article to delve into the inner workings of water heaters. By the end of this, you’ll find out the logistics of what goes on inside one of the most pivotal appliances in your home, to provide you with hot water.

Breaking Down A Water Heater

While electric water heaters and other new types of water heaters are gaining more popularity worldwide, the conventional storage tank water heater system is still the most widely used system. These systems use a tank to store up the hot water for use, for when you need it.

While the provided picture shows you two different types of tank heating systems; electric water heater and gas water heater, we’ll first break down the most important part of the water heater tank system that’s available in both of them, before dissecting the separate systems.

Inside the Water Heater

There are a few integral parts in every water heating system that allows for you to have hot water in your home. These small and delicate parts not only make sure that the cold water is turned into hot water, but also make sure that it is clean enough for your body or anything that you need to wash. Let’s look into what they are!

  • Tank

    Of course in a tank water heater system, you’ll need to have a tank that stores the water you’ll need. This also comes with the additional burden of having a specific amount of water stored, so you’ll need to use it widely. Normally, water heater tanks have a capacity of 40 to 60 gallons or 151 to 227 litres (approximately) or water. However, these can be tailored to your needs, based on the size of your family and the needs of your water.

    When you see a water heater tank, all you can see is the shiny exterior that holds together the water. However, there are usually a couple of layers of insulation to help keep the hot water hot, by keeping the heat trapped inside. One such insulating material is known as Polyurethane foam. The tanks are also designed to withstand a high amount of pressure, which is usually built up from containing such a large amount of water.


  • Heater System

    For both of the different types of heaters, you’ll have different mechanisms. For example, the gas water heaters use gas and chimneys to make sure the water is heated, whereas the electric heater mechanism uses a heating system implemented inside the tank.


  • Thermostat

    This is the same as any thermostat you may have for your home, it uses a thermometer to measure the temperature inside the tank. Electric heaters may have multiple thermostats.


  • Dip Tube

    This is the initial tube which allows cold water to enter the tank and helps it travel to the bottom of the tank to be heated.


  • Shut Off Valve

    This valve is situated outside the tank. It’s main task is to stop the water flow when enough water has entered the tank, thus maintaining the capacity.


  • Heat-Out Pipe

    This pipe is in charge of allowing the hot water to exit the tank. This is also situated outside, usually on top of the tank.


  • Drain Valve

    Often, you’ll need to empty the tank entirely in order to ensure that it can be cleaned for maintenance or any other issue. This is where the drain valve comes in, as it allows you to empty the tank.


  • Pressure Relief Valve

    This valve allows for you to keep the pressure inside the tank at a safe limit, so that no accidents can occur. Usually for a 40 to 60 gallon tank, the pressure needs to be around 50 to 100 PSI (per square inch)


  • Sacrificial Anode Rod

    The sacrificial anode rod acts as a safety mechanism, helping reduce the rate of corrosion inside the tank.

Electric Water Heater

Electric Water Heater

For an electric water heater, the dip tube works to bring in cold water to the tank, and allow for the electric heating element to produce the hot water. With conventional storage heaters, this takes some time, and after it is finished heating, the hot water rises to the top of the tank, and is spread throughout your home via the heat-out pipe.

Throughout this process, all the other components of the heater system will make sure that the tank itself is running at its optimal rate. This includes the thermostat making sure that the water is at the right temperature at all times. With electric heaters, as we have already mentioned, all the different components may include their own thermostat, and this helps to provide even more assurance for you to know if any specific area needs to be fixed. The insulation throughout the tank ensures that the hot water remains hot over a period of time. For electric heaters, you’ll be dependent on a power supply in order to make it run.

The sacrificial anode rod in the tank is placed in order to ensure the tank doesn’t corrode fast. This is maintained by placing a rod that is made of a material that rusts faster than the material used to make the tank. Thus, this reduces the rate of corrosion of the tank. 

The temperature and pressure valves ( T and P valves) are placed in the tank in order to ensure the temperature and pressure inside the tank are maintained. If the water becomes too hot or the pressure is too high, these valves open up to release some water, thus, preventing any accidents. The drain valve is placed inside the tank in order to let the water out for maintenance of the tank, which should be done at least once or twice a year.

Gas Water Heater

Gas Water Heater

Just as with the electric powered water heater, the gas powered water heater brings in water the same way; through the dip tube. However, instead of passing through an electric heating element, the gas heater passes the water through the tank and uses a gas burner. The gas burner produces a toxic gas that goes through the chimney in the middle of the tank. As the chimney excretes this gas outside the water heater, it gets heated up, which in turn, heats the water in the tank.

As this process takes place, the hot water rises to the top of the tank, allowing for the heat-out pipe to spread the hot water throughout your home. With gas water heaters, you can set the temperature of the water to be what you want, and the necessary amount of gas will be sent to the burner in order to maintain that temperature. This way you can easily heat the water in your home.

As for the safety features placed in the water heater system, the same functions are maintained by the T and P valves to ensure no accidents occur in your gas water heater system. As you keep using the hot water, cold water enters the tank, and is ready to be heated up when you need to use some next time.

Water Heater Maintenance & Factors To Consider

A water heater is a very important part of your home infrastructure, and maintaining it should be something you always keep an eye on. This doesn’t just involve your tank, but the other parts as well. Let’s take a look at some important things to consider with water heaters.

  • Cleaning the Tank

    People often disregard the value of cleaning a water tank for long periods of time. However, the tank of your water heaters have various parts inside them that keep running constantly. You should look into cleaning out your tank at least twice a year, in order to ensure it can work at its full potential. Just use the drain valve to empty out the tank.

    There’s a few problems that can occur in your tank. With the constant addition of water in your tank, you can expect sedimentation to occur. This is a build up of stuff that ruins the quality of your water, and in large amounts can also be detrimental to every component in your tank.

    You also run the risk of mineral buildup. Water has various minerals inside it, and with the water sitting in there for a long time, some of it can get stuck to your tank. Some water heaters also have their tanks include an air pump at the bottom of the tank. This allows for the water to constantly be moving, in order to reduce the rate of the buildup.

    Another issue is corrosion. After a while of using the tank, corrosion is something you can come to expect. The anode rod is there to delay this process, but in due time, you’ll need to take a look into it.


  • Replacing the Anode Rod

    The anode rod has the word ‘sacrificial’ attached to it in order to help keep the water environment safer. However, it is created in order to rust faster than the tank itself. Thus, after a while, you’ll need to look into changing it, after it has served its purpose.


  • Testing the Temperature and Pressure Valves

    The temperature and pressure valves do very important jobs by maintaining the temperature of the water, and the pressure inside the tank. However, you should always make sure that they are working in order to avoid any accidents from occurring. A water heater is something we use everyday, and if any of these don’t work, it can cause massive damage.

    For the temperature valve not working, you’ll be able to find out easily by realizing the water temperature is not what you set it at.

    When it comes to the pressure relief valve, you’ll need to make sure it’s working by cooling the water inside, and opening the valve, while having something underneath to catch the water.

The Takeaway

We hope you have found out everything in your quest of the question ‘how does a water heater work?’, because this is something that is good to read up on. When you have all the information, you can always rely on yourself to know if something is wrong with your machine. Now, you can rest easy by knowing how water heaters are sending hot water throughout your house. However, you may need to replace a water heater, when you sense that the heater has more than a few of those components not working properly. There are also various tankless water heater methods out there that are quite new, but with the tankless water heater methods, you’ll save space on having the tanks in the first place. However, they can be a much bigger initial investment. Now you can easily know how well your water heaters work!

Leave a Comment

Your email address will not be published. Required fields are marked *