Everything You Need to Know About Water Heaters: Types, Parts and How They Work 

Regardless of whether you own a home or business, water heaters are one of your most essential appliances. You can use it to get warm water for a refreshing shower, to wash up, or as a health and safety resource.

In order to ensure peak performance, a domestic and commercial water heater needs regular maintenance, and to know how it works.

How many home and business owners know what type of water heater they have or how it works? 

The following is a list of all the essential electrical water heater fundamentals you should know. 

Water heaters, boilers and plumbing are all part of BPSs’ expertise. We can help you if you have any questions or concerns by calling 029 20 484114.

Water heaters: what are they?

An electric water heater heats water in a property and circulates it to different water fixtures for showering, washing, laundry and machinery operation. Cold water is heated by a water heater using electricity or gas. An electric heater heats the water by using an electrical element, whereas a gas heater heats the water by using combustion. The ability to heat water on demand makes a water heater essential for any property whether it be a home or business to be energy efficient and comfortable. 

In a water heater, what are the different parts?

A water heater heats cold water in three main sections:

  1. Tank 

Tanks, usually made of steel, are the reservoirs that hold the water in water heaters. A protective lining is applied to the interior of the tank to prevent corrosion, and polyurethane foam is applied to the exterior to reduce heat loss. 

  1. Thermostat 

In the water heating system, the thermostat regulates the temperature of the water. Water temperature is controlled by this device, which is located near the burner.

  1. The Heating Element 

In an electric water heater, the heating element is used, while in a gas water heater, the burner is used. A heating element usually sits at the bottom of the tank and is responsible for warming cold water. 

Water heaters come in different types. What are they?

Water heaters perform the same function in five different ways. The following differences will help you choose the right unit for your home or business: 

Storage Water Heater 

The most common type of water heater is the storage or tank water heater, which comes with a large tank in which the cold water is heated.

Both electricity and gas are used to power these devices. An electric water heater is usually cheaper, whereas a gas water heater or a gas burner heats water more quickly. Keeping a tank water heater in good working order requires regular cleaning and flushing. 

Tankless Water Heater

There is no tank to store cold water in these water heaters. With a drain valve, you can enjoy an endless supply of hot water as they heat the water on demand as it flows through them. Compared to tank water heaters, tankless water heaters use less energy since they only heat water when it is needed, not continuously. 

One disadvantage of tankless water heaters is that they are more expensive upfront than storage water heaters. Several fixtures may not be able to receive water simultaneously, which can be frustrating. 

Heat Pump Water Heaters 

To warm the water, these water heaters don’t use a traditional heating element. By transferring heat from the air outside to the reservoir’s water, they heat a building without heating the air inside. Due to the system’s efficiency, less energy is required to operate it, resulting in lower energy bills. 

Water heaters with heat pumps can only operate outside under a certain minimum temperature, making them suitable only for warmer climates. In extremely cold climates, they may not work. 

Solar Water Heaters 

A solar water heater uses solar panels to absorb solar energy to heat the water. The biggest advantage of these kinds of water heaters is that they operate freely without being controlled. Your water will be heated by the sun when it is out. However, they can only be effective in locations that are warmer climates with more constant sunshine. If there is lots of clouds, or the climate is prone to rain, these types of heaters won’t work effectively. 

Condensing Water Heaters 

Condensing water heaters will only work in properties that have a natural gas heating element. They work by using exhaust gases from a central heating system which is their energy source that powers the heating element rather than using the gas directly, compared to standard water heaters. These types of heaters are an energy-efficient solution that often saves you money in the long run.

What are the typical problems with water heaters? 

Water heaters can experience different problems due to their age or if they haven’t been serviced and maintained as they should be. These issues include: 

Water Temperature Issues 

If there is no hot water from your pipes, taps, or shower, or the temperature of the water is fluctuating, there could be an issue with the heating element or thermostat. These can sometimes be repaired or are easily replaced. 


Water leaking from your heating system can signify a range of issues, including but not exhausting, faulty pressure relief valves, water pressure problems, a spoilt gasket, a valve that is stuck, or bolts that are loose in the heating element. An experienced plumber will be able to quickly identify the problem and repair or replace any parts that are needed. 

Discoloured Water 

If the water coming out of the water heater is dirty, murky or sludgy it can mean the metallic elements inside the water heater are rusting. This causes contamination which changes the colour of the water. 

Noisy Water Heaters 

A water heater shouldn’t produce much noise when heating water, however, if you start to hear noises it usually signifies that something is not working as it should. It can sometimes be due to a build-up in mineral segments in the base of the tank that vibrate producing the concerning noise.

What to do when a water heater develops issues 

If your water heater is not working as it should, you should contact a professional heating engineer who will be able to assess, check and diagnose the problem before carrying out the required repairs or replacing a part.

In Summary 

Understanding how your water heater works and the common issues that can occur will help to keep it operating effectively and efficiently. There are many types of hot water heaters, but they all apply the same working principles. By knowing what these are you are more likely to be able to maintain and care for your water heater appropriately. We would always advise that you have an annual service carried out on your water heater which will keep it in good working and efficient condition and highlight any potential issues that if you rectify quickly will prevent it from breaking down.

BPS experienced and professional Heating Engineers can come out and assess your water heater system and will advise you of the best system for you, or which water heater you have. 

Our experienced and qualified heating engineers offer advice using their knowledge and ongoing training and industry experience and we will only advise a change if it is beneficial to you in the long run.

Contact us today at 029 20 484114 or email us to arrange your no-obligation commercial water heater assessment, repair, service or new installation for your home or business.