The Differences Between Water Heaters and Boilers

Water heaters and boilers are two systems that are used interchangeably in everyday conversation. While both are vital house appliances responsible for heating, they provide different property solutions. One is used to heat a space, whereas the other heats just the water. It is important for home and business owners to know the difference, especially when there is an issue and a specialist needs to be called. Our article summarises the differences between a boiler and a water heater.

What is a Boiler?

A boiler refers to a property heating appliance that serves the same function as an in-wall heater, HVAC system, or baseboard heater. Essentially, a boiler heats your home through a hot water system and will be the primary supplier of all the hot water needs for showering, dishwashing, laundry, etc. . The heat is typically released to your property through heated flooring systems or radiators. While the name “boiler” might suggest boiling water, the gas burner in the boiler heats the water but doesn’t warm it to boiling point.

The main types of boilers on the market include:
    • Steam boiler
    • Water boiler
    • Oil boiler
    • Combination boiler water heater

How do boilers work?

Boilers heat a space by circulating hot water or steam through a system of pipes to different areas of a building. Most boilers use natural gas, propane, oil, or propane as an energy source to heat the water, usually to 60 degrees or more in a sealed reservoir. The boiler system has a circulating pump that propels the water via the pipe network throughout the home in a loop. While many residential boilers use water to heat, some use steam.

The system often uses radiators, which refer to the hot water loop termination points. As the water cools down, it cycles back to the boiler to be heated, repeating itself. For boilers that use steam to heat, the process begins afresh when the steam cools and turns back into water.

What is a Water Heater?

Like boilers, a water heater is an appliance used to provide hot water in a residential or commercial building. It is the hot water you use for showering, washing dishes, and laundry. The main difference is that this is the only function of a water heater; it does not provide space heating.

The main types of water heaters are as follows:
    • Tank water heater
    • Tankless water heater
    • Hot water recirculation pump
    • Combination boiler water heater
    • Indirect water heater

Water Heaters and BoilersHow do Water Heaters work?

Using a radiant heat system, a water heater heats cold water from the main supply to a desired temperature for use in a property. In a tank water heater, cold water enters the tank from above and is heated indirectly by electric heating rods or a gas burner inside the tank. When the water reaches the required or set temperature, it is stored at the bottom of the tank. The heat potable water comes from the shower head when you go for a bath.

The water released from the water heater’s tank mixes with the cold tank when you turn the tap or shower, which is possible because of the pressure in the pipes. The warm water is typically circulated to different areas of the house through pipes.

In tankless water heaters, there is no storage of water. Instead, the water is heated instantly as it passes through the sink or shower as long as there are mains running water connected to your property.

Water Heaters and Boilers: What is the Difference?

The main difference is that boilers are used for space heating whereas water heaters aren’t; they provide hot water for washing and showering. However, other aspects help to bring out the differences as follows:

Efficiencies of Water Heaters and Boilers

Efficiency is important for any home or business owner looking to control their heating bill. When it comes to the energy source, boilers use different forms of fuel, including gas, oil, propane, etc. Meanwhile, water heaters can run on propane, gas, electricity, and solar energy. Regarding efficiency during operation, it will depend on the type of appliance model you’re using, as well as other variables. Generally, a boiler consumes more power compared to a water heater.

Installation Costs of Water Heaters and Boilers

Buying and installing a new boiler system will cost more than installing a water heating system.
A boiler replacement typically costs between £1,150 and £5,500. The average cost of a new boiler is between £500 and £3000, and the average cost of installation is between £650 and £2500.

Meanwhile, a new water heater system costs are much lower, however, for both, it depends on the type of system you need and the size of the property.

Maintenance Costs of Water Heaters and Boilers

Both a boiler and water heater should be properly maintained once installed to ensure a prolonged life expectancy and efficient operating costs. It is easier to maintain a water heater than a boiler as it is a less complex system, meaning you will pay more for boiler maintenance.

The lifespan of Water Heaters and Boilers

As far as life span is concerned, water heaters and boilers will last anything between 10 and 15 years. However, this will usually depend on how well the unit is maintained. Property owners should always choose a high-quality boiler/water model if they want maximum efficiency from the unit. For water heaters, tankless units tend to last longer than their tanked counterparts. They can add an extra 5 years of life because they contain easily replaceable parts.

Should you Install a Water Heater or a Boiler?

All properties don’t necessarily need a boiler system as sometimes they require a water heater to simplify various functions and because they have other ways of heating the property. A water heater will provide a property with hot water whilst a boiler system will prove hot water and heat.

In Summary – Water Heaters and Boilers

When it comes to heating a home, it helps to know whether you want to heat the space or the water. This will enable you to make an informed decision when shopping for a suitable system for your property.

If you need help understanding which is the best system for you, to maintain, or upgrade, or if you need a repair to your boiler or water heater, contact Total Boiler Services today on 02922 407934 and we can arrange for a suitable engineer to come out to your property.

Our team of engineers are all trained to the highest standards and are all experts in their line of work. We are gas safe registered and offer a professional and trusted service to home and business wonders. From domestic boilers and heating systems to full plant rooms we provide a trusted and reliable service that is second to none.

Our customer service team are on hand to answer your call 24/7 and will understand your needs to ensure we provide you with the right service the first time around, saving you time and money.

We are qualified to work on all commercial and domestic boiler and water heater makes & models throughout Wales and the West of England.


    • Installations
    • Service and Maintenance
    • Gas boiler servicing
    • Oil boiler servicing
    • Combustion analysis
    • Boiler safety checks
    • Gas safe certification
    • Boiler fault diagnosis
    • Boiler inspection and condition reports
    • Plant replacement surveys


    • Gas, Oil and L.P.G boilers
    • New boiler room design and installation
    • Biomass boiler installation
    • Domestic Hot water boilers
    • Plate heat exchangers
    • Electrode boilers
    • System upgrades
    • Flue system installation
    • High-efficiency boiler plant installations

Our team is capable of handling any job, no matter how big or small. An expert from our commercial heating team will come out to your property to assess everything you need to know about your heating system. In addition to planning and managing your new installation, we will decommission any old equipment if necessary. Whether it is a stand-alone system or a full plant room, we install, maintain and repair it.