Types of Boilers - Different Boiler Types Explained


Selecting the most suitable type of boiler for your household involves taking several factors into account, including the types of boilers available on the market.
Types of Boilers - Different Boiler Types Explained

Selecting the most suitable type of boiler for your household involves taking several factors into account, including the types of boilers available on the market. You must consider the size of your property, the number of bathrooms and showers, the water pressure in your area, and the type of property you have when choosing the right boiler for your home.

In this guide, we will outline the three most common boiler types for UK homes, detailing their distinctive features, benefits, drawbacks, and environmental impact. This information will help you determine which boiler replacement is the most efficient option for your household.

Condensing Boilers

In the UK, it is a legal requirement for all newly installed combi, systems, or conventional boilers to be of the condensing type. A condensing boiler stands out due to its larger heat exchanger and the capability to capture latent heat that would usually escape into the atmosphere. As a result, this leads to enhanced energy efficiency, which translates to lower utility bills and a reduced carbon footprint. In terms of energy-efficient boilers, condensing boilers are the top choice, boasting over 90% energy efficiency and offering a highly eco-friendly home heating solution. 

The three primary types of condensing gas boilers available are:

  • Conventional boilers (also known as traditional, regular, open vent or heat-only boilers).
  • System Boilers.
  • Combi Boilers.

Combi Boilers

These types of boilers are an economical option for many households, offering both hot water and central heating control. They are highly energy-efficient, making them a popular choice for eco-friendly homeowners. Because they heat water directly from the mains whenever a tap is turned on, there is no need for a separate cylinder or water tank. This saves space in your home and makes installation quicker.

Moreover, they are highly rated in terms of efficiency and often receive an A rating. This translates into significant savings on heating bills and a more compact heating system. All these factors make them one of the most preferred home heating options in the UK.

Combi boilers have plenty of advantages for homeowners:

  • Instant hot water and central heating with no waiting time
  • Responsive to tap usage and temperature
  • Compact size, ideal for homes with limited space
  • Water is delivered directly from the mains, eliminating the need for a water tank.
  • Powerful showers without the need for a pump
  • Easier to maintain with less pipework required
  • Lower risk of pipework freezing
  • No need for loft space.

However, a combi boiler may not be the best choice for all homes and there are some drawbacks:

  • Homes with low water pressure may not find them suitable
  • Running multiple baths or showers simultaneously is not possible
  • Leaks can result in a loss of water pressure
  • Larger homes may not be suitable for this type of boiler
  • There is no guarantee of compatibility with your shower when using conventional boilers.
  • They require a good level of main pressure.

System Boilers

System boilers are a great choice for larger homes with multiple bathrooms. They require a hot water storage cylinder, but not a water tank, making them ideal when there is no space for a tank. With many of the main components built into the system, installation is relatively quick and hassle-free. Plus, the pump and expansion vessel are built-in, eliminating the need for header tanks. Homeowners don't have to worry about frost damage or leaks, making system boilers easier to maintain.

Their benefits include:

  • Energy-efficient running with low running costs
  • Compact and space-saving design
  • Constant and fast supply of hot water for your home
  • No need for an expansion cistern, which frees up space and reduces the risk of leaks
  • Compatibility with solar thermal systems makes them an excellent eco-friendly option for your home.

Unfortunately, they do have some disadvantages:

  • The hot water supply may run out and require time to reheat.
  • Requires sufficient space for cylinder installation.
  • The tank size limits the amount of available hot water.
  • Insulation is required to prevent heat loss.

Conventional Boilers

Conventional boilers, also known as traditional, regular, open vent, or heat-only boilers, are a popular choice for larger households as they can supply hot water to multiple bathrooms simultaneously. However, they require a cylinder and a water storage tank, making them less space-efficient than other boiler types.

If you're considering a conventional boiler, it's essential to ensure that you have enough space to accommodate the unit and its components. The size of your cylinder and tank will determine how much hot water you can use at any given time, so it's crucial to choose the appropriate size for your household's needs.

One potential drawback of conventional boilers is that you may have to wait for the hot water to reheat if it runs out, which can be inconvenient for some users. Additionally, the installation process for conventional boilers can be more complex than that of other boiler types, which may result in higher installation costs.

Conventional Boilers - Positives

On the positive side, conventional boilers are compatible with solar heating systems, which can help reduce your energy bills and lower your carbon footprint. It's also possible to use them in conjunction with your existing heating system without extensive pipework changes.

Overall, if you have a larger household with multiple bathrooms and a traditional heating system in place, a conventional boiler may be a suitable and energy-efficient option for your home.

Advantages include:

  • Conventional boilers are capable of supplying large volumes of hot water to multiple bathrooms and taps simultaneously.
  • A good option for homes located in areas with low water pressure. Other types of boilers may struggle.
  • An eco-friendly and energy-efficient option is available by using conventional boilers in conjunction with solar thermal systems.

While some of the downsides are as follows:

  • Takes up more space than other boiler types
  • Requires time to heat up water, as it is not available on demand
  • Installation can be more complex and costly due to the need for a cylinder and tank

What Type of Boiler Do I Need?

To ensure that your heating and hot water needs are met efficiently and effectively, selecting the right type of boiler for your home is crucial. Although combi boilers are a popular choice for smaller homes due to their space-saving and energy-efficient features, they may not be the most suitable option for larger properties with multiple bathrooms. In such cases, a tank-based home boiler system like a system or conventional boiler may be more appropriate.

It's essential to keep in mind that each type of boiler has its own unique features and benefits. For instance, combi boilers are known for being space-saving and energy-efficient, while tank-based boilers offer a constant supply of hot water to multiple taps and showers simultaneously.

When you're considering replacing your boiler, it's always wise to seek advice from a qualified heating engineer or boiler installer. They can assess your property's heating requirements and recommend the most suitable type of boiler for your home. This can help you to ensure that you get the best possible heating and hot water performance, while also helping you to save money on your energy bills.