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Types of boilers explained - combi, system and regular

Published on
June 1, 2023
Close up shot of a Padly engineer accredited Worcester Bosch installer fitting a brand new Greenstar Combi boiler inside a kitchen.

Combi, system or regular? 

Choosing the right type of boiler for your home is a crucial decision that directly impacts your heating and hot water experience. With several options available, it's essential to understand the different types of boilers and determine which one best suits your home's demands.

Understanding the distinctions between the various boiler options ensures you make an informed decision that meets your current hot water demands. It's also essential to consider factors like the age of your existing heating systems and the pressure of your mains water supply to make the right choice.

In this comprehensive guide, Padly simplifies the complexities and provides an in-depth explanation of combi, system, and regular boilers.

Combi boilers -streamlined heating and hot water

Combi boilers are the holy grail of heating solutions and the most popular replacement option in the UK. They deliver both heating and hot water from a single, wall-hung unit, revolutionizing the way we experience comfort in our homes. The compact size of combi boilers makes them readily available for homes of any size, providing exceptional space-saving benefits. Instead of requiring a separate hot water storage tank, combi boilers use a metallic heat exchanger to heat water instantly on demand, eliminating the need for additional space-consuming components.

Combi boilers are highly energy-efficient, making them an attractive option for homeowners looking to save on heating bills. As they heat water directly from the mains, they eliminate the need for a large water tank or cylinder, allowing for more flexibility in terms of installation location. Additionally, the instant hot water supply ensures you don't have to wait around for a refreshing shower or other hot water needs.

However, there are a few drawbacks to consider when it comes to combi boilers. When multiple outlets are used simultaneously, the water flow rate may be reduced. This can be a concern for larger properties with multiple bathrooms or households that require high hot water usage. Additionally, the performance of a combi boiler relies on the main's water pressure. If your mains water pressure is low, the efficiency of the combi boiler may be compromised.

Regular boilers - heat only with efficiency

Regular boilers, also known as heat-only boilers, consist of three main components - the boiler itself, a separate hot water storage cylinder, and a cold water storage tank. These boilers supply hot water to both the central heating system and the storage cylinder, providing heating and hot water capabilities.

Regular boilers work by feeding hot water directly to the central heating system, such as radiators, while storing hot water in a separate cylinder for on-demand use. They rely on a cold-water tank located in the attic or loft, which fills the boiler through gravity.

One of the advantages of regular boilers is their ability to provide a greater flow rate, making them suitable for properties with multiple bathrooms or high hot water demands. They are also a good choice for areas with low water pressure mains supplies, as regular boilers do not require high-pressure water supply like combi or system boilers.

However, regular boilers may not be compatible with newer heating systems, and there might be a delay in hot water reaching the desired temperature. Additionally, they require adequate space to accommodate the hot water storage cylinder and the water tank. Installation options may also be limited due to the need for the cold-water cistern to be positioned directly above the boiler.

System boilers - efficiency and convenience

System boilers are an upgraded version of regular boilers, offering both hot water on demand and heating water for radiators. Similar to regular boilers, system boilers have a separate hot water storage tank. However, in system boilers, the tank is unvented, and all essential components, including the pump and expansion vessel, are internalized. This eliminates the need for a cold-water cistern, and the boiler is supplied with water directly from the mains.

The advantages of system boilers include their suitability for properties with high hot water demands, similar to regular boilers. The internalized components and absence of a cold-water cistern make them more space-efficient, offering flexibility in the installation location. Furthermore, system boilers eliminate the potential issues of leaks or freezing associated with cold-water cisterns in attics or lofts.

One drawback of system boilers is that the hot water flow rate within the home is dependent on the pressure of the mains supply. Therefore, they may not be ideal for areas with low water pressure. Additionally, the high-pressure nature of system boilers may not be suitable for properties with older heating systems or those with sensitivity to high pressure.

Understanding the different types of boilers allows you to make an informed decision when choosing the most suitable heating solution for your home. Combi boilers provide streamlined heating and hot water, ideal for homes with limited space and energy efficiency in mind. Regular boilers offer reliable heating and hot water supply, especially for properties with multiple bathrooms or low water pressure mains supplies. System boilers combine upgraded efficiency and convenience, catering to properties with high hot water demands.

No matter which type of boiler you choose, Padly offers a wide range of installation options to meet the unique needs of every home. Our qualified professionals ensure expert installation and long-term value, providing peace of mind for homeowners. When it comes to heating solutions, Padly is here to guide you toward the most efficient and suitable choice for your home's heating needs.

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