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The Different Types Of Boilers

What Are The Different Types Of Boiler?

Finding a new boiler for your home might seem like a simple task but choosing the best one to suit your home depends on the type of home you have and your lifestyle. 

Our guide will give you a breakdown of the types of boilers and central heating systems that are available right now for homes across the UK.

You may have heard of a combi boiler and this is generally the most popular type of boiler system in the UK. The combi system provides hot water on demand and is an efficient choice for many homes across the UK. With that said a combi boiler is not the best option for all homes, for example, a heat only and system boilers are in some cases much better suited than combi boilers in a variety of situations. Choosing the wrong type of boiler could lead to a significant increase in energy bills.

Combi Boiler Pros and Cons

Pros of a combi boiler

A gas combi boiler contains all components within the boiler itself, this makes the boiler system more compact and gives it an overall more neater look. This allows the boiler to be boxed in and makes it more accessible. 

There is no need for a cold water expansion tank in the loft, reducing installation cost and you can get hot water heated on demand without the risk of running out of hot water or it not being heated up. 

Cons of a combi boiler

A combi boiler internally has moving parts and with all moving parts these will tend to wear down over time – this leaves a combi boiler with the potential for things to go wrong. With all combi boilers it is a good idea to ensure that the boiler does come with some form of warranty to mitigate any work that needs to be repaired over time. 

A combi boiler is better suited to a home with a smaller number of people – this is due to the fact that you will only be able to use the hot water from the boiler for one set task. A person having a shower will not be able to use the hot water whilst someone else in the same household is using the hot water to wash up. 

Heat-Only boilers pros and cons

An open vented heat only gas boiler system with a water tank works in tandem with components that are housed externally from the boiler, such as a circulation pump. A heat only boiler will require cold water, as well as feed and expansion tanks in the loft. 

With a heat only boiler you will find that the hot water is stored in a hot water cylinder or hot water storage tank. These types of boilers are most commonly found in apartment complexes and housing of multiple occupants. A heat only boiler will most likely have an on/off switch which allows homeowners to heat the water when they need it and leave it switched off when not in use. 

Pros of Heat-only boilers

Heat only boilers are most commonly suited to larger households where a large number of people will be using the hot water at the same time. They do require space for a cold water feed tank which usually sits in the loft. 

Cons of Heat-Only boilers 

Heat-only boilers do not give you hot water on demand so you usually will have to wait for the water to heat up again once the storage tank runs out of hot water. If you use the hot water in large amounts you will then have to wait for that water to heat up again for it to be used. 

Due to the fact that heat only boilers do not give you hot water on demand they are considered to be less efficient that combi boilers as the hot water will need to be heated by elements and over time these parts become less efficient; over time you will gradually lose heating output from the hot water cylinder.

System boilers pros and cons

System boilers are often referred to as closed vent boilers and are generally a great choice if you might need a heat only boiler but do not want lots of external components. With system boilers the external components are built into the boiler itself.

A system boiler still uses a hot water cylinder, but the feed and expansion tank which is usually placed in the attic is replaced by an expansion reservoir in the boiler. 

Pros of system boilers

System boilers are good for large homes where hot water will be used at the same time frequently. 

System boilers do not require space in the attic for a water tank. 

System boilers are great if you live in an area with low mains water pressure. 


Cons of system boilers

System boilers still require space for a hot water cylinder

System boilers can cost more to install than a basic combi boiler. 

System boilers are not as efficient as combi boilers as heat is lost through the hot water cylinder. 

Once the hot water has run out of the hot water cylinder, this will need to be heated up before the hot water tap can be used again. 

Michael Cornish

Michael Cornish