Boiler Type Guide


Here at Swale Heating we understand that selecting a new boiler can be a confusing and daunting task - for most people buying a new boiler is not an everyday occurence so the terminology can be a tad confusing!

There are a few different types of boiler available and if you want a direct replacement then the type of boilers required will be specific to your property and the way the central heating system is setup.

With our boiler type guide we hope to shed some light on the different types of boilers available and try to outline the main differences between each boiler type and suggests the core benefits for each system.


 Combi Boiler type

Combi Boiler

A Combination boiler, also known as a ‘Combi’ boiler, is a very popular boiler selection for homes across the UK. One of the reasons for their popularity is that they can provide both hot water and central heating from the one appliance.

Unlike regular and system boilers, which require additional appliances such as hot water cylinders, water storage cisterns or expansion cisterns, a combi boiler removes the need for this as it heats your mains cold water supply on demand (i.e. from turning on a tap or shower etc) to give you a continuous supply of hot water.

This is an extremely efficient process as no energy is wasted in storing the water in a hot water storage tank.

A combi boiler therefore also takes up less space in the property once it is installed, which is perfect for a lot of UK homes where space is at a premium.

The image to the right hand side shows an example of a common combi boiler system set-up. Please be aware, combination boilers require a strong mains flow rate and this should be checked prior to installing one. Furthermore, a combination boiler may struggle to supply hot water to multiple outlets if they’re used at the same time, e.g. two showers, therefore, they may not be appropriate for properties with high hot water demand.


Regular Boiler

A Regular boiler or a conventional boiler as some may know it are more commonly found in older properties. Regular and System boilers are an older design of boiler but still offer great functionality and control of your home’s central heating and hot water system. A regular boiler’s two main objectives are to provide central heating and hot water to your home. The way it heats your home is by directly heating the radiators throughout the property to your desired temperature.  The way it provides hot water is by heating a coil, which is fitted into your hot water cylinder in order to heat the stored water.  The hot water cylinder is fed from a cold water storage cistern (or the mains for an unvented cylinder) and a feed and expansion tank supplies the water for the heating system. 

Below you will find an example of a Regular boiler system set-up:


System Boiler

A System boiler operates in a similar fashion to that of a regular boiler. Within its system it still operates using the principle of a stored hot water cylinder, but even though they have this same attribute a System and Regular boiler differ in some crucial aspects. A System boiler directly heats your homes central heating system and also produces hot water, which is stored in your hot water cylinder.  However, a system boiler has many of the major individual components of the heating and hot water system built in, which means that installation is quicker, neater, easier and more efficient.  A system boiler contains the central heating pump and an expansion vessel.  This removes the need for a separate feed and expansion tank and pump being fitted in to the central heating system.

Below you will find an example of a System boiler system set-up with an open-vented hot water cylinder:

Below you will find an example of a System boiler system set-up with a pressurised unvented hot water cylinder:


If you have any other questions or queries then feel free to give us a call and we will point you in the right direction.