Boilers - choices

How do I decide which type of boiler best suits my needs?

There are 3 different types of boiler:

  • Combi boiler (or ‘combination’ boiler)
  • Regular boiler (often also referred to as a ‘traditional’ or ‘conventional’ boiler)
  • System boiler

Combi boilers provide heating and hot water directly from the boiler.

Regular and system boilers heat your central heating system directly and produce hot water for yourcylinder.

Requirements Most suitable boiler
You want to use your loft space for a room conversion or other purpose Combi boiler
You live in a flat or bungalow (i.e. have very little or no roof space) Combi boiler
Your home has more than 2 bathrooms Regular or system boiler
Your main water pressure is low Regular or system boiler
You want to replace an old boiler to improve an existing conventional central heating system Regular, system or combi boiler
You need to have hot water available on tap without waiting for it to heat up. Combi boiler

What is a combi boiler?

A combi boiler provides heating and hot water directly from the boiler.  A combi (or combination) boiler is an ingenious space-saving idea, and an increasingly popular choice in UK homes. In fact, combis now account for well over half of all the new domestic boilers installed in Britain every year.

A combi boiler is both a high-efficiency water heater and a central heating boiler, combined (hence the name) within one compact unit. Therefore, no separate hot water cylinder is required, offering space saving within the property.

Further benefits of a combi boiler are significant savings on hot water costs and the fact that hot water is delivered through your taps or shower at mains pressure. So you can enjoy powerful showering* without the need for a pump.

Another combi boiler benefit is that it can generally save you money on installation time and costs, since no tank in the roof space means less pipe work and a shorter installation time.

What is a regular boiler? 

Regular boilers (also known as ‘conventional’ boilers) heat your central heating system directly and produce hot water for your cylinder.  If you are replacing an older model of boiler, the chances are that you will have a regular (also known as ‘conventional’) boiler.

A typical regular boiler system incorporates a boiler, extended controls, a hot water cylinder which is often fed by a cold water storage cistern located in the loft and a feed and expansion cistern - also located in the loft.

What is a system boiler?

A system boiler heats your central heating system directly and produces hot water for your cylinder.  A system boiler, just like a regular (conventional) boiler works on the principle of stored hot water. However, a system boiler differs from a regular boiler in some important respects.

Firstly, many of the major individual components of the heating and hot water system are built into a system boiler, which means that installation is quicker, neater, easier and more efficient.

Secondly, the hot water is pumped from the system boiler through the heating system to the radiators and hot water cylinder, resulting in a fast response and more economical running costs. The system boiler removes the need for a feed and expansion cistern.

What is a condensing boiler?

The term ‘condensing boiler’ refers to the fact that the boilers produce condense from time to time.  Condensing boilers use heat from exhaust gases that would normally be released into the atmosphere through the flue. To use this latent heat, the water vapour from the exhaust gas is turned into liquid condensate.

In order to make the most of the latent heat within the condensate, condensing boilers use a larger heat exchanger, or sometimes a secondary heat exchanger.

Due to this process, a condensing boiler is able to extract more heat from the fuel it uses than a standard efficiency boiler. It also means that less heat is lost through the flue gases.


Barron Heating Ltd are Worcester Bosch Accredited Installers and can offer a 7 year guarantee on all Greenstar gas-fired boilers
(8 years if a Worcester System Filter is installed).  

For Vaillant and Grant boilers we offer a 5 year guarantee.