Which boiler is for you?

There are 3 different types of high-efficiency condensing boiler:

  • Combination
  • Regular (traditional/conventional)
  • System

Each type delivers all the benefits of high-efficiency technology, but which one you choose will depend on several factors, including your property, your lifestyle and the professional advice of your Corgi registered Heating Advisor.

combi-boilerWhat is a combi boiler?

The high efficiency condensing combination boiler is an ingenious space-saving idea. Combis are the majority of all the new domestic boilers installed in Britain every year.

The major difference between a combi and any other type of boiler is that a combi eliminates the need to store hot water — so no hot water cylinder in the airing cupboard. It is both a high-efficiency water heater and central heating boiler, combined (hence the name) within one compact unit which usually sits in the kitchen or utility room, or sometimes in the airing cupboard. The space savings result from the fact there is no hot water storage cylinder, cold water storage cistern or other familiar components of a regular (conventional) heating system.

The further benefits of this are a significant saving 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 benefit is that it can generally save you money on installation time and costs — no tanks in the roof space means less pipe work and a shorter installation time.

vaillant-boiler1What is a regular boiler?

If you are replacing an older model of boiler, the chances are that you will have a regular (conventional) boiler. A typical conventional system incorporates a boiler and extended controls, a feed and expansion cistern, and a hot water cylinder (usually in the airing cupboard) which is often fed by a cold water storage cistern located in the loft.

What is a system boiler?

Unlike a combi, both a system boiler and a regular (conventional) boiler work on the principle of stored hot water — but a system boiler differs from a regular boiler in some important respects.
Many of the major individual components of the heating and hot water system are built in, which means that installation is quicker, neater, easier and more efficient.

The boiler includes an expansion vessel so there is no requirement for a feed and expansion tank in the loft, which allows the installation to save space.

For Your Consideration

  • You want to use your loft space for a room conversion or other purposes Combi
  • You live in a flat or bungalow (i.e. have very little or no roof space) Combi
  • Your home has more than 2 bathrooms Regular or System
  • Your mains water pressure is low Regular or System
  • You want to replace an old boiler to improve an existing conventional central heating system Regular, System or Combi
  • The number of people in your household means that there is regular demand for hot water on tap, but waiting for the tank to constantly refill and heat up is, or would be, inconvenient Combi

Unvented Hot Water

This is a system often specified by home makers who want a versatile output but need to save as much space as possible.
An unvented hot water cylinder means there is no need for a cold water storage tank whilst still keeping all the benefits of a conventional system and more.

All you need is to site your gas central heating boiler in your property, position the unvented hot water cylinder (normally in the airing cupboard) and connect the two together and add your controls and an expansion vessel.
This means there are no tanks in the loft area, loft space is saved. An airing cupboard contains the hot water cylinder.

This system kit is quite expensive compared with a normal conventional system or a combination boiler.
You’ll definitely need a well skilled installer for this installation which we can supply.

Unvented cylinders shown below come in a range of sizes.

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