Boiler Types

Information for Boiler Types & Central Heating Systems.

Providing help & advice on the types of boilers and heating systems and the options available to customers. 
 

Types of boiler

To conform with building regulations, since 1 April 2007 boilers must be "A" rated to meet energy efficiency and emission requirements (unless an exception is allowed). .

There are three types of condensing boiler: combination or open vent or system.
 

Gas condensing boilers

Nearly all new boilers are now condensing types. Condensing boilers are far more energy-efficient than traditional boilers, as they cunningly reuse heat that would otherwise be wasted.

Some heat generated by traditional boilers disappears up the flue in the form of hot waste gases. But condensing boilers use some of the heat from these flue gases to heat water, making the boiler far more efficient.
 
 

Combination boiler

This is the bestselling boiler type for gas central heating in Britain. A 'combi' provides heat for your radiators and domestic hot water on demand.

The name comes from the fact it combines all the functions of a traditional boiler, hot water cylinder and cold water tank setup. All the major parts are in one unit, which makes them convenient to install.

There are different types, but they all work by taking cold water straight from the mains supply and heating it as you need it. When you turn on a tap, water is drawn from the mains, heated in the boiler and comes straight out of your tap piping hot.

This means there's no need for a separate hot water storage cylinder or cold water feed cistern. But there's a small time lag between turning on the tap and getting hot water, and the flow rate is limited by how quickly the boiler is able to heat up the water.

The advantage is they require less space than heat-only boilers (because there is no storage cylinder), and avoid heating water that's not used immediately. On the down side, the flow rate limits how much water you can use at one time – no filling the kitchen sink while running a bath, for instance.

You might also miss using the (wasted) heat from your hot water cylinder in your airing cupboard.
 
In a new build installation installing a combi is straightforward.
 
Converting an existing open vent or system boiler layout to suit a combi is more expensive than installing a direct replacement boiler since systems need to be modified and new pipes fitted to hot water taps.
 
 
 

System Boiler ( conventional heat-only )

Heat-only boilers provide heat for radiators directly, but they need to be connected to a separate hot water storage system including a hot water cylinder.

These arrangements take up more space than a combi system, but are able to provide hot water to several sources at once and are more suitable for larger houses.

Unless a cylinder is very well insulated it usually loses heat into its surroundings, thereby wasting energy. And the amount of hot water you can use is limited by the size of your cylinder.

For instance you might run a bath, then need to wait for the boiler to heat up the water in the cylinder again before you can run another.
 
As a direct repalcement boiler - replacing an old system boiler with a new condensing system boiler they are an easier and cheaper instalation and can fulfill hot water needs better than the combi option.
 
 

Open Vent Boiler
 

Open vent boilers are very similar to System boilers , heating radiators directly and heating a hot water tank indirectly.

These arrangements take up more space than a combi system, but are able to provide hot water to several sources at once and are more suitable for larger houses.

Unless a cylinder is very well insulated it usually loses heat into its surroundings, thereby wasting energy. And the amount of hot water you can use is limited by the size of your cylinder.

For instance you might run a bath, then need to wait for the boiler to heat up the water in the cylinder again before you can run another.
 
As a direct repalcement boiler - replacing an old open vent boiler with a new condensing open vent boiler they are an easier and cheaper instalation and can fulfill hot water needs better than the combi option.
 
 
 
 
 
 
 

Contact Details

Simon Mason 

mobile - 07783146897
landline - 01733 755667 
 
 
Energy Efficiency Qualified - Part L - Heating Engineer
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