Types of Boiler

Conventional or Non-Combi
A conventional boiler works in conjunction with a hot-water cylinder and at least one valve to provide hot water and heating. The advantages of a conventional boiler are that the hot water flow rate is higher than from a combi boiler making it ideal for large properties with more than one bathroom. Also, if you plan to install solar heating panels then these can only be used in conjunction with a hot water cylinder and a conventional boiler. On the downside the supply of hot water is limited by the size of the cylinder and once it has been used you will have to wait for the boiler to heat up the cold cylinder again. There is also a cost attached to maintaining the temperature of the hot water in the cylinder when it is not being used.

 

   

Combi
Short for 'combination' these boilers provide hot water on demand - when you turn on a hot tap the boiler fires up. This removes the need for water tanks in the loft and a hot water cylinder in the airing cupboard. It also means that the supply of hot water is endless and will almost always be at a higher pressure than can be obtained from a conventional boiler system. The only reasons not to opt for a combi are if you wish to take advantage of solar heating or
if you have several bathrooms all of which may be used at the same time.


   

Back Boilers
These are basically conventional boilers which
have gas fires attached to them.

 

   
Condensing Boilers
Both combi's and conventional boilers can be condensing, this refers to the feature where some of the heat going out through the flue is recovered and used to heat water. Condensing boilers are, therefore, more efficient than non-condensing ones and modern regulations mean that any new boiler must be of the condensing variety. The downside to a condensing boiler is that a condensate drain (usually a 20mm white plastic pipe) must be fitted, it must run downwards throughout its entire length and must empty into a plastic drain. If this cannot be achieved then
pumps are available to take the condensate to a drain point up to 2 metres above the boiler.