We explain about the different types of boiler and their pros and cons, so you can make an informed decision on which type of boiler you need when you come to replace yours.
The term ‘condensing’ refers to the technology inside the boiler rather than the actual boiler type. Since the Building Regulations changed in 2005, all new installations have had to be condensing boilers rather than standard efficiency boilers, because they are at least 25% more efficient than the older models.
Condensing boilers have a bigger and more efficient heat exchanger that is able to recover almost all the heat out of the gas it burns, so that very little useful heat is lost through the flue. This means the boiler doesn’t need to work so hard or use as much fuel to heat your home or hot water, saving you money on your fuel bills and reducing carbon emissions. Because it doesn’t get so hot, the flue of a condensing boiler is usually made of plastic, rather than metal, like the flues of non-condensing boilers.
Because most of the heat is removed from the flue gas and reused, the left over liquid tends to ‘condense’, hence the name, and this liquid is drained away from the boiler into a waste pipe through a white plastic condensate pipe that usually comes out of the bottom of the boiler.
If your answer is yes to any of these, then you have a standard efficiency boiler and could save up to £305 a year by replacing it with a high efficiency model.
Combi, or combination, boilers are the most popular types of boiler in the UK. All the components needed for your central heating and hot water are combined in the boiler’s compact casing. The boiler switches from central heating to hot water when a hot tap is turned on, providing instant hot water whenever you need it.
System boilers include the expansion vessel and pump inside the boiler casing. They need a hot water storage cylinder but do not need water tanks in the loft. They are suitable for homes with more than one bathroom and a high demand for hot water.
Heat only boilers are also known as regular, traditional, conditional or open vent boilers. They need a feed and expansion tank and a cold water storage tank in the loft and a hot water storage cylinder and separate pump, usually housed in the airing cupboard.
When deciding what type of boiler you need, there are a number of points to consider, such as how much hot water do you require and how many bathrooms have you got. Your Gas Safe registered installer is the best person to advise you; they will survey your property, look at the number of windows and the size of your rooms, identify the fabric of your walls and roof and recommend the correct output and type of boiler for your home using recognised industry calculations.
It is worth remembering that if a boiler is too small it will not be able to heat your home adequately or produce enough hot water. If it is too big, it will use more fuel than you really need, so your energy bills will be more expensive and your carbon emissions unnecessarily high.