There are three different types of domestic heating and hot water boiler, combination boilers (known as ‘combi's’), system boilers and open vented boilers. Since April 2005 your new boiler must, by law, be a high efficiency boiler or condensing boiler. This is a boiler that recovers heat that would otherwise be wasted and uses it to improve the boiler’s heating efficiency.
How do they work?
High efficiency or condensing boilers (they are the same thing) have a heat exchanger that uses heat in the flue gasses to pre-heat the water. (They are called condensing boilers because most of the heat recovered comes from condensing water vapour in the flue gasses.) The condensed water is drained away and much less energy is required to raise the temperature of the preheated
circulating water to the desired level.
How energy efficient are they?
Vaillant SEDBUK ‘A’ rated boilers in the ecoTEC range operate with an annual average efficiency of over 90%*. Typically, older types of conventional boilers only achieve efficiencies of 56%*. That means your condensing boiler will use 35% less energy to deliver heating and hot water to your home. This is how a condensing boiler can save as much as 35p in every £1* you spend on energy. This can amount to a saving of over £240* on your annual home heating bill.
* Energy saving and consumption calculated using DEFRA data for a 3 bedroom semi-detached house with an old heavyweight boiler. Money saving calculated using British Gas Internet Tariff June 2008.
Which type will suit your home?
These are the three types of condensing boiler now available:
