Central heating accounts for about 60 per cent of what you spend in a year on energy bills, so an efficient boiler makes a big difference.
Modern boilers are more efficient for several reasons, but their main advantage is that they are all condensing boilers. All well-maintained boilers burn their fuel very efficiently, but they inevitably lose some heat in the hot gases that escape up the flue. A condensing boiler has a larger heat exchanger, so it recovers more heat, sends cooler gases up the flue and is more efficient.
Sometimes the flue gases get so cool that the water vapour in the gas condenses out (hence the name), and even more energy is recovered from the condensing vapour.
Installing a new A rated boiler can reduce your energy bills dramatically, saving you up to £350 per year.