The cost of heating your home, prticularly during the colder winter months, makes up about 60% of energy bills. If you need a new boiler (锅炉)，make sure you buy one of the best boiler brands.    The first question you should ask yourself if you want the most energy efficient boiler is what type of boiler you should buy. All modern boilers that you can buy are condensing (冷凝式) boilers, which are much more efficient than traditional non-condensing boilers. According to a study, you could save as much as £340 a year on your gas bill if you’re trading in an ol-sye non-condensing boiler for a new condensing one.    Getting the wrong type of boiler for your home results in unnecessarily high bills. Learn more about the different types of boilers and which would suit you best in our full guide to the different types of boiler boilers.    Once you’ve decided on the type of boiler you need, the next key question is the size. The size of the boiler in the context of efficiency is its heat output. The higher the heat output of the boiler, the more energy it will be using when it’s switched on. In most cases, larger homes with more radiators(散热器) and more bathrooms will need a larger heat output than smaller ones. Learn everything you need to know about picking the right sizeboiler for your home in our free guide on how to buy the best boiler. 4. The heat output of a boiler affects

A、 installation and maintenance
B、energy consumption
C、operation
D、life cycle
喵查答案：energy consumption