The most effective type of boiler for a given application depends on a variety of factors, such as the size of the space to be heated, the climate, and the desired efficiency. Generally, condensing boilers are the most efficient option, as they are able to capture and reuse the heat that is normally lost in the exhaust gases. These boilers are also more compact than traditional boilers, making them a great choice for smaller spaces. Additionally, they are relatively easy to install and maintain. For larger spaces, a combination boiler may be the best choice, as it can provide both hot water and central heating. These boilers are also more efficient than traditional boilers, as they are able to heat water on demand.