If you choose the most reliable brand of boiler, according to our survey, an impressive 63% are likely to still be fault free after six and a half years get unlucky and pick the least reliable brand, and this falls to a disappointing 45%. Now don’t worry, in many cases the. To demonstrate our confidence we are offering a. If you have tried all of the options above, then your next step is to. A boiler is a heating system that heats your home by circulating.