Often the first sign of a failing boiler is strange or loud noises. This common problem is called “kettling” and is usually caused by corrosion, debris or limescale sticking onto inside surfaces of the boiler’s heat exchanger. This issue needs a professional to rectify it, if the damage is not too significant then a heating engineer should be able to fix the fault. Depending on how old your boiler is, getting a boiler replacement may be more cost effective in the long-run.