Although my combi boiler, a Worcester 24 CDi, seems to be working fine, it has developed a loud clanging / banging noise, which starts soon after it fires up to heat up the water, 3-4 times at a time, which goes clang..clang..clang and then goes quiet until the next time it fires up. Any ideas what it might be and/or have an idea on how to solve the problem? Many thanks
