Hi,
Does anyone have any ideas what would cause the following problem and have any solution?
About 1.5 hours after the central heating in my house turns of there is a loud knocking from the hot tank (I think). The knocking starts of very quietly and slowly spaced, then speeds up gets very loud and then tails of again. This lasts about 3 or 4 minutes and it very annoying.
Cheers,
Ian