Horrendous Banging noise in water pipes

[tiggrrr90]

When my hot water heats up there is an amazing amount of banging and clanging through the house. This happens randomly until the hot water goes off. I had a plumber out who changed the ball valve but still keeps doing it, unfortunately when the plumber was round it didn't make a sound!!!! Someone else was talking about a hammer? something?...I am a female and unfort have absolutely no idea about plumbing, also I would like an idea of what it could be as I don't want to have to keep paying call out charges each time.
Thank you.

[htg engineer]

When the water is heating - it is more likely to be the boiler kettling, or pipes may need to be clipped and lagged. Do you live in a hard water area ? does the noise seem to be coming from the boiler, or pipework from the boiler ?

Water hammer occurs when you run a tap, or the ball valve is filling the tank and the pipes vibrate or bang.

htg