Why the banging noise?

[myshkin]

Hi experts!

I just moved into a new house (new to me anyway, actually built about 5 years ago). When I open the hot water tap in the en suite bathroom, there is a very loud and quite rapid hammering noise which seems to come from the pipes. When the tap is opened fully, the noise goes away. The problem only happens with this one tap.

Any idea what is going on here or what I can do about it? The system is I believe a mains pressure hot water system, with a smallish boiler in the kitchen and a larger hot water store in the other bathroom on the first floor.

Thanks!

 

[Gasguru]

Probably a loose washer inside the tap.

 

[myshkin]

Wow, that's pretty simple... thanks!

 

[WDIK]

Probably a loose washer inside the tap.

without my glasses on I read that as loose water