How do you mean noisy? If you get a banging or hammering sound, this is usually caused by the water pressure being too high and be easily cured by throttling down the pressure at the incoming Stopcock (usually found underneath the sink) or if this fails then check the ballvalve's rubber washer, this may have to be replaced, while your there check the injector nozzle too. Failing that, replace the ballvalve. If it is noisy because it doesn't stop filling the tank, again, check the ballvalve washer. Hope this helps.
Ced, October 2008