I have a tapping noise coming from the ceiling because of the flat upstairs. I live in block of flats. its sounds like a water driping but there s no leak. have been monitoring for about 3 days . my ceiling is fine. I know that upstairs flat had a leak from the cylinder tank upstairs and they stopped the leak. Since then I have problem of this annoying tapping noise. Never had the noise before. Its usually in mornings and evenings. I know their boiler is in the kitchen and the tapping noise where i can hear comes from where they have got cylinder tank. Could you pls advise me what can i do to stop this annoying noise.