Hi
Today I noticed a rushing sound, like distant water or air, coming from the bath plughole and overflow in my downstairs bathroom. It's there all the time, even when the taps have not been turned on for hours. There are no obvious leaks or bad smells in the bathroom, and bath and washbasin are draining as normal.
Sounds like I need a plumber? Could this be a leak somewhere outside? I'd really appreciate some advice. Thanks!