You probably know the usual sound of your toilet tank refilling after a flush: a short rush of water, then silence. If, out of nowhere, that sound goes on much longer, or the tank keeps making small hissing noises when nobody has flushed, it could mean water is escaping somewhere.
A worn flapper or faulty fill valve can let water slowly leak from the tank into the bowl. You may not see an obvious flow, but the system keeps topping up. That’s money literally going down the drain.
Paying attention to these subtle changes lets you catch the problem early. A simple part replacement usually fixes it. Ignoring it can mean months of higher water bills before you realise something is wrong.