The answer to 'faucet foul smell' is that a foul odor coming from a faucet is often caused by bacterial growth or trapped debris in the faucet or drain. This can happen when water sits stagnant in the faucet or pipes, allowing bacteria to thrive and produce unpleasant smells.
Some common causes of faucet odors include food debris, organic matter, and mineral buildup. The smell may also be caused by sewer gas escaping through the drain. If the smell is coming from a specific faucet, the issue is likely isolated to that fixture. However, if the odor is present throughout the home, it could indicate a more serious plumbing problem that requires professional attention.