If your home has a pressure regulator (a bell-shaped device usually installed near the main shut-off valve), it may have failed. Sometimes tapping it gently or adjusting the screw can temporarily restore flow, but a failed regulator usually needs replacement.
Note: If you have no water at all, the supply line is blocked or broken. If water is backing up into tubs and toilets, the main sewer line is clogged. Common Causes of Main Line Blockages main water line clogged
Over time, the ground can shift, or the pipe material can degrade (especially "Orangeburg" or old clay pipes), causing the line to sag (a "belly") or collapse entirely. Warning Signs to Watch For If your home has a pressure regulator (a