Yes — because a Sure-Vent is a mechanical device, it can fail over time. The clearest sign is a foul sewer odor near a fixture where a Sure-Vent is installed, which means the valve is not sealing properly and should be replaced. Slow drains, on the other hand, are typically unrelated to the valve. When a drain is partially blocked, it fills with water during use, causing the Sure-Vent to detect positive pressure and remain closed. If you're experiencing slow drains, have the drain cleaned rather than replacing the valve.
