What does a trap primer do in plumbing systems?

A trap primer is a specific device used in plumbing systems to introduce a small amount of water into a trap, which is essential for maintaining a water seal. This water seal prevents sewer gases from entering a building through the plumbing fixtures. Over time, traps can dry out due to evaporation, especially if the fixtures are not used frequently. The trap primer activates automatically, supplying necessary water to refill the trap and ensure the seal is intact.

The introduction of water is crucial because, without it, the trap can lose its effectiveness, potentially allowing harmful gases into the living space. This aspect of maintaining a seal is essential for health and safety in plumbing systems, making the trap primer a vital component in installations where traps may be at risk of drying out.