Plug 3 / 8" De Dietrich 7621657

A plug with a 3/8 inch thread is a small but essential fitting for sealing unused ports or openings in heating system components. It is commonly used on boilers, pumps, and manifolds to prevent leaks and maintain system pressure. This plug is easy to install and provides a secure seal. Keep a few on hand for maintenance tasks or when adding new components to your heating system. Ensure the thread type matches your equipment.