Why Is There a Hole in the Side of a Boiler Safety Valve?

In this Weekly Boiler Tip, WARE explains the purpose of that small hole on a safety relief valve and why it matters more than many operators and technicians realize.
April 22, 2026

Why is there a hole in the side of your boiler safety valve? Should it be plugged, piped off, or left alone? In this Weekly Boiler Tip, WARE explains the purpose of that small hole on a safety relief valve and why it matters more than many operators and technicians realize. It is not there for pressure sensing. It is there to help protect the valve seat from moisture buildup, corrosion, mineral deposits, and possible valve failure. Safety notice: Always consult experts for complex repairs. Weekly Boiler Tips are compiled by the knowledgeable and remarkably prolific content creators at WARE, a family owned, third-generation, 69-year-old commercial and industrial boiler rental and service firm bas

Sign up for our eNewsletters
Get the latest news and updates

Voice Your Opinion!

To join the conversation, and become an exclusive member of Contractor Magazine, create an account today!