How to Replace a Boiler Sight Glass Step-by-Step (Part 1: Removal & Safety Tips)

In this installment of Weekly Boiler Tips we’ll show you how to safely remove a boiler sight glass step-by-step—so you can replace it the right way. This is Part 1 of our Boiler Sight Glass Series, where we focus on safe removal and preparation. Next week in Part 2, we’ll walk through how to cut and install the new glass for a perfect fit and long-term reliability. This tutorial answers common questions like: How do you replace a boiler sight glass safely? What’s the correct order to isolate and drain a sight glass? How can you avoid pressure or steam spray when removing glass? Should you reuse old gaskets or rings? What tools do you need for boiler sight glass removal? 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 based in Louisville KY. You can learn all about this and more at WARE's Boiler University.