How Float & Thermostatic Steam Traps Really Work

In this Weekly Boiler Tip we begin a short series on steam trap types, starting with one of the most versatile and reliable designs, the Float & Thermostatic (F&T) trap.
Dec. 10, 2025

In this Weekly Boiler Tip we begin a short series on steam trap types, starting with one of the most versatile and reliable designs in the boiler world, the Float & Thermostatic (F&T) trap. You’ll learn:

  • How the float mechanism maintains condensate level 
  • How the thermostatic element removes air (critical for startup loads) 
  • Where F&T traps should be installed 
  • How to diagnose a failed-closed vs failed-open trap 
  • How to use a temperature gun to confirm water level inside the trap 
  • Why steam traps can be hot and still failed, and cold and still working 
  • The ~30°F temperature difference that tells you if the trap is functioning properly 

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.

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