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Testing old cast iron hot water radiators for leaks

How would I test a couple of circa 1916 cast iron radiators that are part of my forced hot water heating system that have been part of a shut off zone in the system for 15+ years. This zone was shut off years ago after a couple other radiators by windows froze, broke, and started leaking (before my ownership). Those damaged radiators were removed. I'd have to look again to see if this zone is tight. Anyway, I thought I'd test these 2 good looking radiators unattached to the zone. I've heard air pressure testing and warm/hot water testing. I heard water testing is best. How do I do this and what tools do I need for the job? What pressure should the water be? The furnace usually says 30 PSI in the cellar. Can I get these tools at Ace HW or Home Depot? Thanks, -forcedHotWater1916


  • Gilmorrie
    Gilmorrie Member Posts: 184
    Please call a pro whose references you've checked. I can tell that your are in over your head. Do not ever used compressed air to hydrotest water systems. The stored energy is huge, and if something carries loose, you could wind up dead. I know.
  • Jamie Hall
    Jamie Hall Member Posts: 22,162
    I look at little things... your boiler reads 30 psi? I hope not... I hope that he gauge is broken... shouldn't need to be more than 15 psi.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England