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Leaking hot water radiators


I am new to the forum and hoping to find some help. I recently had two old cast iron radiators from my 1900s Philadelphia row home (which had been in perfect working order) sand blasted and powder coated by a local place. After hooking them back up and starting to pressurize the system, I discovered that there were small leaks between multiple sections of the radiators. I tightened down the bolts on the sides, which seemed to work a bit for one of the radiators but not for the other.

Does anyone have any other suggestions? Do I have to scrap my beautiful new radiators?




  • unclejohn
    unclejohn Member Posts: 1,833
    Try tightening again with one person on each end going together.
  • kcopp
    kcopp Member Posts: 4,438
    That's the down side of powder coating old rads. Baking process can destroy the paper gaskets.
    You could try this...

  • unclejohn
    unclejohn Member Posts: 1,833
    I have used Fernox cleaner and protector and like their products. Didn't know they made a sealer. Would definitely give it a try
  • Steamhead
    Steamhead Member Posts: 16,886
    Those radiators have push-nipples in them, which can be replaced, and any gaps sealed with hi-temp silicone caulk. Do Not over-tighten the rods or you may crack the radiators.
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service