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antique rad flush?

StevieD Member Posts: 25
Hi Guys!

I am refurbishing the antique cast iron radiators in our home.
The water that came out of them at removal was very dirty, almost black. The insides of the rads are also pretty gunked up. Not to the point of clogging any holes though.

Other than a simple flush with water, is there any kind of chemical treatment I should run through them before reinstallation?

Thanks for any advice,

Steve in MD


  • hot_rod
    hot_rod Member Posts: 22,479
    It depends a bit on what the sludge or deposits are.

    For hard water deposits an acid based cleaner works best.  White colored deposits from frequent water bring filled

    Dirty, oily drain fluid may needs basically hydronic cleaner which is a strong detergent type cleaner.

    A multi direction nozzle on a pressure washer works good for flushing cast iron radiators

    chunks of rust adhered to the surfaces will be hardest to clean out.

    Ive seen a rubber ended tool that goes in a roto hammer to bang out the adhered rust and scale. I think one of the hydronic chemical companies sell that for panel rads

    Probably a UK based company like Fernox😗
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream