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flushing a radiator?

I have a radiator that will only heat halfway,no matter how long the boiler pushes. The air vent valve is OK and a Gorton D.

I imagine its clogged with gunk. I have never tried to flush one out, is this possible? Any best way?


  • Jamie Hall
    Jamie Hall Member Posts: 18,689
    Ah... well...

    a clogged radiator is a rare beasty.  If it's the variety which has cross passages at both the top and the bottom, it is, in fact, very unlikely to be so clogged that it won't heat across.  And the cross passage at the bottom is pretty big -- inch or more in most radiators... the only way I can think of to flush out a one pipe steam radiator (and it's something I've never tried, so I'm just talking here) would be to disconnect it, take it outside, and run a hose into it.  But I've never done it.

    What pressure are you running?  Is it possible that the steam pressure is too high (over two pounds) and the vent is closing -- and staying closed?  I have seen that happen.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • GarvinP
    GarvinP Member Posts: 9
    Thank you Jamie

    Well only about 2 lb,..the rest of the rads get hot and I have taken the vent right off this one  and only the first several sections of the radiator get hot,..it takes a long time to do it and you can't (i can't) detect much air coming out of the vent hole,(I'm sure some does to get any heat in those sections)..Even after the boiler runs for a very long time only those get hot,..I dunno,.The only thing I could think of is clogged,..BTW I thought in most rads the steam goes across the bottoms then up but now that I think of it, most sections heat  at a section at a time,..(?)
  • Inlet Valve?

    Have you checked the inlet valve on the steam pipe coming into the radiator? Sometimes these break and don't open even though you can turn the knob on top.

    - Rod
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