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Manual for a Capitol Gas Boiler model number 9-11B.

I have a late 1940's to early 1950's Model Number 9-11B- 180,00 BTU Capitol Gas Boiler made by the United States Radiator Corporation of Detroit, Michigan. I know the manufacturer is long gone, but I would really like to find a manual for this boiler and haven't been able to locate one. Any ideas of where to look would be helpful.

The reason behind the need, is that my pressure and temperature gauges are no longer working and I would like to find a replacement part to work with the old dinosaur. Additionally, I have not been able to locate the temperature/pressure relief valve on the boiler and would like to put one on. There is a Bell and Gosset pressure relief valve on the supply line which is rated for 30 lbs. My boiler service company didnt' seem phased by the absence of a code valve on the boiler when they serviced it, but I am a little concerned. Anyone have any thoughts on whether or not I am at a serious risk here having only the Bell and Gosset relief valve on the system? I don't want to blow up the family...

I know everyone would recommend replacing the boiler for efficiency, but I would really rather just repair what I have for now.

Thanks for any insights or direction.


  • Steamhead
    Steamhead Member Posts: 16,712
    Gauges and relief valves

    are pretty much standardized parts these days. I'm not sure what (if any) code is in force in your area, but the relief valve on the inlet line might meet your code if there is no valve between the relief and the boiler.

    Your heating contractor should be able to get these parts and install them for you in such a way as to meet code. If you're not happy with your regular contractor, try the Find a Professional page of this site to find another.

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