Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Coin Key radiator air valve

David_12
David_12 Member Posts: 1
Being new to old houses (!) I'm fairly certain that the small air valve on two of my radiators are "coin key" valves. It is a steam system and these valves are letting lots of steam out, so that I have to replace water too frequently. Are they indeed coin key valves? Is there any kind of adjustment on them? Do they wear out? And so on....

Comments

  • bob young
    bob young Member Posts: 2,177


    probably a hoffman 500 good for steam or hot water. fibre discs. replace with conventional steam air valve if possible. if not get a direct replacement . believe it or not ---they work
  • Mike T., Swampeast MO
    Mike T., Swampeast MO Member Posts: 6,928
    \"Coin Key Valve\"

    Believe that is the common name for a valve that could be operated either "by coin or by key" and used on WATER systems to remove air.

    A one-pipe steam system will have air vents (very often bullet-shaped) designed to let out air only. Once steam hits them they are supposed to close.

    I've never worked with steam but do know that many? most? all? of the air vents are directional--there should be an "up" arrow or similar. (Am pretty sure that the "point" of the "bullet" faces up.)

    If you replace on your own I've heard that the ones sold at home some home improvement centers are Chinese and quite poor in quality--you'll probably be better off going to a good plumbing/heating supply house. They come in different sizes (rates of venting) so you should probably either write down any numbers or take one with you.
This discussion has been closed.