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CI Radiator Plugs

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EBEBRATT-Ed
EBEBRATT-Ed Member Posts: 20,145
in THE MAIN WALL

Working on a system that at one time was vapor. 25 years ago, they had a plumber install a HW boiler and convert it to HW.

I was there this winter when it was cold and it seemed to heat ok. Because it was vapor and now HW it never had air vents on the rads and the plumber never put any on when he did the conversion.

Instead, he installed a standard air scoop with a vent but the scoop is installed backwards. At some point someone added a Spiro vent on the return. I drained the system because of a bathroom remodel and started taking some of the 1/8" threaded plugs out of the vent tapings. Not all the rads have any vent tapings. I got 2 out with my impact they are slotted screw plugs, but the rest won't budge and I didn't want to break them.

Of course, the weather turned cold again so I had to get the heat back on. House is not occupied right now.

Somehow the air must get out eventually because it heated this winter but right now it does not heat well.

So two options.

The slotted screw plugs are not a good option to remove IMHO.

There are 1" radiator plugs at the top end of the rads. I am either going to drill and tap the plugs or try and get them out and install 1" X 1/8" bushings.

Just wondering if anyone has tapped those caps and are they thick enough to tap?

Comments

  • hot_rod
    hot_rod Member Posts: 27,414

    probably not all caps are created equal. The cast iron type seem to be plenty thick to tap.

    Use an 1/8” NPT it is the finest thread pitch 1/8-27

    1/4 NPT is 1/4-18

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • offdutytech
    offdutytech Member Posts: 248

    Give it a try with the tap it should work. Just have the new bushings on hand for a backup.

    Owner of Grunaire Climate Solutions. Check us out under the locate a contractor section. Located in Detroit area.

  • kcopp
    kcopp Member Posts: 4,669

    You should be able to find a nice spot on the radiator itself. I have done this a number of times. Go slow and steady. Good amount of oil.

  • mattmia2
    mattmia2 Member Posts: 16,681
    edited March 15

    might be more meat if you drill near the edge of the plug rather than near the center. this is where you can do a lot of things with a milling machine and an end mill or d drill or other bit that isn't self feeding that you can't freehand with a hand held drill.

    i wonder if there is some sort of a piloted mill that you could use like you use a hole saw on larger plugs to drill out the middle of the air vent plugs, drill a small hole in the middle of the plug with a twist drill then the mill's pilot follows the pilot hole.

    aren't you retired….

    EBEBRATT-Ed
  • Big Ed_4
    Big Ed_4 Member Posts: 3,529
    edited March 15

    If the heat is working find any thoughts of letting sleeping dogs lie … Some old conversions wanted to trap the air in the radiator and use it for expansion . Trapping air in a over size radiator is a service tip for over heating ..

    There was an error rendering this rich post.

  • mattmia2
    mattmia2 Member Posts: 16,681

    if you put the spirovent where it belongs the air might work itself out or is the circulator on the return so you can't without moving that too?

  • Steamhead
    Steamhead Member Posts: 18,468

    I would just drill out the 1/8" plugs, re-tap the holes and install vents that way.

    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
    PC7060Grallert
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 20,145

    @mattmia2

    More on the "retired " part later.😀

    mattmia2
  • Big Ed_4
    Big Ed_4 Member Posts: 3,529

    Old plumbers never retire , we just slow down with rules to live by.. :)

    There was an error rendering this rich post.

  • 109A_5
    109A_5 Member Posts: 3,959

    @EBEBRATT-Ed can you drain the system, pull a vacuum on it to get more of the air out, then refill and bleed the radiators that you can ?

    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
  • pecmsg
    pecmsg Member Posts: 7,043

    Coobeast 35 Pcs Screw Extractor and Left Hand Drill Bits Set, Easy Out Screw Extractor Kit with HSS Steel Reverse Drill Bit for Broken Nuts, Stripped Bolts Remove - Amazon.com

    Has made drilling out problems easy!

    Grallert
  • Grallert
    Grallert Member Posts: 1,113

    I like to drill and tap the plugs out but I use reverse twist drills on the off chance the plug will back its self out while drilling. It happens sometimes.

    Miss Hall's School service mechanic, greenhouse manager, teacher, dog walker and designated driver

  • pecmsg
    pecmsg Member Posts: 7,043
    https://forum.heatinghelp.com/discussion/comment/1892302#Comment_1892302

    I found it happens most times. Just the heat generated helps.

    Grallert
  • Intplm.
    Intplm. Member Posts: 3,005

    Is it in your plan to move the Spirovent and installing it where the air scoop is? Maybe cut in a purge tee(s) on the return? That might be enough.

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