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Radiator vents with street elbows

I have two radiators that are located so that installation and removal of vents is difficult (vent contacts the adjacent wall).  In order to remedy the situation I have installed a 45 degree 1/8" street elbow at each radiator and then connected the vent.  I using Hoffman 1A vents.  The radiators are heating however the problem that I am finding is that the vents are accumulating some condensate.  Do the 1A vents have to be vertical in order to work properly, or can I rotate the street elbows slightly to permit condensate to drain?  Thank you.



  • Jamie Hall
    Jamie Hall Member Posts: 22,928

    have floats in them, and need to be vertical or very very close to that to work properly.  That said, you might be able to tweak them just a tad -- I can't see that much condensate would collect in a street elbow, though...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • ChrisJ
    ChrisJ Member Posts: 15,462
    edited December 2011
    Hoffman 1A

    I had this issue with one of my radiators and the Hoffman 1A.  After draining the vent a few times I decided to swap it out for another new 1A.  Since then I have not had any problems but mine are 90 degree to the radiator.

    Another option may be a 90 degree street elbow with a Hoffman 1B.  I believe a 1B is the straight equivlant to a 1A and is avaliable at pexsupply.com

    I'm sorry if I'm way off, some pictures may help give us a better idea of what will work for you.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • Abracadabra
    Abracadabra Member Posts: 1,948
    dont understand what you are doing

    Wouldn't a 45 st. el decrease the room you have even more, since it sticks out even further into the area between the radiator and the wall?
  • ToddB
    ToddB Posts: 75

    I was thinking about switching to a 1B, but was unsure if it was the right application given the 1/4" NPT and that it is called a "convector" air valve.  I suppose that I could use a 1/8" nipple and reducing elbow to install the vent.  Do the 1A and 1B have the same venting rates on their 1 to 6 scales?
  • ChrisJ
    ChrisJ Member Posts: 15,462

    Not sure, but I can only assume the 1A and 1B are identical other than the 1B is intended for a convector.

    I'd go for a 1/8" to 1/4" reducing elbow if you can find one and try it out.  Chances are it'll work great.  The 1-6 scale on the 1A is FAR from accurate.  You can make it do almost any amount on just one setting by sliding the cap around horizontally.  Its a shame too being its such a good vent otherwise.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • Dave in QCA
    Dave in QCA Member Posts: 1,785
    Hoffman Vents

    Hoffman vents that have a right angle connection, 1A, 40, etc., have a tounge that protrudes from the vent and is supposed to be hanging in free air inside the radiator.  This device is desinged to draw the water out of the vent and prevent occumulation of water which causes the vent to spit.  If the tounge is laying inside a horizontal pipe it cannot function correctly and the spitting of water and/or water logging of the vent that you're experiencing is to be expected.
    Dave in Quad Cities, America
    Weil-McLain 680 with Riello 2-stage burner, December 2012. Firing rate=375MBH Low, 690MBH Hi.
    System = Early Dunham 2-pipe Vacuo-Vapor (inlet and outlet both at bottom of radiators) Traps are Dunham #2 rebuilt w. Barnes-Jones Cage Units, Dunham-Bush 1E, Mepco 1E, and Armstrong TS-2. All valves haveTunstall orifices sized at 8 oz.
    Current connected load EDR= 1,259 sq ft, Original system EDR = 2,100 sq ft Vaporstat, 13 oz cutout, 4 oz cutin - Temp. control Tekmar 279.
  • ToddB
    ToddB Posts: 75
    Thank you

    Thank you.  That is exactly what I thought may be happening.  It appeared that there was enough room for the vent's tongue to move, but I believe now that it may be impeded by the street elbow wall.  The radiators do heat well, so I do not think that the condensate it having a large impact, but I do not like the idea of collecting water and potential spitting.  I think that I may try the 1B with a revised connection method to play it safe.
  • Rod
    Rod Posts: 2,067
    Remote the Radiatior Vent

    Hi- I'm not quite sure where you are planning to go with this. A 1/8 inch pipe, size wise, has plenty of venting capacity ( almost enough to support a Gorton # 2 main vent ) so I don't see the benefit of going to a Hoffman 1 B.  If the clearance is that tight,  remote the vent away from the end  to a location where you have suitable clearance by using a 90 degree street elbow, a nipple coming up at a 45 degree angle and a 45 degree elbow to get the piping back to the horizontal before attaching the Hoffman 1A.   You could remote the vent 10 feet + away from the radiator and it would still work fine. You just need to slope it a bit so any water runs away from the vent. If you are getting excessive water then the problem is elsewhere and not at the vent.

    - Rod
This discussion has been closed.