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Reconnected radiator in one-pipe system

I recently reconnected a ~6 foot finned radiator in a back room of our second floor unit and have been getting inconsistent heat as well as water (heavy deposits) out the valve at the end, as well as water hammer. This unit had been disconnected over 6 years ago and is fed on it's own line from the boiler. After some preliminary searches online I boiled the valve in vinegar and also confirmed the pitch on the radiator but am still experiencing the same symptoms. I've been working my way through "We Got Steam Heat" and am questioning the feed pipe design that was put in place as well as the possible need for an adjustable valve due to the overall design of the single-pipe system heating this second floor unit. In addition, I have not been able to locate a main valve on either of the feeds leaving the boiler.

Can someone weigh in on whether or not the two-elbow feed (BackRoom_1.jpg) is appropriate, as well as whether or not the valve (BackRoom_2.jpg) should be replaced with something adjustable to help balance the system as a whole? I've included a diagram of the system (SecondFloor_Steam.jpg) and can provide more detail where required. Any help is appreciated as I have been trying to get this back room heated to alleviate some cold walls in the adjoining nursery. Thanks in advance!


  • Paul S_3Paul S_3 Posts: 1,257Member
    Pictures of boiler piping....and pics where this comes off the main would help.....are you sure everything is properly pitched? The way the piping is it looks like you really cannot get much pitch......whats the pipe size? I think i see a bushing between the 2 ells.....i would just put a regular may have to add more venting at the top of riser and a shut off valve
    ASM Mechanical Company
    Located in Staten Island NY
    Servicing all 5 boroughs of NYC.
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  • BobCBobC Posts: 5,072Member
    Make sure both the convector and that horizontal pipe are pitched right. What vent are you using now, convectors are happiest when they are vented slowly.

    More pictures of the boiler and piping would help.

    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • Jamie HallJamie Hall Posts: 12,161Member
    The way that is piped you may have real trouble getting adequate pitch to drain -- two elbows like that almost guarantee that either the horizontal pipe run will pitch the wrong way, or the convector will.
    Br. Jamie, osb

    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.

    Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
  • Danny ScullyDanny Scully Posts: 1,220Member
    Baseboard and 1-pipe steam don't play nice together...any other radiation options?
  • AbracadabraAbracadabra Posts: 1,948Member
    You need to hookup the convector as a two-pipe setup. There's been threads about it posted before.
  • SteamheadSteamhead Posts: 13,581Member

    You need to hookup the convector as a two-pipe setup. There's been threads about it posted before.

    It's also covered in "The Lost Art of Steam Heating".
    All Steamed Up, Inc.
    "Reducing our country's energy consumption, one system at a time"
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Baltimore, MD (USA) and consulting anywhere.
  • Big Ed_4Big Ed_4 Posts: 1,199Member
    What type radiators in the rest of the house ? If cast radiators look around for an replacement .. pipe and tube backboard should be piped with an return ... Pipe and tube baseboard in design needs its cover for convection ...
    I have enough experience to know , that I dont know it all
  • ADanemayerADanemayer Posts: 3Member
    Thank you all for the confirmation regarding the convection radiator. I had a suspicion that this was not piped correctly (the previous owner was a "self-taught professional" who left his mark in many ways) and will be looking to purchase a cast radiator in the next couple months to match the rest of the system.

    As far as the original diagram of the piping, I realized that there is one feed out of the boiler that splits to the back room and then to the rest of the unit. Apologies for the inaccuracy there.

    For now I am going to replace the cap where the first elbow sits and use a space heater until I can locate a replacement radiator. Anyone looking for a ~6 foot length of convection radiator? ;)
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