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System Balancing and Interested Previous Owner Hack


I continue to learn more about my new (to me) steam heating system.   The last radiator off my main is not getting warm by the time the boiler shuts down.

Closed down the Vent-Rite #1's on a few of the rads in little used areas and that helped.

Noticed yesterday that the rad in the same room as the thermostat appears to have originally been the last radiator off the main, but at some point, the previous owner plumbed it (with copper!) to be the FIRST rad off the main.

While I still need to dial in my main venting (Gorton #2's are on the way), is it typical for the room with the thermostat to be the last one off the main?

I think this makes sense (you'd want the house to heat up before the thermostat shuts down the boiler), but with poor venting (I am planning to replace a single Dole 3c with 3 Gorton #2's), I can potentially see how someone would think this hack (making the thermostat-room rad the FIRST radiator) to be a worthwhile energy-saving step.

My thoughts are to fix the main venting, then, if that doesn't resolve the last rad issue, re-plumb so the last rad is the thermostat room rad.

What do you think about this approach?


  • first rad last rad

    what about moving the thermostat, or getting a honeywell visionpro with remote sensor in the colder area.

    when you have got the main venting increased, and the radiators slowed down with hoffman 40's, then you can start balancing the system.

    the best approach for venting is to get the air out of the mains, as fast as possible, before any riser has started to fill with steam [[slower radiator vents accomplish this]. then as main vents close, the steam will begin pushing the air out of the risers and radiators. next you will want to see which radiators are lagging behind the others on the same floor. these can be given slightly bigger hoffman 1-a vents.

    i think once you have the venting increased, the difference between first rad--last rad will be imperceptible.--nbc
  • Rod
    Rod Posts: 2,067

    I think you'll see a big difference with larger main vents. I would just install your new main vents first and see what the outcome is I don't like making more than one change at a time and then like to "live with it" for a while. If you make several changes at one time and have an adverse affect, then you don't know what change caused the problem.

      Next would probably be to slow down the venting a bit on the largest radiators. What setting do you have them on now?  It maybe the larger radiators are hogging all the steam. I have VentRite 1 s  and have been very happy with them.

    I can't even imagine what the piping must be like to make the last radiator on the main the first radiator on the main.

    - Rod
  • a3inverter
    a3inverter Member Posts: 64
    edited November 2012

    Completely agree with the "one variable at a time" approach..that is what I intend....and the first variable I plan to change is the main venting.

    I like the Vent-Rite's so far...all but one are pretty vintage...they show as having been manufactured in Newtonville, MA...right down the road from me.

    I'll post some pictures of my setup once I find our camera...

    In terms of the settings on the large radiators...I had tried setting a few of the large ones to closed (all but one of the Vent Rites are old enough to be manufactured in Newtonville, MA and don't have the numbered dial...just a 4-lobed metal knob) and got some decent heat out of the last one.  Two of the ones in the middle of the main were *blasting* out the heat and had gotten hot all the way across...
  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,849
    Radiator nearest the thermostat

    The radiator closest to my thermostat is a huge 6-column, 24-section radiator. it's on the second takeoff from the main, but its riser is shorter and larger in diameter than the one that comes off before it, so, all things being equal, it would be the first to get steam and it would shut the thermostat down in short order. It has a Gorton #4 vent to slow down its venting, so the upstairs radiators with the Gorton #6 through D vents can fill before the big one fills.
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
  • Bio
    Bio Member Posts: 278
    Balancing system

    "Vent Main very fast and Radiators Slowly" this is the way to do it, put Hoffman 40 on all radiators and your Vent-rite 1 set at 5 which is close to be as H40 than be very, very patient, all radiators will heat up at the same time, this is the way I did it and the house feels very comfortable in all rooms, no over heating in any room nor too cold in any either, adjust Vent-rites 1/2 number at a time, good luck
  • a3inverter
    a3inverter Member Posts: 64

    Installed 2 of the 3 Gorton #2's I purchased last night...third wouldn't fit with the fittings I had.

    They appear to be working as promised - from the time I heard the sound of boiling (I'm assuming this is when the steam starts moving through the main) coming through the main vents until when the vents got nice and hot and the sound stopped and no air was flowing out of them was around a minute, maybe less.

    Walked up the two flights of stairs to the problematic last radiator and the supply line to it was nice and hot, with the bottom of the first couple sections starting to warm up.

    This last radiator (with a Vent-Rite #1 fully open) still doesn't warm up the room as much as the occupant would like and I perceive the room to be "cold"...so I am going to run this way for a bit, and perhaps get a Maid O' Mist #6 to experiment.

    Thanks all for the feedback...
    RDSTEAM Member Posts: 134
    Which rad

    Is not heating? Is that the one that had been re-piped? Maybe the copper has sags in it which is causing bellies of water.
  • a3inverter
    a3inverter Member Posts: 64
    Rad in Question

    The radiator re-piped with copper has no issues getting hot.  The radiator that was staying cold is presently the last one off the main.

    I just put a Jacobus #6 on it and am waiting for the next boiler cycle.
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