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Venting Observations

Now that the main is finally vented well, I've done a little skimming and flushing of the boiler, things are lining out. Sight glass is much more steady and I finally have my system almost perfectly balanced. Boiler actually never even gets to 1oz now when running since the steam is heating more area, more evenly. The radiators are just sucking up all the steam and my previous theory that the 3" header is a little small, is apparently wrong. Couple observations along the way:

1) I have one or two Maid O Mists that I think are Duds out of the box. When I switch them with a Gorton the same size, it works perfectly. Maybe you get what you pay for sometimes. Others however, work great.
2) Good old Hoffman 40 fill the gap nicely between the #5 and #4. So does a Ventrite 1.
3) I ditched 2 varivalves at the end of the system on radiators that were still heating up slowly. replaced them with a Gorton D and a Gorton 6 and balanced it out almost perfectly.
4) Big Mouth "burps" just a little steam right before it closes.
5) Hoffman 1A, #5, #6 and a couple #4 are working everywhere based mainly on radiator size... except a single radiator with a long run out. I'm suspecting that run out has a partial blockage. I wonder if it was left partially or mostly closed over the years or someone was trying the "throttle" the radiator using the valve.... or just lack of condensate flow from imbalance. Not sure how I could flush it out. I'm hoping with use, over time it's starts to clear itself a little. It's heating up descent now. Its valve stem may need repacked.

Here's one theory, I've seen that valve stem leak a little steam when pressure climbs, It's unnoticeable at 0.5-1oz. But, maybe it's leaks more under vacuum as it's heating so rather than drawing more steam in under vacuum, the leak balances the run out to atmosphere and slows the steam.

Anyone of the veterans seen that?


  • What makes you think you have a blockage in no. 5?
    If you had a pool of condensate, I would suspect some water hammer from it.?—NBC
  • FredFred Posts: 6,577Member
    How big is that radiator that you question? I have some large radiators that don't heat all the way across unless it is near Design day. A fully hot radiator is not the gauge for successful balancing. Having the room it serves comfortable is my measure for proper balancing. JMHO.
  • mikeg2015mikeg2015 Posts: 377Member
    It's I think 55 EDR. It's about the same size and height as 3 others. Goal is just to get them heated across fairly evenly, os proportional to the size. The radiators are sized fairly well for the heat loss of each room. SO this room is a little cooler than the others. But it's a LOT better than before.

    Most of them do heat all the way across on recovery from setback in the morning. It takes about 30 minutes from a warm start. But this one only heats about 2/3rds across.

    But I do agree, that you can manipulate the vent size to balance things. But fortunately the dead men ran their calculations.

    I think they also intentionally ran the main counter clockwise starting towards the NE corner of the house and circling to the west, south and back. This way, the shaded part of the house get heat slightly sooner. I guarantee this was not by accident.

    Actually, I think I know the company that installed it originally, and they are still in business 110 years later doing mostly commercial and industrial pipe fitting and mechanical work.
  • mikeg2015mikeg2015 Posts: 377Member
    Good point about the blockage and hammer. I was thinking maybe in the vertical near the valve. But that's probably unlikely it would stay silent.
  • 110 years ago, the boiler would have been fired up with coal, and kept burning until spring, so main venting was not so important as it is now.
    If you use a temperature setback, for economy, I would only use a couple of degrees, as the same amount of fuel has to be burned to reheat the system, and house contents. A constant setting, at a lower temperature (65 deg.) can be just as comfortable as 70-60 deg.and uses less gas.—NBC
  • mikeg2015mikeg2015 Posts: 377Member
    I have evidence of the coal days. There coal dust up on rafters in the boiler room and a room that was likely used as a coal bunker. I also found an old oil nozzle, so I’d wager it was converted at some point to oil.

    I mainly use setback for comfort but my thermostat tracks run time so I need to compare a couple days trying a smaller setback. I suspect it still saves. Ultimately heat loss goes down and more importantly, stack effect is reduced.

    I do like that with radiant heat, comfort is maintained at a lower air temp. I have one schedule for summer, spring/fall, winter and winter 2 - boiler. Heat pump handles Most all the heating above 38f.
  • mikeg2015mikeg2015 Posts: 377Member
    .. so how I’d economy improved by not using setbacks? Why would boiler efficiency drop with using a longer run time vs short runs all night?

    With my Winter 2 schedule, setback is only 65f at night, 67f daytime. Normal temp is 68f. During the day, down stairs controls the temp, at night ustairs controls the temp. I do this by setting back more upstairs daytime, downstairs at nighttime.

    Really easy to do. Just use 2 thermostats. Can use isolating relays if you have ac or heat pumps or a single transformer of heat only.
  • Try a constant 65, and see if anyone notices!—NBC
  • mikeg2015mikeg2015 Posts: 377Member
    edited December 2017
    Interesting idea. Though I’m pretty sure my wife will go for it.

    I might trim the setbacks a little smaller and see how it does.
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