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Residential steam boiler high water-level alarm / shut off

ChrisCodes Member Posts: 4
edited July 2020 in Strictly Steam
We are in the process of selling our house (in NYC) that has natural gas fired, single-pipe steam heat (Burnham boiler from about 2008).
The inspector that came told the buyers that the boiler should have a high-water level alarm in case the auto-fill gets stuck on and the water rises too high in the pipes and comes out of the radiators.
(side note: This made me chuckle because for the first 4yrs that we owned the house the auto-fill was broken, and I would just go downstairs and manually fill it whenever we noticed the heat wasn't coming on! It's since been replaced and works great)

Since hearing this news from the inspector I've been looking around to see if I could find such an alarm and I've found nothing!
I've found one other post on these forums of someone who rigged up a high-level shut-off on a boiler installation, but I would have thought there'd be more discussion of it if it were common practice. I'm definitely able to sweat copper and can handle basic mechanical stuff and wiring, but cutting and threading 2" steam pipes is not something I have the tools for, so I can't see where I could even put such a device (if it exists).

So two questions:
1. Is this common? ...or do you think the inspector is just trying to make the homeowners feel like he's doing he's doing a good job?

2. Suggestions for how to do it / part numbers? It'd be great if there was some sort of special sight-glass with a probe at the top for this, since there's no place on the boiler where such a probe could be fitted. Perhaps adding a T between the top of the glass and boiler, or a branch on the pipes with the pressure sensors (same height as the top of the sight-glass)? This way I could avoid having to modify the steam pipes... but what to use as a water sensor that wouldn't be affected by the steam?

Thanks in advance!


  • ethicalpaul
    ethicalpaul Member Posts: 2,802
    Ask the guy to show you on any residential steam manual where the part is, and how to acquire one.
    1 pipe Peerless 63-03L in Cedar Grove, NJ, coal > oil > NG
  • EzzyT
    EzzyT Member Posts: 1,113
    A high water level alarm isn’t required as per any codes.
    Creative Solutions Plumbing & Heating LLC
    Lic #12683
    Co-Owners: Fred Drescher, Jr & Eliezer "Ezzy" Travis
  • ChrisCodes
    ChrisCodes Member Posts: 4
    He's not my inspector - he's the buyer's so I didn't get to speak with him. I got this info by way of the real estate agent who was there during the inspection.
  • ChrisCodes
    ChrisCodes Member Posts: 4
    I know it's not per code - and told my agent to be sure to relay that to the buyers...
    EBEBRATT-Ed Member Posts: 8,602
    He is asking for something that probably not code required (I don''t know New York Codes) but what @EzzyT is good enough for me.

    If this was a commercial job it would probably be a good idea (though overflow traps can be another alternative) but still probably no code required

    JUGHNE Member Posts: 8,192
    If it were actually required.....would a F&T installed above the water line dump the water if overfilled and then a water sensor could trigger an alarm. You certainly want a floor drain or sump pit.
  • Jamie Hall
    Jamie Hall Member Posts: 15,432
    Never heard of such a critter being required, though it would have it's points. Actually wouldn't be all that hard to do, if one was slightly ingenious. I like @JUGHNE 's idea, but I can think of several other ways to go, depending on what kinds of gadgets one likes to play with...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Danny Scully
    Danny Scully Member Posts: 1,319
    I did this and posted it awhile back.

  • ethicalpaul
    ethicalpaul Member Posts: 2,802
    edited July 2020

    He's not my inspector - he's the buyer's so I didn't get to speak with him. I got this info by way of the real estate agent who was there during the inspection.

    Yep, I figured. I meant tell him via the very efficient seller -> agent -> agent -> buyer line of communication :)

    On the bright side, if that's all they can find to complain about, you're golden!
    1 pipe Peerless 63-03L in Cedar Grove, NJ, coal > oil > NG
  • ChrisCodes
    ChrisCodes Member Posts: 4

    I did this and posted it awhile back.

    Hi Danny, yeah, that's the post I was referring to!

    Just to be clear, it looks like you're using a regular low-water cutoff and a Taco "Zone Sentry" valve - the "normally open" type. So if the low water cutoff actually turns on - i.e. there *IS* water - then the Taco valve shuts off. And it looks like you rigged that up to the same set pipes on the side of the boiler where you've got the pressure gauge - yes? Not familiar enough with the boiler internals to know, but doesn't steam come out of the hose when the boiler's heating?

    We have a sump / pump right next to the boiler so this whole thing would work.
  • motoguy128
    motoguy128 Member Posts: 335
    A vaporstat set at 0.5psi cut out will trip if it over fills by about 16” above the pigtail.

    I agree you could use a LWCO as a shutdown device with a NO zone valve.
  • retiredguy
    retiredguy Member Posts: 354
    edited July 2020
    The guy that is buying your house or his inspector probably worked for a commercial/industrial business that had a steam boiler that was equipped with a high water cut-off and alarm. The code on these boilers changed so often that even the insurance and/or the state inspectors had to consult the latest code book to be sure of what was and what was not code.
  • Danny Scully
    Danny Scully Member Posts: 1,319
    @ChrisCodes, you are correct, however, the hose was just for effect. There is a vent there normally.
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