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Probe LWCO below sightglass

Detroiter48214
Detroiter48214 Member Posts: 15
in Strictly Steam
So, I've got a new Utica PEG-112, and it has an odd design that places the LWCO probe BELOW the sight glass. The manual refers to a LWCO check that you perform by draining the water below the sight glass with the boiler off. You then turn the boiler on, and if everything goes well, the low water light should come on after 15 seconds.

It seems to me that a LWCO check with the boiler off is not especially probative. At the same time, I've tried checking the LWCO with the boiler on, and I've always chickened out before the LWCO kicks in. Has anyone else encountered this design?

Comments

  • Robert O'Connor_12
    Robert O'Connor_12 Member Posts: 728
    Was the new boiler skimmed?
    If not, you should (or have the installer skim it).
    Look on pg. 22 of the installation instructions that were left with appliance.
    Many times a probe will foul requiring it to be removed and cleaned because oily film and crud collects on it.
  • Detroiter48214
    Detroiter48214 Member Posts: 15
    Definitely--I've skimmed it a number of times myself. Boiler wand and so on. The water's pretty good now. I've seen the LWCO work, too--it's just that, for fear of a dry fire, I've never really tested it with the boiler running.
  • Robert O'Connor_12
    Robert O'Connor_12 Member Posts: 728
    clean the probe
    before you add water.
    turn it on.
    does it fire?
    it shouldn't.
    now add water up to probe.
    it should fire.
  • Fred
    Fred Member Posts: 8,542
    A LWCO probe below the sight glass certainly doesn't leave any room for failure of the probe or LWCO. Is there any way to move that probe up some? What is Utica's explaination for placing it there? Is there a buffer amount of water below the sight glass maybe?
  • Detroiter48214
    Detroiter48214 Member Posts: 15
    I really don't know why they do it, and it's apparently not an error; in fact, it seems the boiler comes shipped with the LWCO hooked in.
    Doesn't look like there's any other spot for it, either.
    The probe does sit a few inches above the water line. I guess that's something, right?
    Is it possible for damage from dry firing to occur if there's still a small amount of water in the boiler?
  • Fred
    Fred Member Posts: 8,542
    I would think it depends on how "little" that amount of water might be and if it is suffecient to cover all of the floor of the block. I would call Utica and ask how much water is in the boiler when the LWCO is activated. It's even worse than the probe being that low, the water will have to be below that to trip the LWCO.
  • Detroiter48214
    Detroiter48214 Member Posts: 15
    I think I will call Utica. I'm interested to see what this design choice is all about.
  • Detroiter48214
    Detroiter48214 Member Posts: 15
    Well, I called in, and they say that there should be a decent safety margin between the time the sight glass bottoms out and the time that there's a risk of dry fire. I'm still not sure why they do it.
  • Fred
    Fred Member Posts: 8,542
    I'd always make sure that probe is clean and the LWCO is tested and working regularly. This is a case where I think I'd want an auto water feeder on the system too. With the probe that low, there should be little risk that it will add water unless it is really low. Maybe that's why they put it that low, as long as that "safety margin" is there.

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