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Bleeping blinking lights - what do they all mean??

trisha Member Posts: 13
Hi All,

I have a problematic Peerless Steam boiler (62-14) (about 15 years old) which heats a 4 story 8 family building (approximately 8500 sq ft) (posted about previously here).  I've always had issues with the boiler in terms of expense and complaints about uneven heating but the last few years have gotten worse.   I noticed last year and this that the boiler seemed to be short-cycling.  Between the two plumbers (the first who installed the boiler and the second who has helped service/troubleshoot it) I use, a third plumber I brought in as an objective opinion, and feedback from this site, I know: 1) the header piping is terrible (wrongly configured and undersized), 2) the boiler is over-sized for the building, and 3) there are other things I need to address beyond the boiler issues (insulating pipes, finding a better thermostat system, considering TRVs).

I offer the above by way of background- the specific question I have today is about a new way that my boiler is now misbehaving.  Here's what happened:

Having been chastised about not keeping the water clean (which likely has contributed to some of my issues), I was trying to be much better this winter about emptying a bucket or so every week.  About a month ago, I did just this in the morning.  The water level in the water gauge (the thing that looks like a test tube to me) was at about 50% before I took out about 2 gallons.  The light on the low water cut-off came on (as I assume it should), and I left figuring the water feed would kick on and add water.  That night I got a call from the tenant who has the thermostat in their apartment saying the boiler didn't seem to be staying on long enough to reach the thermostat setting (this was in the middle of the really cold temperatures).  When I went to the building I found that the water level in the guage was low, maybe about 35% of the way filled (I'd been told about 50% was the happy place).  I observed the boiler for a bit before I did anything and,  indeed, it was coming on, burning for no more than a couple of minutes and then turning off again.  I don't recall at that time what the indicator lights were doing, but for sure no water was being added.  At that point, I manually added water to fill the guage to about the 75% mark, after which the boiler came on and stayed on so that the heat rose through the building.

Ever since that incident, this scenario has been replayed every couple of days, with my tenant now going downstairs and adding water when they realize the boiler isn't coming on and staying on.

This has never happened before.

Yesterday, I spent a couple of hours watching the boiler and the indicator lights and this is what I did and observed:

1) I emptied about 2 gallons of water (the boiler was not running at the time) until the LWCO red indicator light came on.  It blinked red for awhile then went off without adding water.

2) I emptied another small bucket of water.  The LWCO indicator again came on, first blinking then going to solid red, at which point the green light on the water feeder began blinking and started adding water with the light then turning solid green.

FIRST QUESTION: why didn't water get added after the first two gallons I took out - is the blinking light sort of like a warning or does it just mean that LWCO is assessing the situation?

A little later, the boiler came on and I went to watch it operate.  It ran for about a minute, then turned off.  The LWCO indicator light went solid red, then started blinking, after which the green light on the water feeder started blinking.  Then both lights when off without water being added.  The boiler came on again, but again only fired for a minute or so before turning off.  A few minutes later it came on again, fired for about 5 minutes before the red light on the LWCO began blinking, then the green light on the feeder blink came on, with both lights then going off without water being fed.

At this point, I added water to the system (so the water in the guage rose from approximately 30% to 70%.  The boiler then immediately came on and stayed on.

SECOND QUESTION: What's going on??  If I had to speculate with my puny steam plumbing knowledge, I would guess that somewhere between when the LWCO senses that the water level is low and when the water feeder would actually add water, that water is returning from the system and going back into the boiler.  So, just when the water feeder would add water, the LWCO senses the addition of this water and turns off the alert.  Does this sound right?  If so, how do fix that (it sounds like the feeder should kick in sooner, before the water comes back). Or if not, what part do I replace???

The only change that was made to the boiler was that a few years back (and I think at least a year before the short cycling started) the second plumber changed the (I think) LWCO from the big bowling ball looking thing to an electronic control.  He did this because of my spotty maintenance record with respect to cleaning the water, thinking, I think, that there would be less harm if I was neglectful with the electronic control.  In the current situation, he has speculated that this might not have been a great idea because the electronic controls are too sensitive for how my system is operating.

Any thoughts on that?

Sorry for this very lengthy post, but I keep thinking it must be something very obvious to someone in the know.

thanks in advance for any answers


blinked red, then  (blinking I think)

I t


  • BobC
    BobC Member Posts: 5,408

    It sounds like the automatic water feed needs some work and the LWCO probe should probably be cleaned as well. call someone in and have them service it and have them look for the leak as well

    The more important issue is where is this water going? If you have to add water much more than once a month something is leaking, that leak has to be found and repaired if you want that boiler to have a long life.

    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • How about a new thread for this question?

    Your post will get lost in this LWCO problem.--NBC
  • Eastman
    Eastman Member Posts: 927
    those are her threads

    I posted it here so people had easy access to the previous information.
  • LWCO and piping problems

    Ask your plumber first to clean the probe of the LWCO, and then test it for operation.

    Next show him the installation manual for that boiler, and have him compare the required piping diagram with what is on your boiler, and have him rectify that, so that the piping is finally installed correctly. Check the pipe diameters as well as the layout.

    I believe a large amount of water is being blown up into the mains, and without a proper equalizer, the boiler is being starved of water, and its life shortened by a factor of 2 or 3.

    These modern boilers will only work properly when the piping has been installed following the instructions in the manual, and naturally the warranty is voided in the case of failure due to improper piping.--NBC
  • trisha
    trisha Member Posts: 13

    Thanks for the replies.

    If there was a leak in the system, wouldn't I see it somewhere? - either water coming out of a leaking radiator and damaging a ceiling or some obvious puddle on the return line (which is above ground).
  • BobC
    BobC Member Posts: 5,408

    One failure mode is where the leak occurs above the normal waterline INTO the firebox. The only clues would be disappearing water and a plume of steam coming out of the chimney.

    One way to find out if this is true is to overfill the boiler and let it sit for several hours and then looking around the boiler and into the firebox for any signs of water. Water in the firebox would have been turned into steam by the fire but now will just sit inside the firebox.

    Hopefully there is another reason for the waters disappearance.


    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • icesailor
    icesailor Member Posts: 7,265
    Coming of the tides:

    I don't normally post here because in no way do I consider myself an expert on Steam. I reviewed everything said and there isn't a thing I disagree with. I'm here to learn.

    Two things. Is that a 1 1/2" equalizer in the shadows in the photo's of the boiler piping? It looks like it is fed through the run of the tee and the branch/bull goes to the header.

    You owned the building for 15 years. The boiler was replaced. The risers look to be what can come out of the boiler. The header is wrong as is stated. But I have observed in what steam that I have done is that the manufacturer decides where the maximum efficient water line should be located and give some sort of plate to locate it. I worked on a large Peerless (EG) Steam Boiler that had a ton of problems. One being that it would surge and kick off. The water level was being maintained so that the water was just showing in the gauge glass. Any surge would kick it off. The I/O manual was there and I found Peerless's water level from the floor. About 4" higher than was being maintained. The combo feeder/LWCO as installed, maintained the level at this level. I marked the jacket with a magic marker and the gauge glass and told the owner to keep it around that point. It would steam better. It did. The rating plate and the level plate were in a packet that the installer didn't bother to open. Perhaps you have a water feeder/meter that isn't maintaining a proper water level. You mentioned that there was no rating plate on the boiler. I had to get a new plate and install it on the boiler from Peerless with all the information for that exact boiler with a serial number. I have also found many steam boilers that had auto-feeders that maintained levels that were way below that level line. But where I worked had very few steam boilers.

    I'm not in any way suggesting that anything and everything said by others isn't true. Its just something that I didn't see mentioned. Often, its the broken shoe lace that trips you up. Is the factory water level clearly marked on the boiler and is it filled to that line?

    For as long as you have had problems with this, sooner or later, someone has to just grab the BIG bucket out of the truck, the big pipe wrenches and step ladder, and start to fix the things that need to be fixed.

    Its fixable. And the right person can and will fix it.
  • icesailor
    icesailor Member Posts: 7,265
    edited February 2014
    Low Tide:

    Additionally, that boiler model number given for your boiler may not be correct. I looked it up and the largest one for that listed series has only two risers (2") but still needs a 3" header. Your has three risers.

    If it is the suggested boiler, the proper water level for THAT boiler is 25 7/8" from the top of the boiler foundation. If it is a bigger boiler, it might be different.
  • Steamhead
    Steamhead Member Posts: 16,237
    Even without seeing the manufacturer's piping diagram

    I can tell you that boiler is piped totally wrong.

    What's probably happening is the improper piping causes water to be pulled out of the boiler along with the steam. This causes the water level to drop, and the low-water cutoff will then stop the burners. Sometimes you can actually hear the water rushing thru the pipes when this happens- assuming it doesn't cause banging.

    Have it repiped properly. Where are you located?
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
  • trisha
    trisha Member Posts: 13
    Lost in Brooklyn

    Thanks for all the comments and input.

    My immediate problem is why water isn't being added the way it should, so I'll start there.

    It happened again this week that I got a call from the tenant on the top floor that the heat was only lukewarm. On investigation, I found the boiler off, with the low water indicator on the LWCO flashing red and the feed indicator on the water feeder on as well. The water level in the site glass was very low. When I manually added water, the indicator lights went off and the boiler came on. No troubles since then, but we'll repeat this cycle again in a day or two if more water isn't added.

    From my rudimentary understanding, there are three sensor/controller parts involved in adding water the boiler: the probe inside the boiler, the LWCO and the water feeder. Here's what I'm thinking:

    (1) If the probe weren't working right, it wouldn't be sending the right information to the LWCO, i.e., sensing that the water level was ok when it wasn't which would have caused the boiler to crack, or sensing that the level was low when it wasn't which would cause water to be added and overfill the boiler (which is never the case).

    (2) LWCO (McDonnell Miller PSE 800 series)- I don't think this is my problem child because it has been reliably turning off the boiler when the water level was low and indicator lights turn off when I add water so it seems like the probe and the LWCO are talking just fine.

    (3) water feeder (McDonnel Mill UniMatch WFE) - I am suspicious that this is where the issue is. If the red light is flashing on the LWCO, that means it is calling for water. And the water feeder seems to be receiving the message since its indictor light is flashing too. But no feeding is happening.

    First question - is my logic above correct, or have I over-simplified because I don't really understand how the whole system works? Second question, can only the automatic feed function on a water feeder be malfunctioning (my plumber tested the manual feed and, since that worked, said the unit was fine)?

    It seems to me that I should start with changing the feeder and maybe cleaning the probe and see if that resolves this particular problem.

    The longer term issue is that I have an oversized and poorly installed boiler. I was quoted $6000 to fix the piping on this boiler, versus $30K to install a new, presumably smaller and correctly piped, new boiler. Obviously spending $6000 is preferable to spending $30K, but I'm wondering if, because this boiler is oversized, I will always be fighting an uphill battle. In other words, can an oversized boiler be made to work efficiently in a smaller building?

    thanks in advance for the help!
  • trisha
    trisha Member Posts: 13
    water leak

    HI Bob,

    thanks for that suggestion. I've been on the roof a couple of times this winter (though can't say whether the boiler was on or not) and never noticed a plume. If the water was going into the firebox, wouldn't I hear something when the boiler was running - spitting or crackling or something? Isn't is possible that with how much the boiler was been running this winter due to the very cold temperatures, that what I'm losing is evaporation that should be being replaced if my probe-LWCO-feeder system was working properly?


  • Dealing with the symptoms

    The problem with your boiler is more than the LWCO and water-feed.

    Running a boiler which shuts off repeatedly, and often puts excessive thermal stress on the iron sections of the boiler. Don't concentrate on the symptoms, but rather on the cause-bad piping, installed cheaply, and badly. Don't let the situation get to the point of " the call at midnight Friday".--NBC
  • MJW
    MJW Member Posts: 7
    Water Feeder

    Did you check water feeder screen filter?
  • Fred
    Fred Member Posts: 8,541
    Logic makes sense

    Your logic about the interactions between the LWCO, the probe and the water feed makes sense but the real question is where is the water going? The LWCO should not be calling for water everyday and certainly the boiler should not lose enough water to shut the boiler down. Are any of your wet returns buried below concrete? I know you say you don't see any leaks but there has to be one/more somewhere.