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)