flooded steam boiler

[Remingtonsteele]

Peerless steam boiler in a 6plex ran fine for a month now floods every day.
when I drain it & restart it will run fine I have watched it cycle for hours but the next day its flooded and down.
high limit, low limit, low water cut off, M&M 47-2 fill valve everything seems to operate normal. but sometime in the night it floods. what am I missing here?

[snupytcb]

is it strictly steam or does it have a hot water loop?

[Remingtonsteele]

stricty steam old one pipe system, with radiators

[flange]

lower the pressure, and allow it to go to 0 psi before restarting. those old systems typically run 1-2 pounds max. if you dont allow a one pipe system to shut off every now and again, condensate gets logged in the rads and water is made up. when it does shut off, the condensate comes back and floods the boiler causing you to have to drain it.

[Remingtonsteele]

ok, I have drained it to 0 psi 3 times. every time I restarted it. after restart the sight glass will over fill but I dont hear the auto fil kick on. I bleed off 5-10 gallons then it will stabilize and run till the next day (6-10 hours). it is set to run 2 psi on the low end and cuts off at 5 on the high end.

[Remingtonsteele]

also each time I drain it I get between 50-100 gallons to drain down to 0 psi

[Dallas Duster]

Could the makeup be overfilling?

[fartbutstudly]

As flange stated, Lower both cut in and cut out. 0 psi cut in, 2 psi out. If you want to really control a steamer, try a vapor-stat, senses in oz. of pressure! I would verify safe operation of LWCO, and close the make-up water. Make sure your mains are pitched, { 50 year old hangers come loose} sagging mains hold condensate. Always check operation of main vents..

Good Luck stay safe

[meplumber]

Fart is on to something, that I was about to suggest. I would check my main line vents. I have seen one pipes flood a few times due to a bad main line vent. Any chance there are thermostatic vents on the rads? A combination of malfunctions can drive you nuts chasing your tail.

[Remingtonsteele]

ok, thanks.
The fill valve could be overfilling, just not doing it when i'm monitoring the system.
i'll try adjusting the cut in/off set points. LWCO does work it cuts out in blowdown & draining.
I ordered a new M&M filler too its 10+ old anyway. I do have some condensate trapped I can hear it when the boiler heats back up but I havent tracked them down yet. that fill valve aint cheep so I wanted a second opinion befor I order it. I'll put in the new valve and change the sets and see what happens.

[Remingtonsteele]

I am new to this building so I'm still getting familiar with them piping & system, some radiator vents have been pluged off, others are there. I had one complaint from a tenant her vent valve was leaking water but have not addressed it yet I thought it may be due to the system flooding and the steam pushing it up. I thought if I can stablilize the boiler the vent may be fine. Thus far I have only seen 1 main line vent in the boiler room. I have felt like I was chasing my tail on this one, thought I had it dialed in twice now then I get the phone call....."my heats not working". Then I hang up the phone and scream. lol.

[ascj]

My experience is fix the venting and piping........and then your boiler stabilizes.

[meplumber]

My experience is fix the venting and piping........and then your boiler stabilizes.

Same here. On small steam systems, always look at the piping and venting first.