Way overfired boiler

HowardLong

I have a boiler in a 3 story apartment building that used to also heat the 2 sections next to it. We can see the pipe in basement where the returns used to connect. It has a shared wall with one section and the other section of the building was completely removed and torn down years ago.

The section of the building that it heats now is only 800sqft EDR, but the boiler there is a LGB-9S, which is rated to 2633sqft! The vents are getting soaked with water and then getting stuck, I've started replacing the old single vents with Gordon no2s and have double the venting capacity to try to help with the issue, but it's not enough and I don't want to add 20 vents. We've already downfired the boiler to the ratings on the boiler plate as low as it can go. Is there anything else we can do short of replacing the whole thing with a smaller unit?

mattmia2

if the piping is right and the water quality is good it shouldn't be throwing water everywhere, it will just short cycle. is it 1 pipe or 2 pipe?

HowardLong

It's a 2 pipe system. I don't think the water is very good. I had an old tech come out and he skimmed it but I don't think it helped. I can still see the sight glass level bouncing and inch up and down. I have PH strips to test the water and it comes back at ~7.

mattmia2

that skim port with the ell pointing up isn't going to work, it will fill the boiler above the skim level and the oil will just stay in the boiler. if the oil is still there after 30 years is somewhat doubtful. the piping itself at the boiler looks good although on 2 pipe pressure that is too high can push the water out of the boiler and in to the returns. do the traps work? i assume they have not been looked at in a long time.

HowardLong

When the tech came out and skimmed he turned the port down, this is just an older picture. I've already replaced a trap on one of the radiators which was broken. It didn't have any actual guts, just an open pipe, so I put a working one in. There are these 2 traps in the basement as well though that I haven't touched. They come off of 2 of the return lines.

Jamie Hall

Those two traps you show in the basement are … just weird. If the outlets go below the water line, they won't vent anything (if they went into a dry return they might be crossovers) and I have to ask what the pipe is to which they are attached?

I will also ask what pressure this system is running at, maximum? Anything over 2 psig is going to be a problem…

I think you need to trace every single pipe you can find and figure out what it is supposed to be doing and how, if it needs to be vented, how it is vented.

As to fixing the ridiculous mismatch between boiler size and installed radiation… more copious venting isn't going to help. Almost anything you do isn't going to solve the problem of having to bring that monster up to a boil, so this is one case where you're stuck with really poor efficiency. However, it is likely that it might help to have a time delay on restarting after an on cycle.

techforlife

Sounds like too much steam pressure. Pigtails/manifold clogged?

HowardLong

I'll get some more pictures and I'll make a drawing of all the pipes.

Those pipes come up from 2 return lines, into the traps and into a 2in return around the boiler.

This boiler used to have an Illinois Vapor Heating System which let the boiler go into vacuum intentionally. It's long since been defunct, but the float bowl is still in place, just valved off so it isn't connected to anything. The original venting/vacuum sealing mechanism is long gone though. I assume that's why these two little traps are installed way up at the ceiling, something to do with this vapor system.