Leaks/ Water Hammering after New boiler 2 pipe

nicosiahills

Good Morning
Hope all are well and safe! Purchased 3 story Mix use corner property (9 stores 16 apts) 18mos. Ago and previous owner of 30 years put Band AIDS on every fix. I’ve been a Landlord for 40 plus years New to a 2 pipe system. I replaced most shut off valves and Thermostatic Traps. Old Boiler since 2006 with wrong pipe risers started leaking from side. I replaced with same boiler but gas conversion. 30inch high 2.5 inch risers to a drop header of 4 inches. Boiler went on for 3 days no problems. 30 feet down on main header 4 to a 3 inch to a 2 inch developed water leaks. Replaced a few feet of 2 inch then after water hammering 3 inch into a 2 inch. After that the 3 inch nipple started leaking. Replaced the 3 inch nipple and notice 4 (2x12) floor joists cracked and split above 3 inch main header thus straps snapped, reinforced all joists with lolly columns and plumber slowly jacked up 3 inch to where it should be, however wasn’t getting the proper pitch because the whole area was settling ( Since 1927) , Boiler back on after 4 hours severe water hammering, Previous Boiler was working on 2 sections of a 7 sections Peerless.
Thank you for your input in advance
Matthew

Jamie Hall

I think you have a project on your hands...

To avoid trying to put bandaids on the bandaids, I'd start right back at the beginning.

How well does the new boiler match the installed radiation in the building? I hope it was sized to that, and not just like for like.

Then start looking at your steam distribution piping. Make sure that all your mains pitch continuously down to a drip somewhere, and make sure that any reductions in size are done so that water can't possibly pool at the reducer -- which usually means, if the reducer is in line, an eccentric reducer. Next, what happens at the ends of the mains? There must be provision for condensate to get out of them. Depending on the system, this may be a drip to a wet return. It might, if there is a lot of headroom, be an F&T to a lower dry return. There must also be a way for air to get out of them. This might be a crossover trap to an adjacent dry return, or it might be a vent. Then take a look at the dry returns. They too must pitch so condensate can drain, and it's common for the to follow the pitch of the adjacdent mains -- so they will need a drip to a wet return at the outer end. Sometimes they will be sloped back to the boiler, in which case they will need a drip at the boiler, of course. The dry returns on a two pipe system absolutely must be vented. Since they never see steam, being separated by traps or water seals, they can be ties together at the boiler, before they drop, and vented there.

Wet returns -- if you have them -- must, in fact, be wet. Make sure that they are completely below the boiler water line for their full length.

Make sure all your runouts and radiator returns are properly pitched.

Make sure your pressure is correct -- cutout no more than 1.8 psi.

I you don't have it, get a copy of "The Lost Art of Steam Heating"...

JUGHNE

Could we see pictures of the reducing set up for the steam main?
More pictures the better including the boiler piping floor to ceiling. More input from here if we can see the situation.

nicosiahills

Good Morning Jamie
Thank you for a quick response. The boiler size was sized ok. We went around all the mains and returns and all the pitches are good. I’m sorry what is a F & T? I do remember we changed 6 thermostatic Traps in the basement 2 in the front ,2 in the Middle , 2 in the Back. Could these be them, Did I put the wrong ones? My Bad if it is. I will provide photos. I do have the Book. I never had time to read, however watched a few videos of Dan Holohan. Thank you
Matthew

nicosiahills

Good morning Jughne,
Thank you for your response, I will provide detail photos,
Maybe I installed the wrong traps in the basement,
Thank you
Matthew

Jamie Hall

If they were thermostatics and you exchanged like for like, pretty much, that should be fine. F&T traps are a very different critter; there are uses for them on steam systems, but not the same ones. Pictures of the ones you replaced would help a lot!

nicosiahills

Good morning Guys,
Hope all are well and safe! Thank you for your input and advise. We have an update of terrific News. Upon researching and checking all information that was provided having Boiler mechanics troubleshooting, we hit the problem dead on. There was absolutely NO Water Returning from return lines. The way water was trying to return was from all the headers thus when Boiler would fire up Bang WATER HAMMERING EVERYWHERE, There is a small condenser tank where all return lines come in and the tank feeds the boiler. We installed hot water tanks in front of the piping and I noticed a drain valve behind the tanks. I opened and a few drops came out. It was in line of a y pipe. The Boiler technician Tom opened the 2 unions and there was a strainer with huge clogged wall. We cleaned and flushed out the pipe. We installed before the Y Strainer a Tee and 2 Ball Valves for in the future we can flush the system out come Spring,
NO MORE WATER HAMMERING!!! The Boiler is running efficiently on 3/4 of 1 pound of Pressure. Everyone is Happy!
Thank you
Be well & Enjoy your Holidays
Matthew

Jamie Hall

Glad you found it!