Don't see main vents

Johnson_Rod

Hi - relatively new owner here (2 years) of an older house w/ a one pipe steam system.

The ancient boiler that was in the home when I purchased cracked last winter, and I replaced it w/ a Burnham IN5 along w/ converting from oil to gas. The house is 2 floors - roughly 1500sq heated.

Based on some signs of either imbalance or wet steam (mild water hammer, uneven radiator heating, and lightly audible radiator vents) I'm looking to balance the system better and have a couple of general questions after reading Dan's book.

1. Is there a non-visual way to determine whether the mains are vented if you can't visibly inspect them in their entirety? The basement is about 75% finished, and I inspected every visible main, wet and dry, but don't see any vents. The unfinished part of the basement the boiler sits is about 8' x 20' of which the two visible mains seem un-vented.
2. The I&O only diagrams the near boiler piping when both supplies are used. They installed with only a single supply and capped the 2nd one, which is not ideal from what I understand, but is acceptable to the manufacturer based on the model. So I'm not sure if the near boiler piping is optimal as installed. (pics attached)

Other steps I'm taking -
- After they had installed the new boiler, they mentioned it would need to be cleaned, but that didn't happen and I didn't think too much of it. It's obvious to me that it should have been cleaned/skimmed immediately post-installation. I have them coming this week to clean it. They did NOT install a skim port, thought the I&O does show there's a place for it. When I discussed it w/ the installer, he told me they usually skim this model from the safety valve.
- I will be insulating all the visible piping this weekend.
- Once I can figure out the main venting situation, I'll remedy that if necessary.

Thanks for any advice you can offer.

JUGHNE

If you can see the end of the steam mains before they drop to wet returns or dry return pipe, that would be where the vent would have been, if any. There may be a plugged tee there. They could be hiding under new insulation or just poking thru old insulation.

The standard here would be to bring each steam main down to the horizontal header above the boiler. Yours are tied together with a tee near the ceiling.....it may be indicated in the manual to do separate main risers.
A proper skim port consists of maybe $40 of material/money out of their pocket. If there is a opening for a dedicated skimming/top blow down port, now would be the time to get the plug out before it becomes permanent. From reports here these usually need more than one skimming. A proper skim port with valve would let you do this yourself after the initial skim.
They did use quality pipe fittings though.

The check has probably cleared the bank already?

Abracadabra

The pipe along the wall that's painted white about 2 feet above the floor with a serious pitch to it looks like the return. Follow that pipe to where it connects to a steam main and take a picture. That should be where at least one main vent should be.

Jamie Hall

Abracadabra said:

The pipe along the wall that's painted white about 2 feet above the floor with a serious pitch to it looks like the return. Follow that pipe to where it connects to a steam main and take a picture. That should be where at least one main vent should be.

Unless there are crossover traps on this system!

Johnson_Rod

@JUGHNE - Thanks - yeah the guys have been paid out for the installation/conversion. Good to know they used quality materials though. The installer sent someone here today. I expected them to skim, but it sounds like they threw squick in instead. I wasn't home when they came. That was a mistake.

@Abracadabra - i followed it the length of the north side of the house where it bends 90 degrees to run against the back wall of the house and gets buried behind sheetrock. So it sounds like picking spots on the wall to demo is the only way I'm going to find where that return connects to a main.

Also I found a 45 degree elbow to one of the risers coming off a main that seems like it may have had a vent at some point removed and filled? Not sure... Just seems like a strange protrusion in a very specific spot. Pic attached

Fred

Looks like a riser to where a radiator was removed at some point. Try to find a Tee at the end of the Main/Dry Return where it drops to a wet return.

Abracadabra

If you are talking about the nub on the 45, that's there due to how they cast the elbow. I think it's where the molten iron is poured into the cast.