New steam boiler installed...Noticing problems with distribution...main vents?

Hipape

After living in my home for 20 years, largely ignoring my boiler the entire time, I had to replace it. Now I am devouring all I can about proper care of this amazing technology. Its a single pipe system in a 120 year old house. I replaced the a 31 year old Weil-McLain EG-50A-PI (net out = 123MBh) with a New Yorker CGS-50C (net out = 85MBh - the original one was oversized based on number, sizes and shapes of our radiators) I have read a lot in the past week about Main Air Vents - I get it - need to displace the air in the mains quickly to balance steam delivery throughout the house. We have two main lines and I think the vents are located at the end of the dry return - in a location that appears to be a bad choice based on comments about water hammer - directly above the vertical pipe that becomes wet return. Are these vents? They have 1" threads - is that even a thing?


Anyhow, I've hung out by the boiler (a lot, as it turns out) and held my finger of the holes on these shiny things hoping to feel air getting pushed out - nothing. And the dry return coming from the right, a shorter line, get hot way sooner than the return from the left. And from a cold start, the one on the left takes about half an hour to feel warm.

Anyhow, its getting cold here in Wisconsin and the contractors are all super busy - I'm wondering if there's a hazard to waiting another season w/out properly functioning vents? And when the time comes to replace, should they be positioned further away? Leave the non-functioning ones there since they clearly don't let anything out?

Appreciate any thought you may have!
Thanks!

SlamDunk

Go to supplyhouse.com and order two gorton #2 vents. You may have rduce down to 1/2". You can probably order elsewhere online.

The job is easy, maybe an hour. Just need a couple pipe wrenches.

Jamie Hall

That's not the best place for a vent -- but it will work just fine. Not to worry. As @SlamDunk said, buy a couple oof Gorton #2s and put one on each line.

Technically those are steam main extensions, not dry returns -- but that's OK.

KC_Jones

I know it’s not your question, but could you take a few pics of the whole installation from a couple angles?  I see something on the boiler piping that doesn’t make sense and I hope I’m just not getting a good picture of it.

It would be a shame to have a brand new boiler piped incorrectly.

nicholas bonham-carter

Jaimie- What's wrong with that main vent location? The new vents can be on a short extension off the present tapping, just enough to break any water hammer slugs.
Hipape-Next topic for you to study-pipe insulation, which with the improved main venting will make a big difference in the speed of steam arrival.
Do you have the installation manual for the boiler, and is that a third return coming down behind the boiler?--NBC

JUGHNE

Those are probably 3/4" iron pipe size/thread. They would measure about 1" on the outside. Ideally they should be about 16" back on the horizontal pipe, this is avoid water hammer.

To get pretty well the same protection that method provides, you could just remove what is there, add a 90 ell pointing back towards the pipe it is mounted on, then add a 6-10" length of pipe, then another 90 pointing up with a tall nipple and reducing coupling. Then screw in the new vent, Gorton #2's have 1/2" male pipe threads.

The horizontal pipe you add should drain back to your first 90. This would mock the slope you have on the return pipe.


And yes, could we see all of the boiler piping....something odd??

EBEBRATT-Ed

@nicholas bonham-carter & @Hipape

The vents should be located 18" upstream of the wet return drops to prevent water hammer. Condensate comes down the main pushed by steam hits the back of the tee and can force water up into the vent

But everyone used to do them that way and if the pressure is low they will usually work without an issue

@Hipape

If it was me I would mount the new vents on long nipples. Get them up as close to the ceiling as possible this will help keep the water out of them.

And measure the height of your "header" it should be 24" minimum above the middle of the boiler sight glass. Doesn't look like you have that

SlamDunk

JUGHNE said:

Those are probably 3/4" iron pipe size/thread. They would measure about 1" on the outside. Ideally they should be about 16" back on the horizontal pipe, this is avoid water hammer.

To get pretty well the same protection that method provides, you could just remove what is there, add a 90 ell pointing back towards the pipe it is mounted on, then add a 6-10" length of pipe, then another 90 pointing up with a tall nipple and reducing coupling. Then screw in the new vent, Gorton #2's have 1/2" male pipe threads.

Like this:

SlamDunk

Jamie Hall

If you go to the trouble to make the arrangement which @SlamDunk suggested (love the cat, by the way), I might make one further addition: you might consider putting a union on each of the horizontals. That way you could assemble the Gorton to the short nipple going up and then hook the whole thing to the connections to the pipe. Otherwise you might have a clearance issue with the overhead...

Hipape

Wow! Thank you for your feedback. I am trying to learn here Jamie - What is the difference between steam extension and dry return?
NBC - the pipe in the background is not a 3rd return, but the gas line. Also, I am in the process of measuring for 2" fiberglass insulation for. for pipes in the basement.. This looks doable..
Meanwhile, I did look at the installation manual and it the piping does seem wrong: The header is supposed to be offset horizontally from the riser a minimum of 2 inches. The size of pipe heading into hartford loop looks wrong - should be 1-1/2" but its 2"

Here are some more photos of the system - I guess I need to have a talk with my contractor!
Following are some more pix of: This is the header with tape measure from floor - its roughly 52-1/4 inches from bottom to floor.

and the sight-glass - midpoint is ~ 27-1/2" - so riser is ~ 24-3/4 above middle of sight-glass

And a couple of other photos...




So, I need to have a conversation with the contractor about the install! So, I'm getting mixed messages on where to place air vents: 6-10 inches upstream, 18 inches upstream, where they were is not the best, but probably ok? Can someone explain/point me to a description of the water hammer mechanism? As in, why going upstream some distance protects the vents from damage?

thanks again!

mattmia2

Does the manual say anywhere that you can use only one riser connection to the boiler? It looks like the diagram shows both riser connections being used out of the top of the boiler.

KC_Jones

We would need to know the boiler size to know if he needs both risers, the manufacturer only requires it on the larger models, I'd speculate he's fine

1 1/2" pipe is 1.9" OD, I think you are fine on that. Even if it was 2" pipe, that's not a problem. Pipe specs in the manual are minimums, going bigger isn't an issue.

The rest of the piping looks fine. What I had noticed in the original pictures is only one main take off, but 2 returns. I was worried there was something weird with the other main feed, but it appears there isn't one, which is strange in and of itself. The piping is fine as is, to my eye.

As for the vents. That location isn't perfect, but I can tell you I've been running mine like that for years without issue. Location is original to my system like yours appears to be. The most I would do (and did when I replaced mine with a vent tree) is use a 6"-8" long nipple and offset them from the main a bit to lessen the chances of having an issue. No way would I be tearing things apart to move them back 18", that would be the correct location by the book, but in reality your location can be made to work IMHO.

Hipape

@mattmia2 - The boiler is the CGS50 so, from piping diagram, only one riser is needed. @KC_Jones - the single main (pipe going through wall in 1st picture) goes ~ 5', through a 90deg, another 8', then a tee+90: one leg goes to front of house, other leg goes to back of house.

Piping question: Is it a problem that there is no horizontal offset in header shown in piping diagram? Or is that only an issue for 2 riser install?

Finally, back to the vent: the ceiling (drywall) is only 8" above main extension/ tee where current faulty air vents are (first picture in post). Does this mean I need to punch a holes in the ceiling? Are there any special concerns - like the holes need to be a certain size? Thanks again!

KC_Jones

With a single riser, you don't need that offset. The offset with 2 risers is to allow for some movement, it's called a swing joint.

mattmia2

Hipape said:

@mattmia2 - The boiler is the CGS50 so, from piping diagram, only one riser is needed.

Oh, so that cryptic double asterisk that just says "optional" means that the entire piping arrangement A is optional for the models in the left column?

Hipape

@SlamDunk @Jamie Hall , @JUGHNE , @EBEBRATT-Ed - if I were to offset the vents from the vertical pipe as shown in your annotation, is it important that the lines I use to offset be parallel to the main extensions? Or can they be rotated in the horizontal plane to point in a different direction? In order to fit the Gorton #2 vents, I will need to cut holes in my ceiling. Also, if I implement your recommendation, how to I make the horizontal slope down towards vertical drop.

Last question - I have set the pressuretrol to cut in at 0.5psi and cut out at 2.5psi (Honeywell Main=1.5, Diff = 1) - Is this low enough so that if I took the original suggestion and put the new vents were the existing vents are (at top of vertical to wet return) would I be replacing damaged vents all the time?

Thanks again! I've ordered insulation for NBP (as far down as bottom of equalizer - do I need to go further?) I suppose I should continue the mains...one step at a time... Thanks again everyone!

neilc

cut in at 0.5 is good,
you should be trying to cut out at 1.5,
not sure of your math in your "last question"
post a picture of the Ptrol head on

Hipape

Geez, I hope I interpreted this correctly, I've attached a photo of where ptrol is now:

Below is how the ptrol looked before I messed with it. My interpretation: cut in at 3.5 and cut out at 6.5

Hmm... maybe cut in = main-diff and cut out = main?

mattmia2

Originally was cut out at 5 cut in at 3.5. Still way too high.

neilc

scale on the right is cut out, first picture looks about 1.5 / 2ish,
scale on the left is differential, and subtracted from the right setting for cut in, you look about 1,
so,
looks like you're cut out is 1.5 / 2ish, and you would cut in at 0.5+/-,

Hipape said:

Hmm... maybe cut in = main-diff and cut out = main?

Yes,

neilc

if your pressure gage is getting up around 2 or higher,
try lowering the right main scale slightly till it cut's out at 1.5
if the boiler does not cut back in, lower the differential scale a bit

Hipape

Ahh.. my gauge is 30psi full scale - I've never seen it budge. I would need to add a low pressure gauge somewhere to see what's really going on.. Assuming my ptrol is working properly (Is that a reasonable asumption?) it appears to be set appropriately: the kPa scale shows 10 which corresponds to 1.45psi...So, roughly speaking, cut out at 1.45psi, cut in at 0.45psi.

Uh-oh: Looking at the differential scale, the kPa and PSI marks don't make any sense! The scale shows that 5kPa is just hair below 1 psi, but the standard conversion factor (which works on the main scale) says it should be 0.73psi. Is this a defect or "feature"

neilc

so your 0-30 could be defective, and needing replacement,
or it could be clogged behind it, and need cleaning, and its port back into the boiler,
and while we're talking, has the pigtail been checked and cleaned, clear back to the boiler ?

adding a 0-3, or 0-5, under the Ptrol would be helpful,
but if the 0-30 is good, you should see some movement, at least off the pin, .
does / is the 0-30 (go) to 0 when the boiler is off
does the Ptrol shut the boiler off on pressure when it's been firing?
any burner cycling before the thermostat is satisfied?

I'm an inches and feet guy,
you keep your kPa's to yourself
#smiling
#pigtail

JUGHNE

All of these HW Ptrols are just as inaccurate in PSI as they are in kPa, so not to worry.
What you need to go by is a good 0-3 PSI gauge...could cost about $50....but still less than the control.