One pipe steam system in North Carolina

CMiller

I'm looking for a qualified person to help us with our one pipe steam heating in central NC. I've had a couple people out who are 'knuckleheads' and don't seem to understand the nuances of this type of system. Any suggestions?
Thank you,
CMiller
Durham, NC

Ironman

How about posting some pics of the boiler and its near piping along with describing what problems you're having? We can probably help you a lot from here if we have enough info.

My best friend is a rep for central NC. I'll ask him if he knows someone.

SlamDunk

I'm in Raleigh, you will be hard pressed to find anyone who knows anything about residential steam. Very few homes down here are old enough to have had steam. Of those, few that actually still do.

The handful of steam contractors in this area focus on commercial/industrial.

Your best bet is to post your issues here.

CMiller

Thanks for the responses. I've posted some photos of the boiler and what I think are key items. Let me know if you want me to send anything else.

We have the following in the house, which is about a 3600sq/ft brick home, built in 1928.

13 one pipe radiators
4 two pipe base convectors
2 wall one pipe in wall convectors (one has been removed, other is not working at all)

Other than what is noted above, all are working and providing adequate heat. We have a LOT of water hammer at start up and sometimes it continues a bit. I've replaced most of the radiator vents with Hoffman No.40 or Hoffman No.1a adjustable vents with larger radiators set to vent faster. I've checked levels on radiators and shimmed up a bit when in doubt about pitch.

I'm not 100% sure about the downstairs scenario, especially with the two pipe and one pipe coming together. To me it doesn't look like there are any steam traps for the two pipe.

At one time a radiator was removed and that short branch was just plugged. The branch sometimes stays cold while the main is warm.

Most pipes are fiberglass insulated as far as I can see, and it appears to be in good condition. In many cases the pipe joints are sometimes not insulated, although elbows are.

The boiler was serviced in December and consisted of the following:
"Drained water to check clarity. Water does not seem to have lots of sediment build up or excessive cloudiness. Refilled boiler to a normal water level."

The main reason I'm doing this research, work and writing in is due to the water hammer and its slamming a various places around the house...not least of which is the bathroom behind my daughters bedroom, which is consistently the worst culprit.

I would appreciate any advice you have!
Thank you,
Craven

Jamie Hall

Well... there are negative things which could be said about the near boiler piping, and undoubtedly will be -- and some of those problems aren't helping the hammering. But I will leave that to others...

What you do need to do is to check every single near horizontal pipe in the system. Your description of the hammering being worst near start up is classic -- as the system starts, the first steam to get into those pipes condenses (they're still cold!). Now that condensate has to drain away, or the following steam will pick it up and slam it into the next available corner. Once the pipes are up to temperature it's much less of a problem.

So... think like a puddle of water. How would you drain? The near horizontal pipes have to drain either back to the main they came off of, or to the far end, where there has to be a vertical pipe down to the floor -- called a drip. It probably was fine when it was built, but over time you can find that pipes lose their pitch and the water can't drain; they mustn't be actually horizontal, but pitch -- typically around an inch in ten feet -- to where the water can drain. Further, that pitch must be consistent -- any sags in the pipe (quite common!) will allow water to pool and get slammed around. The horizontal pipe coming off the side of the main in the third picture looks like a likely first candidate...

Same thing applies to the steam main -- the condensate in the steam main has to be free to drain somewhere.

It's a shame about the insulation. That is going to make it harder to make sure the pitch is right and the pipes straight -- but I urge you to do whatever you have to do to make those checks.

Mike Cascio

Also the main vents appear to have shot water out at some point and are extremely undersized. Could you give the approximate length of the steam main as it leaves the boiler and wraps around the basement before it drops down? I suspect you would need at least a few gorton #2's or some bigmouths.

adambnyc

From the pics it looks piped wrong, but aside from getting all that redone, some basic stuff

Just some basics to check. Has the system always had surging or did it start recently?

Does the system actually cutoff when too much pressure builds?

What is your pressuretrol set to?

When is the last time someone removed the pigtail from the pressuretrol to clean it? It could be clogged and causing high pressures.

Your main vents show signs of water leakage. Suggest changing them, and again, make sure pressuretrol is actually working.

The boiler water looks very dirty. Consider draining and cleaning out boiler until water looks clearer.

SlamDunk

See? This forum is your best bet! Best of luck!

Ironman

The near boiler piping is definitely wrong and should be re-piped.

As mentioned, make sure all risers are sloped toward the steam main and that the main slopes away from the boiler, toward the return. I only see one return and two steam mains which means that possibly one of them is piped counter flow. The way to tell is to see if it has a return it drops into after the last rad. If not, it's counter flow and should be sloped TOWARD the boiler.

What pressure are you running and when was the last time the pigtail was cleaned?

Definitely looks like you need some main vents replaced.

Fix any leaks including the packings on radiator valve and replace leaking vents.

CMiller

Thanks everyone. I apologize about my earlier photos...I did have them in some sort of order and labeled but they got all rearranged. I've looked at a few things and can confirm the following:

A real bummer that you all think near boiler piping is wrong. Something I definitely can not fix myself.


@Ironman - Length of Steam main is approx. 160' before each arm meets a center pipe, which runs about 30 feet before reaching the vent, at which point it turns 90 degrees and runs 15', turning 90 degrees again, running 10 feet and then dropping.

@adambnyc - This is my first winter in this house so I don't know what it has been doing in the past. But since we started it up and after the boiler was serviced in December (including pigtail clean out) we have had water hammer, which has gotten worse over time. We had some spitting from radiator vents etc. but I've replaced most of them and now they mostly hiss some...no more spitting.
-I don't know if it cuts off if there is too much pressure. How do I find this out?
-Pressuretrol is set to .5 cut in/1 cut out. It was higher than this a few weeks ago but lowered after receiving and reading up on Dan Holohan's book. But nothing really changed from what I can tell.
-I believe the water was changed at time of last service in December and also a cleaning agent was put in. Do I drain with spigot on side into metal bucket and then use manual feed to refill? Do I do this while boiler is running?


I've attached a sketch of the layout from what I can tell (there are few areas that are not accessible to me at this time so I'm making some assumptions for areas in the far crawlspaces. I would like to replace the main vents (should I add one at the plugged spot where radiator was removed?)

Thanks again,
Craven

Ironman

How old is the boiler?

Jamie Hall

First off, don't fret the near boiler piping. It's not right -- I told you people would mention that -- but it's not so wrong as to be a catastrophe. Should it get fixed? Probably, some day, but let's tackle the other stuff first.

As I said in my first post here, the very first thing to do is to check the slope of all the piping. No sags, good pitch, a place for the water to drain to.

Now venting... and traps.

On the convectors, which have two pipes connected. They should have traps on the outlets, and these need to be working properly for them to work. It's not always easy to tell, but the outlet below the trap should be at least somewhat cooler than steam hot. You do show a vent on the return pipe from the convectors. That vent is very important, and I'd suggest a Gorton #2 at that location. Maybe two of them. The heat output of the convectors can be controlled with their inlet valves.

That other main vent -- the one on the steam lines after they have joined and headed back towards the boiler -- is also very important. Given the reported length of the steam mains, I'd be very much inclined to put two or three Big Mouth vents there.

Vents on the one pipe radiators -- mix and match to get the heat you want out of each radiator, but don't try until you get the new main vents in place.

On the boiler water. What cleaning agent was put in? There are very very few which don't make matters worse, not better. Generally speaking unless your water is really odd, just plain water is the best. At some convenient moment after the winter is done with us, I'd drain the boiler when it is off and refill it with just plain water to about half way up the gauge glass. Then start it up and run it until the water has been boiling for perhaps ten minutes and then just let it be. But do the drain and refill with it cold.

CMiller

@Ironman - I think it was installed in 2005

@Jamie Hall - Thanks for the additional info. Here is the description of service in November (I had them come back in Dec., which is my previous note). This was the main servicing:

"Removed and cleaned pigtail pipe serving pressure control, tested control. Removed and cleaned low water probe. Checked burners, fluue piping and draft. Drained, flushed and refilled boiler and added 8 way water treatment. Replaced boiler drain, old drain would no longer seal."

From what I can tell, there are no traps on the convectors...just an elbow from bottom corner down through floor. (I'm not sure if this is something that I can change myself.) I'll check slopes of pipes and get new main vents for a start and then see where I am.

Thanks again.

Jamie Hall

Hmmm... well, it's remotely possible that the convectors have orifices in either those return elbows or in the feed valves. In which case pressure becomes a bit critical. However, before we go waltzing off into esoterica,, a simple question: do they provide the heat you want? If they ain't broke, as the say, let's not worry about trying to fix them.

The venting and pipe slopes are still more important than anything else at this point.

SlamDunk

8-way....there is a tread about 8-way you should search for. some people think it is the best stuff on earth and a couple, like me, says it wreaked havoc on my steamer. you probably need to add to your list- flush and fill boiler twenty times.

nicholas bonham-carter

If that main is a continuous loop, then the main vent will be closed by steam arriving on the shortest side. That may be why the rad on the opposite side does not work, as it is air bound.
Ideally the loop should be two mains, which each terminate and drop into a wet return.
Enlarging the capacity of the main venting will help here, but some risers on the opposite side may need to have Gorton D’s Installed to take care of removing the last bits of trapped air.—NBC

Lance

Due to the age, and assuming it must have worked once before, I would flush or replace the low returns. A boiler can show clear water and returns can be restricted. I noticed all the spit trails from vents blowing water out. This is a strong indicator of poor return flow that can create flooding and hence noise. I had a system 90 years old that the only way to clean out return was to replace it. It tried to fool us with clear water after drain down and flushing. Sometimes the job isn't the job, the real job is finding the qualified people.

JUGHNE

It seems the continuous loop would have been in favor with the constant steaming of a coal boiler.
But today as you point out the main vents location would be lop sided.
One needs to find the center of the tetter-totter and place the vents there. (we called the kid sitting in the center the "sugar bowl")

But I would go for the low hanging fruit and put a Big Mouth or Gorton 2 at the connection where the pipe is capped on the back side of the house that had the radiator removed.
The OP posed this question above.

CMiller

Hi, I'm back on the forum with questions becuase something in our system has changed this year. There is severe water hammer that sounds itself at an upstairs rad (front of house) that never had any problems before with sound or heat, etc. It is very loud.

I have also just discovered that one of the downstairs radiators does not seem to be producing heat at all either. It is also on the front of the house and is actually the radiator that is directly over the boiler.

I've done things that I can do to address.

My first question is if at first guess one would think it is the wet return that has not been cleaned and/or changed since my last postings in early 2018. Last year everything worked beautifully (except the one radiator that alway has had a problem and I think is due to a poor repair years ago that is accessible only by removing the lower level ceiling below it).

I know I'm at the point where I need to call someone in, but from my research I'm stuck with the standard boiler service person that isn't necessarily up on this type of system...since so many people have eliminated.

Any help/advice/comments welcome. Thanks,

Craven

neilc

so what else has changed ?
new flooring in that room ?
disturbed radiator?
children(or others) that play with valve knobs?
Is the supply valve fully open, it needs to be or it could be the hammer,
what is the pressure at the boiler while running making heat? is the pigtail serviced and clean?
the cold radiator downstairs, is its vent working ?

CMiller

no changes. Valves fully opened. I just cranked the heat a bit and the one not working kicked in. However, the rad is in the wall and I opened up the cover to discover that the vent is totally inaccessible. I'm not even sure how one would get the radiator out or serviced without demoing where it is located.

The pigtail was cleaned/serviced winter of 2017/18.

When I turned it up and it had been running for a bit it read 2psi.

neilc

so the rad not working, does, kindof, let's not fix it, yet.
the one hammering,
is it banging right there in or at the radiator?
or in the pipe coming up to it?
or can you tell?
the second floor is all one pipe, correct?
I'm still thinking about the valve, and maybe it dropped its disc,
or the vent isn't allowing air back in, and not letting that rad drain well(?)
the boiler at 2psi, isn't bad, could be better, could the Ptrol be turned down a bit more?
pressure is not your friend.
and that 2 year old clean pigtail might want attention also,
might be worth checking.
water in the old pictures look dirty, and you posted some pictures of rad vents spitting, along with the main vents,
is that all corrected?

clammy

Drain and flush the boiler out get rid of the 8way cleaner, flush out the returns ,possible remove the return vent and put a hose adapter on it and hook a hose up and flush the return out back to the boilers boiler drain . Change out those small Hoffmann main vents and install some gorton #1 . If it was running good last year ,then the 8 way loosen all the junk in the boiler and piping .if possible use the skim tapping and skim the boiler . The near boiler piping isn’t good but it looks like they just piped into the original header usually doing that’s a crap shot but if it’s been running fine I would attribute it the eight way cleaner loosening up a decade of crap . Get the drain running clear and the sight glass clean and then see how she runs . Have you removed the sight glasss assembly and clean the nipples going into the boiler . Usually I just wand the boiler when dirty and neglected as long as whoever installed the boiler left a couple of tees and plugs to do so otherwise just fill one flush and drain a few times all those cleaning agents wreck havoc on waterlines by loosen up all the good stuffand usually it’s followed by hammering and banging peace and good luck clammy

CMiller

@neilc the hammering seems to be at the source of the radiator...but sometimes I think not...it just may be the end of the line for the sound? Early on this season i tried to turn off the valve completely to see if that eliminated the noise but it didn't actually close the valve and the rad still heated up fine. I did later remove this rad and check it and reattached it but nothing really changed with the sound so I didn't hurt or help it, but the valve did work again when I fully closed it after that. I will say though that I'm not 100% sure this radiator is working with a consistant heat. Lots of noise but not always a full amount of heat. I removed and cleaned the vent and it seems to be working normally...and isn't that old.
Boiler was only at 2psi at top of cycle...mostly at 0. Ptrol is set at lowest.
I can try to clean the pigtail....is this something you'd say I could do? I'm handy but I don't want to mess with something that I shouldn't. Seems fairly simple with the connections.

Water is clean in glass, not spitting at main vents, which were replaced with a Gorton #! and a Big mouth.

All the second floor is one pipe...or each stems off the one pipe in the basement. (no 2 pipe conv.rads upstairs.).

CMiller

Thanks for the info @clammy I'm not sure those are things I can do myself but will put on the list when I finally find someone that can service this properly. From earlier comments I understand the cleaner should not be done as it can cause problems like you suggest. So I guess this summer I'll need to flush everything a couple of times at least?

Thanks again!
Craven

dopey27177

Looking at the drawing of the cast iron convectors I see a problem if the returns on the convectors are dry returns.

If they are dry returns hot air or steam under pressure blows thru the return piping. This collides with the condensate water in the return piping.

To install steam traps on each convector is costly and is a maintenance problem in the future.

The best way to correct this problem is to drop the return side of each convector to below the boiler water line into a common wet return. Then tie it into the existing wet return to the boiler.

That may be one or all of the problems.


Jake

dopey27177

Another problem I just noticed in the drawing the front and back steam mains are joined together at the point marked I cant see this connection.

If the drawing is correct the piping needs to be split and dropped to the floor. One more vent valve will need to be installed so both end of steam mains (dry returns) are vented, this might be why the one rad is not venting.

Jake

neilc

When you reconnected the radiator, did you check it for pitch? towards the supply valve?
It should lean slightly downhill, to the supply valve.
Or does that riser lift at all from the floor, and maybe a horizontal section is holding condensate?
shimming both ends of the rad and setting correct pitch may help.
And then there's the valve,
you say it closes now, keeps the heat out,
so you know your pushing down on that disc I mentioned,
but is the stem raising it, or just allowing it to float, and that would settle and hold back condensate, = hammer.
You could try removing the top of the valve, and seeing that the disc is still attached to the stem, and if not attached, reach in there and remove the fallen disc, and enjoy renewed silence.
Use 2 wrenches, one to hold back on the valve body.
This is done with the boiler off, no pressure in the system.

The gage and Ptrol both being after the pigtail, the gage sees 2, and that's what the Ptrol reacts to, but we really aren't sure of the pressure on the boiler side of the pigtail.
It would be handy to add a second gage, either prior to the piggy, or on another port somewhere, which I don't really see. One of these gages could be a low pressure gage, 0 - 3, 0 - 5,
you want to keep a 0 - 30 to keep the insurance folks happy.
To check the pigtail, Boiler Off at switch, I would undo the wires at Ptrol, unscrew Ptrol from pigtail, and see if pouring water in pigtail floods it, or passes to boiler.
Use wrenches on the bottom of the Ptrol, do not twist it by the body.
If the pigtail floods then you need to try snaking it and see if it clears, or unscrew pigtail from boiler, and go at it from both ends. While it's off, poke the hole clean back into the boiler.
As you reassemble, add some water to pigtail to prime the loop.

CMiller

OMG @neilc that was it!
"Or does that riser lift at all from the floor, and maybe a horizontal section is holding condensate?
shimming both ends of the rad and setting correct pitch may help."
I had it pitched correctly but I lifted the rad up as much as the riser would allow...literally 1/4" ...and it worked! I didn't write sooner because I've FINALLY been sleeping! lol. Thank you. I will keep all the other things in mind though b/c they will need to be done to keep the system running smoothly.

Thanks again!
Craven

neilc

CMiller said:

OMG neilc that was it!

Aahh,
I just read stuff on the interwebs , , ,
glad it's quiet and working for you

luketheplumber

just out of curiosity which city are you in i live in durham nc and could come take a look at it