Steam Noob - Trying to figure a banging system!

SinglePipeNoob

Hey folks. I recently bought a new house and we got (single pipe) steam heat! The house is also happy to let us know about this in the early hours of the morning. Whenever we turn on the system it bangs and clangs like nobodies business. I have read Dan's book ('we got steam heat') and have done a few things to try and fix the issue:

1. Made sure all the radiators are pitched towards the inlet valve using a spirit level and some shims
2. Cleaned out the boiler a few times (I hired someone to do this actually - John DeGrace plumbing) and have since run it through myself as the water still comes out slightly brown after settling out
3. Boiler pressure is set to approx. 0.5 psi - the needle bounces around 0.5-1 psi ish when it is running
4. Removed asbestos insulation (contractor did this) and I replaced it with fiberglass as far as possible but some of the pipe runs under boards, etc and I can't tell what is in there without tearing down walls

As stated, we still have a lot of banging whenever the system starts up however. I have noticed a few issues with the system, most relating to the fact that it looks like the previous owners were not all that careful with maintenance or who they got to do some of the work on the system (I think it was a knucklehead):

1. There is an incorrectly pitched pipe that is basically horizontal. I have turned off the valve for this radiator to try and stop this one banging - if left open the radiator spits water out the vent and makes a horrible noise. Could this still affect the rest of the system?

2. Several of the inlet valves are rusty and look to have leaked at some point in the past. How can I tell if they need to be replaced? Same with the valves

3. I have set the water level in the boiler based on the sighting glass and this is ok. When I run the system however it goes all over the place - the water level raises up or oscillates a lot. Is this just due to the increasing volume of steam in the boiler pushing the water around inside and this displaying in the level?

4. The vents are all also old and the system seems to have pretty terrible balance in terms of even heating

5. Is there any temp. dependence to the banging? Our boiler seems oversized so actually only runs for a short period then turns off. If we set a lower/higher temp. inside the house (I've been using 68F) could this help prevent any condensate banging when the system starts up again? This one is a long shot I know

Thanks in advance for any advice. I've also seen that there are a couple of contractors in my area but only two that were recommended here (NJ 07110) - any advice for others? As said I used John DeGrace last time and the guy who came seemed knowledgeable about the systems - at least he had read the book too!

Kahooli

Take as many pictures to show as much of the system as possible.

SinglePipeNoob

Will do tonight. Thanks.

I also just read one of the guides here about bouncing water levels in the sight glass and it seems like a lot of this could be related to having dirty water? This seems reasonable in my system which I got cleaned recently but the last cleaning was 3 years ago under the previous ownership!

EzzyT

@SinglePipeNoob has anyone done a full system analysis to confirm that the Boiler is sized right, near Boiler piping is correct, proper and adequate main venting, properly sized and balanced radiator vents, and possible incorrect piping in the system? That’s where you should start.
Plus I cover your area of NJ you sent me a private message and we can discuss the issue you have going on.

AnthraciteEnergetics

Make sure all rad valve are either fully open or fully closed. Turning off the radiator valve for the horizontal pipe should reduce it, as you'll air-bind that riser assuming the valve still seals up. A broken rad valve could be the problem, try to determine which radiators are making noise the fiddle with the valves - fully open or fully closed.

Sight glass level should bounce no more than an inch or so.

SinglePipeNoob

@AnthraciteEnergetics
Thanks. It bounces significantly more than an inch. It either raises all the way out of the tube or oscillates around the top. I did open all the valves as a check and have been trying to close the ones I think are a problem but to no avail. I just get the noise elsewhere! One of the rad. vales does have rusty water that has leaked down the side of it at some point in the past which I am assuming is not a good sign...

Jamie Hall

On the banging. Make sure all the radiator inlet valves are fully open. If you want to shut off a radiator or two, the proper way to do it is to not allow it to vent. Some vents you can turn upside down and they will stop venting.

Then... patience. Go around with your spirit level -- the longer the better -- and check every single pipe which is close to horizontal. No matter how short or how long. They must pitch back to the main, with no dips or sags which can hold water. It doesn't take much to make a horrible bang! And you do have to check the whole length of the pipe -- particularly in an older house, pipes have a way of sagging (you wouldn't think they could, but they can -- and do). Pipes which are tidily hidden under a floor and above a finished ceiling are real nuisance that way, but you may be able to locate the banging a little more closely and see if maybe one of them is causing a problem.

The boiler water really shouldn't bounce like that. That is usually a sign that it needs to be skimmed -- not just flushed. Look around here on the wall for thoughts about skimming.

AnthraciteEnergetics

Rusty water - often a leak around stem or in the union connection to the radiator. There is a nut that allows you to tighten the packing gland around the stem, that sometimes works its way loose. Try to snug it up (but not too tight). If you have to, loosen the outer nut holding the packing gland to the valve body and take the stem compleletly out and inspect the internals (with system ignition power shut down). It doesnt have to seal when closed, it just has to be fully open and not leak.

Removing or replacing these valves can be a real pain.

Skim your boiler to remove oil (the typical cause of surging water lines) assuming you have a tapped port at the top for that purpose. This forum has info on this process. Your contractor should be able to install a nipple in the skim port and also do the skimming for you.

Koan

+1 on skimming. My boiler sight glass bounced about 3/4 inch before skimming and was dead flat after. Even a very small amount of oil can make a the level bounce. since the oil floats on top of the water, you have to carefully and slowly float off the top layer of water in the boiler. It takes hours - several hours. open a port just above the water line, heat up the unit and keep it running, open your feed to a dribble. The new feed water makes the oils on the top overflow out of the port. I finally got my boiler super clean, but skimming was the only thing that stopped the sight and gauge from bouncing. It is possible someone sprayed penetrating oil on a valve

You may have other issues as well, but a good skim can really help.
It would really be a good idea to post a bunch of pictures of the boiler from all sides. Those can show if the boiler piping is an issue, many here can look quickly and tell. It is not possible to really help without pics.

EBEBRATT-Ed

Fix the venting and you may be able to make this boiler steam and heat without building pressure which it shouldn't normally do.
Check pitch on all piping and radiation.

Post some pictures of the boiler and near boiler piping...........I have a bad feeling..........

BobC

Skimming is the first thing I would do, it takes a couple of hours but is easy to do if you have a skim port. What kind of main vent does the system have? I would also replace all the radiator vents with something that is adjustable - NOT THE DURST JUNK THEY SELL AT HD. It's going to take some experimenting to get it balanced and the best way is to start with all radiator vents set low and then increase (in increments) the ones that are slow to heat.

Please send us pictures of the boiler, the piping around it and the steam piping including the main vent.

Bob

SinglePipeNoob

@EBEBRATT-Ed and others. Pictures are shown here. I also went and took a spirit level to all the pipes in the basement. All of them appear to pitched correctly (along the whole length) other than the one that I already mentioned - we have one pipe that is back pitched so it is angled the wrong way. I have this radiator turned off at the valve for now.

I also highlighted the vents. There are 2 at the end of the return lines and strangely (at least it seems strange) there is a BIG vent on the main line from the boiler pretty close to the boiler itself (see pic).

Dave0176

Is that an EG-50 boiler?

SinglePipeNoob

Dave0176 said:

Is that an EG-50 boiler?

Yes. Why do you ask? Is there something about this model that I should know?

MilanD

Your banging could be related to steam velocity with only one riser coming out of the boiler. Although the install manual shows one-riser installation, both tappings should be used on the boiler to form a 2 riser header, as this slows down the steam and sucks less water up from the boiler. That's probably why your water jumps around in the boiler when making steam. I think this is explained in LAOSH book, how water line in the boiler with one riser will, in essence, pitch towards the one riser. When you get to it, repiping it with 2 risers may help a lot.

MilanD

Something like this is happening inside, now think steam escaping on one side pulling water along. This will eschew the water line diagonally towards the riser, and water will constantly slosh inside from horizontal to diagonal.

https://www.youtube.com/watch?v=HG0M9wPDnzY

Dave0176

SinglePipeNoob said:

Dave0176 said:

Is that an EG-50 boiler?

Yes. Why do you ask? Is there something about this model that I should know?

Just asking because it’s a fairly large boiler @175,000 BTU and 454 sq ft steam. If that’s a 2-1/2 riser and header then believe it or not it’s piped properly per the minimum.

Just wondering if it was sized to your radiation. Meaning all your radiators measured and an EDR figured?

Neild5

It looks like the TRV does not have a drain pie on it.

EBEBRATT-Ed

@Dave0176 ,

looks like maybe a 2 1/2" riser. 2 1/2 x 2 90 at top of riser?? 2" supplies with unions.

Reducer to equalizer looks concentric.

Doesn't look right although basically pipe correctly

Can't believe I wrote that

Dave0176

EBEBRATT-Ed said:

@Dave0176 ,

looks like maybe a 2 1/2" riser. 2 1/2 x 2 90 at top of riser?? 2" supplies with unions.

Reducer to equalizer looks concentric.

Doesn't look right although basically pipe correctly

Can't believe I wrote that

I did look long at that header, hard to tell from the pics, but if it is indeed 2” then it’s undersized.

Regardless when I install an EG-50 I use two 3” risers and a 3” header.

Dave0176

Here’s my version of an EG-50 header piping. An that equalizer is 2”. This customer had 435 sq ft of connected radiation, this boiler was installed with a two stage gas valve to stage fire the burner between high and low to keep steam pressure between 4-8 oz

SinglePipeNoob

@Dave0176 We bought the house over the summer and the system was already in place. No idea what was done to size it, etc.

Fred

It looks to me like the equalizer end of that header is reduced on the horizontal. If it is, that will allow water to lay in the header, up to a level where it can drain into the equalizer. That will cause water hammer (banging) It should be the same size pipe to the elbow and then reduced on the vertical equalizer pipe.

JUGHNE

If the "flat" horizontal steam pipe goes to a radiator you might raise the entire rad maybe 1/2" on the valve end and 3/4" on the other end. If this would get that pipe sloped correctly it may stop the spitting and hammer at that point.
Perhaps narrow down the hammer location.

SinglePipeNoob

@JUGHNE Thanks for the advice. We have bee going around re-pitching the radiators this weekend. We tried raising the problem one up on a 2x4 plank and it didn't help with the angle of the pipe. It looks like it needs to be cut and repositioned

Danny Scully

Here is what I am seeing in the header. It looks like a 3” riser, to a 3 x 2-1/2 elbow, to a 2-1/2 x 2-1/2 x 2 tee, to a 2-1/2 x 2 x 2 tee...so the header is reducing on the horizontal. It needs to be addressed.

lchmb

the big vent at end of main is not in the best location. Should be back from the elbow and raised above the pipe..

JUGHNE

As many above have said about the concentric reduction on the horizontal header.
Think of the header as a drain line that must drain water to the right into the drop pipe to the bottom of the boiler. You have over a 1/2" of water sitting in that pipe because it will not drain away over the reduced fitting. That water sits there and when the steam hits it on start up that would be pretty good water hammer. Then as the steam rises up the vertical risers to the steam main, condensation will run back down into the puddle of water in the header probably causing wet steam for the entire system.
How close is your problem spitting rad to the boiler?

SinglePipeNoob

Thanks for the advice all. I've managed to reduce the issue with the hammer by cleaning out the boiler water and changing the angle on the radiators so they all slope towards the valves. I do still have a couple of issues - I need some valves replacing and someone to look at the header as you suggest. I think it is time to use one of the contractors recommended here!

LionA29

Lots of good guys on here will fix you up. @Dave0176 & @EzzyT will be able to help you.
Good luck.