Why would water be coming into the top of the sight glass during boiler operation?

JodiMe

We've had some boiler issues recently and while the tech was out last, he pointed out that water is coming into the sight glass from the top and that it should NOT happen. My husband didn't ask what could cause it. They're coming back out again, but I'm just curious what the pros here can tell me about what might be causing that to happen???

I appreciate your help!

Fred

The most likely reason is the boiler needs to be skimmed. It likely has oils in it. That is the most common reason the top portion of the glass is wet or you see spirts of water drop down from the top of the glass. Has there been any new piping or boiler work done recently that might have but oils into the system? Have the service tech skim it for you and show you how to skim it. It may need tow or three slow skims, over a few weeks, to get all the oils out. Hopefully the boiler has a skim port.

JodiMe

They came back and skimmed it and added a treatment to the boiler. It still seems to be happening. Do they need to skim it again? We attempted skimming once on our own, but couldn't get the port open.

Fred

How did they skim it if the skim port can't be opened? Draining water from the bottom of the boiler doesn't work for getting oils out. How long did they skim it for? A good slow skim takes several hours. Do you know what chemicals they put in? Most of those chemicals are not a substitute for skimming.

KC_Jones

How much is the water bouncing in the sight glass? It it's bouncing excessively than it probably still needs skimmed. Cleaners are no substitute for good skimming.

JodiMe

They skimmed from the proper port. When we tried, we just couldn't get the port to open because we don't own a long enough wrench to get enough leverage on the bolt.

It's a trustworthy company and it did take a couple hours to skim. I'm not sure what they put in to clean the system, to be honest. They made it sound like the cleaner was more of a helper than a substitute.

They are coming out again to replace some leaky valves, and I did mention that water is still coming in to the top of the glass. They could be planning on skimming again, I was just hoping to pick someone's brain here in the meantime.

JodiMe

KC, the water isn't bouncing a lot but there's liquid coming in from the top. I'll try and post a video later.

Fred

I'm sure it just needs more skimming. I've had to skim my boiler 4 or 5 times after replacing any piping. I don't know what brand boiler you have but mine is a Burnham and it is super sensitive to any oil. Also, depending on what chemicals they put in, if they put to much in, it can cause foaming and unstable water in the boiler.

KC_Jones

Anything more than 1/2"-1" is generally an indication that more skimming is needed. If the water coming in the top looks like condensation on the inside of the glass that is another sign. If it's water actually flowing into the top that could be foaming or surging. Not sure what they added, but some chemicals can cause this if too much is put in. It could be they have some kind of plan in mind and just need to complete their process.

nicholas bonham-carter

Have them leave a full port ball valve, and nipple and cap on the skimming port, so you can continue skimming after they leave.
it not worth paying a pro for 4 sessions of 2 hours each to do the job right.--NBC

Abracadabra

Where is the water level in the gauge glass when boiler is off?

JodiMe

It's right where it's supposed to be or slightly under. Never over.

Here is a video. The crud came into the sight glass after they skimmed and put the treatment in. I'm assuming it's undissolved cleaner?

JodiMe

It won't upload the video....

Abracadabra

upload to youtube and provide youtube link

JodiMe

Youtube was being glitchy. But here you go....

https://picasaweb.google.com/jmtuisku/February132016?authkey=Gv1sRgCM62hsax6_ijbw#6250820704911442082

Abracadabra

picture of the boiler from the side the gauge glass is on please?
Including all the near boiler piping?

How exactly was boiler skimmed? Proper skimming takes hours.

http://www.gwgillplumbingandheating.com/webapp/p/555/skimming-a-steam-boiler

https://www.youtube.com/watch?v=2ydzKcBKOVc

http://www.comfort-calc.net/Skim_a_Steam_Boiler.cfm

Fred

It just needs more skimming. I see the skim port next to the water gauge with a plug in it. Is that the place where they skimmed from? If so, tell them to put a nipple and a full port ball valve and cap on there and leave it permanently so you can skim it yourself. At some point in the future you will have piping or other repairs made that will require skimming. If they leave that plug in there, in a year it will be almost impossible to get it out. The skim port should be permanent.

Abracadabra

I doubt it was skimmed properly.... *shrug*

JodiMe

Thanks. They skimmed it from the port on the other side of the boiler.

Could dirty water also be causing water hammer?

Steamhead

That boiler was made by Dunkirk, and it doesn't look like it's piped correctly.

Can you take a pic of the left side where the steam pipe comes out? I bet we find the steam outlet was reduced from 2-1/2" to 2"..............

JodiMe

It's actually 2 1/2.

Fred

Water hammer is typically caused by steam hitting water that has pooled somewhere in the system. Can you tell where the hammer is coming from? Check the piping and make sure it is properly. Radiator run-out lines should pitch back towards the mains, Mains should pitch towards the pipe that drops down into a wet return, at the end of the main or if it loops all the way around the basement, it should pitch down a little all the way around and the lowest point should be as it returns to the boiler room and drops down to the wet return.
I see a Bull headed Tee up where the main goes in two directions. Looks like old piping but it still should have been corrected with the new install. They should have brought each of those pipes down into the header.
If it were me, I'd ask them to take that bull headed Tee out and drop eah end of that main into the header. It may cost you a few bucks more since it has been there a while and probably not addressed in you quote but you have to live with this boiler a long time. Now is the time to get it right. If you do that, let that work be done before you worry about additional skimming since the pipe change will add more oil to the boiler.
I can't see any of the wet return or the Hartford loop. Take a picture of the back of the boiler and any piping back there as well.

Paul48

Put some arrows on that main, so the steam knows which direction to go....

JodiMe

Our returns do wrap all the way around, and are mostly pitched right. We are having them correct the one pipe that is not pitched correctly this week for a pretty $2500. So I know that is part of the water hammer issue. In addition, we are also having some old radiator valves replaced as they are all leaking. My guess is that they are not just leaking but stuck in partial positions, adding to the water hammer.

I have also already requested them to add the ball valve and nipple to the port while they're here.

I will speak with them about the tee, also.

Thanks!